This file contains many users' tips for turning metal on a metal lathe. (There is another file here with tips for turning wood on a metal lathe.) In addition you will find many more turning tips in the lathe files here associated with specific brands like Sherline or Taig. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2010 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ========================================================================== From: Dean Williams Date: Wed Feb 2, 2000 1:06am Subject: Re: Facing Problem of a Neophyte Marc; I have seen this tiny divot or crater in the center of a facing operation. Sometimes if your tool is not dead center a small tit is left. As you pass the center of the face with the tool, sometimes the tit will be torn out leaving a dent. This isnt always the case, but I've seen it before. If you are using the drill rod to make tooling with, well, thats what its for. If you are buying it for presision rod, then it is pretty good for that too. If you need a general prupose steel for turning, there are better choices. Try C12L14 or C11L17. Check out and for supplies. There are other suppliers. These are just two that come to mind. Dean W ------- Date: Fri, 15 Dec 2000 11:37:05 -0600 (CST) From: Tom Benedict Subject: Re: horrible chatter... For parting, a couple of points: One, the slower the spindle speed, the less chatter you get. (Yeah, there's an ideal speed for just about any cut. For parting it's just really really slow.) The wider the piece, the slower the spindle speed for practically any cut. (I'd say ANY cut, but I know someone can pull an example out of their experience to show I'm wrong.) 1-1/4" brass is pretty big. For parting, the narrower the tool, the easier it is to part. Makes sense. If you're ramming a 1/4" wide parting tool into a part on a small lathe, it'll chatter like crazy. If you use a 1/32" wide parting tool, it'll chatter a lot less (assuming, of course, that it's a rigid tool.) The narrower the tool, the easier it is to snap. So make sure it's completely perpendicular to the workpiece, and is well supported. For parting, using a back toolpost helps immensely. Nick convinced me of this, so I bought a back toolpost for my parting tool. I've since had call to do a number of grooving operations with other tools, so I'm probably going to get a whole stash of these things for all of those tools. Using the right relief angle for the material you're cutting reduces chatter a lot. As Nick said, brass requires zero relief. Other materials will have other requirements. One bit on tops: If you make the spindle too tall, it will make the top unstable. I made an unspinnable top that way. Neat as a gag, but not much fun as a top. I hacksawed about half an inch off the spindle, chucked the whole top up in the lathe, and faced the sawed end off. Worked great. Have fun making the top! Tom ------- From: Ron Ginger Date: Wed Sep 20, 2000 8:57am Subject: Re: Thinking about getting a Sherline Lathe? On Tue, 19 Sep 2000 21:17:38 -0700, Alan Marconett KM6VV wrote: >Only part I was a little suspicious of was the piston's ".002 fit", >right from taking a cut on the Sherline lathe. Maybe. I think you ought to be able to turn any part to a desired thou without problem. Getting things to a TENTH (.0001) is a bit of a trick where more luck is needed. You need to plan your cuts well. Lets say we wanted a .500 piston, and were starting with some stock about .625 or so. Id make one or two cuts of about .030, getting down to maybe .060 over the size I wanted. Id then stop and measure carefully, and reset the handwheel to zero. Lets assume the measurement now is .558. I would dial in another cut of about .030 and make that cut. Id stop again and measure carefully. If that cut was right on what I expected (.528) I would know I had the handwheel right, the backlash out, and I can confidently dial in that final exact cut (.028) and wind up right on. If my second measurement was a bit off I would try to remove about half of the remaining stock and measure again. Note its best if your final measured cuts are each close to the same measurement, in the example about about .030. If you make the part say .003 oversize, then have to take of a final cut of just .003 its much harder. Remember all machines have some flex and the flex in a .030 cut is lots more than a .003 cut. Rudy is a great guy. We have had him speak at the New England Model Engineering Society twice now. He is a rather quiet, but very methodical guy. If you get a chance to talk with him at one of the shows do it. He is always at Cabin Fever and NAMES and has gone to PRIME once, Im not sure if he is going this year. He does all his drawings by hand, in ink. He uses an old Leroy letting set. I asked him why he didnt get a CAD system and he said he felt his drawings had become a kind of trademark for him. I have found all his drawing to be correct, and he is very proud of that reputation. He checks everything very well. If you build one of his projects you can expect it to fit as drawn. This is NOT true for a lot of the stuff published in the magazines. ron ------- From: Kory Hamzeh Date: Thu Nov 23, 2000 00:13am Subject: Getting a good finish when facing I'm new to the list and this is my first post. I've own a sherline lathe and mill for about 2 years and I've build various things, include Rudy K's steam engine. One thing I'm having a lot of problem with is getting a good finish when I'm doing a face cut on the lathe. It doesn't seem to matter what the material is: aluminum, brass, CRS, I seem to suck consistently. I've tried HSS bits, carbide, and the diamond tool holder bit. I do get great finishes for normal cuts (reducing diameter). It's just facing that I don't have done. The finish ends up very roughs with many many concentric circles. Any hint or ideas on what I should do or not do would be great. Thanks, Kory ------- From: ron ginger Date: Thu Nov 23, 2000 8:12am Subject: Re: Getting a good finish when facing Sounds like you are feeding to fast. Try feeding slower, and be sure the tool has a small tip radius. Clearly, if the tip is a sharp point, then you are effectively cutting a thread with the point. If the tip has a radius, the sides of that radius are smoothing out the 'thread' before and after the extreme tip. I seem to get better results on feeding out from the center, rather than feeeding in to center. Im not sure whats 'right'. ron ------- From: Les Grenz Date: Thu Nov 23, 2000 9:48am Subject: Re: Getting a good finish when facing I agree. Finish is always determined by rate of feed in comparison to surgace speed and the radius of the cutting tool. I also, after facing, take a kiss cut from the center to the outside. Works for me also. Also the problem is when facing as one gets to the center the surface speed becomes less and less. On CNC machines the spindle speed can be programed to speed up as the diameter decreases keeping the surface speed constant. At least that is the way it works on my neighbor's hardinge lathe. Regards from Les Grenz & the Queen City of the Rockies. ------- From: Kevin P. Martin Date: Thu Nov 23, 2000 10:58am Subject: RE: Getting a good finish when facing Kory Hamzeh wrote: > The finish ends up very rough with many many concentric circles. This could describe one of two effects: 1-If the "concentric circles" form a relatively even spiral, you are feeding too fast for the tool's end radius, and this is leaving a sharp groove like the one on a phonograph record (remember those...? :-)). Try a slower feed or a larger tool nose radius. 2-If the "concentric circles" are uneven circular zones, you might be trying to take too light a cut, and the tool is cutting for a while, then skipping for a while. Try a deeper cut, smaller nose radius, or a different tool geometry (more positive rake, more relief, less side cut angle) that reduces the tendancy for the tool to be pushed away from the work (which in this case would be axially away from the headstock). This can also occur if there is too much flexibility in the setup, so make sure you clamp the saddle -- don't just rely on the leadscrew. Kevin Martin ------- From: Date: Thu Nov 23, 2000 6:09pm Subject: Re: Getting a good finish when facing 11/23/2000, clearx~xxs... writes: << >> The finish ends up very rough with many many concentric circles. >Sounds like you are feeding to fast. Try feeding slower, and be sure >the tool has a small tip radius. >> I use carbide and love it, I get great results that look like the surface of a music CD, so here is what you do: One; start with carbide, yes it does work even for interrupted cuts! Use one with a replaceable point, HSS does work nice, but will drive you crazy unless you are the pro from way back sharpening them, for a fly- cutter this is very hard!! make sure that the tip is not loose this will make a really bad finish but tight makes a nice finish. Two; you want the flat part of the carbide to sweep across the surface and not use the tip or point if you may, this will tend to "thread" it and that is not what you are looking for. Three; Just as always hard materials heavy cut slow speed, soft materials faster speed and lighter cut a good medium speed works great for alumin. Four: with the cutter over the piece cut to the left and finish to the right, do the same pattern every time your starting to cut, can be a little heavy say about 5/1000" and finish to the left with a 2/1000" cut always finish with a light cut. Five; Suprisingly lube seems not to help a lot, with Titanium slow speed, it throws sparks and will set your house on fire, but I get a nice finish with it, with steels, stainless or not a sight amount of cutting fluid is OK Six; the last and most important, make sure that the work piece is set in the vise, nice and tight, real tight and make sure that it is level as you can, don't be discouraged with the first pass if you get a cut on one side of the material, this means that it was not cut right in the first place, this provides that you mounted it in the vise straight yourself, I flycut (face mill) every day and never have a bit of problem and my results come out the same every time, if you follow this to the letter you will get results that will blow you away, there are times that I show it to someone and say that I milled this and they reply "no way," good luck. Best Regards, Chris of Bradenton FLA ------- From: Al Lenz Date: Fri Nov 24, 2000 1:09am Subject: Re: Getting a good finish when facing --- In sherlinex~xxegroups.com, "Kory Hamzeh" wrote: > The finish ends up very rough with many many concentric circles. Kory, I see that you already have some good responses but here's one thing that wasn't mentioned. If for whatever reason the crossfeed handwheel gets "stiff" ,i.e. harder to turn than normal, you can get the results that you described. Lets say that you are turning the handwheel CCW, (cutting from the center out). As you turn the handle thru the top half of the arc you are pushing TOWARD the work. Likewise turning the handle thru the bottom half of the arc results in pulling AWAY from the work. Believe it or not, under the right conditions there can be enough flex to cause rings in the finish. You are actually pushing and pulling the tool very lighhtly into and away from the work. In my case the cure is to bite the bullet and just go ahead with the overdue maintenance, clean, relube, adjust, etc. :) Al ------- From: Charlie Lear Date: Fri Nov 24, 2000 3:26am Subject: Re: Re: Getting a good finish when facing On Fri, 24 Nov 2000 06:09:45 -0000, Al Lenz wrote: >arc results in pulling AWAY from the work. Believe it or >not, under the right conditions there can be enough flex >to cause rings in the finish. You are actually pushing and >pulling the tool very lighhtly into and away from the work. Absolutely, couldn't agree more. In my case, I was using two fingers and my thumb to provide a steady movement to the knurled edge of the handwheel, not using the handle. Maybe I wasn't steady enough! One of my pet projects (once I make a ball turning attachment) is to make a set of ball handles for the cross-slide, as its a lot easier to smoothly twiddle them compared to a disc. Cheers Charlie Lear, Melbourne, Australia clearx~xxs... Hutt Valley Model Engineer Soc. http://steammachine.com/hvmes Eastern Bays Little Blue Penguin Foundation: same site /penguins ------- From: Gordon Couger Date: Sat Nov 25, 2000 3:24am Subject: Re: Getting a good finish when facing You are having problems because the surface speed is change so much from the center to the edge. If you have a variable speed motor run it fast in the center and slower at the edge. Use a bit with a good radius. At least 1/8 inch and I like a quarter better but a Shoreline might have trouble with a quarter inch radius. Use lots of lubricant and don't turn the chip back on the work let it run free and hook it off with a hook to keep in from tangling. Go slow on the feed but take enough that it doesn't skip and hone the bit before the last pass/ ------- From: Kory Hamzeh Date: Sun Nov 26, 2000 8:00pm Subject: RE: Getting a good finish when facing Thanks to everyone for their suggestions. This weekend, I was able to get excellent finish facing brass using cheap Chinese C-2 carbide tools that I bought from MSC for $0.99 and moving the crosslide by turning the wheel by the edges instead of cranking it. I think I need to flatten the tip of the other tools also. Thanks, Kory ------- Date: Fri, 5 Jan 2001 11:20:14 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Lathe Center Height Subject: [taigtools] Lathe Center Height > What is the best way to measure the center height of the Taig Lathe? > Once you have this measurement, is this what you should use to set > your tool height? How do most of you set your tool height, eyeball > it or measure it some way? Thanks for any help, Eric I tend to chuck up a piece of scrap, take a facing cut, and either a) shim the tool randomly, take another facing cut, repeat until no pip is left b) mic the pip and shim half that dimension. You can also use the tailstock point to set the toolbit. ------- Date: Fri, 5 Jan 2001 15:02:11 -0600 (CST) From: Tom Benedict Subject: Re: Lathe Center Height I chuck up a short length of something with a small diameter in a collet, then move the tool in and use it to pinch a short ruler or other thin piece of straight stock between the tool and the stuff in the chuck. If the ruler leans toward you, your tool is too low. If it leans away from you, the tool is too high. If the ruler stands straight up and down, your tool is right on. Tom ------- Date: Mon, 29 Jan 2001 14:36:30 EST From: SLEYKINx~xxaol.com Subject: Re: tool holder As far a cemented (brazed) carbide bits vs indexable. I believe they both have their merits and faults. They certainly perform differently. I have a grinder for grinding the carbide bits and have made several special shapes with them to cut things HSS wouldn't work well on. I tend to use the cemented bits for roughing and in places I think the carbide is apt to chip. I can grind the carbide but one chip in an insert and that point is toast. You have a 60* point on the indexable bits so you can get in closer, especially nice working close to the live center in the tailstock. You have a nearly flat front face on the cemented carbide bits and can really hog into things. Both have the ability to leave very nice finish cuts. Bottom line ... start with whatever you can get your hands on first ... you will probably end up with both anyway. The speeds need to be faster than HSS for good finish. YMMV Glenn Neff Medford, OR ------- Date: Thu, 08 Feb 2001 10:27:39 -0600 From: Nick Bristow Subject: Re: rocket nose cone? mikepshannonx~xxyahoo.com wrote: > I am a novice/learning machinist. How can I machine a rocket nose > cone out of aluminum. Can I do it on a lathe. The shape I am talking > about is a cone (which would be easy to make) but with slightly > curved sides (which is the problem). Thanks! Michael Shannon Hi a very inexpensive but practical way is to make a profile of the cone on 3/4 plywood. With a very thin blade cut it in half so you have 2 half profiles. Mount these on either side of your lathe at the proper height. Use a coarse flat file (about 1" wide) and move the file back and forth as the lathe turns. Once the aluminum get down close to the size of the profiles go to a finer file. Continue until the file is following along the plywood profiles. It is pretty low tech but works great. It is also a lot quicker than constantly re-aligning your lathe. This is how many machinists at the turn of the century turned complex shapes. Nick ------- Date: Sat, 17 Feb 2001 09:08:20 EST From: WRSmith2x~xxaol.com Subject: Workshop Tip Occasionally, one needs to do 120 degree spacing of work in the bench lathe. Rather than setting up an index plate and latch arm, a very simple way to do it this is to use a short wooden block under the chuck jaws. Make a block of wood that when set on the lathe bed will stop the jaw of a 3-jaw chuck at the headstock center height. In the tool post, mount a short length of drill rod sharpened to a conical point and hardened. Place the wood block on the lathe bed and rotate the chuck jaw against it. Bring the cone point of the rod against the work and tap its end with a hammer. Do this using each of the three chuck jaws. The result is a quickly done 120 degree spacing. ------- Date: Sun, 18 Feb 2001 10:04:33 -0600 From: Nick Hull Subject: Re: Cutting tubing? *Hi-- what would be the best way to cut tubing ( 5/8",SS or brass) in a 6"Atlas? I have a tool holder that takes 1/4" tools-- any particular type of cutoff tool recommended? Technique? Haven't tried it yet, but I imagine as you cut towards the ID and the tubing gets very thin, it could deform, grab, etc. Thanks from a newbie. Paul: The easiest way is to cut it with a hack saw while turning slowly under power. Alternately, you could use an Xacto Razor Saw, instead of the hack saw (finer blade, less waste and less force on the tubing). ------- Date: Sun, 18 Feb 2001 18:11:03 -0600 From: Bill Aycock Subject: Re: Re: Cutting tubing? With due respect to your experience- there is a BIG difference in parting off solid stock and thin walled tubing. My best way, after several bad experiences, was to put a solid mandrel inside the tube, and use a normal tubing cutter. The mandrel prevented the normal sharp reduction in size at the cut. I then used a regular tool to trim the end. The mandrel helped here, too. Bill ------- Date: Sun, 18 Feb 2001 21:54:27 -0600 From: "J Tiers" Subject: Re: Re[4]: Re: Cutting tubing? >For a LOT of stuff where people have said "Slow way down to do X", >I've tried the OTHER way - GO FASTER - sometimes it works WELL. It's >RARE for my lathe to slow down below 500 RPM! Tubing cutting and similar stuff on a floppy machine like the Atlas is best done fast. Done slow, it gives time for the cutter to pass thru on one portion and get caught on the remaining uncut portion of the circumference. This occurs if you feed in too fast or otherwise get a "dig-in", which is much easier the floppier the machine is. (Try it on an AA for real fun !!!! I did, the tubing folded up before anything important actually broke, I did not even have time to worry before it was over). If you go FAST on spindle speed, there is less chance of feeding in too fast, as each rotation is quicker, and you simply don't have time. The mandrel idea works well on the lathe, especially if you don't have a 6 jaw chuck. (BTW, they are/ were on sale at J&L.) If nothing else, use a wood mandrel. Easy to finish to size, no problem if you cut in. Jerry ------- Date: Sun, 18 Feb 2001 23:51:36 -0600 From: Jon Elson Subject: Re: Re: Cutting tubing? Keeping the place to cut close to the chuck, you would use a cutoff tool (a narrow, square-ended tool) and plunge in at a right angle to the axis of rotation. If the tool is ground right and sharp, it will make both sides of the cut clean. For brass, you want the lathe turning quite fast, probably close to 1000 RPM. For SS, it would be much slower, around 400-500 RPM. The brass can be done dry, the SS will likely need some cutting oil. Jon ------- Date: Mon, 19 Feb 2001 06:17:22 -0800 From: Roger Van Maren Subject: Re: Re: Cutting tubing? I've never used a 6" Atlas so I don't know how flexible they are, but I don't see what the big deal is here. I would suspect if you consistently have trouble parting off you probably have excessive wear or other mechanical issues with your lathe. Rigidity of the setup is the most important. First, grab the stock with the most secure method you have available. In order of preference for thin wall tubing: collet, machined soft jaws, 6 jaw, 4 jaw, 3 jaw. If the jaws of your chuck are worn/tweaked it may only look like it's held securely. I used to use an old Monarch lathe that had a 16" 3 jaw that had a few mils of wear at the ends of the jaws. It worked OK for bar stock etc. but thin stuff was difficult to get a good finish on. Second, make the cut as close to the spindle as possible. The less the stock has a chance to flex, the better. Parting also shows a sloppy spindle more than most other operations. One of the shops I used to work in had an old babbitt bearing South Bend with a slightly sloppy spindle. Not much, it was actually a pretty decent machine otherwise and I turned out some really nice parts on it but it had just enough wear to make parting a tricky proposition. Third, make sure your tool is sharp and honed and right at center or a few mils below. Remember also that the narrower the cut, the less force is needed. For a job like this I'd probably grind a square bit into a narrow grooving type tool about 30-40 mils wide and not much longer than the wall thickness of the tubing. Forth, some kind of cutting goo would probably help even on brass. I'd definitely use some on stainless. Once you start cutting, DON'T MESS AROUND. Use enough force to make the tool cut! If you don't feed hard enough the tool just rubs up against the stock and gets dull. If stainless this is VERY important. It will work harden and you'll never get through it. Pardon me if this is too basic or already been covered. I confess I haven't followed this thread very closely. Roger in Livermore ------- Date: Tue, 20 Feb 2001 06:04:43 -0600 From: Nick Hull Subject: Re: Cutting tubing? > Apparently some previous owner used the Hacksaw method with my lathe > and left some curfs in the bed!! Why take such a risk? There is NO risk if done properly. I always stop the lathe before the cut is complete and finish by rotating the chuck by hand. On really delicate jobs the piece could get messed up when it starts to come free under power. I have used cutoff tools sucessfully in larger lathes, but the hacksaw method is so easy and needs no special tools I use it all the time. It's fairly easy to finish up the rough cut surface (if required), much easier than grinding a special tool or even changing tools. The hacksaw does not need heavy pressure, and should be held lightly when the cut is almost complete to minimize breakthru problems. ------- Date: Tue, 20 Feb 2001 16:36:34 -0500 From: "S or J" Subject: Re: crimping (spinning?) door knob ferrule >We have several old glass doorknobs where the glass has gotten loose >in the brass base or ferrule. I chucked the shank of one in my lathe >and spun the assembly while pressing a blunt piece of rod against the >brass. Unfortunately, the brass started "smearing" instead of >curling down against the glass knob. I feel sure there is a >technique for this; can someone decribe it? Dennis Hi Dennis: A common form of putting a crimp into a round metal collar or ferrule involves applying inward pressure at more than one spot, or totally symmetrically around the tube, as in crimping cartridge necks tight to the bullet. In the case of a pipe cutter, the pipe (think tube) is supported by rollers on one side while meeting a round cutter directly opposite. A pipe cutter actually does a little crimping on a water pipe if it is tightened too aggressively in the process and more so if the pipe cutter's cutting wheel is dull. The fact that the cutter can rotate prevents the smearing you are experiencing, so a device similar to an oiled dull pipe cutter (which you would have to make) could work on a knob that was (for safety) rotated by hand, not under power. With no disrespect intended, I would simply try to solve the problem of the loose glass by pouring some thin adhesive like hobbyshop cyanoacrylate glue into the joint. If someone has a true metal spinning solution, I will read that information with great interest. Steve in Thunder Bay, Ontario ------- Date: Tue, 20 Feb 2001 11:33:49 -0600 From: "M K (Skip)Campbell Jr." Subject: Re: crimping (spinning?) door knob ferrule I believe I'd try setting it in glass up position and fill the void with super glue. Just a thought. Skip Campbell ------- Date: Tue, 20 Feb 2001 09:53:10 -0800 From: "Bob May" Subject: Re: crimping (spinning?) door knob ferrule Do it with a smooth roller in your knurling tool. An alternative is to get some clear epoxy and epoxy the glass in. Use the slow stuff and heat it up to about 150F so that the epoxy flows (it turnes to a water thin liquid) well. Please note that the high temp will make it accelerate the curing process to where you can get a 5 minute expoxy speed out of the slow stuff. Bob May My new web space address is http://webu.wigloo.com/bobmay/ or http://nav.to/bobmay ------- Date: Tue, 20 Feb 2001 10:30:02 -0800 From: "Bob May" Subject: Re: crimping (spinning?) door knob ferrule Cyanoacrylate depends upon small clearances to work. Make the stuff try to work over more than about .0001" and you are starting to have trouble. The filling types use a filler to get some strength with thicker sections and even then, they don't work all that well. Heat the epoxy up and it will flow like water and setup in a very short order. On top of that, you don't lose any significant amount of it's basic strength. I do JB Weld like this and it also works well. Bob May ------- Date: Wed, 21 Feb 2001 16:43:57 -0000 From: marti595x~xxbellsouth.net Subject: (followup) crimping doorknob ferrule Thanks for the many excellent responses. I had considered the epoxy method, but felt it would be pretty tedious getting the epoxy where it needed to be. Also, the threaded hole would have to be blocked to prevent epoxy from running down. I tried a "quick and dirty" method that worked: I manually crimped the ferrule all around with "channel lock" pliers, then used the good old 109 lathe to rotate the assembly while using file and emery cloth to smooth the ferrule. If I need to do any more knobs, I may try to be more scientific! again, thanks Dennis ------- Date: Tue, 27 Feb 2001 22:27:15 -0600 From: "J Tiers" Subject: Re: Height of tool > I would think that the height in relation to center would vary > the larger the piece being turned? Sometimes I get fairly smooth cuts > but most of the time I am less than satisfied. The height has a lot to do with it, and so does tool grinding. If you let the tool get too far below center, you will inadvertently establish a negative rake, which takes more force to cut. However, it will not do as well as a deliberate negative rake tool operating on center. Also, ABOVE center can put you in a situation where the tool will dig in deeper as it flexes down (and it will, on any lathe). This will at least give trouble with exact sizing, and on a flexible lathe like Atlas may cause a dig-in with tool or work damage, or just terrible chatter. You are almost always OK on or slightly below center (very slightly). Exceptions: It seems to be agreed that cutoff and threading are best ON center, for various reasons, including getting correct thread form. Machining books often give a slight advantage to above center, about 5 deg above relative to horizontal, but I don't find it works well for me, and is a pain to set up due to tiny measurements. Leave on center and go would be my best advice. Tools ground to "slice" give better finishes in many materials than tools ground to "plow", and tools ground to guide chips away give better finishes than tools that get a build-up. Chips stuck to the tool start tearing or plowing, or may re-weld to the surface. Oil helps slide them away. So cutting oil helps in many cases for this or other reasons. Finish has to do with speed (faster is usually better, especially with carbide), tool grind, material (some are stringy or smeary), feed rate, etc. There is a decent on-line guide that the Army put out, I don't have the URL handy but I am sure someone will oblige. Sherline (Sherline.com) has (had?) a tool grinding guide on their site with some info. Jerry ------- Date: Wed, 28 Feb 2001 13:46:57 -0000 From: david.kuechenmeisterx~xxatl.viasat.com Subject: Re: Surface finish [was ID #'s found] I've found from experience, and had confirmed by some of the senior machinists at work, that the quality of the finish depends on three things. First, the clearance and rake angles need to be ground correctly on the tool bit. On steel, I grind clearance angles of about 10 degrees. I grind the rake angles at about 10 degrees, as well. These angles are always based on the assumption that I'm working with my tool bit set at the work's centerline. Use the ruler method to find the centerline. Second, the feed rate and rpm must be correct for the material. CRS needs a cutting speed of about 100 sfpm, and the rpm is wagged from the formula RPM = SFPM*4/D where D is the diameter in inches. A good feed rate for roughing cuts is about 0.004 - 0.006 in/turn. Finishing is higher. Last, and the lack of this condition is usually the one that causes me problems, there must be a sufficient radius ground on the toolbit nose. For a roughing bit, just a nice rounded nose is enough. As the grinder is slowing down, I just touch the nose of the bit to the wheel and get a smooth radius. Anything sharp will just make the finish look as if it is being threaded. The tip is going to break eventually, as well. Different materials need different numbers, but the principle in cutting is the same. ------- Date: Sat, 24 Mar 2001 00:11:03 -0500 From: "Rich D." Subject: Re: Help getting smooth finish karenwhite60x~xxhotmail.com wrote: > Hi all, I am having trouble getting a smooth finish when turning > 5/8 cold rolled steel between centers. Any suggestions?? Using both > Taig Right hand tool, and Taig round nose tool. Using "Mightee" cutting > oil. Also, could someone PLEASE tell me aproxx. how fast I should move > carriage, eg., aprox. how many turns per minute of carriage hand > wheel?? And how deep of a cut?? ANY help would be very much > appreciated. Thanks in advance, Jeff Jeff: If you have already roughed out the bar, sharpen to a very keen edge a carbide tipped tool with at least a small tip radius. Use a fine feed and flow the cutting oil on the steel continously with a cheap brush (3/8" acid brush) so that the cut is always wet. About 800 rpm will do. Fine feed would be about .002" per rev. and about .005" depth of cut or less will do. Rich D. ------- Date: Mon, 2 Apr 2001 15:54:29 EDT From: catboat15x~xxaol.com Subject: Re: Introduction and questions In a message dated 4/2/01, rjmax~xxbmts.com writes: > I am tempted to get the 4-jaw for the flexibility, and ability > to center accurately without shims, but I remember how much time it > used to take me to set up a 4-jaw! I used nothing but a four jaw chuck for several years (could not afford a three jaw) I find I still use the four jaw for most of my work (play) and with a little practice it does not take much time to set up, You can eyeball the center, turn the chuck by hand and see which way to move, usually done in one or two tries. If you dont want to set up the DTI for rough work, just use a tool and turn back wards and see where it scrapes. Another hint, I keep a surface gauge set up at head stock height from the ways and use that to help center work. (One advantage of the often cussed flat ways of the Atlas.) John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Wed, 18 Apr 2001 23:36:41 -0400 From: Stan Stocker Subject: Re: Motor upgrade [TAIG BUT ALSO GEN INFO ON TURNING TIPS] Chris; No doubt some feel that 1/6 HP is fine for this lathe, and they may be correct. I tried a 1/10 and stalled it, so changed to a spare 1/2 HP old GE motor. Stalls are pretty much a memory now, but I've also learned about how hard you can push a small lathe ;-) With that said, a 2 inch hunk of aluminum is pretty healthy for a lathe of this size and weight. Doable, but big hogging cuts are pretty much out. On a larger lathe, I take 50 thou or larger passes on stuff like this all of the time. On the Taig, I tend to stay under 20 thou per pass, although you can cut heavier. You might want to double check your tool grind for aluminum however. Aluminum likes a lot of top rake, and shearing/slicing cuts. I use 20 to 25 degrees of top rake and about 7 degrees of side rake on tools for aluminum, with the edge honed to a high degree of sharpness and a mirror finish. Along with WD40 or kerosene as a lube this reduces cold welding to the tip a great deal and gives a good finish. Throw away brazed carbide tools just don't work well with aluminum on a small lathe like the Taig, the horsepower just isn't there for a zero or negative rake tool. They will work, but finish quality tends to suffer unless you restrict yourself to quite shallow (< 0.010) cuts. I just chucked up a piece of 1.75 inch 6061 and made some trial passes, so some real numbers could be posted. Using an M2 HSS 1/4 inch toolbit ground for aluminum and freshly honed, at 1375RPM, passes at 35 thou without bogging were possible if I didn't try to hog the cut, perhaps about 5 thou advance per revolution. At 10 thou I couldn't make it bog down feeding fast. At 500 RPM the finish quality went downhill fast. I could take 45 thou cuts dry at 2110, but it wanted to bog down. 20 thou cuts gave good finish at 1375 or 2110. 880 RPM just slowed down the cutting and dropped the finish quality a bit. Using a new ISCAR brazed carbide 1/4 inch tool, again at 1375, the max cut was about 20 thou, and it wanted to bog down. At 30 thou I could easily stall the lathe, and started to get some fairly nasty chatter. At either depth there was tearing of the cut, unlike with the HSS toolbit. 10 thou cuts went fine and 5 thou cuts gave a very nice finish. Using kerosene or WD40 for lube improved finish quality, but didn't make a significant difference in depth of cut capacity. If you are using indexable carbide tooling, the 222 inserts have too large a radius for use with a 1/6 HP I'd guess, they tend to bog a bit even with 1/2 HP, so drop down to a 221 and see if life gets better. Hopefully this gives you some concrete numbers to compare your results to. If you choose to upgrade your motor, there are a number of posting in the file area about using motors from The Surplus Center, they have a nice PM unit with controller for about $50 these days. I intend to order a few for some other projects. A new 1/2 HP motor will be in the area of $75 to $100 dollars, depending on make and supplier. Stan ------- Date: Sat, 05 May 2001 16:14:02 -0400 From: ron ginger Subject: Re: radius cutting on a sherline Carol & Jerry Jankura wrote: > Gerald: If you have a picture of one of the units, > you might be able to draw your own prints. > From what I see, the radius cutter is simply a yoke that > "encircles" the end of the part and holds a cutter. About the only > critical items in building one are that the point on the cutter must be > on center with the chuck rotation and that the pins which act as > a hinge to allow youto move the yoke should be accurately aligned. I think radius attachments are the most common tool in old issues of MODEL ENGINEER. They seem to have run one about every year. The style sold by OWL is most common, but it has one drawback. The tool feed by a simple lever is hard to use to get a good finish. You really ought to make a worm wheel so you can do a fine finish. The lever will work, but the surface finsih will be poor, then you will likely clean it up with a file or sandpaper and there goes any accuracy of the ball. One common style is to use your boring head, mounted on a tool block with its axis horizontal. The boring bar adjustment can then be used to set the diameter. The kit sold by Metal Lathe Assoc is of this type. I believe George Thomas has this style in one of his books. ron ginger ------- Date: Sat, 5 May 2001 14:05:15 -0700 From: "David Goodfellow" Subject: Re: radius cutting on a sherline Hi Gerald: Take a look at the following url. It's plans for a radius cutting attachment similar to the one sold by OMW. I built one for my Taig lathe (but sold it with the Taig) and it worked fine. I later bought one from OMW and found it was basically the same design. The url for the plans is --[SNIP] Gerald: I gave you a bum steer. You can get there from that url, but it's complicated. Go instead to http://www.metalwebnews.com/mr.html And look through their list of projects for a ball-turning tool. Dave Goodfellow ------- From: "Paul & Charlene Wilson" Date: Tue Jun 26, 2001 7:53 am Subject: Re: [atlas_craftsman] turning problem >> I'm turning a piece of 12 in long 4140 steel shafting 2 in diam. My cut is taking about .006 in a pass, and a hss bit...a good sharp one, along with best quality cutting fluid. The cut is toward the headstock. The problem is, for the first 6 in of the cut, I am getting a lot of skipping on the cut surface. After about 6", it settles down, and the rest of the cut is pretty good. Can anyone figure out what the problem is? << Bob, I am not an expert but your description points toward a problem with either your tailstock or center. Is the tailstock tight? Is the center seated properly in the tailstock? Are there any burrs in the tailstock or center? If it is a live center, is the bearing good? Center tight in the bearing? If it is a dead center, is it properly lubricated? Is the center drill on the shaft too shallow? Just some idle thoughts, good luck. Paul ------- From: fyunchx~xxa... Date: Tue Jun 26, 2001 12:30 pm Subject: Re: turning problem If your stock is a salvage part, perhaps one end is heat-treated differently than the other. Try reversing the part and see if the skipping remains the same. Also try cleaning the rack and/or leadscrew--it may be that the outboard sections, which typically are used less, are crudded up. W.C. Gates ------- From: Jon Elson Date: Tue Jun 26, 2001 1:38 pm Subject: Re: [atlas_craftsman] turning problem I'll just about bet that you are not supporting the free end of the work with either the tailstock center or a steady rest. You need to support anything much longer than 6" or you will get vibration. Even worse, if the tool binds up in the cut, it could bend the spindle! If you ARE using a support on the free end, then I'd check the tightness of the gibs on the saddle, and make sure the center or rest is properly holding the work, and not allowing it to vibrate in some manner. Jon ------- From: HUNLEY31x~xxa... Date: Mon Jul 16, 2001 11:51 pm Subject: Sequence of work? For my first project I'm going to try a toy cannon barrel (non firing). I could use some advise on what sequence the work should be done. 1) turn the outside of the barrel 2) drill the 'trunion' or whatever the rod that the barrel pivots on is called 3) drill a hole in the barrel 4) wheels will be solid, should they be faced before or after the axle hole is drilled. Thanks, Hank ------- From: fyunchx~xxa... Date: Tue Jul 17, 2001 1:53 am Subject: Re: Sequence of work? Cannon barrels (called TUBES, properly): Sequence depends on whether the tube you are making is small enough to fit back into your lathe spindle, and whether the stock you start with has some extra length. I typically put a center hole in one end, then move the stock out, supporting the far end with a live center, then true up the outside of the stock. Then you drill the bore, which for a non-firing cannon doesn't have to be very deep, using a drill bit in the tailstock chuck. If the stock fits into the headstock chuck, do it there, Otherwise use a steady rest to support the outboard end. Then, make a plug to fit into the muzzle; this plug has a center hole. You can then support the muzzle end with a center in the tailstock while holding the back end (breech) in the chuck, while you turn the outside. Then swap ends and turn the cascabel (ball on breech). Do it in the chuck if the work fits, otherwise, back to the steady rest. It is often worthwhile to make up some split rings of brass or aluminum to allow clamping the part without the part being marred by the chuck jaws. Then drill the cross hole for the Trunnions. Press or solder in the pin. The real fun begins when you want figure out how to safely attach the trunnions on one to shoot! Wendall Gates ------- From: HUNLEY31x~xxa... Date: Tue Jul 17, 2001 11:39 pm Subject: Re: Sequence of work? (Wendall) Good tips, I'd try the firing version, but don't have a drill bit that long. I like the 'plug' idea as I don't have a taper attachment. I read somewhere that a ball with a center drill hole will suffice in the tail stock and act as a bearing when using the tailstock offset method. (I think I just confused myself.) If I survive I'll post the results. ------- From: fyunchx~xxa... Date: Wed Jul 18, 2001 1:30 am Subject: Re: Sequence of work? (Wendall) Everybody I know uses a real center, not a bearing ball, in the tailstock when supporting outboard work. Since you are working brass, a solid one (lubricated) should work OK. LIVE centers (made with ball bearings) are better for heavy work. You can used the compound rest for machining tapers. Make wedges about 4" long out of 1/8" thick aluminum sheet which have the required taper (milling machine, or file by hand). Place the wedge against the work (while still a uniform cylinder). Loosen the clamp screws with allow the compound rest to rotate, and rotate the rest so its side surface is flat against the tapered side of the wedge, then lock the compound rest. Use the carriage lock to hold the carriage immobile, and cut using the compound feed. My other suggestion--stick to non-firing cannon models until you know a LOT more about metals and machining. :>) Wendall Gates Santa Cruz, CA ------- From: "Ron Odum" Date: Wed Jul 18, 2001 7:01 am Subject: Re: [atlas_craftsman] Re: Sequence of work? (Wendall) You might want to take a look at this site...Very nice pictures and well researched specifications: http://www.wwd.net/steen/ Soon as I get my lathe and my skills up to speed, I suppose an accurate scale WBTS model cannon will be my first project.. Ron Odum Mansfield, LA http://thesawdustpile.homestead.com/MyHome~main.html "A man can never have too many tools." ------- From: "jerdal" Date: Wed Jul 18, 2001 11:01 pm Subject: Re: [atlas_craftsman] Re: Sequence of work? (Wendall) > Everybody I know uses a real center, not a bearing ball, in the > tailstock when supporting outboard work. Since you are working brass, > a solid one (lubricated) should work OK. LIVE centers (made with ball > bearings) are better for heavy work. If I recall correctly , the reference to a ball bearing as a center referred to offsetting the tailstock to turn a taper. In that particular case, a ball bearing or ball end center will provide a much better and more geometrically correct support than a standard center. This is because of the off-angle, which causes an angular interference with a 60 deg center, but has no great effect on a sphere used as a bearing. ------- Date: Tue, 21 Aug 2001 22:29:40 -0500 From: "Dana Zimmerman" Subject: RE: Centering on a 4 jaw chuck From: Skip Evans [mailto:skip_evansx~xxhotmail.com] Sent: Tuesday, August 21, 2001 8:52 PM To: atlas_craftsmanx~xxyahoogroups.com >>> I learned a valuable lesson this evening. When centering a piece of square stock in a 4-jaw chuck using a dial indicator---- Snip ---- gone wrong? Well, I was exactly 1 revolution off. I guess I will have to remake the part. <<< Just a thought. A pair of corner to corner lines, scribed, pencil, felt-tip Sharpie, chalk, soapstone, or whatever, would have made this more obvious when you rotated the piece by hand to check clearance before beginning to machine. A simple tell-tale. The "Measure twice, cut once" chestnut, well known in woodworking circles is good for metal too, and "Measure two different ways as a cross-check can help as well. A related chestnut in metalworking I've heard, is "Dead on to the mil, off by inches" Take heart, it happens to all. ------- Date: Wed, 22 Aug 2001 11:09:55 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: Centering on a 4 jaw chuck Here's the way I would attempt to center the square (or rectangular) stock on a lathe... Carefully measure and scribe the stock so as to locate the center (or any location). (Hope you are more precise than i am) Mount the stock and roughly center it in the chuck. Mount a drill chuck in the tail stock and chuck a wiggler (center finder). Bring the point of the wiggler to the center point marked on the stock, so that it touches with a little pressure. The spring in the wiggler will keep it in place.. Indicate on the ball of the wiggler. Leo ------- Date: Wed, 22 Aug 2001 12:07:30 -0500 From: jmark.vanscoterx~xxamd.com Subject: RE: Centering on a 4 jaw chuck Scribing it seems like a lot of extra work. Why not just mount it in the chuck centered approximately, tighten firmly, but not tightly. Use your dial indicator on the tall side (rectangular) rotate 180 degrees, repeat until TIR < .001. Next do short side, turn 180 degrees, repeat as above. Snug up chuck jaws, recheck. Repeat if there is a problem. This is how I did it for a long time when all I had was a 4-jaw chuck. Trying to mark it can just introduce other errors. It is difficult to mark as accurate as a dial indicator can measure. Mark V.S. in Austin, TX ------- Date: Sun, 26 Aug 2001 16:10:59 -0500 From: Bill Aycock Subject: WTB: Follower rest for 618 I had great success on the last request I put here. (for a milling unit.) SO: I am interested in getting a follower rest for my 6 inch Atlas. I often need to clean the ends of some thin walled tubing so it will accept a centering fixture. Now, I have to be VERY carefull, to not chatter, or, worse,- let it grab on the cutter. A follower seems to be ideal for this. So- if anyone has one that is available- let me know. Thanks- Bill Bill Aycock --- Persimmon Hill Woodville, Alabama, US 35776 (in the N.E. corner of the State) W4BSG -- Grid EM64vr baycockx~xxHiWAAY.net w4bsgx~xxarrl.net ------- Date: Sun, 26 Aug 2001 19:54:35 -0500 From: "jerdal" Subject: Re: WTB: Follower rest for 618 You wrote: > I am interested in getting a follower rest for my 6 inch Atlas. I often > need to clean the ends of some thin walled tubing so it will accept a > centering fixture. Now, I have to be VERY carefull, to not chatter, or, > worse,- let it grab on the cutter. A follower seems to be ideal for > this. So- if anyone has one that is available- let me know. Are you sure you want a follower and not a steady? A follower only holds against cutter pressure, and travels with the carriage. It does not hold the part securely. It also tends to be in the wrong place for working on the end of a piece, as you suggest. What you are saying seems to relate more to a steady rest, which you place on the bed. It acts as a full bearing and allows the piece to rotate within it. Then you have freedom to work around the end of tubing etc rotating in it. Jerry ------- Date: Sun, 26 Aug 2001 21:22:43 -0500 From: Bill Aycock Subject: Re: WTB: Follower rest for 618 Jerry- When I do the work I need to do on the tubing, I have a fixture that I use to adapt to a live center, and have another fixture within the tubing to let me hold it better. Both these require that I have the inside clean at the ends. With a follower, I can make the small cuts needed by turning the compound. With the short lengths of tubing I use, there is not much room to use a steady rest. I know a steady rest is better for many things, and if I get a good buy, thats the way I'll go, and change the fixtures to get more room, if possible. Thanks for the note- I appreciate the advice. Bill ------- Date: Mon, 27 Aug 2001 00:38:06 EDT From: catboat15x~xxaol.com Subject: Re: WTB: Follower rest for 618 In a message dated 8/26/01, baycockx~xxhiwaay.net writes: > I often need to clean the ends of some thin walled tubing For the occasional job I have used a wood steady or follower rest. Make a hole in a chunk of wood, clamp it on the bed (steady rest) or the cross slide (follower rest). Grease it well and away you go. Oh the follow rest is not a hole but a partial hole to leave room for the tool. And more of a problem as chips can get under the wood scarring your work. but does the job if you are careful. ------- From: "Terry" Date: Mon Jul 9, 2001 11:42 am Subject: Turning down a rod I'm trying to turn down a length of 1/4" aluminum round stock to .235". Finished length needs to be 5". Here's what I'm doing: 1. Cut a 6 or 7" length of metal. 2. Mount the rod in a collet, with about 3/4 to 1" protruding. 3. Center drill the end. 4. Remount the rod so about 1/2" is in the collet, and the other end is held by the tailstock center. 5. Turn down to size. My problems thus far have been lots of chatter and poor turning after I get more than an inch from the collet. Also, when I used the dead center, the piece was deformed by the center. I suspect two culprits here: -- The rod is too thin and long to support itself during turning. A moving steady might solve this, or I could turn the piece in shorter sections. -- The tailstock is out of alignment. This could cause the toolbit to take progressively larger cuts as I move down the piece, putting excessive forces on the center-supported end. Am I on the right path here? Anything else I need to be watching out for? Thanks in advance for your advice. Terry ------- From: Stan Stocker Date: Mon Jul 9, 2001 12:31 pm Subject: Re: [taigtools] Turning down a rod Terry: If the rod is tapered over its entire length, fattest or thinnest at the tailstock, it is the tailstock offset. If the thick or thin section is towards the middle, with each end very close or exactly the same in size, the work is deflecting, whipping, or your center hole is off center. If the work is whipping (most likely as you specifically mention chatter and finish problems) a follower rest is called for. As an alternative, consider simply advancing the work through the collet an inch at a time and turning down the diameter in a series of cuts, each 1/2 to 3/4 inch long. As you are only taking a cut of 0.0075, for a diameter reduction of 0.015, deflection shouldn't be an issue with an inch of everhang, provided your tool is nicely ground and stoned. For one off use, the follower could be as simple as a hunk of maple or other hardwood secured to the cross slide T slot, preferably the same slot as the one holding your toolpost. Snug it against the work, take a pass, and repeat after advancing the cutter. Low tech, but quick and easy if you want to put off making a real follower rest and get the job at hand finished first. You can blend the slight variations from one section to the next with a bit of 600 grit silicon carbide with WD40 or kerosene as a lube. With care, the variations won't be more than a few tenths at most from one turned section to the next. Lubricate the dead center, if you are deforming the center hole with the tailstock ram pressure, you are almost certainly deforming (flexing) the shaft by applying excessive tailstock pressure in the attempt to eliminate chatter. 5 inches of 1/4 inch stock will flex when you try this, although heavy tailstock pressure can be of use in reducing chatter with larger turnings. Stan -------- From: "Nicholas Carter and Felice Luftschein" Date: Mon Jul 9, 2001 12:33 pm Subject: Re: [taigtools] Turning down a rod >>Not much experience with aluminum, but my 'guidebook' says that you >>need kerosene as a cutting fluid. WD-40 is a bit safer, although lately I have been using "Cool-Tool II", which seems quite safe and is a bit thicker, and works on steel as well. Several other things: Lube, WD-40, to avoid chip welding to the toolbit. Very sharp toolbit, with proper rake angles for aluminum so that the tool cuts and doesn't push the work. Make sure it is at center height - otherwise it will be pushing the work out of alignment as well. Try different speeds - faster may be better. > off making a real follower rest and get the job at hand finished first. I have used a hunk of brass, bored 1/4" and mounted to the back toolpost. The tool is mounted on the compound slide so that the follower is always in the same position, but the tool can be adjusted. See this picture of some small turning using this method: http://www.cartertools.com/ntaig9.jpg ------- From: ptolemyx~xxb... Date: Sat Aug 18, 2001 12:09 pm Subject: Morse Taper This morning I started turning my first Morse taper as part of a gear-cutting mandrel I'm making. I made a mistake that I bet about 50 percent of all amateur machinists make at this point. I set up the angle for the cut using an existing Morse taper and then turned the part down to nearly the desired size. I checked the taper before the final cut and -- you guessed it -- I had cut the taper at twice the desired angle! Duh! Fortunately, I left enough extra on the chucked end of the part to allow me to correct the mistake this afternoon. Neil p.s. At least I failed with finesse -- my rough taper was off by only about 4 minutes of arc being an exact double Morse. ------- Date: Sun, 19 Aug 2001 16:39:33 -0000 From: ptolemyx~xxbellsouth.net Subject: Re: Morse Taper Jerry Jankura wrote: > Is it something like "The taper is 20 degrees, > so you should only rotate the headstock 10 degrees Yes -- though I was using the compound slide. I set the angle to be the total angle of the taper, and not the angle between the edge and center. I originally set up the angle using a morse taper "dead" center. My conjecture was that if I set the center in the gap between the compound slide and my chucked part, the angle would be exactly correct when the top of the center was parallel to the bed just as the center fell through the space between the slide and the part. It turns out I was right -- to within four minutes of arc -- but obviously (in retrospect) the angle was double what it should be. For my second try, I chucked a morse taper "backwards", that is, with the small end of the taper facing away from the chuck, and used this to align the compound slide. This was not quite as accurate, but it gave me a starting point for "sneaking up" on the final taper. I adjusted the final taper by leaving the slide in place after each cut, but backing off the main screw to leave a tiny (almost invisible) gap under the cutting head. I then "rotated out" this gap by turning the compound slide what amounts to a few minutes of arc at a time. I constantly checked the taper against the tailstock I was going to be using it in. Eventually, I got it pretty much on the nose! Biggest lesson learned: If I had drawn a diagram of the cut first and thought a little more about the geometry, I would have seen the original angle was too big by double. Neil ------- Date: Fri, 31 Aug 2001 09:50:17 -0700 From: Frank Evan Perdicaro Subject: More on chatter Lots of good discussion so far. Two other thoughts. 1) Use lead to dampen vibration. It has high density, and thus shifts resonant frequency with little volume used. In addition to high density, lead does not conduct sound well: no lead bell will ever ring. It is fairly standard practice to used lead sheeting as a sound damper. Quite common in plumbing applications (wrap noisy water pipes and waste pipes with lead; secure with band clamps). The 1980s Ford Mustang GT and 5.0 liter LX cars had lead sheets under the carpeting in the back half of the car! 2) There is a product for motorcycles called "Bar Snake". It is available in rope-like form and in liquid, castable form. Specifically designed to kill vibration, it is a mixture of silicon rubber and lead shot. My guess is a few sections of Bar Snake would be useful in the workshop. A 10" section would probably fit inside an Atlas lathe spindle. Hold it in place with rubber stoppers. High purity aluminum (hard to find) is also a sound killer. More effective per unit mass than lead (lots more volume). High purity copper is also good and is used in several commercial applications, including Delta commercial wood cutting blades (one of those is mounted in my electric miter box right now). ------- Date: Fri, 31 Aug 2001 09:51:46 -0700 From: "Bob May" Subject: Re: Re: Why does my 12 X 36 chatter? The thing that all have to remember in this thread is that all lathes will chatter if the cutters aren't done right. It's not a function of how solid the lathe is but rather how much force can be generated and then shed by working the work. I've done chatter free work with a flimsy Unimat and made a nice Hardinge lathe walk the floor. It's all in how you do the job. There are some jobs like brake drums that are naturally flexible and they tend to chatter a lot more than other more solid work but you can do the work without chattering. Bob May http://nav.to/bobmay ------- Date: Sat, 01 Sep 2001 05:12:19 +0000 From: Jon Elson Subject: Re: More on chatter One way to get rid of a vibration is to change the natural frequency of whatever is vibrating to a frequency where noting in the environment excites it. That can be hard to do in systems where things run at different speeds, like cars and machine tools. The other way is to absorb energy, rather than letting it build up. Lead shot works well, not only because of weight, but the rubbing of the lead beads absorbs a lot of energy. Lead sheets bonded to an energy absorbing urethane or foam is another technique. The lead is a damping mass, and the soft stuff 'works' back and forth between the lead and the vibrating thing, absorbing energy. In some systems they actually have to supply cooling air to keep the energy absorber from overheating. Anything that is soft and dissipates energy when 'worked' will absorb vibrations. Pure aluminum, if you've ever handled some, is really quite flexible. it is nearly as flexible as lead, and totally un-machinable. I got some pieces of extruder stock once, and it was useless except for recycling. It did impress people who didn't know what it was when I could bend 1.5" solid rounds with just a few fingers! ------- Date: Sat, 1 Sep 2001 09:25:27 -0700 From: Frank Evan Perdicaro Subject: Re: Digest Number 616 >Something I don't understand, you mentioned that high purity Aluminum is >a good "sound killer" because it has more volume than lead. I was under >the impression that we wanted more mass to dampen the vibration >which was the SOURCE of the noise. Am I missing something? Probably missing something. What I was calling "sound killer" is more properly termed "phonon propagation in crystaline metals". Like density, conductivity, color and temperature expansion, this is a property of solids. Metals that have high "sound killing" have that property regardless of mass. Lead happens to have both high mass and high sound killing, but low hardness. Uranium has high mass, but low sound killing, and high hardness. Cast iron has moderate sound killing, moderate mass and moderate hardness. This subject is often ignored or misunderstood because it is rather recent (Nobel Prize in Physics, about 1974) and really hard to understand. If you were a graduate student in physics in the last 20 years you probably understand. Otherwise, it is unlikely you do. Want an introduction? See Charles Kittel's book "Introduction to Solid State Physics". A sandwich of dead soft aluminum and rock wool is sometimes used in office partitions to kill sound. Light, cheap, effective and non toxic. ------- Date: Sat, 1 Sep 2001 22:01:49 -0500 From: "jerdal" Subject: Re: Digest Number 616 Several different issues here. 1) If you have a mechanical resonance, adding mass to the resonating system will change the frequency of resonance. This may be sufficient to get it away from the driving frequency and eliminate vibration. Mass does not "dampen" vibration by itself, other than to change frequency, or alternately to cause a certain energy input to result in a lower amplitude of vibration. 2) You can also employ a material which has high inherent sound transmission losses, or has poor sound transmission characteristics, inserted between the source and the resonant system. Systems of sheet metal which are two sheets with a viscous material between them are very lossy and fall into this category and also the next. The same principle could possibly be used in a tool mounting if cleverly arranged. Bet someone has done it already. 3) You can lower the sharpness (Q) of the system resonance, so that it is lossy and tends to actually dampen (lose as heat) the vibrations. The lead shot filled boring bar is an example. The sheet metal sandwich is another if say it is part of the enclosure, and would rattle and clang if not damped. Jerry ------- Date: Sun, 2 Sep 2001 11:38:05 -0500 (CDT) From: dswrx~xxwebtv.net Subject: MBOI... Hi Lathe Laddies! Here's a tip for you... You need to chuck a finished surface... You know that the recommendation is to use "soft copper" to protect the surface... But, you don't have any... I had the same situation... making a die holder for one of the 13/16 jobbies. No copper, whut to do, whut ot do? (bingo) Plenty of copper... house wiring cable, 12 gauge, three nice soft copper conductors "suitable for chucking"!!! (don't cut it out of your house... go buy some) 8-) Leo ------- Date: Tue, 02 Oct 2001 00:47:40 -0000 From: zr1zr1x~xxnetzero.net Subject: Atlas Through Bore (Was Re: Atlas Price) Hello, I went thru some of this a while back with very similar wants. The barrel in question sounds awfully like a Shilen 5 1/2, ie 1.25" at breech and about .750" at muzzle. My Atlas 12x36 has just over 3/4 inch thru the spindle which means to me at least that chambering between centers is going to be the method for a while. If one considers an Asian lathe, the 12x36's seem to have a 1 3/8" or 1 1/2" hole thru the spindle which handles most barrels ok with maybe exception of some unlimited or 1000 yd stuff; these lathes can typically give the user a choice of chambering between centers or in the chuck. Smaller Asian lathes that have limited capacity thru the spindle seem to be kinda short in bed length for most rifle barrels; also the lowest speed for threading and reaming seems just a bit high to me. I have watched several benchrest rifles being chambered thru the headstock on a larger lathe that incorporated a spyder at the end of the spindle to support the barrel. So it seems that for rifle barrels, my Atlas at least is a chamber between centers where as some with larger Asian or domestic built lathes give the option of chambering in the headstock; I think either method of chambering will do a good job; one just has to get used to the specific methodolgy and the machine. Regards, Rick W. Plano, Texas ------- Date: Fri, 12 Oct 2001 14:20:38 +0100 From: Tony Jeffree Subject: Re: 4-jaw chuck centering At 06:36 12/10/2001 -0600, you wrote: >Does anyone have a quick, accurate way to center a square rod in an >independent 4-jaw chuck? Too bumpy for a dial indicator. >John B. Shadle, CMC Online Clockbuilding: >http://geocities.com/jshadle.geo/online_clock_building >http://geocities.com/jshadle.geo/ Depends how accurate you need. For example, you could accurately scribe across the diagonals on the end of the rod & bring the tailstock ram up to see if the intersection is on-centre, but you're not going to get it really accurate that way. Alternatively, and more accurate, turn the chuck to make one face of the rod vertical, and advance a cutting tool so that it just touches the face. Move the tool out of the way (without changing the cross-slide setting), rotate the chuck 180 degrees & see how far, and in what direction, you have to advance the toolpost to just touch on the second face. Both have worked for me. Regards, Tony ------- Date: Fri, 12 Oct 2001 10:19:09 -0500 (CDT) From: Tom Benedict Subject: Re: 4-jaw chuck centering On Fri, 12 Oct 2001, John Shadle wrote: > Does anyone have a quick, accurate way to center a square rod in an > independent 4-jaw chuck? Too bumpy for a dial indicator. Got a pretty accurate way that's dead-slow. It's similar to what Tony was describing: Mount a TDI on the cross-slide. Use this to roughly align the bar by eye. Once it's aligned by eye, bring the tip of the TDI up against one of the flat faces. Rock the four-jaw back and forth. The needle on the TDI will oscillate back and forth. When the face is completely vertical (I'm indicating on the side facing me), the TDI bottoms out. Move the cross-slide until the TDI bottoms out at zero. Note the reading on the cross-slide! (I'm using dial indicators on mine, so I don't bug with backlash. If you're using the handwheel, take backlash into account and only crank it in from one direction. Back the cross-slide out, rotate the part, and crank the cross-slide back to the original position. Rock the four-jaw back and forth and note where it bottoms out. Working in pairs, shift the jaws so the part moves half the distance between your two readings. Move the cross-slide to zero out the TDI. Note the reading on the cross-slide. Back the cross-slide out, rotate the part 180 degrees, and move the cross-slide back to the last position. You should be very very close to zero run-out. Repeat as necessary to get it as tight as you like. Now do the same on the other axis. There's a neat corollary to this I used in making that steam engine (thanks for the tips, everyone!!) Once I had a part centered, I used that as my 0,0 point. I laid out all my drawings with a coordinate frame off of that 0,0 point. To move from 0,0 to a given point, I'd zero out the TDI, then move the cross-slide in the direction I needed to go by the distance I needed to be from the center of the part. Then I'd shift the part in the 4-jaw until the TDI read zero again. This made it really easy (and fairly fast!) to shift the part around in the 4-jaw very precisely. No clue if this is news or not, or if it's useful to others. Just something I hit on while avoiding the milling attachment. Tom ------- Date: Thu, 1 Nov 2001 12:35:22 -0700 From: "Maxwell Sandford" Subject: Re: Tailstock question From: To: Sent: Thursday, November 01, 2001 12:16 PM Subject: [atlas_craftsman] Tailstock question > I have a 101.07301 6". It came with a Jacobs chuck mounted on a MT1 > adapter for the tailstock. The adapter has a flat tang on the end. > It will only seat correctly if the tailstock is extendend to about > 3/4" looking at the graduation markings. If the tailstock is > backdowned to '0', it forces the adapter forward and out of it's seat. > I have seen MT1 reamers and drills with a tang. I guess the question > is, should MT1 attachments with a tang work with the tailstock of the > 6" set to '0'? > Also, is a tang necessary to keep the chuck (or drill bit) from > turning in the tailstock? I have only used mine for light drilling > and have not had any problems so far. John Van Brocklin Tang is not necessary for operation, but is provided as a means to remove the adapter. In the case of the lathe tailstock, retracting the ram pushes out the adapter. Many MT female sleeves have a slot that permits a wedge to be inserted. Tapping the wedge removes a stuck male adapter easily. Most of the adapters I use on my 6" have the tang removed to permit the adapter to move further back into the ram, and the ram to be retracted to its zero. I have only had problems with the adapter rotating on heavy cuts with large diameter drills or with a boring head mounted in the tailstock. Tailstock MT adapters can be prevented from rotating by screwing in a bar perpendicular to the unit. The bar rests on the ways and prevents rotation. ------- Date: Fri, 2 Nov 2001 01:26:21 EST From: anthrhodesx~xxaol.com Subject: Re: Tailstock question In a message dated Thu, 1 Nov 2001 16:34:08 -0600, Randy Pedersen writes: << I believe the tang is for removing the MT from an adapter or drill press or mill that uses MT bits or holders. You use a removal wedge thru the slot in the adapter or shaft. Somebody correct me if I am wrong but I have never seen any tailstock with a slot for the tang. >> Lathe tailstocks don't ususally have the socket adapted to drive the tang but drill press quills sometimes do. And as you noted they usually have a slot through which to use the removal wedge. As Morse tapers in particular appear to have originated for self hold on large drill bits and to have been adapted to the lathe because they were convenient for the purpose, slight inconsistencies in their function for the lathe application have to be accepted within that historical development. Regarding the tang on a chuck arbor, it's possible that you could shorten it a bit so that it wouldn't eject until the tailstock quill had been retracted almost all the way in but be careful. If you shorten it too much the arbor will never self eject and you'll have to dismantle the tailstock to use an alternative approach to eject it. Also, after such alteration, you cant use it on a drill press because you now have no means of removing it (the wedge has nothing to bear against). Anthony Berkeley, Calif. ------- Date: Mon, 5 Nov 2001 09:48:39 -0800 From: "Marcus & Eva" Subject: Re: Beginner question >>In fear that I am overlooking something really simply, I'm almost hesitant to post this question, but here it goes anyways. I am making a cannon and am currently cutting the 1 deg. taper the length of the barrel (2.75 X .405) and I cannot keep the work in the 3-jaw chuck. I am taking light cuts but the work always seems to work free. It is also very difficult to get the bar stock I am using to run true (+- .001 to .005). I have already tightened the chuck to the point that it digs into the T6 alum. (when I re-chuck I use a clean place on the work) I dont think I can go any tighter on the work.Please advise, Devin Cox << Hi Devin: It sounds to me like one of two things is happening to your setup: Either your workpiece is projecting so far from the chuck and you have so little being gripped by the jaws that the cutting pressure is levering the part out of the chuck, or your chuck is defective and needs to be replaced. The way to tell if the chuck is OK or not, is to take a bit of soft copper or aluminum round stock and squeeze it in the chuck. Check to see if the squash marks are even across the length of the material. If they make deeper impressions at the end that was deepest in the chuck, then the jaws are sprung or worn and need to be reconditioned or replaced. A more sensitive test for the same condition, is to get a hardened dowel pin and smear the chuck jaws with a light film of machinists blueing or, in a pinch, with Vaseline. Chuck the dowel so the jaws just grip it, and then release it again. Inspect the surface of the dowel for grease marks, they should be even all across the length that the chuck was gripping. Heavier marks at the end deepest in the chuck is a "no good" sign. If the chuck checks out OK, then you need to modify your setup. The traditional way to do this is to mount the part "between centers" and shift the tailstock to make the long axis of the cannon non-parallel relative to the long axis of the lathe. That will make the part tapered as it is cut with the carriage. On a Sherline, you can't shift the tailstock, so you rotate the headstock instead. Thing is, you have to rotate it AWAY from you (counterclockwise) if you want the headstock end to be the big end. This is opposite to how you would tilt the headstock if you didn't have the part supported by the tailstock. YOU CANNOT USE THE 3 JAW CHUCK TO DRIVE THE PART IF YOU ARE TURNING TAPERS BETWEEN CENTERS!!!!!!!!! It will twist itself out the chuck and trash the jaws in the process. If this confuses you, make a sketch of the relevant parts and it will become clear. If you need the taper to be accurate, this setup will require a lot of farting about, to get the headstock twisted by the correct amount. You don't just tip it 1 degree, you have to tip it the amount that will get you one degree misalignment OVER THE LENGTH OF THE PART. A long part will require more tilt of the headstock than a short part. Notice that this is true only when turning between centers; if you are turning a part supported only by the chuck, then you simply set either the headstock or the compound slide (if you have one) over to the correct angle (one degree) and start cutting. Confusing, ain't it!! Cheers Marcus PS: Don't expect too much from a 3 jaw chuck; 0.003" out of round is typical for these chucks. "Dead Nuts" accuracy requires a 4 jaw independent chuck. ------- Date: Mon, 5 Nov 2001 17:05:09 -0500 From: "Vince Pearman" Subject: Re: Beginner question Turn the barrel between centers using the lathe dog, instead of holding the piece in the chuck. If you're using the chuck you can't pivot the headstock and still support the end of the piece on center, if you try the piece will twist right out of chuck and possibly damage the jaws as well. ------- Date: Mon, 5 Nov 2001 16:06:39 -0800 From: "Craig Libuse" Subject: Re: Beginner question >I will also use the dog to turn the taper, however I have no idea >how to do so. I am hoping it will become obvious when the machine >is in front of me. Devin, There is an illustration on page 17 of the Sherline Instruction Manual that should have come with your lathe that shows taper turning using a faceplate and drive dog. It is also shown in "Tabletop Machining" on page 126. If you don't have either of these, try www.sherline.com/latheins.htm for the lathe instructions on our web site. The illustration is shown under the section entitled "Taper Turning". Hope this helps. One picture will explain it all. Craig Libuse Sherline Products ------- Date: Tue, 13 Nov 2001 00:20:35 EST From: catboat15x~xxaol.com Subject: Re: Machining question > how do you machine a crank? For a model engine you usually have one bearing. A crank web and the crank pin. You can do this out of one piece of stock the diameter of the crank web. (You want a full web if possible as any extra space in the crank case is detrimental to running) Machine the main shaft on the center of your piece, offset in the four jaw the proper amount to get the throw you need. OK now for balance you can cut away some of the crank web each side of the crank pin. If this is shaft induction then you have to figure out where to put the port in the shaft to give proper timing (as well as the location of the exhaust and bypass ports). Not a really simple process. I did make a diesel 0.12 cu inch displacement engine one time, and it actually ran. Even the designer said it would not last long using the machinable materials specified with our proper heat treatment. The other way is to make it out of three pieces as I have done with several steam engines (much lower RPM) Separate shaft, crank and pin all held together by locktite, brazing, press fit or whatever. Good luck John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Tue, 13 Nov 2001 07:49:12 -0600 (CST) From: dswrx~xxwebtv.net Subject: Re: Machining question Skip Evans is working on a crank that has one crank journal and two main journals. Check out his progress at: http://skipevans.homestead.com/Millingcrank.html/ Leo (pearland, home of lots of fig trees) ------- Date: Tue, 13 Nov 2001 15:37:02 -0800 From: "GuyW" Subject: Re: Treadmill Motors / finish quality LONG Regarding quality: here's some info I've collected, don't remember if I've posted it here (but I may have, since some of you are quoted): Guy [NOTE: SOME IDEAS ON SOURCES OF (AND SOLUTIONS TO) LATHE CHATTER] Interesting post #1 I ripped off the Chaski board (I steal all my best ideas!)for application to Gingery machines: "What I did notice was that the Taig has an extrusion body filled with what looks like cement. On top, is a dovetail steel bed much like that of Hardinge. Martin of Germany builds 30,000 dollar table saws with a cement filled steel sandwich structure. This structure absorbs 6 times as much vibration as pure cast iron and cast iron absorbs 10 times as much as rolled steel and aluminum. So I know the Taig will excel here." Posted by emchd on December 17, 00 at 20:34:42 Interesting post #2 Posted by Forrest Addy on December 27, 00 at 05:15:45: This is an edited version of my postings to Jack Erskine several screens down that some of you may find helpful. Jack wrote of a finish problem similar to chatter that he had that he could not solve despite Herculean trouble shooting and remedies where he practically rebuilt his headstock all to no avail. ---> Those of you who have bought small Asian built lathes equipped with single phase motors or if you converted a three phase machine to single phase by replacing the motor with a single phase unit, you may have encountered a finish problem. If the feed marks are closely examined they seem to resemble the grooves in an old fashioned record, that is they may have varying depth or an irregular appearance much like chatter. Extreme cases may look like hell. It's sometimes difficult to distinguish this problem from another -- tool chatter. If the finish problems cannot be eliminated by the usual chatter remdedies, you might be coping with vibration "phonographing" the finish. The problem may be caused by a torsional vibration in the single phase motor, sometimes called "cogging." The armature of a motor is tightly gripped by the magnetic fields that cause it to rotate. A single phase motor acts something like a single cylinder engine where the power pulses may be several times the average torque of the full revolution. This pulse is transmitted by the belt to the spindle and the opposing torque transmitted by the motor stator to the machine. The consequent vibrations may meet where the tool contacts the work, recording itself on the finish like on a phonograph record. Here's a trouble shooting method: Slack the belts so they will barely drive the lathe while it's in a light cut. If possible, isolate the motor by slacking off the mounting bolts and slipping hose washers between the motor base and the mount and between the bolt head and whatever it bears against. Tighten the bolts just enough to hold the motor in position. The objective is to inject as much compliance and dampening as possible in what is usually a fairly rigid drive. If things wobble around a little it's OK. That's our plan. Take a couple of trial cuts and see if there's a significant improvement in the finish quality. This suggestion is intended to support diagnosis, not a fix. If the pattern disappeared when the machine was practically de-coupled from the motor, that indicates the problem is definitely motor, not belts or tool chatter. The only solutions are to either to de-couple the motor via rubber motor mounts or procure a new motor smoother in operating characteristics. Often, there is something about in a lathe/bench assembly that propagates motor vibration. You might try placing sandbags here and there on your lathe bench or motor mount. Inert weight like sand or pea gravel blots vibration to an amazing degree. If sandbags cure the problem, chances are the bench or whatever need stiffening or reinforcement at those points. If your checkbook can stand it, a new motor might be the best solution because you can upgrade in power at the same time -- that is if your electrical system can stand the extra load. The best solution is naturally expensive: either a DC motor and solid state drive or a 3 phase motor preferably with a solid state drive if not a rotary converter. I also suggest a softer acting V-belt known as "Link Belt." This is a V-belt comprised of interlocked rubber/fabric links. Links can be added or removed to secure the desired length. Their principal advantage is their forgiving nature and vibration mitigation. Another big advantage is you won't have to dismantle your spindle to replace the V-belt, just cut the old belt off and link together the new belt. Needless to say, the smoother the drive the better. when I bought my lathe new in 1971, it came direct driven by a 3 phase motor but I replaced the motor with a 5 HP single phase to suit my power. I had the same perplexing "phonographing" problem. I solved it after a fashion by relocating the motor from the machine to the floor nearby using a V-belt drive. I got good productivity and good finishes but naturally it wasn't as smooth as a Monarch 1760, one of the last and best engine lathes built in the US costing $75,000. A few years ago, I upgraded my lathe motor to 10 HP 3 Phase with a variable frequency drive. The motor happened to be precision balanced but I don't think that was a factor in performance improvement. It made an incredible difference not to have the 60 Hz torsional impulse or cogging. Where I used to see faint ripples in a cold drink set on the headstock, the machine now runs dead smooth. Where the gear noise used to be annoying, it's now a smooth musical whir. If anything, I now get better finishes with my machine than on the Monarch, thanks to a smooth drive free from torque impulse and vibration. A cautionary note. A 3 phase motor running on a static converter still develops significant torsional vibration and 2/3 rated HP. It will run smoother on a rotary converter and develop full HP. Therefore I suggest if you wish to change out single phase motors you obtain two three phase motors. One to run your lathe and another the next nominal HP larger from which to build a phase converter. I'd really like to suggest a variable speed drive but that might be too expensive for most people. I'm sure your own creativity will solve your vibration problem. I suggest using found materials where possible. Perhaps a small automotive engine mount or suspension component. Here in blubbery USA, there's a large traffic in exercise machines. Naturally, they are seldom used and may be bought cheap at yard sales. They have smooth running 1 HP DC motors with a cheap variable speed drive that might be suited if your lathe is used exclusively for light work. Interesting post #3 Posted by Joe Fangohr on January 25, 01 at 21:30:07: On another subject, I read often of different methods to reduce vibration in machine tools. I have a bench mill, and it vibrated something awful. The first thing I did was check the motor shaft for runout. Mine was reading about .004 tir. I pulled the offending thing out, put it in my arbor press and tweaked it straight, or actually got it running about .001 tir. This helped some but it still had what seemed like way too much vibration. Another thing I noticed that was causing the vibration was the v-belts. They would just flop all over the place when the mill was running. Some of this was probably caused by the pulleys being poorly made, but most I think by the v-belts wedging themselves in their grooves and then getting pulled out of them each revolution. So I chucked the whole lot, v-belts and pulleys, and made me some poly-v step pulleys out of cast iron. If you are not familiar with these, they are the flat belts commonly used on cars these days that look like flat belts but have a number of tiny v grooves. The difference is unbelievable in how much smoother my bench mill runs now, and quieter too. I wouldn't say that it now cuts like a turret mill or anything like that but it sure doesn't vibrate so much. I also did this to our tablesaw at work; it's a contractor saw since we have to be mobile, and before if I put something like a wrench on the saw table while it was running, the wrench would quickly make its way right off the side from the vibrations, and now you can hardly even feel any vibration with your hand! IT definitely cuts much smoother than I ever dreamed it was capable of doing. I think that the poly-v belts give the smoothness of flat belts and the gripping power of v-belts, kinda the best of both worlds. Didn't have anything to do so thought I'd ramble a bit, you all have a nice day! Joe --->Interesting post #4 Posted by Joe on May 08, 01 at 07:55:09: ...wooden pulleys on the lathe headstock have a lot to recommend them, not the least of which is the fact that the coefficient of friction of leather to wood is greater than leather to cast iron or more particularly steel. An 1850's era woodworking lathe that I own had been converted to a v belt drive, seemingly by putting a wooden "disk" in place of the original pulley and then turning the disk so that it had a groove for the belt to ride in. It took me a few minutes and a bit of keen observation to see that the wooden pulley was original construction and had been considerably larger and longer and had probably 75 percent of it removed in the adaptation. Someone *really* wanted the lathe adapted to electric motor drive. In fact on this lathe the smallest diameter of the cone pulley was actually cast iron and "made" right to the headstock shaft and served with wood screws to hold the wood portion of the pulley in place. With some creative intuition I was able to "reconstruct" the original wooden pulley from laminated maple. This takes some time but a bandsaw helps as does choosing your step thicknesses to be some multiple of 3/4 inch. The other factor to think of is the pulley in the countershaft has to "match" the pulley in the headstock. Otherwise, it's possible to have the belt tight on one step and yet be loose on another. (Match is "approximate" since the leather belts will stretch a bit - within 1/2" is likely close enough.) You may want to consult the formulas in "Machinery's Handbook" which take into account the distance between the two shafts also. Another good reason for making at least one of the two pulleys from maple. The usual practice (my 1850's lathe notwithstanding) was to have the pulley in the overhead drive made of wood and the pulley on the headstock of the lathe made of iron. The reason for this was to have any slippage that occurred in the leather belt visible on the pulley nearest to the operator. Hopefully the operator would thus be more attentive to the belt tightness and more inclined to keep his machine "up to snuff." It was also recommended by Machinery's Handbook that the pulley diameters chosen result in a "logarithmic" ratio between the different speeds. However, I have examined most of my early flat belt drive machine tools for this and found it to be a "late" convention. Most 19th century machines do not incorporate this. Usually the iron pulley on the lathe was machined inside and out and even balanced if necessary with a small weight. Anything to make the lathe easier turning without vibration. To tell you the truth, I actually have in my barn the two pulleys you need from a Royersford 21" upright post drill press. However, it's a long way from New Hampshire to Tactical Link and likely you'd be better off financially to try to get your pulleys locally. The $50 shipping fee plus the $20 I would probably want for the pulleys will likely buy you enough maple to make the two pulleys twice over, or purchase an entire scrap drill press from a junkyard locally. Anyway, hope this all helps. Best regards, Joe K in NH aka "Yankee Mechanic" ---> John Meacham, of High Desert of California, Palmdale, Littlerock, posted on Atlas e-board on 07/13/01: "..Atlas manual recommends a heavy wood slab under the lathe made of 2 X 4s set upright, through bolts and glue. Wood and cast iron both are good vibration dampers. Also I would not recommend setting the current table on concrete blocks. If it ever vibrated or fell off you would have a really sore toe. Buy the manual from Clausing and there are instructions for building a lathe stand.." ---> Dee Schuyler posted on Atlas e-board on 8/30/2001: All this talk of vibiration and chatter, I was out at a big machine shop recently and I saw a lathe with a bungee cord around the chuck, naturally I had to show my ignorance and ask the operator what it was for, was I suprised when he told me it kept the chatter down, so I guess anything is possible. on his machine it worked. Guess that is the bottom line! ---> Randy Pedersen posted on Atlas e-board on 8/31/01: If you have ever watch brake drums being turned they are usually wrapped with a thick leather or rubber belt to remove the harmonic vibrations to stop the chatter marks. On disc brakes we always used a thin spring steel strap with lead weights attached to do the same thing. ---> Frank Evan Perdicaro posted on Atlas e-board on 8/31/01: Lots of good discussion so far. Two other thoughts. 1) Use lead to dampen vibration. It has high density, and thus shifts resonant frequency with little volume used. In addition to high density, lead does not conduct sound well: no lead bell will ever ring. It is fairly standard practice to used lead sheeting as a sound damper. Quite common in plumbing applications (wrap noisy water pipes and waste pipes with lead; secure with band clamps). The 1980s Ford Mustang GT and 5.0 liter LX cars had lead sheets under the carpeting in the back half of the car! 2) There is a product for motorcycles called "Bar Snake". It is available in rope-like form and in liquid, castable form. Specifically designed to kill vibration, it is a mixture of silicon rubber and lead shot. My guess is a few sections of Bar Snake would be useful in the workshop. A 10" section would probably fit inside an Atlas lathe spindle. Hold it in place with rubber stoppers. High purity aluminum (hard to find) is also a sound killer. More effective per unit mass than lead (lots more volume). High purity copper is also good and is used in several commercial applications, including Delta commercial wood cutting blades (one of those is mounted in my electric miter box right now). ---> Another idea from posts: static balancing of pulleys and chucks to smooth rotational vibrations. ---> Hi, I am new to the world of metal working and I could use some advice. I had a 1922 Dalton Six metal lathe follow me home. It has been in storage for the last 25-30 years and it appears to be in good condition and well equipped with tooling. It needs a good cleaning, and lubrication as well as having the flat leather drive belt replaced. What types of oil should I use on this machine, and where should I use it? How do I go about replacing the leather drive belt, and how or where do I get a replacement? Are there any good books on machine tool restoration, and repair? Where might I find any manuals or information on this lathe? Any and all help greatly appreciated. Thanks, Greg Fosmark Duvall, WA ANSWER 1: hi, greg, the dalton is a really nice little machine, and will do good work once you have it dialed in. there's a "secret"...for getting good work from light machines....not really very secret, tho, cos the war production board put out a pamphlet about this technique back, during the war when every machine in the country was expected to work three shifts, 24hrs a day. this "secret" is in the mounting......make up forms, and pour a heavy cement base for the lathe, somewhat like an elongated truncated pyramid, with a clearance area for the operator's feet. arrange a three point mounting for the lathe, and bolt the lathe down firmly with cement anchor bolts......the sheer mass/weight of the cement base adds rigidity and damps out vibration.....after stripping the forms away, when the concrete has fully cured...pry the concrete base up from the floor, just enough to fit three dense rubber pads under it....three point mounting again. the magnitude of difference this makes with a light lathe in the south bend/logan class has to be seen to be appreciated. mount the motor and countershaft either above or behind the lathe, on wall uprights or ceiling joists....making a small lathe "self-contained" may look pretty, but is a bad idea, cause any little bit of vibration or resonances in the motor or c'shaft will be transmitted to the lathe bed....and the idea of the heavy base is to isolate the lathe from external influences, as well as to enhance rigidity. if you can find a light c'shaft clutch assembly, bush it nicely, make a hardwood sleeve to increase the diameter of the pulley face of the clutch, and use a small pulley on motor for single reduction.....bring the lever for the clutch down to a convenient point over the lathe. the difference in convenience in having the motor run constant speed whilst you start/stop the spindle with a clutch, as compared to having to start/stop the rotating mass of the motor, may well be only a minor convenience, but it's well worth doing. belting is straightforward.....since you're out in duvall, you'll have a seattle phone book....look in the yellow pages under "belting" or "power transmission".....best is to learn to "skive", that is, form tapered ends, and glue up leather belts....all belts stretch, and will need to be shortened from time to time.....or...have the supplier cut you a roll of a suitable width of light "oil-proof" cotton/rubber belting, get a "clipper vise lacer" (i've seen those come up cheaply on ebay) and run metal laced belts...... oil is straightforward....just get a gallon of any good make of spindle oil.....i prefer "vactra" myself. getting the lathe set up....cleaning, oiling, adjusting bearings if needs be, deburring/flaking/adjusting gibs, etc., is really easy on a small machine like the dalton.....its been too many years since i've even seen a dalton for me to remember anything about them...i think i remember them as having bronze on spindle, and split caps...unless the spindle has been run dry, your chances are very good you'll not have to do much work on the spindle and its bearings.... well, there's a start....good luck....... : ) cheers carla ANSWER 2: Carla's post was right on the money, as usual. I'll share a little of my experiences with you, as well. Years ago I knew a fellow in his 80's who had both an impressive collection of old engines and a reputation as a first class machinist. He and I became pretty close friends and he became a sort of mentor to me. When I began putting together my own shop, he helped me set up all the machinery and gave me the line shafting. Now, today a lot of guys will scoff at a bunch of pulleys and shafting lurking over your head but believe me, I wouldn't have it any other way. My first lathe was a Sebastian and it had an adapter on it to support the cone pulley and the motor. It worked but I couldn't get a nice finish. Bill told me to get the shaft hung from the ceiling and bolt the motor to the floor and try it. The difference was amazing. Most of the motors we have available to us are not balanced nearly as well as we think and, if it is fixed rigid to the lathe, the vibration carries through to the machine and makes itself known to you as a fine chatter. I have run machinery with the motor bolted to the wall, and to the rafters, and both of those locations were noisy, the hum of the motor is a 60 cycle vibration and the building simply begins to resonate at that frequency. Most annoying. The concrete floor does a wonderful job of dampening the vibrations. Hang your countershaft and your lineshaft, you will belt your motor to the lineshaft and run a straight belt and a twisted belt to the counter- shaft clutch pulleys. Drive the lineshaft at 250 rpm (pretty much a standard for small lineshafts). If you have an induction repulsion motor, they are the best, they have high starting torque and start smoother than capacitor motors. Very few machine tools had capacitor start motors on them, they start with a jerk and tend to vibrate more. If you can get single ply leather belting, use it over canvas/rubber. The oil that invariably gets on the belts will turn the canvas/rubber belting into a gooey mess in 10 years. A single ply belt, about 3/32 thick and 1/4 narrower than your pulleys will transmit all the power you need. If the belt is too thick, it takes more tension to make it drive and is hard on the bearings all the way around. It is the friction of the belt against the pulley that drives, so a supple belt can conform to the pulley and do the work without pulling it real tight. I lace all my belts with rawhide shoelaces. This is easy to learn if you buy the Robert Smith books "Advanced Machine Work" and "Elements of Machine Work" from Lindsay. Metal laces slip and wear the pulleys. Rawhide laced belts can be lumpy if not done right and this too can set up a vibration. Cemented belts are wonderful but they are a pain to shorten when they stretch. It is advisable to slack the belts, if possible, when the machine is going to be idle for a period of time to limit the amount they stretch. I also have a 10" Logan and a 9" southbend and I have run both of them from a lineshaft for several years with good results. I wish I could run my B'port from it as well. The darn v-belt drive is a source of irritation, a new belt will run smooth for a few months and then get lumpy and start to vibrate. Maybe this is why Southbend stayed with flat belts on their lathes until relatively recently. Good luck with your machine, and if it seems like a lot of work to set up the drive arrangement, it is but you get out of it what you put in. ------- Date: Sat, 24 Nov 2001 09:50:27 -0500 From: Jim Ash Subject: Re: Turning a radius At 11/24/2001 10:10 AM +0000, you wrote: >Just a curiousity. What is the method for turning a convex radius on >the end of a shaft when you don't have a radius tool? Stephen There is a cool method documented by Guy Lautard in his books that has worked well for me. It's basically a series of calculated stepped cuts. You create a table of step sizes in both X and Y movement. If you were to 'zoom in' on a stepper-driven CNC, this is how they do it. It works for all kinds of curves, internal or external, and can also be used for non-spherical radii, like a torus (donut). If you're not comfortable with trigonometry or dreaming up the math for your specific need, email me back and I'll detail the calculations for you. Jim Ash ------- Date: Sat, 24 Nov 2001 11:13:16 -0500 From: "Rich D." Subject: Re: Turning a radius Jim, I have done that a few times. Very time consuming and leaves no room for error. You have to close out the world to keep total concentration on that machine turning the handles the ***correct*** way :-) Deciding on the number of steps vs cutter radius determines the finish quality. Trouble is, it can run into the hundreds easily. Each step coordinate has to be calculated. A spreadsheet makes this go very quickly. CNC is Sooooooo much quicker. RichD ------- Date: Sat, 24 Nov 2001 21:50:35 -0500 From: Jim Ash Subject: Re: Re: Turning a radius The first time I did it, I made a ball about 1" diameter in about 20 steps. One of Guy Lautard's tricks is to blue the work after cutting the steps, then lathe filing until the blue strips just disappear. The whole procedure, filing and all, took me maybe half an hour. I'd looked at radiusing tools, but the Sherline tool is only intended for jobs where the center of the radius being cut is the same as the spindle, that is to say, spherical forms only. I suppose you could get creative and shim it up for toriodal forms. But even the 'traditional' ones offered by OMW can only cut a limited radius. What if I wanted to make a little metal football say 2" inch long, with a turned radius of 6"? Guy's method works for any raduis job, if you can do the math. If I had a lot of parts to make, maybe I'd get one of the radius tools. But my needs are usually for one-of-a-kind jobs, so It just isn't worth it. Don't discount the step method until you've tried it once. If nothing else, you'll learn some lathe filing. Jim Ash ------- Date: Sun, 25 Nov 2001 02:14:04 -0500 From: "Rich D." Subject: Re: Re: Turning a radius Devin, This is the procedure I used before I switched to CNC. Profile Milling or Turning: X=Radius*Cos D = SqRt of R^2-X^2 Y=Radius*SIN D = SqRt of R^2-Y^2 Think of the radius as a vector that swings from 0 to 90 degrees. 1. Use arc segments of 90 deg maximum to calculate a machined form. Most arcs (of 90 deg) can be formed with 30 X/Y coordinate steps. Use a cutter radius (endmill) of 30% of machined radius. Use more steps for a finer finish or a larger cutter radius. 2. Divide your arc(s) into a practical number of steps (of degrees) as above. 3. Calculate each step as follows: Radius*COS D = X (Horizontal-Long-dimension to 45 deg) Radius*SIN D = Y (Vertical-Short-dimension to 45 deg) Y is in the reverse order of X (the remainder of the table repeats at 45 deg) (Round off to 3 places) 4. Tabulate the coordinate all the steps for X and Y. 5. If milling, the radius of the end mill must be added (external) or sutracted (internal) to the desired part radius. 6. When you reach 90 deg and need to continue, flip X and Y and start from the beginning of the table. This will require some thought on your part to get oriented but, once you get started, the table calculations roll right off the calculator. A spreadsheet makes this a snap and is not prone to errors. I once did a "casting" with some offset features that had almost 300 steps. I sent it to a friend that input it to a spreadsheet and faxed the results back. I found one error! Very time consuming. Long, long ago. RichD ------- Date: Tue, 25 Dec 2001 22:32:44 -0500 From: "Rich D." Subject: Re: Finish Holyelvisx~xxaol.com wrote: > I need some tips to getting a good finish on steel. I was not able to do it by hand so I made a power feed attachment inspired by one I saw on Varmint Al's webpage (though not sherline specific it's packed with useful info, especially for the beginner. I.e. me). The whole power feed attachment cost me about $15.00. It does a lot better job than doing it by hand, but not as nice as I would like. Devin < Devin, My method: Very sharp brazed tip carbide tools with a slight tip radius and cutting fluid (dark brown threading oil works well) applied with a brush in the cut as the material rotates. Don't let it go dry. Make the last cut just a couple of thou and be sure the cutter is really sharp. Follow with 600 grit emery cloth an oil. RichD ------- Date: Wed, 26 Dec 2001 10:39:42 -0500 From: "Rich D." Subject: Re: Finish > Do you buy the carbide tool with the slight radius or do I have to > grind the radius on the bit? Devin Devin, Tool bits come ready to sharpen. That's the fact. Some brand may happen to have a ready to go bit but, I don't know who that would be. Carbide tipped tools have to be sharpened with diamond for a good edge. A new tool can be touched up or slightly modified with a hand held diamond lapping stick easily. These come in sets and are worth having. RichD ------- Date: Wed, 26 Dec 2001 20:59:04 -0000 From: "hssmike" Subject: Re: Finish Devin, Most High Speed Steel toolbits come with a 10* clearance angle on the end of the bit. You will still need to grind side relief and you should grind top relief also. Carbide is meant to "plough The material off, whereas high speed is meant to cut it off. If you sharpen carbide to a very sharp cutting configuration it will chip the edge of the tool resulting in poor finish. Most carbide tools come ready to use. Mike ------- Date: Wed, 26 Dec 2001 17:13:36 -0500 From: "Rich D." Subject: Re: Re: Finish Mike, Yes, they come ready to use the way you describe but, for fine machining and long wearing edges, you can't beat a truly sharpened carbide tipped tool bit. The normal clearance angles as used for HSS work fine. They do not chip under normal or even interrupted cuts. Machining cold rolled steel at high surface speeds will wear the the tip down and crater it but, a quick pass over the diamond and you are back in business. One thing that will tear up a carbide tip is reverse rotation in contact with the work. If you get it stuck, pull straight out. Don't reverse the work. I also use HSS bits, but mostly for form tools. All my sharpening is done on plated diamond lap wheels as sold by Glendo and Rio Grande. None of my comments pertain to insert tooling. RichD ------- From: Jon Elson Date: Sat Jan 19, 2002 2:04 am Subject: Re: [atlas_craftsman] Turning dissimilar metals at the same time. Skip Evans wrote: > I am about to start turning two metals sandwiched together (brass and steel). I am doing to be sure the diamters are equal but I am concerned that when the tool moves from the steel to the brass I may end up with different diameters. Is this a valid concern? < It depends on the rigidity of your machine. If you are taking a very aggressive cut, there will be more of this effect than if you make a final cut that is quite thin. If your tool is sharp, you should have only a little of this, unless the steel is quite hard. Now, are you concerned about a variation in the micro-inch range, or in the several thousandths of an inch range. You will likely still have the former, but unless your machine is very loose, the variation should be under a thousandth. Jon ------- From: "Marcus & Eva" Date: Sun Jan 13, 2002 1:17 pm Subject: Re: [sherline] Cutting thin tapers in aluminium From: "Daniel Munoz" To: Sent: Saturday, January 12, 2002 2:13 PM > Hi guys, > I'm trying to cut some tank canons using 3/8" aluminium rod for my > modeler's club. The scale is 1/35, and the taper's part of the gun is > about 0.18" in the bigger diameter, 0.06" in the smaller, and about > 3.75" long. Each time I tried, the surface finish was very bad. I tried > with HSS tool, carbide insert tool, slow and fast turning speed, slow > and fast cutting speed, even a special try (!) using slow power feed > with a power screwdriver attached to the handwheel. I also tried using > cutting fluid and cutting wax ! :-( > > The surface is always a little jaggy, and I guess it's because the taper > have a tendency to deflect in the middle. If I take light cuts, the tool > don't take the cut but push the rod instead. If I take heavier cuts, the > surface finish is worse and the taper also deflect and bend the rod (I > know have a perfect gun to shot around corners!). I don't know what to > do to have a good surface finish; I didn't have those problems when I > machined brass rods, maybe it's because the brass is harder ? Any > advice, please ?? > > Here's how I mound the rod on the lathe; First I surface cut the ends > and drill a hole with a center drill on both side, and then drill a deep > hole one one side, figuring the gun's hole. Then I mount the rod between > center points using the lathe dog, and to make the taper I rotate a > little (about half a degree) the headstock, using the lathe dog as an > universal joint between the headstock dead center and the tailstock live > center. I have the compound slide attachment, but can't figure how I > could use it because the length of the taper I need for the gun is > larger than it's maximum travel. > > What am I doing wrong ? I've seen some commercial guns in aluminium for > tank models, and some are really small, much smaller than the one I try > to make. How do they do that without bending the rod !? Thanks in > advance for your advice. Daniel Hi Daniel: You have chosen a rather difficult turning challenge. The problem you are having arises from a couple of places. The first is that the diameter to length ratio is very small so you're getting part deflection. You've worsened the problem by having a hole down the middle, so there's no strength left in the material. A sharp tool bit with almost no tip radius is needed that presents to the cut at 90 degrees to the long axis is essential to minimise the deflection, but tends to leave a rougher finish. You have very little hope of turning these shapes to final finish without accepting that you will have to finish them with abrasive paper unless you rig a taper turning setup and a hydraulic folllower like gunsmiths use to turn rifle barrels. If I was making these, and didn't want to bother with such an elaborate rig, I would do the following: 1) set up a collet in the headstock that will accept the full length of the bar. Make your bar 1/4" too long. 2) set up the compound slide to the correct taper. 3) drill the bore 4) turn a small stub to the smallest diameter but parallel and about 1/4" long 5) cobble up a Delrin block that you can clamp to the headstock that has a hole in it the same diameter as the stub and concentric with the spindle. You will use this in place of the tailstock which you can't use because it gets in the way of the compound slide. 6) stick out the first 1/2" and turn it to final dimension 7) advance the part in the collet and turn the next 1/2" 8) once you are sticking out to the point that the finished bit starts to whip at the free end, clamp on the delrin block and lube the hole with grease. 9) keep going in 1/2" segments till the whole length is cut. 10) get out a fine file and your abrasive tape. Cheers Marcus ------- From: "Bad Brad" Date: Sun Jan 13, 2002 4:37 pm Subject: Re: [sherline] Cutting thin tapers in aluminium If you are trying to cut 7000 series aluminum the surface finish will be ruff. Dull tools, wrong hieght and wrong spindle speed will all give poor finish quality. Aluminum also likes to weld to the tool bit and forms a false edge which will also give a poor surface finish, use some sort of cutting fluid. Forrest ------- From: "Daniel Munoz" Date: Mon Jan 21, 2002 12:01 pm Subject: RE: [sherline] Cutting thin tapers in aluminium Hi guys, I finally had a success with my thin tank cannon tapers (scale 1/35). Maybe my trials and errors will interest some beginners like me. First, if you want to take a look to the result: http://pages.infinit.net/dmunoz/tank/panther.jpg (24KB) From left to right, the original material, the cannon half machined with 2 taper sections cut (out of 3), the cannon finished (a Panther tank cannon), and the pointed nose carbide toolbit I used. I first started to learn how to grind HSS tools with a friend machinist, hoping that it will improve the surface finish, but this wasn't the way to go (but still was very interesting !). The taper was too thin when mounted between points, specially with the deep gun hole in it, and when the cutter was in the middle part, no matter how well the HSS toolbit was sharp, the bar was pushed instead of been cut, resulting in an horrible surface finish. So, I finally used my 3 jaw chuck, the compound slide attachment, and after setting the proper angle (0.6?) in the slide attachment I cut the taper in 3 times, sections by sections, as close as possible to the chuck to avoid deflection (using the live center to support the bar), and re-chuck the bar between each taper sections that have been cut. Obviously, the problem when solving the deflection problem that way was to re-chuck and keep a perfect alignment, and also to exactly match the proper taper diameter between the current taper section and the previous one. For the alignment, I cutted first the original bar between points a little to a smaller diameter, resulting in a "perfectly" round and aligned bar. As the original bar was large, the deflection problem was avoided here. There is a (very!) little alignment problem because of the not perfect chuck alignment, and I think it could be completely avoided using a collet instead of the chuck, but that was good enough for me, and the live center helped to keep the alignment good when gripping the bar in the chucks. To keep an exact match between 2 taper sections, I simply do the last cuts very lightly, 0.5/100 mm at a time (about 0.0002") when I was close to the diameter section I wanted, and finally match it almost perfectly using a magnifier for the last cut. One thing that amazed me is that I didn't use the HSS cutter, the finish was not that good enough for me and a very light cut as needed for the finished diameter was worse. It seem that 2.5/100 mm (0.001") is a minimum in aluminium using HSS if I want to keep a good surface finish, even using cutting fluid. I used instead a carbide toolbit (cost me about 3$), and the result was amazing. First, to reach the proper diameter, I could very easily take deep cuts, 0.5mm (0.02") was really not a problem, and in both directions. And the finish was good, but the cutting speed needed to be very high (as recommended for carbide I think). Also, the 0.5/100 mm (0.0002") cut was really shine, the surface finish beautiful and like a mirror. I used a little of paint thinner and a cutting fuild for the very last cut that improved a little the finish, but even without that it was almost perfect (perfect for my needs of course!). I think I will give a try to more carbide toolbits in the future, and keep the HSS bits for special shapes needs. I hope my little experience will interest others, and as usual I will be happy to read some comments. Bye, Daniel Quebec, Canada. ------- From: sleykinx~xxa... Date: Sun Jan 20, 2002 3:35 pm Subject: Re: [atlas_craftsman] Woodruff key > Anyone have a spare Woodruff key 1/8 X 1/2 ? > MSC only ships 25 & only need one. Thanks, Herman Cut a slot across the center of the end of a piece of 1/2" round stock and part off or cut off two each. Way faster than mail :) ------- Date: Mon, 25 Feb 2002 18:44:35 -0500 From: "Daniel J. Statman" Subject: Re: What am I doing wrong (turning on lathe) From: "savagehb308" To: > I am trying to make some replacement door hinge pins. I started with > a piece of 1/2" cold rolled, in the 3-jaw at one end, center drilled, > then Live Center at the other end. I need to turn the pin down to > about 3/16", the head will be just over 3/8". > OK. I'm turning the pin first. What I get is little "burrs", almost > like a miniature rasp as I turn down the pin... > What am I doing wrong? I've experimented with speed (not running too > fast, maybe 1/4 speed?), and I've tried feeding faster & slower but > no change. I don't get any chatter. I cleaned it up with a file, and > the runout is very little, only like .001, so I'm very happy. > PS: This is my first project since I've had my lathe! It's very > exciting to actually make chips!! Arden What type of tool bit are you using? Is your live center pushed firmly into the end of the part? It sounds like you are getting chatter, why do you think you are not? You say you have varied the feed, but have you varied the speed? 1/4 speed is not very descriptive and could be too fast. Generally, if your tool is chattering then you should lower the rotational speed of the part and increase the speed at which you feed the tool into the part. Also if you have too small of a radius on your tool tip and you are feeding the tool too quickly, you can get a surface pattern which looks like small spirals down the shaft. Regrind your tool and feed it slower. Hope some of this helps. If you want more specific answers then please feel free to ask more questions. Daniel J. Statman, Statman Designs www.statmandesigns.com ------- Date: Tue, 26 Feb 2002 00:56:59 -0000 From: "jamesbknighton" Subject: Re: What am I doing wrong (turning on lathe) Just a thought... Make sure your cutting bit is tight in the tool holder and that it is properly oriented to the workpiece. I know this is pretty basic, and I don't like admitting to such things. But in my inexperience I once carelessly placed the cutting bit in the holder upside down and then couldn't figure out why my cut was crap. This kind of chatter can also occur if either the tool or the workpiece (or both) aren't securely fastened into their respective fixtures and there is unwanted movement relative to each other. It doesn't take much movement like this to ruin a cut, the bit, or the workpiece. JBK ------- Date: Mon, 25 Feb 2002 19:54:14 -0000 From: "David Simmons" Subject: Re: What am I doing wrong (turning on lathe) Also, check that your tool tip is just under the centre line of the part. Often, if the tip is above or to far below you will get the galling you are talking about. Also, and I have seen this a hundred times, make sure the tool is not hanging to far out of the holder. If it is the tip will bend down and then pop up as you are cutting. HTH, Dave S. ------- Date: Thu, 28 Feb 2002 18:22:01 -0800 From: stevejacksonx~xxbigfoot.com Subject: 'electrical' lathe dog Just a data point. Was in Lowes (home improvement store) buying a few electrcial items. While searching I noted a "bronze ground clamp". It is a 2 piece clamshell with a serrated "V" in each half and a cross drilled nipple on the top that accepts a 1/4 bolt - viola: dog! It came in 2 sizes for clamping to different grounds. As the taig is apart for the lead screw mod I can't test it but it does clamp very tightly. Pardon me if this revelation is old news. Steve "The things that come to those who wait are usually what's left by those that got there first." ------- Date: Thu, 28 Feb 2002 16:24:06 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: 'electrical' lathe dog Forrest at Taig always said one could use a hose clamp. See our web pages http://www.cartertools.com/nfhome.html ------- Date: Wed, 10 Apr 2002 20:53:15 -0700 From: "John Johnson" Subject: Turning RR Wheels on a Mandrel Glen, With a 10" Atlas should have no problem turning a railroad wheel up to about 6" with no problems on a mandrel. To make a mandrel for this purpose is a good lathe project by itself. Pick a round barstock about 4"-5" long and about 1/8"-1/4" larger diameter than your axle. Turn down the end so the wheel fits on, not too tight or too loose and up to a shoulder. The length of this area should be 1/16"-1/8" less than the width of the wheel at the axle hub. Then drill and tap the end of the mandrel for a bolt as large as you can manage. Make a washer for the bolt to fit through and use it to hold the wheel on the mandrel with the bolt. You can put a small shoulder on the washer so it registers inside the axle hole. I use socket head cap screws for the bolts as I can get a good grip on them when tightening down with an Allen wrench. Then just mount the mandrel in your lathe chuck and turn your wheels. You can do one side and then turn them around to do the other side and have good register because of the mandrel. Hope this helps. John D.L. Johnson www.LocoGear.com ------- Date: Thu, 11 Apr 2002 07:49:07 -0500 From: Charles Brumbelow Subject: Re: Steady rest [USING MANDREL INSTEAD] A couple of things about using mandrels with chucks and/or large wheels. First, the mandrel needs to be returned to the chuck in the same position where it was made to avoid the effect of chuck runout. Ideally the mandrel would be made and -- without removing it -- the wheels would be turned. Second, the cuts one can take when the wheel is mounted on the mandrel must be lighter than could be taken if the wheel itself was clamped in the chuck or bolted onto a faceplate. Charles From: ------- Date: Thu, 11 Apr 2002 10:53:48 EDT From: catboat15x~xxaol.com Subject: Re: Turning RR Wheels on a Mandrel In a message dated 4/10/02, jjohnsonx~xxlocogear.com writes: > With a 10" Atlas should have no problem turning a railroad wheel > up to about 6" with no problems on a mandrel. A second way to make a mandrel: Especially if your chuck is not the best in the world is to first face off one side of the raw wheel to get a flat surface (three jaw or four jaw) and drilll - ream the axle hole. Do all your wheels first so they are the same. Then put a piece of stock in the chuck maybe 1/8-1/4 inch smaller than the finished wheel. Face, drill, tap this piece and screw in your mandrel stock. Then turn and size as before to use a cap screw or nut and washer to hold the wheel. Don't remove this set up until all wheels are done. This assures that the wheels will be the same and even if your chuck is not true turning the mandrel in place makes everything concentric to your own equipment. John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Thu, 11 Apr 2002 11:26:16 -0500 From: "Skip Evans" Subject: Re: Turning RR Wheels I had some stock slip in a mandrel. I used the green thread lock to secure the stock. I worked great. I used the drill press to push the mandrel out. No problems. ------- Date: Thu, 11 Apr 2002 10:33:11 -0700 From: "Bob May" Subject: Re: Steady rest It's all in how hard you make the lathe work. The mandrel method works fine but you don't take .25" deep cuts with one or the mandrel bends or slips every time. You just take smaller cuts and everything is fine. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Fri, 12 Apr 2002 02:31:43 -0000 From: "mrb37211" Subject: [FULL SCALE] Wheel Lathe at East Broad Top Railroad Due to the number of mentions, I posted Chris Coleman's picture of a wheel lathe at the East Broad Top Railroad. More of his fine EBT machine shop pictures can be found at: http://www.spikesys.com/EBT/Pics/2000fs.html For that matter, if you like railroads, check out his whole site. Charles ------- Date: Sat, 15 Jun 2002 06:01:33 -0000 From: "markzemanek" Subject: How do I eliminate burrs? I've now taken some of my first cuts on my Craftsman 618, and tried to create a smooth finish on some aluminum block, without success. I turned what is essentially a three inches diameter piece, and 1.5" x 1.75". I don't know "exact" spindle speeds, since I am using a surplus motor (1725 rpm) that came with its own pulley; the countershaft also has a one step pulley. At any rate, I've been experimenting with my two slowest speeds (using the back gears), and judging by the curl of the chips I'm turning, I'm using the right speeds, though the maximum amount of metal I can remove in one pass seems minimal to me (15 thou). If anybody has a formula I can use to determine the rpm's of my machine, it'd be much appreciated. Anyway, besides trying to learn how much metal I can remove in one pass, I'm trying to get a fine finish on the turned block, but haven't been able to do so. I'm starting in the center and am taking a cut one thousandths deep, backing out very slowly. The finest I can achieve is what I'd call a "cats tongue"...the finished piece is a bit raspy, with a fine burr. I believe the machine can do better than this, so I ask the question....what am I doing wrong? I hope to turn this "first piece" into a toolpost for my boring bar. Mark (new to machining, and finally turning & learning) ------- Date: Sat, 15 Jun 2002 10:46:19 EDT From: CaptonZapx~xxaol.com Subject: Re: How do I eliminate burrs? You didn't say what alloy the aluminum was, and that can make a difference. The softer alloys are 'gummy', and tend to tear if not cut with a sharp bit with correct geometry. CZ ------- Date: Sat, 15 Jun 2002 12:25:57 -0400 From: James Meyer Subject: Re: How do I eliminate burrs? >You didn't say what alloy the aluminum was, and that can make a difference. The softer alloys are 'gummy', and tend to tear if not cut with a sharp bit with correct geometry. CZ < Exactly my first thought too. The shape of the cutting tool is very important. You can't cut cast iron and aluminum to the same surface finish with the same tool. Lubrication, or the lack of it, will make big differences too. Try rubbing the surface of the aluminum with good coat of paraffin (candle wax) just before the final pass. Jim ------- Date: Sun, 16 Jun 2002 01:37:16 -0000 From: "latheplaya" Subject: Re: How do I eliminate burrs? Go see Varmint Al: http://www.cctrap.com/~varmint/alath.htm He has good info on tool bit shape, lubrication, and getting a smooth finish. I use Natural Butter Flavor Crisco spray with good results on some metals. Cheers, Derf ------- Date: Sat, 15 Jun 2002 22:53:25 -0500 From: "jerdal" Subject: Re: How do I eliminate burrs? In general, aluminum turns pretty well, although the gummy types are a pain. However, putting together the "i am trying out the slowest speeds" with the "cats tongue" finish, and the "1 thousandth deep cut", that rough finish sounds right. I think you are "plowing". A higher speed will "knock off" material instead of allowing it to flow around the tool, which it can at slow speeds. I don't know the bit you are using, but a rounded end, good and sharp, should do well if HSS. The radius of rounding varies with stability and power of the machine. For that machine maybe a 1/32 radius, maybe a bit more. I know the 618 is small, although I have never used one. However, I find that speeding up the revs and putting oil on the part will produce a much nicer finish if the machine can handle it. In fact, aluminum turning is one of the few uses for WD40. The mix of oil and kerosene or whatever in it seems to be a great cutting lube for aluminum. The gummy aluminums seem to cut sort of like brass, in that any significant rake may pull the tool through the backlash and radically deepen the cut. So a minimal rake might be better for gummy stuff, even though it might not be "textbook" for "aluminum". my 2 cents, some settling may have occurred. J Tiers ------- Date: Sun, 16 Jun 2002 01:55:19 -0400 From: Stan Stocker Subject: Re: How do I eliminate burrs? Hi Mark: Here are a few items to try: 1) Up your speed, use WD40 or kerosene for a cutting fluid. 2) If using carbide insert tooling, go up to a #2 radius, i.e. change from a 321 to a 322 insert, or if using ground tool bits, increase your top rake to around 15 degrees and increase your tip radius. Hone/stone the cutting edge to a good finish. 3) Double check the advance per revolution of the spindle, make sure your set up for not more than 0.007 per rev advance, .003 to .005 would be better. 4) Try to find a piece of 6061 round stock and make test cuts in it if the above items don't do you any good, some aluminums just tend to cut nasty. Good luck, Stan ------- Date: Sun, 16 Jun 2002 06:18:07 +0000 From: Jon Elson Subject: Re: How do I eliminate burrs? It sounds like you are making a facing cut, rather than turning a diameter. The shape of the tool needs to make a chip of some width, so that each rotation overlaps the previous and next turn's cuts. So, a finely pointed tool, pointing directly into the face of the work, will always give a poor finish. Lay the tool so one face is almost parallel to the face of the work, and you'll get a better finish. Don't take too fine a cut, ie. both the depth of cut and the advance per revolution need to be above a certain amount or work hardening can occur. That will always give you a rough finish. In general, faster spindle speeds will usually give better finishes. For a 1.5" diameter aluminum part, you should be turning at about 1500 RPM with HSS tools, and even faster for carbide. For a 3" diameter part, it should be 750 RPM. Jon ------- Date: Sun, 16 Jun 2002 07:39:58 -0000 From: "markzemanek" Subject: Re: How do I eliminate burrs? Thanks to all who assisted with suggestions regarding my rough finishing cuts in aluminum. To those who asked about the type of aluminum I'm using, let me add that I'm not quite sure what the alloy is. I do know it's an aeronautical grade, as I purchsed it in the surplus yard at a Boeing warehouse south of Seattle. It didn't have any identification on it, but I have previously purchased 6061-T6 from this yard before. The scrap aluminum blocks in that yard can be huge, and I "think" it's what used for structural support in Boeing's aircraft. I've also been informed that the cheapy brazed carbide tipped bits I'm using ($3.99 Harbor Freight specials!) may need to be smoothed and profiled. I don't yet have the proper tools to do this yet. I do, however, have some HSS blanks, but no grinder; hope to change this later in the week. I did use WD-40 in the latter part of my experiment, and while it did "begin" to create a better finish, it still wasn't very good. I was indeed facing while performing the finishing cut...this was a piece of block I was turning, and I wanted to keep it as a block! As suggested by several of you, I'll try increasing speed. This is my first turning project, and I plan to make a boring bar holder with this cube. I know I'll get there...it's just a matter of the learning curve. Stay tuned... Mark ------- Date: Sun, 16 Jun 2002 07:55:46 -0500 From: "jerdal" Subject: Re: Re: How do I eliminate burrs? I would NOT use carbide for aluminum, or for anything much with the 618. 1) It builds up on carbide possible a little worse that on HSS, and the main factor is that it can catch and break off pieces. I have had the brazed carbide tip of a threading bit get torn completely off the bar. The buildup leads to very bad finushes, as the cutting ends up being a sort of plowing done by the buildup, not the edge. 2) The 618 is too small and light to run carbide at the high speeds and deeper feeds that it wants for good finish. If you have to use carbide, hone the edge with a diamond stick like the $6 "Eze-lap" sticks woodworking stores have. The coarse grade will do minor re-shaping as well as honing. I think that HSS will do you much better. Grinding is a pain, which is why I try to pick up used toolbits at sales. There are usually lots of interesting and useful shapes, and you only need to sharpen, not form, the bit. JT ------- Date: Mon, 17 Jun 2002 05:07:55 +0000 From: Jon Elson Subject: Re: Re: How do I eliminate burrs? markzemanek wrote: > Thanks to all who assisted with suggestions regarding my rough > finishing cuts in aluminum. > To those who asked about the type of aluminum I'm using, let me add > that I'm not quite sure what the alloy is. I do know it's an > aeronautical grade, as I purchsed it in the surplus yard at a Boeing > warehouse south of Seattle. It didn't have any identification on it, > but I have previously purchased 6061-T6 from this yard before. The > scrap aluminum blocks in that yard can be huge, and I "think" it's > what used for structural support in Boeing's aircraft. I have made the mistake of trying to machine elemental aluminum, which is used for some extruder work. It is REALLY soft, nearly as soft as lead, and horribly difficult to machine. Without knowing anything about a particular chunk of stock, you could have something like this. > I've also been informed that the cheapy brazed carbide tipped bits > I'm using ($3.99 Harbor Freight specials!) may need to be smoothed > and profiled. I don't yet have the proper tools to do this yet. I do, > however, have some HSS blanks, but no grinder; hope to change this > later in the week. You want to use positive rake tooling for aluminum. This is a cutting tool which works a bit more like a chisel, trying to peel off a slice, than a scraper, trying to rub off a bit of material. On the lathe, this would mean that the very tip of the cutting edge, at least, rises up toward the workpiece. This can be done by tilting the insert, or by molding a chip-breaker groove into the insert, and using it flat. These tools will need to have a relief on the front face of the insert, tapering away from the work at the bottom. Some horrible ASCII art follows: (Work) (tool) \ | )V------------- | \ / \ \ \_________ This is a side view, looking along the front of the workpiece, and the tip of the insert. The V is the chipbreaker groove in the insert. Jon ------- Date: Mon, 17 Jun 2002 05:15:38 +0000 From: Jon Elson Subject: Re: Re: How do I eliminate burrs? > > I've also been informed that the cheapy brazed carbide tipped bits > > I'm using ($3.99 Harbor Freight specials!) may need to be smoothed > > and profiled. I don't yet have the proper tools to do this yet. I do, > > however, have some HSS blanks, but no grinder; hope to change this > > later in the week. jerdal wrote: > I would NOT use carbide for aluminum, or for anything much with the 618. Gee, I've been using carbide almost exclusively for the past 12 years, first on a 10" Atlas, now on a 12" Atlas/Craftsman. > 1) It builds up on carbide possible a little worse that on HSS, and the main factor is that it can catch and break off pieces. I have had the brazed carbide tip of a threading bit get torn completely off the bar. The buildup leads to very bad finushes, as the cutting ends up being a sort of plowing done by the buildup, not the edge. < I often use the same insert tip for months, and they only break when I do something stupid. > 2) The 618 is too small and light to run carbide at the high speeds and > deeper feeds that it wants for good finish. You are correct that you don't want to run negative rake carbide on small machines, as they take a LOT of infeed force and HP. But, positive rake tools work fine, even on the small lathes. I remember fooling with HSS bits for hours trying to get the right shape, and then having it crumble. Threading was the worst. I just use the inserts as they come, and I'm quite happy with them. I do buy them on sale, as they do get expensive, especially name brand inserts. Jon ------- Date: Mon, 17 Jun 2002 13:22:05 -0000 From: "wcbarry2002" Subject: burrs.lathe tools..how to do it(grind your own) ..after reading the many replies to the question of how to get rid of burrs and how to sharpen lathe tools, ie, have u considerd looking at the excellent reprins sold by lindsey..especially the south bend booklets....sometimes a picture is worth a thousand words...the booklets are cheap,too,plus it will answer many questions you may have on the operation of your lathe,be it an atlas or other...just my two cents worth.. Barry ------- [NOTE TO FILE: THERE HAS BEEN MUCH DISCUSSION ON OTHER GROUPS ABOUT THE USE OF CARBIDE TOOLS WITH SMALL LATHES/MILLS. Most home users think that HSS (high speed steel) is a better general choice as it can be sharpened more (and more easily) than carbide and also reduces stress on the small machines. Many have been successful in using carbide tips, particularly useful when dealing with nasty metal with hard rough skins. There are two general types of carbide tips. The bits with brazed carbide tips are often sharper at their cutting edge than the carbide tips (inserts) that screw on and are thus replaceable. A sharper edge will be an advantage for the small machines cutting many materials. Larger machines can use brute force and more aggressive feed to hog off deeper cuts with the duller, stronger edge of carbide inserts thus speeding production. Obviously carbide inserts can be sharpened to be more suitable to small machines or a particular job. Before making a heavy investment in carbide, it would seem smart to purchase a few of each type and experiment on scrap material.] There is are a lot more discussions about bits in the file here called Cutters Collets and Arbors. ------- Date: Mon, 17 Jun 2002 22:33:11 -0500 From: "jerdal" Subject: Re: Re: How do I eliminate burrs? > Gee, I've been using carbide almost exclusively for the past 12 years, > first on a 10" Atlas, now on a 12" Atlas/Craftsman. I have used it on a 109, with what I then thought were reasonable results, so I have you beat there. But, a properly ground HSS bit will work BETTER, and you can grind rake angles that are almost impossible to use with any grade of carbide. The smaller the machine, the more you want to use a "slicing" bit to remove serious amounts of metal. It just uses less power than other shapes, and chatters less too. And, since carbide is not really capable of getting towards knife edges, it follows that there are better choices. Carbide is bits of hard stuff in a matrix, and you need bulk material behind the edge to avoid tearing hard bits out of the matrix. Too sharp, and the edge is all matrix and hardly any hard bits. What there are are not supported well, so they tear away. It could be thought about as somewhat like the "angle of repose" for sand or gravel, etc. A balance between a sharp edge and what wears away fast. Of course you CAN use it, and it has some desirable features. I use it sometimes. But most folks don't dress the edges or grind to any shape past what is provided on the raw bit, due to lack of equipment. That is no help. HSS is charmingly low tech to support, and can work much better on small machines when ground well. So what's the problem with recommending its use? Jerry ------- Date: Mon, 17 Jun 2002 20:59:56 -0700 From: "GSNEFF" Subject: Re: How do I eliminate burrs? Gosh .... don't tell me I have been doing things wrong all these years :) I used carbide almost exclusivly on my 6" with very good results. I did make a tool block to hold the carbide an tossed the lantern stuff. On my 12" the only non carbide bits I use are formtools. I have an HF QC tool holder and it is not set up to hold HSS bits properly and I don't own a lanten post for it. Carbide likes speed ... no, faster than that :) You don't have power so you have to make inertia work for you. When I first heard the saying "if your chips ain't blue yer turnin too slow" I thought they were kidding ...they aren't. For facing an aluminum block in the 4 jaw just crank it up to the highest RPM you feel will let the thing stay together and face it off by hand. You need to vary the feed rate as you get to the center you need to slow the feed. Of course power feed is not an option on the 6". Until you get a machine that outweighs the family sedan your best bet is more speed. Especially on interupted cuts. If you go to back gear and try to "muscle" it off you will strip the back gears. Watch the lube in the bearings and if you have a bronze bearing 6" watch the heat and you will be fine. For good deals on carbid inserts check e-bay ... I got a bunch for about ten cents on the dollar all new in old boxes. YMMV Glenn Neff Medford, OR http://www.superford.org/?vID=1089 ------- Date: Tue, 18 Jun 2002 07:34:49 -0500 From: "jerdal" Subject: Re: Re: How do I eliminate burrs? Carbide use on 6" is not wrong, just not necessarily optimum. > it. Carbide likes speed ... no, faster than that :) You don't have power > so you have to make inertia work for you. Right, you can't keep up the speed and take deep cuts. With HSS you can grind for taking off 0.125 inch wide chips easily, certainly on the 10 or 12 inch machines. Turn direct to the finish cut size, two passes to done. With carbide and fast speeds, ain't gonna happen. So you run slower, and the tip geometry isn't optimum. Metal removal rate is lower, more tedious cuts. > Until you get a machine that outweighs the > family sedan your best bet is more speed. If you did have that machine, you would use MORE speed, and still take off 1/16 x 1/2 inch chips with carbide. I have argued FOR use of carbide, same as you. Same reasons, "works fine for me". Since I started using better ground HSS, the insert tools are not getting very much use. Maybe I learned something........... And, I stand by the weird interaction of aluminum and some carbides. I did have a thread tool tip torn off, and the chunk had a huge buildup on it. Seems like it suddenly welded on, regardless of oil, and dug into the work, ripping off the piece. Aluminum likes faster and wants cutting lube. Jerry ------- Date: Tue, 18 Jun 2002 08:09:42 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: Re: How do I eliminate burrs? Carbide v. High Speed Steel tool bits... I have both... but... special shape tool bits are the exclusive domain of HHS, if you want to shape your own. example; a tool that will cut a 0.043" square groove for a c-clip... a tool that will form a RP25 tire shape for a locomotive driver... a round seat for an o-ring, etc. Of course, you have to have a bench grinder and a Dremel grinder.. Leo (in sunny pearland, and not too hot.. around midnight) ------- Date: Thu, 20 Jun 2002 11:03:28 +1000 From: "Charlie Lear" Subject: Re: Round to square On Thu, 20 Jun 2002 00:24:47 -0000, witstock7 wrote: >I have some square stock that I would like to be able to turn so that >it has a round end. I don't have a four jaw chuck and am wondering >if there is another technique I could use to hold the stock and get >that round end. Measure it across the corners. This is measurement "X". Chuck a stub length of round stock, brass if you've got it, slightly larger (say 1/8") than X. You may need to turn down a piece of larger stock if you don't have something the right size. Drill it through size X or very slightly larger. Use a scriber or centre punch to make a little mark on the bush next to the #1 jaw on your chuck - the actual jaw doesn't matter, you want to be able to replace it in the same place it was when you drilled it out. Use a felt pen or scriber to mark the bush roughly midway between two chuck jaws. Remove from the chuck, and use a hacksaw or razor saw to split it lengthwise at the pen mark. You now have a split bush. Put the bush in the chuck, slip in the square stock, and tighten - hard enough to close up the split in the bush a little, not hard enough to distort it. You'll see exactly how much to do it. If the bush is too thin or the hole is too big and it distorts before gripping the stock - toss it and make another. It's quick and part of the fun! Don't make the wall thickness of the bush too thick, else you'll strain the chuck tightening it up. Also don't take too heavy a cut because the grip is only on the corners of the stock. Then save up and get a four jaw chuck! 8-) Cheers Charlie ------- Date: Wed, 19 Jun 2002 21:33:33 +0100 From: "David Simmons" Subject: Re: Round to square Two other ideas: If long enough, you can center drill the ends and turn between centers. This is a little dangerous as an interrupt cut is not recommended when you use a lathe dog. Lock the dog to the face plate in possible. Also you can turn up a collar with a wide C/S , drill and tap across the C/S and use Grub Screws to center the square Stock. Place thin brass shim stock between your work and the screws to avoid marks. Hope that gets you going. "If there is not at least three ways to do something, it is impossible:)" Me - 2002 Later, Dave S. ------- Date: Mon, 24 Jun 2002 20:00:26 -0000 From: "witstock7" Subject: Square into round - resolved By combining some of the suggestions offered in response to my earlier, I have successfully turned my square stock with a round section. I took a piece of round brass stock that was larger than the square material and bored a hole slightly larger than the diagonal of the square material. Four set screws through the side of the bored portion secured the square stock well enough for me to turn it. Basically I guess I made a primitive four jaw chuck. I used this technique to make a few tee nuts for use on my mill table. When I used my original Sherline nuts I sometimes screwed the clamping screw completely through the nut and left a scar in the groove. This cannot happen with my shop made tee nuts because I did not tap the holes completely through them and the clamping screws will therefore not be able to scar the mill table again. Nelson Wittstock Medina, Ohio ------- Date: Mon, 24 Jun 2002 18:33:01 +0100 From: "David Simmons" Subject: Re: Square into round - resolved Nelson. Glad to hear it - sometimes it just takes a little thought and a few tries, and a little nudge to solve a problem. Years ago I designed and built jig fixtures to machine castings - it was a real challenge. Every casting is a little different, and in one case the castings where rather large - several tons. It took four weeks to build the jigs, and the custom tooling, but only three weeks to machine two hundred castings. I went $10,000 over budget on the fixtures - but made up for it in the time savings because of the designs I used. Trick is to think twice, measure three times, and machine once. For us it is a little less of a problem - but the same rules apply, unless you have very deep pockets:) Later, Dave S. ------- Date: Thu, 5 Sep 2002 01:29:20 -0500 From: "Al Lenz" Subject: RE: How to align a cylinder in a lathe > From: kimvellore [mailto:kimx~xxblueneptune.com] > Sent: Wednesday, September 04, 2002 10:58 PM > To: sherlinex~xxyahoogroups.com > Subject: [sherline] How to align a cylinder in a lathe > I am taking baby steps here and I am stuck with the first step. > I have a three jaw chuck in my lathe and I bought a 12" hard wood > cylindrical rod it is ~1" dia. The problem I have is I assumed that > once it is in the three jaw chuck and tight it will be straight and I > can move the tail stock in and hit the center of the cylinder but it > does not seem to happen that way I can move the tail end quite a bit. > So my question is how do you normally get this straight. Do you have > to mark the center at the tail stock before you put it in the lathe? > It is difficult for trial and error because once the tail stock is in > it indents the work piece and the second time it tries to follow the > indent. Any help is appreciated. Thanks Kim Hi Kim, This is precisely the purpose of a steady rest. It forces the outside diameter to run true. However, if you don't have one, there are always work-arounds. Try just snugging the work in the 3-jaw and run the lathe at a fairly slow speed. Then use something like a wooden pencil to GENTLY apply pressure to the tail end. With a little practice, you will be able to get it dead true. Tighten the 3-jaw and repeat as required. Your center drill should then hit dead on unless there is a deep off center indentation, in which case you might have to face it off. Al Lenz ------- Date: Fri, 11 Oct 2002 11:31:15 -0000 From: "tnance0913" Subject: Chucking a square bar Could you guys tell me how to chuck a square bar in the four-jaw chuck so that is is dead center? I don't see how you could indicate the sides of the bar and I don't know if indicating the corners will tell you much. I know there has to be a really simple solution, but I can't see it. I was thinking of using the cross slide. I figure I could run it in until the tool touches the bar and read the handwheel. Then I could rotate the chuck 90 degrees and take another reading and keep doing this until the two readings are the same. But that's a real cheesy way of doing it. There has to be a better way. Thanks in advance for any help. Tom Nance Corpus Christi ------- Date: Fri, 11 Oct 2002 09:49:59 EDT From: Holyelvisx~xxaol.com Subject: Re: Chucking a square bar I attach an old hack saw blade to the tool post and then lay the other end on top of the stock and put the dial ind. on top. This is a trick I learned about from Home Shop Machinist. Devin ------- Date: Tue, 26 Nov 2002 02:41:30 -0000 From: "J Hamilton" Subject: replicating round parts on the lathe [TAIG FORUM] Hi all. Great forum. I've been monitoring for a couple of months, and learning a lot. Many thanks. My question is about duplicating a part on the lathe. I wish to manufacture a run of the same part. I'm wondering if anyone has a plan for a jig to to hold a master part off to the side with a guide "probe" or bearing surface attached to the cross slide to stop the cutting bit at the correct depth. A key duplication machine would be a shorter explanation, only in this case I'm turning the stock, not the cutter. James Hamilton ------- Date: Mon, 25 Nov 2002 20:41:05 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: replicating round parts on the lathe The t-slots on the back of the headstock and tailstock can be used to bolt a piece of angle which can in turn hold a template. You can then make a follower, remove the crosslide nut and have the cross slide follow the template, possibly by spring loading the cross slide so the follower bolted to it feeds againt the template. Fine feed could be via the compound. This probably doesn't make much sense, as I have a cold. See our web pages http://www.cartertools.com/nfhome.html ------- Date: Thu, 16 Jan 2003 22:22:32 -0500 From: Stan Stocker Subject: Re: 4-jaw run out [ATLAS GROUP] Skip Evans wrote: > I have 2, 4 jaw chucks 6" and 8". The lathe is Craftsman 12x36. I am > having a problem getting round stock centered. > I can get round stock centered with a dial indicator close to the chuck. > (Approx .001 runout). Four inches out, the run out is .010 on the 6 inch > chuck and .012 on the 8 inch chuck. Is this normal? > Skip Evans http://skipevans.homestead.com Hi Skip; Sounds pretty normal to me. You may be able to tap the work a bit at the far end to reduce the runout before you do the final snug on the jaws. You may want to double check with a nice bit of one inch (or so) ground shaft that you have verified to be straight by rolling on a surface plate. As the jaws wear a bit in use, you find runout increases. There are a number of ways to fix this, all I know of either involve special fixtures and a surface grinder, or a plate specially made to load the jaws. You then grind the jaw faces in the lathe to ensure the faces are truly parallel to the spindle axis. I keep some drill blanks in my drawer of inspection equipment for doing alignment work on collet tooling, chucks, and other testing or alignment tasks. The jaws have to have some free play in their slots, or they couldn't move. The screws aren't exactly on the center thrust line of the jaws, so when you snug things up the free play gets taken up differently (as the jaws cock just a tad) every time you clamp up a piece of stock. As this happens the piece moves just a bit, the clamped surfaces scuff a bit, things wiggle around. You can fiddle your way past it to greater or lesser extents depending on the quality and condition of the chuck, your patience, and the requirements of the job, but this is just a "nature of the beast" sort of deal. If you need very low runout on a piece of work, and don't have a collet setup, you need to support the free end of the work with the tailstock on a precisely drilled then bored center hole. The boring has to be done using a steady rest so the work is running on its circumference for the boring operation. Doing both ends of the stock this way and turning between centers is the best way I know of to do precise work. Done with care, you'll generate a center hole that is within half a thou of true center, often better. It is more work than is required for most situations. Although I have done picky work this way, the reality is that I usually start with a bit of stock that is oversize and do all the turning and boring without unchucking whenever possible, or do the entire job between centers if remounting will be required for additional operations. As long as there is some material taken off at all points, all the shoulders and surfaces end up concentric, or at least with care (and a lathe in good alignment) the ones that count do. If the work will pass through the spindle bore, or is short enough, you can center drill with the end of the work just past the jaws of the chuck. Dial in the work for as close to zero TIR, face off, then center drill. If your tailstock is in alignment, this will give a pretty darn good center with less work than setting up a steady. For really critical between center work, even CNC certified live centers are not as accurate as carbide tipped dead centers, although for most applications we mere mortals encounter a nice $40 Skoda live center is plenty good. Cheers, Stan ------- Date: Thu, 16 Jan 2003 21:35:12 -0500 From: Ron Fitzpatrick Subject: Runout [atlas_craftsman] Skip: When setting up work in a 4 jaw chuck you should first use "coppers" on your jaws. The copper does two functions, one being that it keeps you from damaging any finished machined surfaces with your jaws and two that it will allow you to move the far end with some sort of a soft non- marking hammer (typically a neoprene "dead-blow" hammer or a hammer with a "babbitt" head). First you indicate work at chuck to run true and then you move indicator to far end, rotate work by hand and when you find low side use dead blow hammer to hit on opposite side. Movement should be approximately half of runout. Continue this until you get that end running true then go back to chuck and recheck. You will probably find chuck end now runs out so retrue and then go back to far end and recheck. What you are essentionally doing is cutting the runout down in a series of steps by going back and forth. Keep doing this process until both ends run true. Just remember to keep checking from end to end EVERYTIME you adjust either the chuck end or the end sticking out. ------- Date: Thu, 13 Feb 2003 06:45:23 -0000 From: "jimknighton1948 " Subject: Hand held gravers and other manual turning stuff.... [SHERLINE GROUP] I don't know how much interest there is in this subject, but I've been exploring methods and techniques for turning smooth curved metal shapes using hand-held tools. If there are others who are doing this I would appreciate hearing from you and some of your experiences, both positive and negative. This shouldn't be too far out in left field given the availability of the W.R. Smith t-rest and related articles about making and using gravers. For those of you who might be interested in the subject check out the following link (make sure that both lines are joined into one without spaces). You might have to be a member of this forum to access this file, but I think you will find it worth the trouble. http://groups.yahoo.com/group/mwhints/files/Spherical% 20Turning/Sphere-1.pdf The author describes in this article tools and techniques for forming spherical shapes and complex curves using hand-held tools on a metal lathe. Admittedly, he describes this as a dying art in 1967 when he wrote the article for Model Engineer magazine. Still, the subject seems like it ought to be of interest to contemporary hobbyists particularly those who aren't ready to jump into CNC quite yet. I've purchased the W.R. Smith t-rest from Sherline and made a set of gravers as per the enclosed instructions. For what it's worth, I didn't find it difficult to make those gravers. Neither was it difficult to figure out how to use them. My first attempt at using them was a simple aluminum knob of roughly spherical configuration and I was astonished at how easily and how quickly I was able to shape and polish the part. It's not like turning wood, mind you, but I found the shaping process to be delightfully rewarding and not at all difficult. Since then I've done several other experimental shapes with equal success, all out of 3/4" aluminum round stock. Unless I'm missing something here, this is a technique that really should be better known and widely used. Also for what it's worth, the t-rest works quite nicely with a lathe equipped with risers as mine is. The t-rest fits on the steady-rest riser as long as the riser's clamp is oriented to the rear of the lathe. If facing the front, the clamp interferes with the SHCS holding the rest's locking cam in place and prevents it from seating properly. Are there any other people out there who are interested in this subject and/or have experiences to share? If so, I would love to hear from you. Regards, JBK ------- Date: Thu, 13 Feb 2003 16:38:07 -0000 From: "Nelson Wittstock" Subject: Re: Hand held gravers and other manual turning stuff.... I'm glad to see there is someone out there interested in doing graver turning. My initial experience with turning was on a wood lathe and at first I had thought that the same techniques would be applicable to metal turning. Having used my Sherline lathe for a while now I am well aware of the differences in how the materials are dealt with. The other day I tried turning a contour on a piece of steel and I found that turning the X and Y cranks simultaneously in a coordinated flow is going to require a lot of practice. Last summer I bought W.R. Smith's video on graver making and hand turning but haven't had a chance to get into trying it yet. I'd love to hear more of your experiences with gravers and maybe I'll get inspired. Nelson Wittstock ------- Date: Thu, 13 Feb 2003 18:19:48 -0000 From: "jimknighton1948 " Subject: Re: Hand held gravers and other manual turning stuff.... Nelson, I'm sorry about the faux pas with the previous message. I inadvertently hit the send button and I don't think its possible to erase or retract messages once sent. My interest in manual turning predates my purchase of the lathe and initially was largely academic. People have been doing decorative turning in metal for several hundred years - long before Maudsley and his recognisably "modern" lathe. It seems that prior to ground form tools and CNC this was the norm particularly for decorative turning. One of the things that intrigued me about the Sherline from the very beginning was the notion of hand-held turning, particularly since the W.R. Smith t-rest and gravers offered a chance to discover for myself a bit more about these techniques. I admit to being aprehensive about this process particularly since I had to make my own gravers. I'm not sure why I found the thought so daunting, but I did. I suspect I've been unduly influenced by the general negativism that seems to be evident in past threads concerning this subject. Also, the diminutive size of the gravers themselves left me a little cold. Its taken me a -long- time to work up the nerve to actually try the technique. Of course, getting my lathe set up and working as I wanted was the priority for a long time as well. To date, I've had good luck experimenting with the gravers. I've made spheres, urn shaped knobs, smooth curves, decorative trinkets, etc. all with equal facility and ease. I've only done this in aluminum so far since that is what I mostly had on hand in the scrap box. Based on my experiences to date I have no fear or aprehension about turning mild steel with this technique, however. In some respects turning aluminum with the gravers is unlike wood turning. It's a much harder material and you can definately feel it under your hand. The gravers built according to W.R. Smith's instructions are all alike in shape differing only in hardness or toughness of the steel. This is a little misleading, however. The actual cutting action can occur at pretty much any point on the diamond shaped business end depending on what contour you are trying to shape. It is almost like a multipurpose cutting tool if there is such a thing. Being accustomed to wood turning chisels, I didn't see how this dinky little diamond shaped graver could possibly cut the range of shapes and forms that it actually does. The link in the previous post points to a document that suggests that tiny gravers are not the only hand-held turning tools, although they might be the ones best suited to the miniature machine shop. More than anything else I was struck by the author's positive attitude about hand held turning tools. This attitude is what got me off the dime and into the shop. After some hands on experience with this stuff my reaction is quite positive and also wonderment that this subject is treated so lightly and dismissively. Is anything about this hobby "easy?" I think not, and this is no exception. Still, I don't think hand turning metal in this manner is any more difficult than any other aspect of the hobby and there is an intimacy in the process that I find quite attractive. Just like wood turning, it is rewarding and pleasurable to see an interesting shape emerge from a raw lump under your own hands. Regards, Jim Knighton ------- Date: Fri, 14 Feb 2003 01:27:43 -0000 From: "cobbkev " Subject: Re: Hand held gravers and other manual turning stuff.... I haven't tried 'graving' yet but it sounds like those little gravers resemble an amazing wood turning tool I've recently discovered. Mine is called a Skewchigouge. It's basically a solid round bar ground to a diamond or a triangular shaped tip. It shears and scrapes but the shape also can rough like a gouge. It's now the only wood turning tool I use. I think there are other manufacturers that call their product by some other name. I assume the different approach angles would be similar in metal just different feed rates? ------- Date: Fri, 14 Feb 2003 03:15:11 -0000 From: "jimknighton1948 " Subject: Re: Hand held gravers and other manual turning stuff.... I'm not familiar with this tool but from the way you describe it it sounds at least superficially similar to the graver. While playing with the graver I found myself wondering if this diamond shaped cutting tool would have any applicability in a wood turning environment and/or how I might use it. Who knows? Maybe it really does? The article I referred to in a previous post also describes a hand held metal turning tool that bears a similarity to the woodturner's gouge. The metal working equivalent apparently is fully circular in form whereas the gouge is essentially an arc, i.e., part of a a circular form. The article also describes a chisel-like tool that bears at least a superficial resemblence to a skew, although the illustrations suggest a much heavier construction and different cutting angles. I don't recall it specifically mentioned but there is probably a metal working equivalent of the parting and round-nose tools as well. I guess that "form follows function" here as much as anywhere else. I've not attempted to use metal turning tools other than the gravers, but given the information source quoted above I have to believe they work reasonably well in their "native" environment. I've also found a clock-maker's web site (other than W.R. Smith) who describes making and using gravers in much the same terms he does. This site also makes reference to gravers with different geometries than the symetrical diamond (although no examples are given) and also to larger sized gravers than the 1/8" currently familiar to us. The site specifically stated that gravers larger than 3/16" were too big for watch/clock making purposes; the suggestion being that larger gravers might have application for other purposes. For instance, might a 1/4" graver have application turning Sherline sized ornamental shapes? If so, what kind of a rest would be required? Apparently this is a broader field than I had originally suspected. Regards, JBK ------- Date: Tue, 04 Feb 2003 23:32:07 -0000 From: "Thomas " Subject: Milling a groove with a lathe? [TAIGTOOLS GROUP] I'm playing with my new milling attachment for my lathe and want to make a finger plate like the one in the Mach. Bedside Reader 1. What's the best way to mill a 90 degree v-groove on it's face? Should I angle the work piece and mill the groove with a straight endmill? Or should I make an arbor to accept a 90 degree angle cutter (they seem to have a minimum shank of 3/8"). Could I just take some 1" bar stock, bore and tap half of it for 3/4-16 and drill a hole in the other end to accept the shank? What are your thoughts? btw, I had the honor of speaking with Mr. Lautard, the author of all the TMBR's, about a pantograph engraver. He was great fun to chat with, and I came away with a page full of notes and my mental gears whirling :) What an interesting guy, and very down to earth! Thomas ------- Date: Tue, 4 Feb 2003 16:19:28 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Milling a groove with a lathe? You can make an arbor for a vee cutter from the 1132 blank arbor. You could also use a flycutter to cut the groove as well, just sharpen the toolbit to the groove dimesions you want. Probably easiest to just put the work at a 45 deg. angle and use an endmill. See our web pages http://www.cartertools.com/nfhome.html ------- Date: Tue, 11 Feb 2003 20:48:43 -0000 From: "tonyryue " Subject: An update on the chattering steel problem I suspect that there may be others new to machining that might benefit from my experience in tracking down the problems that I described in a post two weeks ago. Here are some initial impressions: 1) Got some 12L14 steel. Wow! This stuff cuts like butter! Highly recommended for the beginner. 2) Got some "Safe Tap" cutting fluid. In Canada, Busy Bee Tools sells this stuff in a 4oz container for about 6 bucks, so no big outlay if you don't like it. Greatly improved finish and advancing the tool becomes almost effortless. 3) I have discovered that my concepts of accuracy needed some tweeking. Got some shims (sampler pack from Lee Valley Tools under 10 bucks) that let me shim to the half thou. I was slightly off, but the technique of using a drill shank in the collet and a thin piece of metal between it and the cutting edge worked easily and effectively! Things are going so well that a cylinder for my first steam engine ended up too short by a large margin; I just love seeing those threads of metal peel away! Thanks to all for the expertise. Regards, Tony ------- Date: Tue, 18 Mar 2003 14:10:44 -0500 From: Damon Gentile Subject: Chuck spitting out work, natives run for cover! Hey folks, had some trouble yesterday when my chuck loosened up and lost grip of the work yesterday. First time I dismissed as a fluke, second time told me to stop for the night. 10x36, 5" 3-jaw, and maybe 600 RPM. The work was 2" diam steel rod 5" long, end drilled 3/4"diam to about 3" deep. I was using a boring bar with carbide insert to slowly open the hole. And I was also using a steady rest, about 2" out from the chuck. The part was about 8" long, and I had drilled/bored the end and cut off the 3" piece I needed with this same configuration (steady was about 3" further out). Rechucked the remainder for a second slice. After the 2nd or 3rd pass with the boring bar, it walked out of the chuck. Rechucked, tight!! and minutes later it let go again. Is there something horribly wrong that I'm missing with my setup? Only think I can think of is to swing the compound around so I can get the steady closer to the outboard end of the work. Thanks, Damon (getting tired of changing undies from loose work!) ------- Date: Tue, 18 Mar 2003 20:31:17 -0000 From: "yrotc78u212" Subject: Re: Chuck spitting out work, natives run for cover! damon, you are screwing the piece out of the chuck because the steady rest is not holding the work in line with the spindle center line.the rollers (or bushings on the steady rest) are forcing the bar to one side pulling the piece out. 1)did you first center drill the end,bring up the tailstock and turn a section true that the steady rest will ride on? 2)did you then setup the steady rest,with the tailstock center still in the end,so that the rollers are just touching the part that you trued up? remember bar stock is not as true as you think and being 2 inch stock with the steady rest that close to the chuck it`s not going to bend but yank the work out. mark ------- Date: Tue, 18 Mar 2003 15:36:14 -0500 From: "Rigrac" Subject: Re: Chuck spitting out work, natives run for cover! Damon: Might be silly question but are you SURE steady rest is on center. Steady rest either slightly above or below center will still show workpiece to run true but will walk job out of chuck if below and push job into chuck if above. Ron ------- Date: Tue, 18 Mar 2003 15:42:12 -0500 From: Damon Gentile Subject: Re: Re: Chuck spitting out work, natives run for cover! Yup, I think you hit the nail on the head. It's a little off center. I did turn the OD, but tonight I will be sure to recenter using the tailstock only, then bring the steady into alignment. Thanks, Damon ------- Date: Tue, 18 Mar 2003 19:03:52 -0500 From: "RD Burch" Subject: Re: Chuck spitting out work, natives run for cover! Regarding the work coming out of the chuck when using a steady rest: I believe your steady rest is not aligned with the lathe center line. Chuck up your part in the lathe chuck. Make sure it is running as true as you can get it right at the jaws. Run the steady rest up close to the jaws and adjust it to either just touch or a cellophane thickness away. Then when you reset the steady rest towards the tailstock it should be okay. Put a visible mark on the part right at the chuck jaws that you can see while the part is turning. Make a practice of checking frequently to see that the part is not walking out of the jaws. Bob Burch, Akron, OH ------- Date: Tue, 18 Mar 2003 23:59:02 -0600 From: Jon Elson Subject: Re: Chuck spitting out work, natives run for cover! If you were having a lot of vibration (chatter), that can do it. But, my guess is that your chuck jaws are worn - sometimes called "bellmouthing". It is common that the outermost tips of the jaws get worn more, and eventually the part is only held by the rearmost part of the jaws. You can often see this condition with a light held behind the jaws, looking for light shining between the jaws and the work. If this is the case, there are several techniques for grinding the jaws back into proper shape so they hold work for the full length. One other possibility is that your steady rest was not right on center, forcing the bar to work around in the chuck. You want to get the work set up and turning true without the rest and turn the spindle slowly by hand or just nudge the belt tension, and make sure the work is true. Then, you bring the steady rest jaws in to support the work against cutting forces. They should just barely touch the work when you are not cutting. Jon -------- Date: Wed, 19 Mar 2003 11:13:59 -0800 From: "Bob May" Subject: Re: Chuck spitting out work, natives run for cover! First thing I am going to assume is that the rod is solid where you are chucking. If you have hollowed it out then it will walk a lot easier. Next, the cutting oils were all over the piece and thus you have just lubed the place where you were grabbing onto. This assists in allowing the work to walk out. Next is that the work may not be perfectly square in the chuck and that will give a little bit of give to the chuck to work interface. Lastly, the work is hot compared to the chuck so when you chuck the work up, it cools (and you know what happens when you cool something) and thus the chuck isn't holding as tight. If you have hollowed the work out all the way, the chances of being tight are a lot harder as the work will flex a lot more than a solid piece. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Wed, 19 Mar 2003 17:09:46 -0500 From: "Richard Farris" Subject: Re: mist coolers ? > I've been wondering about a mist cooler for the 10". I love this > little machine and work it well, but I think I spend all the time > just dripping cutting oil on it. -Damon I use my mist cooler about 10-20 percent of the time. I've got a huge stainless chip pan under my Smithy Granite, and the edges are turned up about an inch. The pan and the bench have a slant toward the left front corner where a stainless drain pipe drops to the floor. I put a plastic bucket under the drain line to catch the lubricant/coolant. The Machine is leveled within the pan and all bolt holes thru the pan and into the bench are sealed with silicon caulk. The touchy part for me is alway the rigging up of the spray tip to follow the traveling tool tip when turning. When milling, the work moves so that's not too much of an adjustment problem. I use a water-based coolant - can't remember it's name as I picked up a 5 gal bucket of concentrate at a machine shop bankrupt auction about 3-4 years ago and have hardly made a dent in it. Matter of fact, I don't think there was a trade name on the bucket. Just was marked coolant concentrate on the auctioneer's tag. Misting works good for me - fairly easy adjustment of the mist with my mister unit ( got that at a different auction for about 15 dollars ( US ). Hope this helps. Dick ------------------------------ Date: Wed, 19 Mar 2003 17:54:01 -0500 From: "Rigrac" Subject: Re: mist coolers ? Damon. My 13X42 South Bend uses an accessory tank of approximately 4 U.S. gallons that has a simple pump like the one you would use on a parts washer. My nozzle is attached to the saddle in about the area that would be the directly above the rear way saddle casting. Nozzle then moves along with carriage to keep coolant directly on tool. I also have a chip pan under lathe that is sloped to drain coolant back to tank. I also have the pump on its own switch so that it runs only when I want it. I have put a bypass line just in front of ball valve that controls actual coolant flow so pump is not "dead- ended " when electrically turned on but not actually supplying coolant. As too "spray misting " which to me is a mixed supply of air and coolant to form fine mist we used to do this at work a lot but now have to have vacuum system along with it to pick up fine mist in air as they say it can cause respiratory problems. Flood type system as described in earlier paragraph is the preferred choice. Ron ------------------------- Date: Thu, 20 Mar 2003 15:09:00 -0500 From: "John Glowacki" Subject: Re: mist coolers ? On Thu, 20 Mar 2003 12:25:49 -0500 Damon Gentile wrote: >Wow that sheds a light on it. Is synth mist safe (er) ? >Otherwise, messy flood... -Damon >John Glowacki wrote: >> Damon, >> I am a chemist working for a large Industrial Hygiene >> (OSHA) laboratory. The majority of the samples we test >> are worker breathing air from industry. A fairly new and >> popular test that we run is for "Oil Mist". This is the >> mist that is created from machine cutting/cooling oils. >> The following is directly from the OSHA web site and >> pertains to mineral oil mist. >> HEALTH EFFECTS: Explosive, Flammable (No adverse effects >> when Good Housekeeping Practices are used) (HE18) >> Accumulation in lungs (Pneumonitis) (HE10) >> ORGAN: Respiratory system, skin >> OSHA also has a fairly low PEL (permissible exposure >> level) of 5mg/M^3. Keep in mind this is for "mineral" oil >> mist. Many of the cutting oils used today are synthetic. >> Often the health effects can be more serious. My point >> is, be very careful. Some people can become very >> sensitized to cutting oils just from being exposed to the >> liquid. When you create a mist, you are aerosolizing the >> liquid to form very small particles of oil, which then can >> be inhaled, and lodge in your lungs. Another >> consideration is, often these soluble oils can grow >> bacteria. Now you aerosolize the bacteria, and breathe >> it in. Not good. >> I generally like to cut "dry", as the machine was >> intended. At least that's what it says in the manual. >> John Glowacki I would say no. Your lungs are designed to breathe air, not dust, or liquid, or an aerosol. Your nose hair and sinus passages do a pretty good job of filtering air. When you create an aerosol or mist, you are forming very small particles. The very small droplets will make it past the sinus and into the lungs and stick in the alveoli (small air sacs). If you are a smoker, it only makes matters worse. If you want to cool your work and/or tooling, use flooding. John Glowacki ----------------------------- Date: Thu, 20 Mar 2003 18:25:17 EST From: LouD31M066x~xxaol.com Subject: Re: mist coolers ? The way life works is: A) product is marketed B) product is used and misused C) problems show up D) manufacturer claims product is safe E) lawyers for both manufacture and injured party earn large fees in court room and appeal process F) company goes belly up G) conclusive study study finds product was either safe or unsafe...too late to do either company or user any good. Short History of chemistry in 20th Century. The important lesson is even if tested prior to introduction some unforseen ill effect may arise...and lots of products were never tested by anyone not on manufacturer's payroll if they were tested at all. The Romans were gave us the expression...Let the buyer beware! Louis -------------------------- Date: Tue, 25 Mar 2003 12:29:58 -0600 From: Jon Elson Subject: Re: Large pieces Brian Squibb wrote: >I need to turn some bar - 1 inch by about 12 inches >The bar wont go through the chuck so I can drill a centre in it, it is two >long and heavy (it is 316 stainless) too hold centrally on the outside of >the chuck. You need a steady rest. It clamps to the bed, and has a ring with 3 adjustable supports, that gives support to the workpiece at the end opposite the chuck. It takes some care to set it up right so that the far end is turning on center. You can then face off and center drill the far end. You then flip the piece around and do the same on the other end, and you can now turn between centers. Jon --------------------------------- Date: Tue, 25 Mar 2003 14:02:57 EST From: n8as1x~xxaol.com Subject: Re: Large pieces Brian ............if u dont have a stdy ,or a dedicated centering machine , or a swivel table on ur drill press & 15 min. to set up & dial it in,.......use ur center finder & center punch both ends of bar .........put a chuck w/ center drill in hdstock...........support rt end w/ t/stock in deep c/punch mark .......put left end c/punch to the center drill & hold on as you advance t/stock.............. best wishes docn8as ps........a 24 in long bar ,1in in dia.WILL chatter w/out a stdy ,so start looking , or fabricating one ............... ------------------------------------- Date: Tue, 25 Mar 2003 17:36:09 -0500 From: "Rigrac" Subject: Re: Large pieces Brian: If you have a spare 3 or 4 jaw chuck you can make a threaded plug for it to screw in to the back and if it has a center drilled hole in the end just mount it on the end of the shaft and then use your tailstock center as normal. Of course if you need to face and center drill shaft on that end then you would have to follow same procedure but then set steady to shaft and then remove chuck at tailstock end. We at work make up what we call a "Spider" which is just a piece of burned out plate in the shape of a cross (+) drilled on ends for a pinch bolt and then heated up and the very ends (approximately 1" ) bent at 90 degrees. Now in effect what you have is a 4 jaw like tool that you can adjust to get shaft to run true. Again you have to set up on steady and then remove "Spider". Also "Spider" must have a center drilled hole in it to be supported by tailstock center. You should also put "coppers" under ends of pinch bolts where they contact shaft so as not to damage shaft. Ron --------------------------------- Date: Wed, 26 Mar 2003 04:18:10 -0000 From: "Bill Collins" Subject: Re: Large pieces --- In atlas_craftsmanx~xxyahoogroups.com, Brian Squibb wrote: > I was wondering whether a faceplate might do with the work through the > centre. Brian Hi Brian, you can make a temporary steady rest from a block of wood. Drill a hole the size of your stock and use a half round wood rasp to slightly enlarge the hole so the stock just slides through, make sure the height is the same as the center height on your lathe.Chuck up one end of the stock in your chuck then use your center drill in the tailstock to center drill the piece, flip the piece over and center drill the other end. Remove the piece from the chuck and set the temp steady aside. Now attach the faceplate to your lathe, insert a center in the spindle and the tailstock.On the stock affix a dog and mount the stock between the centers.Then you can machine the length to what is required.You should leave enough extra stock on the length to make up the distance used by the dog.Good luck. Bill C. ------------------------- Date: Wed, 26 Mar 2003 02:38:32 EST From: catboat15x~xxaol.com Subject: Re: Digest Number 1412 you need a steady rest. A gadget that fits on the lathe bed and has jaws or arms that hold work someplace near the end, Use the steady to drill your tail stock hole and go ahead normally. As an inprovision when I had to do some strange work (facing off a copper boiler tube) I improvised a one time use steady rest from wood. Made up an L shaped piece of hardwood ply with glue and screws, clamped the short leg of the L to the bed (thank goodness for the Atlas flat bed, this time) set it next to the head stock to mark the center of the spindle with the wood in place. Used that center and a compass to draw then coping saw a hole the size I needed. Moved the L down towards the tail stock near to where I would be working, greased the tube and the hole and faced off the end of the tube, worked fine. In your case make the hole to match your bar, Move your improvised steady to near the end of the bar, drill your center hole, put the wood steady aside as it may come in handy again. proceed to do your work on the bar held between centers. John LBSC Virginia LBSC Tich 200 some feet of 3.5 inch ground level track ------------------------------------- Date: Wed, 26 Mar 2003 04:45:28 -0500 From: "Cindy/Wayne" Subject: Re: Large pieces Brian, Check out the picture and files section on the home page of this group. I made a steady rest from a split ring of steel, threaded rod, and some brass stock. I have sold these rings to several list members for $5 each to make their own. Any one else finish one of their design? I still have some rings available if any one is interested. The shipping is more than the price of the ring. Wayne(rice)Burner Not going to retire at these prices :>) --------------------------------- Date: Wed, 26 Mar 2003 22:44:49 EST From: n8as1x~xxaol.com Subject: Re: Large pieces In a message dated 3/26/2003, rigracx~xxsympatico.ca writes: >Brian: Could be a language thing but photo shown in your link is what I call >" Follower Rest ". Have only ever used this when cutting long thread, but >it would seem that author is shown to be doing straight turning with it. >Guess I am learning something new. one other point abt. travelling stdy worth mentioning ..........tends to negate bed wear in front of chuck, due to stdy bending down the rod so that tool tendes to stay at center of rod as carriage drops down & subsequently rides up, thereby giving a truer cut to a well used lathe !!!!!!! best wishes docn8as ------------------------------- Date: Thu, 27 Mar 2003 00:22:41 EST From: n8as1x~xxaol.com Subject: Re: Large pieces [FACEPLATE USED AS DOG DRIVER] In a message dated 3/26/2003, brianx~xxsquibb.org.uk writes: > Only thing is that [FACEPLATE] is plain expect the 3 mounting holes, so it > is a bit limited. However I do have access to a large Bridgeport > so I could mill some slots. Is it best to make them radial or circular? for a dog driver , one radial slot from periferee inwards ( stopping short of short of spigot ,of course ) will suffice ...for a faceplate try 4 radial slots ( or 3 enclosed radials & one thru the periferee)..OR series of thrded holes for screws to anchor clamps is an alternative ....depending on ur clamps anything from 1/4 in to 1/2 in ( or just put them in as needed) ...many modelers use an aluminum sacrificial plate bolted to the b/plate & simply drill /tap per project . best wishes docn8as ------------------------------ Date: Thu, 27 Mar 2003 19:14:00 -0000 From: "Bryan Hassing" Subject: Direction of feed during facing? Hi: I have read in Joe Martin and Doug Briney's books that feed during facing operations should be from the center of the piece toward the outer edge. I have done facing by feeding the lathe tool from the edge toward the center with seemingly equal results. What would make one direction of feed more preferable than the other? Thanks. ------------------------------- Date: Sat, 5 Apr 2003 14:40:05 -0800 From: "Patrick Lee Rooney" Subject: RE: Flood cooling on a lathe From: Damon [mailto:dgentilex~xxspf.fairchildsemi.com] Sent: Saturday, April 05, 2003 2:20 PM To: atlas_craftsmanx~xxyahoogroups.com Subject: [atlas_craftsman] Flood cooling on a lathe >>> Never having done flood before, but building a new bench and wanted to at least have it ready if the day comes. Is flood something that will generate a complete and total mess? Flood the part and my shop, too? Or can it just run neatly down? I assume some RPM limits, too. Anyone with advice or general thoughts? Thanks, Damon <<< Hey Damon..it depends on lots of things. My CNC machining center was built with flooding in mind, so it stays and goes where it should. I retrofitted my 11" Rockwell with a mist setup first, but that mist made me cough for days afterwards. Can't be a good thing. I replaced it with a flood setup, and it gets EVERYWHERE. Don't much use it because of that. Sort of reduced the macching process for me, as I always worried about fluid getting on stuff it shouldn't. I drive myself (and others!) crazy trying to keep the machines clean, so maybe it isn't an issue with others. Never thought about putting one on my Atlas! It is nice to have when necessary though. Regards, Pat -------------------------- Date: Sat, 05 Apr 2003 17:51:58 -0500 From: Damon Gentile Subject: Re: Flood cooling on a lathe Gets everywhere from coming out of the nozzle or flung off the workpiece? Not worried about keeping the lathe clean (meticulous after the chips settle) just trying to not 'pinstripe' everything within sight. -Damon -------------------------- Date: Sat, 5 Apr 2003 18:30:38 -0500 From: "mertbaker" Subject: Re: Flood cooling on a lathe It won't be pinstripes: more like racing stripes, & lots of 'em. Mert MertBakerx~xxprodigy.net -------------------------- Date: Sat, 5 Apr 2003 15:14:27 -0800 From: "Patrick Lee Rooney" Subject: RE: Flood cooling on a lathe Can't really put a lathe through it's paces without getting it loaded up with swarth, oil and coolant. That doesn't bother me either. The coolant really splatters when it hits the cutting tool. Once it is picked up by the chuck, it produces quite a radial pattern. After an hour of work, my arms are wet, it has puddled on the floor and is burning off the overhead lighting. The CNC has a cover that closes down over the business end, and almost all of the coolant is recovered. Pat. ------------------------- Date: Sat, 5 Apr 2003 19:25:59 -0600 From: "Ronald R Brandenburg" Subject: Re: Flood cooling on a lathe In my experience, flood cooling is best left to NC and CNC machines that are enclosed otherwise it's a mess at all but the lowest speeds. Ron... ------------------------- Date: Sun, 06 Apr 2003 01:07:44 -0600 From: Jon Elson Subject: Re: Flood cooling on a lathe I've seen them run flood while parting off 3" aluminum bar stock on a big lathe at work. The spindle RPM was slow, and the coolant ran straight down through the bed ways - no mess at all. But, it would make a big mess at 1000 RPM! Jon ------------------------- Date: Wed, 7 May 2003 08:41:56 -1000 (HST) From: Tom Benedict Subject: Re: turning parabola for Bell Nozzles On Wed, 7 May 2003, Gissing, Robert wrote: > I am involved with a group who are trying to build a rocket engine, not > too big or complicated, and I was asked to try and build a model of what > the engine would look like. I was hoping to turn a Bell nozzle out of > aluminum for the nozzle. I have a Taig lathe, and was wondering if > anyone on the list would have any ideas on how to turn a parabolic > profile by hand. Here's how I've cut arbitrary, but tight-tolerance, mathematical curves by hand. (I got a copy of The Machinist's Bedside Reader a couple of years after I did this, so it was kinda neat to see I'd hit on the same idea Guy Lautard wrote about. He's got pictures in his book, so if the rest of this makes no sense, consider grabbing a copy. It's a darned good read.) Calculate the curve so that you can come up with a set of position vs. diameter coordinates. I was doing curves that had positive and negative slopes, so I had to do this using two tools. But if you're doing a parabolic curve, you can do this next part with a single tool. Use a tool that'll cut on the appropriate side. For the inside of the nozzle, that'll be a normal boring bar. For the outside, it'll be a tool that cuts toward the tailstock (assuming you're doing this in a single setup.) Very carefully locate the tip of your tool. For the outside, I'd take a light cut and measure the diameter of the part. For the inside, it's similar. Take a light boring cut and measure the diameter. Ideally do this using a telescoping gauge or a plug gauge. Now carefully make a series of cuts so that you bring the tip of the cutter to each of the coordinates you plotted. This will produce what looks like a stepped paraboloid. If you kept your step size small in your coordinate list, it'll be pretty close to shape. If you used a larger step size, you've got more work ahead of you. Here's where it gets fun... Blue the whole thing using Dykem or some other marking dye (I used a magic marker). Then get out a hand file and take very very light cuts as the lathe is spinning. The idea is to file down the high points until the dye just disappears. You know the bottoms of the grooves follow the curve you want because you put the tip of the tool at the right coordinates at each step, so right when you file the tops all the way to the bottoms, you're done. This is tougher on the inside of the nozzle. This is why I wound up making straight-walled de Laval nozzles instead of bell nozzles. But you could probably do something similar using some emery paper glued to a stick with a nice curve on it. The ones I was making were never over 1/4" in diameter on the inside, so this wasn't a viable option for me. All of this is a little hard to describe without pictures. Sorry about that. I hope some of that made sense. Guy Lautard did a really good job of describing this. He was writing about making ball handles, but the same technique can be applied to lots of stuff. If you're doing liquid fueled rockets, my guess is your nozzle throat will erode, so you'll need to make a lot of these. The ones I was making weren't subject to much wear, so there was never really the need for me to do this next part. But if you need to make a bunch of them, and the thought of using an emery stick on the inside of a bunch of nozzles doesn't appeal to you, give this a try: Instead of boring each nozzle by hand, you can use a form tool to cut the bell and throat in one go. To make the form tool, chuck up a length of drill rod slightly larger than the inside diameter of your bell nozzle. Using the same trick that you used on the outside of the nozzle, form an inside-out image of the inside of your nozzle on the drill rod. Polish it until it's completely smooth and shiny. Using a mill, cut flutes into the form tool. (With a shape like this it's probably easier said than done. Remember, I haven't tried this.) File the backs of the cutting edges until there's just about 0.020" of land behind each one. This is to provide chip clearance. Harden and temper the drill rod, and stone each of the cutting edges until they're razor sharp. To use it, drill and ream the nozzle blank for the throat diameter. Chuck up the form tool in the tailstock like a countersink. Very carefully feed it in to the work until it has cut to full depth. You should now have a bell shaped cavity with the right throat aperture and exit aperture. The same kind of tool can be used on the other side to make the converging part of the nozzle. > Once I figure out how to turn these, I want to make some out of copper > to try them in static engine firing tests. Yeah, I know why you're using copper, but it's a lousy gummy material to machine. If you have the choice between pure copper and a beryllium copper, choose the latter. But be careful. The swarf is toxic. Tom ------------------------ Date: Tue, 20 May 2003 06:47:18 -0500 From: "Paul Siegert" Subject: RE: Burning up lathe centers! Any time you put a dead center into a piece of stock you should use the appropriate grease in the 60 degree center hole you have drilled. The pressure should be tight enough to hold it on center, but not "gritted down" tight. Best recommendation is to buy a live center for the tail stock if you can afford one. If you are doing accuracy work, look for a live center that has .0002 or better concentricity. Bison from Poland makes a good live center that are much lower cost than say Royal, which are excellent, but expensive. PITS tools online (ebay) sells MT2 live centers that are advertised at .0002, but I don't know what the going price is on Ebay or what they sell them for directly through their Ebay store. I suspect they are from China, but the ones shown on-line look like they are well made and ground with triple bearings. I have bought Chinese tools from PITS in the past with good success. Paul -------------------------- Date: Tue, 20 May 2003 08:23:03 EDT From: JMartin957x~xxaol.com Subject: Re: Burning up lathe centers! In a message dated 5/19/03, Ron_SSSSx~xxswbell.net writes: > Allan, > I don't understand how you are burning a dead center unless you are > maybe using it in the tailstock? NEVER use a dead center in the tailstock! > Ron... Have no idea what this means, unless you are suggesting that using a plain center in the headstock in the tailstock is wrong. It isn't. I think there may be some confusion of terms, which is understandable. English is a live language, and in common usage the terms "live center" and "dead center" have changed somewhat. The traditional definitions are as follow: Centers may be plain (solid steel soft or hardened, solid steel with a tip of a special hardened steel, solid steel with a carbide tip) or with bearings (ball, needle, roller). The "live" and "dead" designations are based solely on whether they are driven or stationary. The headstock center, which turns with the spindle, is a live center. If that same center is put into the tailstock it becomes a dead center, because it does not revolve under power. It gets confusing because in today's usage, a ball-bearing center is sometimes referred to as a "live center", and a plain center as a "dead center" regardless of where it is used. Plain centers are designed so that they may be trued up in the lathe. Extreme accuracy, in fact, requires that the headstock center be trued not only in the lathe in which it will be used, but also in the same position in the spindle in which it will be used. A soft steel center may be trued up with a regular steel or carbide cutting bit. A hardened steel center might be trued with a carbide bit, but the harder centers are more usually trued with a toolpost grinder. Soft steel plain centers are perfectly adequate in the headstock as the work revolves with them, but would wear quickly in the tailstock. Try finding one, though. Almost all of the plain centers sold today have hardened steel or carbide tips. These are suitable for either headstock or tailstock use. In the tailstock they should of course be lubricated. I use the traditional white lead and oil. It is necessary to keep a close eye on the tailstock center, because as the workpiece heats up it may expand enough to bind things up. John Martin ------------------------------ Date: Tue, 20 May 2003 08:36:24 -0700 From: "James L. Hainline" Subject: Re: Digest Number 1477 Allen, Make sure you have a hardened center in the tailstock. Although I was taught to use white lead or red lead for center lubrication in HS machine shop circa 1950's, I now use moly grease or straight STP to lube the centers. Don't forget that the work piece lengthens as it heats up so you have to check the tailstock stting from time to time as you work. Jim ---------------------------- Date: Mon, 26 May 2003 23:23:11 +0200 From: "Isak Levinson" Subject: Straight shaft Hi All, I'd like to machine a straight shaft on a lathe, about 2.5' long and 3/16 wide. This shaft is for a RC helicopter tail rotor. The material is some kind of steel (I don't know exactly what steel). I start with a 5/16' blank.First I drill a center hole on one side, with the minimum material is extending from the chuck. Next I hold the blank with the chuck and a dead center. Before the dead center is in contact with the blank it is clear that the center hole is not exactly straight with the dead center. When the center holds the blank I machine the part to the desired diameter. When the center is released the part returns to its natural form, which is bent. No matter what I did I couldn't machine a straight shaft. Is this the right way to machine a shaft ? Thanks, Isak. ----------------------------- Date: Tue, 27 May 2003 00:51:21 -0000 From: "Charles Hixon" Subject: Re: Straight shaft Isak, I'm not an expert, but from what you describe, I would prefer to replace the dead center with a live center and possibly indicate in with a four-jaw chuck instead of using a three-jaw chuck. If I needed a shaft of those dimensions, I'd take a long, hard look at what's available at the hardware store in that diameter that I could saw up. Charles ---------------------------- Date: Tue, 27 May 2003 06:17:54 +0200 From: "Isak Levinson" Subject: Re: Re: Straight shaft Thanks for the reply. I did indicate it. there is no runout near the chuck, and near the center. I think that the problem is that there is a force applied to the rod by the center. While the center engaged there is no major runout. When the center is removed, the part returns to its natural (relaxed) position, which is bent. --------------------------------- Date: Tue, 27 May 2003 01:51:18 EDT From: catboat15x~xxaol.com Subject: Re: Re: Straight shaft > I'd take a long, hard look at what's available at the hardware store in > that diameter that I could saw up. For good straight shafting order out some drill rod (in the US) or silver steel (in the UK). It is usually dead on to size and straightness. A common material for making various pins, shafts, rods and of course the raw material for drills, reamers etc. Besides using drill rod, (my original suggestion) some steels especially cold rolled shafting and flats has built in stresses. When you cut away part of the surface the stresses will relieve themselfs and warp, twist, bend the steel. Hot rolled generally does not do this, but is not very pretty in the raw state. If you are determined to use the steel you have been using you can try to fix it by heating to a red heat and cool under sand, ashes or some material that will allow it to cool slowly. This should relieve any built in stress and strain. John in the high desert of California 12 inch Atlas Mini Mill ---------------------------------- Date: Tue, 27 May 2003 10:45:00 -0000 From: "colin_jet" Subject: Re: Straight shaft > Next I hold the blank with the chuck and a dead center. > Before the dead center is in contact with the blank it is clear that the > center hole is not exactly straight with the dead center. When the center > holds the blank I machine the part to the desired diameter. When the > center is released the part returns to its natural form, which is bent. Isak Sounds as if the headstock and/or tailstock are not aligned or your lathe chuck isn't square to the axis of rotation. If you do as you described, and the point of the dead center (live would be much better) doesn't line up EXACTLY with the centre-drilled hole, then you've no hope of machining a parallel shaft. I suggest you go back to first principles and try lining things up with the usual test cuts on a thickish rod of aluminium, using a vernier or micrometer to check for the same diameter at both ends. Then do the same using the center. As it's a Sherline, the headstock probably needs hammering (sorry - tapping lightly to one side :-) Colin -------------------------------- Date: Tue, 27 May 2003 07:03:26 -0700 From: Keith Green Subject: Re: Straight shaft You've opened up a can of worms here. The first question I have is; Why not use 3/16 stock in the first place? That question aside, you need to find a book with a good section on shaft-turning in it. The explanation of the proper way to do it can get quite involved. If you're shaft has ony one bend, it's not so bad. The problem you're having is caused by the natural bend in your stock. Probably can't unbend it either, as it will tend to return under a cut. What you need to do is center the end with the job in a steady-rest. While in the steady, turn a short section past the end for about an inch. Move the carriage close to the chuck and machine another section there. Now you have a centered end and two portions of shaft running concentric with that center. Turn the job around and, with the steady running on the short turned section that was next to the chuck, center the other end. With the job between two centers, the short turned sections should now read zero. The rest of the shaft should run out no more than the amount you need to remove to clean it up to the size you want. I should note here that, when you center something like this, your procedure should be center-drill, followed by a sharp-pointed re-centering tool in the tool-holder. Turn your compound to 30 deqrees and make sure the tool is as close to center-height as possible. Crank the compound in to cut a dead-true center. As I said, find a book. Or a piece of 3/16 stock. Good luck. keith --------------------------------------- Date: Tue, 27 May 2003 08:12:11 -0700 (PDT) From: BRADFORD CHAUCER Subject: Re: straight shaft You are not going to be able to do so on a shaft that long and thin without additional support. You will need both a steady and follower rest to keep the shaft from bending. That said, why are you doing this at all?? I's start with 3/16 drill rod which is available in 3/16 from places like Grainger or McMaster Carr. Then If you need end holes or end machining, I'd hold it in a 3/16 collet and end or center drill, or machine off the saw cut area. I see no good reason for starting with 5/16 stock. Also for this application, why use steel at all?? There is minimal torque on the shaft. I'd consider aluminum or even some non-metalic composit to save on weight. --------------------------------------------------- Date: Tue, 27 May 2003 23:02:41 -0000 From: "colin_jet" Subject: Re: Straight shaft -- parallel vs. bent --- In sherlinex~xxyahoogroups.com, "jeastwoodlm" wrote: > Colin_jet, what you say is quite true if the problem is to make sure > there is no taper in the machined shaft. I think the problem to solve > here first is the bend; once he can machine a straight shaft, he can > look for taper and apply your suggestions for aligning the head and > tail stocks. >>From reading Isak's description of the problem, it didn't sound to me as if bending was the issue, other than a bend introduced into the part from misalignment of the headstock/chuck/tailstock centre. << He did say that the hole that he'd drilled right up against the chuck jaws didn't line up with the dead centre, so something is clearly not in line. Isn't it??? I've had exactly this problem with my big lathe, so suggested the fix I found necessary. Be interesting to know the outcome. I make model heli parts on my lathe as well, and I'd have gone for a piece of silver steel of the correct diameter to start with as suggested by others. That's exactly what I did for a couple of mainshafts I made. Colin ------------------------------------ Date: Wed, 28 May 2003 00:46:11 -0000 From: "Gary Drake" Subject: Re: Straight shaft Isak, If your center drilled hole is in the exact center of the piece you are turning you should be able to turn your piece down to 3/16" without bending by turning back about 1/4" of the length at a time. Confused? Allow me to clarify. After center drilling (being sure all is in alignment) and when center drilling it is often helpful to do your drilling with your part pushed into the chuck so just a bit sticks out from the chuck. This will keep the part from wobbling. Then pull out of chuck the desired length and snug the center, just enough to keep the part in place. Your shaft is now ready to turn. You are relying the 5/16" shaft to bear the weight of the turning forces but once you remove the material there isn't any material left for support. So sneak up on your target diameter but only turn back about 1/4". Dial back your screw and then cut back another 1/4" and so forth until you have your desired length. With this practice the small dia. will be more closely supported by the larger dia. Hope this works, Duck ------------------------------ Date: Tue, 27 May 2003 14:42:49 -0500 From: "Rodent" Subject: Re: OT: eureka for dummies... ----- Original Message ----- > This is most likely for old hats for ... for ... old hats, but... > Needed to machine the end of a 8x32 bolt so it would go inside the end > of a spring.Well, chucking the bolt head produced a very wobbly bolt. > Tried to figure out how to "dial" in the bolt, when I looked > at the drill chuck in the tail stock. > Took the screw and loosely chucked it tail stock. Then moved the tail > stock over so the head of the bolt entered the headstock chuck. > Tightened the headstock chuck and withdrew the tail stock. Bingo, the > screw ran true! Your method is similar to how I center my boring bar / tool rest drill chuck holder. I chuck the boring bar in the lathe chuck and adjust height / angle of the tool holder and the position of the carriage until the boring bar slides into the holder. As far as small fasteners, I deal with stuff like this all the time, although 8-32 is a bit large. Most of my stuff is either 4-40 or 6-32. Anyhow, there are several ways to deal with this, some more involved than others. As you found out, bolt heads are hard to get a good bite on and may or may not be concentric with the threads. Ideally you want to chuck on the threads, which can be done directly if the bolt is long enough and the head will clear the back of the jaws. The only problem is the bolt will want to screw itself in if you get too aggressive taking a cut. Plan B is to find a nut with the same size hex as the bolt (assuming its a hex head bolt) and run it down on the bolt a ways. The chuck jaws should clamp on both the bolt head and the nut. Option 3 is to drill / tap a round piece to screw the bolt into, then fit it in chuck. The bolt will most likely unscrew itself when you take a cut, so you need some way to hold it in place. A locknut or a spacer in the back of the chuck works well. ------------------------- Date: Wed, 28 May 2003 00:50:43 -0500 From: Jon Elson Subject: Re: OT: eureka for dummies... For modifying screws, I have made a set of female-threaded mandrels. Just pieces of round stock with threaded holes in them. To turn a screw, screw it into the mandrel, with a nut that can be used to lock the screw at the required depth. To turn female-threaded parts, I also have mandrels with male threads. Again, a nut can be used to lock the part at the right point. Jon --------------------------- Date: Tue, 17 Jun 2003 17:05:14 EDT From: JMartin957x~xxaol.com Subject: Re: Turning a HEI distributor shaft > The current problem I have is the very end of the distributor > shaft needs to be turned down. But the distributor will not fit > through the spindle (too short) and neither end of the dist. shaft > is center drilled. Even worse, the end of the shaft that needs to > be turned is not anywhere near round. So how do I turn something > that cannot be centered or held in the chuck? Steady rest is the way to go, but you need something round to run in the rest. If there is nothing nearby on the shaft that will do, you might make up a cathead. Nothing more than a piece of smooth pipe or hollow bar, with sets of 3 or 4 setscrews at each end. The cathead runs in the steady rest, and the screws allow you to get the shaft running the way you want it. John Martin ------------------------- Date: Thu, 19 Jun 2003 10:17:23 EDT From: catboat15x~xxaol.com Subject: Re: Digest Number 1517 [Re: Turning a HEI distributor shaft] Atlas used to have a Jacobs chuck with bronze jaws that was used to support starter and generator shafts when truing commutators. Lacking that, how about putting a piece of bronze in your three jaw and drilling, boring, reaming a hole to fit the shaft you want to hold. Oil it good and go ahead. John in the high desert of California 12 inch Atlas Mini Mill Rusty file -------------------------- Date: Thu, 19 Jun 2003 15:28:28 +0100 From: Brian Squibb Subject: Re: Digest Number 1517 >putting a piece of bronze in your three jaw and drilling, boring, reaming a >hole to fit the shaft you want to hold. Oil it good and go ahead. I have done something similar for facing off bolts. Rather than get collets (expensive) or use standard chuck to grip the bolts (5mm - 10mm) I turned and drilled out a piece of soft aluminum for each size bolt; and made a thin slit down one side. Slide the bolt in, grip in the chuck and voila -- a perfect bolt holder. Brian ------------------------- Date: Wed, 25 Jun 2003 10:15:54 -0500 (CDT) From: dswrx~xxwebtv.net Subject: The final cut... I'm bringing a piece of drill rod down to 0.3745" for a drill chuck arbor. And the old bug-a-boo has got me in a dilemma! When I get down to the final few cuts, I have seen my 0.001" oversize vanish to a 0.001" (or more) undersized, no matter how hard I try. I have resorted to sanding sheets to overcome this, but I know there has got to be a better way! Can anybody divulge their secret solution to this problem? Leo (pearland, tx) Oh Yea, trying to get the tail stock center "spot on" is a B#$^& too! 8-) --------------------------- Date: Wed, 25 Jun 2003 13:43:09 -0400 From: HUNLEY31x~xxaol.com Subject: Re: The final cut... Leo, Is the work hot when you take the final cut and cool when you measure it? Larry --------------------------- Date: Wed, 25 Jun 2003 12:58:29 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: The final cut... Yes Larry, I have done that, but found out about that trap a while ago. 8-) I think one of my problems is having my compound gib real tight, and making it hard to increase the feed a micro amount. But, I just came in from the shop and am celebrating! I carefully made several very fine shaving cuts and got the thing exactly right. (but maybe not for the 0.00000000 crowd! 8-) ) Gonna find the Scotch and... Leo (pearland, tx) BTW: measured the same on both ends... 2" apart, using a 0.001" increment mike. ------------------------------ Date: Wed, 25 Jun 2003 13:19:00 -0400 From: Stan Stocker Subject: Re: The final cut... Hi Leo, Do a few passes without advancing the cutter at all. This will usually take off around a thou. Are you letting the work cool to room temp before doing the final measure and cutting pass? A 3/8 piece of drill rod warm will measure a thou or more oversize. More than once a piece has been cut "dead on" and found to be undersized 20 minutes later. Cheers, Stan ------------------------------- Date: Wed, 25 Jun 2003 12:09:17 -0400 From: "mertbaker" Subject: Re: The final cut... Use a very sharp toolbit, hi speed, & slow feed. Drill rod is tough, and the toolbit will dig in if it's not ground just right, or if there's a lot of slop in the Xfeed. Set the toolbit angle so it tends to push out of the work to negate any slop. Mert MertBakerx~xxprodigy.net ------------------------------ Date: Wed, 25 Jun 2003 10:59:21 -0700 From: "Bob May" Subject: Re: The final cut... Stop when you are oversize and let the metal cool for a while. Go back and measure it again and it may now be the right size. Use a more scraping cut if necessary as the cut you probably did was with a more pointed tool and that means that you are measuring the peaks of the cut rather than the average or the valleys of the cut that you did. Sometimes just burnishing the surface will bring it down to undersize also. I might note that if you are doing a straight pin, you can always heatshrink the part on and the extra thou will probably be pressed back to the valleys of the cut. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------------------------------- Date: Wed, 25 Jun 2003 18:18:00 -0400 From: Charles Gallo Subject: Re: The final cut... Simple - You REALLY can't (or it's darned hard) to take a .001 cut - deflection, rubbing, etc will all mess with the results. Leave yourself a .005 - .010 final cut, and TAKE it Charlie -------------------------------- Date: Wed, 25 Jun 2003 21:08:20 EDT From: JMartin957x~xxaol.com Subject: Re: The final cut... Simple. Make your last two or three cuts all approximately the same depth (not diameter, but depth of cut). The problem is when you go from a large cut to a small one - the loading on the machine and the corresponding flex changes. Say you're .018 over. You could take a cut of .008, measure, then .001. The machine will act differently for these two cuts. Instead, take .005, measure, then .004. The .004 cut will put essentially the same forces on the machine and work that the .005 cut did. Same feed and speed as well. John Martin --------------------------- Date: Wed, 25 Jun 2003 21:25:16 EDT From: catboat15x~xxaol.com Subject: Re: Digest Number 1525 Leo: First the obvious, to reduce by .001 you need to feed .0005 or half a division on your dial. Secondly if your tool is not exactly on center the dials don't mean a thing. make a little sketch and you can see why. Thirdly I would make a second run when you get to the .001 over size and see if the tool still cuts some when making a second pass. (Our Craftsman and Atlas lathes are not the stiffest in the world). At times when making press fits and needed just a bit cut off the diameter I have used a file to put a slight taper on the end of the shaft to where the mating part will just go onto the shaft I set the tool to miss the taper when it is being fed and take a "smidgen" off the shaft. BTW you are taking the tool back a ways and coming up into the cut again to take out any backlash in your cross slide or compound. (A trick I read on here is to tighten the compound gibs right down and do all your fine cuts with the cross slide; when you tighten those gibs to where you can't move the compound, you eliminate a lot of measurment errors.) Last point, let the work cool to room temp before making your final measurements and adjustments. What are you using to measure the diameter,? slide calipers (even digital) are not as close as a mike. John in the high desert of California 12 inch Atlas Mini Mill Rusty file ----------------------------- Date: Wed, 25 Jun 2003 22:13:06 -0400 From: "Rigrac" Subject: Re: The final cut... When ever I am working on real fussy stuff where size is super critical I use a dial indicator on my cross slide to measure the exact amount I am feeding cross slide in. This way you are not doubting how much cross slide moved in . Ron In Burlington Ontario Canada ------------------------------ Date: Thu, 26 Jun 2003 00:29:58 EDT From: n8as1x~xxaol.com Subject: Re: The final cut... > Simple. Make your last two or three cuts all approximately the same depth > (not diameter, but depth of cut). The problem is when you go from a large > cut to a small one - the loading on the machine and the corresponding flex > changes. amen...& by using SHARP hi speed bits w/ plenty back & SIDE rake (& honed w/ india stone),it is possible to shave a half thou. in steel.... forget it w/ carbide .....FWIW ...standard practice years ago was to leave 2-3 thou depending on how rough the rough really was ( 2 is usually enuf ) , & finish to size w/ 8 in.second cut or smooth file & #120 /240 .....where both finish & truth were paramount , it went to the grinder......when working to tenths, w/out grinding , abrasives are required .....& yes w/ proper technique , one can finish w/file/abrasive, & not lose practical concentricity......can also ,improperly done, take the truth out !!!!. ( & filing left handed IS safer ,particularly w/ the old " knuckle buster" chucks )......the ready availability of carbide, plus inexpensive q/change has allowed many new operators to bypass learning to properly grind hi speed bits ,( in q/change holders , they MUst still have back & side rake for best results, either put in w/ chip breaker or notching the bit) , consequently with less than optimum results ,plus dependence on others.......xcept w/ hardened stock, i reserve carbide for roughing cuts on cast iron.... ( & sometimes finishing c.i.). best wishes docn8as ----------------------------- Date: Thu, 26 Jun 2003 05:40:26 -0000 From: "rpm2290028" Subject: Re: The final cut... Dear Leo, There's an old trick in the first Bedside Reader, where you swivel the topslide around say 6 degrees, and then use the topslide infeed and leave the main infeed well alone. This has the effect of advancing the tool a little bit along the work, but also infeeding a tiny amount. Depending on the angle that you set, one thou on the topslide feed will equal 0.0003 infeed of the tool. There's a little bit of trig to get this exact, but basically you can have a very fine infeed with the lathe you have. You can then creep in with,say, one 'tenth' nibbles, until you're much closer. Everything that has been said about cooling, sharp tools etc still count, but this gives you more control of your advance towards that magic dimension. Apparently, or so I've read, old-timers used to have their topslides 'permanently' set to about 6o degrees, because this gave them a direct reading off the topslide of tenths off the diameter. I haven't worked out the math( not my strong suite) but i'll take their word for it. Any 'old-timers care to comment? You'll also need a michrometer that measures to four decimal places, otherwise you will never know exactly where you are in the cut. Good luck! Richard in Los Angeles. ( The actual reference is the First Bedside Reader, pages 12-15, entitled 'How to put on a mighty fine cut'.) -------------------------------- Date: Thu, 26 Jun 2003 10:11:07 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: Re: The final cut... Good suggestion, Richard. If you have enough room to adjust the compound (top slide) at very acute angles, you can get some very precise movements. Assuming 90 degrees is a right angle to the bed, and 0 degrees is parallel to it... If you set your compound at 3.75 degrees, an advance of the compound of 0.001" will yield an advance of the tool of 0.00006". At 7.5 deg., .001 will yield 0.00013, 15, 0.00026, 30, 0.0005, 60, 0.0009, and so on. I have my compound slide adjusted, so that it takes quite an effort to get it to move in small increments... Makes for a more stable tool, but a bear to adjust! 8-) Leo (pearland, tx) ----------------------------- Date: Sat, 28 Jun 2003 04:13:07 -0000 From: "forbes_rl" Subject: How to get a good finish turning drill rod? I could use some advice on how to get a good finish when turning drill rod. I'm turning about 10" of .75" dia O1 drill rod. I'm using one of the cheap carbide-tipped tools from Enco (C5 grade). I'm turning a slight taper (about 1 degree) so I have the work mounted between centers. There is no problem cutting the metal; the tool seems to cut fine but... I'm having big problems with tool chatter which ruins the finish. I try to follow the "reduce speed, increase feed" rule; I'm taking a cut of .010 to .015, using a fairly low speed and driving the feed wheel fast enough to feel resistance. Still a lot of chatter! Any suggestions? Alan Marconett posted a while back that he was able to get a good finish on drill rod...Alan, are you there? Rob ------------------------------------------- Date: Fri, 27 Jun 2003 23:07:14 -0700 From: "Marcus and Eva" Subject: Re: How to get a good finish turning drill rod? Hi Rob: If your problem is chatter rather than a torn looking surface, you need to reduce the size of the radius on the end of the tool. Carbide likes high speeds, deep cuts, and fast feedrates...when you get them correct the surface finish is really bright and the chips come off blue from the heat. It's hard on a Sherline to push it that aggressively...I do better with high speed steel and Rapidtap, but it's impossible to get the same bright finish of a carbide tool that's been run correctly. You can, however, get a very smooth turned surface that's easy to polish to final finish. The secret is to keep the tip radius very small but very sharp and smooth. I grind all my tools with a dead sharp tip, and then dress the radius with a medium India stone. 5 swipes or so, with the stone gives me a tip radius of about 0.005" which is just about right. Sad to say, the cheapo carbide tools are usually not a really good bet on a small machine, especially if you don't have the means to regrind them. The tip radii are almost always too big, and the tools start to chatter. The chatter chips the cutting edges and then they don't cut. Hope this helps. Cheers Marcus ---------------------------------------- Date: Sat, 28 Jun 2003 08:22:30 -0700 From: "keith green" Subject: Re: How to get a good finish turning drill rod? Don't think the follower will work here as the piece will change diameter by too much (.174 or so) over the ten inches. The problem you're having is almost certainly flexing of the workpiece. Your speed should be somewhere between 1200 and 1500 but will be limited by the imbalance caused by the dog...using HSS tooling will reduce the speed requirement to between 425 (80 sfpm) and 530 (100 sfpm). Of course you can't run this speed with that length anyway; maybe 30% of that. Reducing the toolnose radius will help as well. As a last resort, use a steady-rest and move it along as you work. Cut the taper in steps so that the final cuts have varying depths of cut (caused by the residual steps), thus reducing the tendency for the harmonic to develop. Last, get yourself a lathe file and some emery. keith ------------------------------------- Date: Fri, 25 Jul 2003 07:16:36 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: setting tool height with lantern post? I use the "lantern" type tool post. Came with the lathe. To set the tool height, I took an old carpenters try-square. Put a center in the spindle, and slid the square across the ways, with the blade pressed against the center point. This put a nice line on the blade of the square. When I change tools, I put the square back on the ways and adjust the tip of the cutting tool to the mark on the blade. Makes good use for the square, 'cause the square wasn't square anyway! 8-) Leo (pearland, tx) -------------------------------- Date: Tue, 15 Jul 2003 10:03:25 +1200 From: "Richard T. Perry" Subject: Graver technique? The clock project continues. This weekend, I took the plunge - I tried turning pivots with gravers for the first time. I was using music wire in 1/8" as my "play around" stock - And frankly, it wasn't as bad as I thought it would be. I was using basically the techniques and materials specified in the WR Smith text that Sherline provides with the watchmaker's rest, and with the exception of taking some time to really figure out what "sharpened" and "dull" were, it was fairly routine. Now, I did make several booboos - I broke the tip off the sucker at one point (digging in) and I slipped one other time and scored the face of the collet (cr$p!). I do have one question for the collective - the technique Mr. Smith uses takes the edge of the "diamond" into contact with the metal (trying to keep the tip out the way.) Works great, if you're just turning down a shaft. How do I form a square shoulder that way, though? I eventually wound up using the tip area for that (in both a turning and a facing "mode") like I would use a HSS tool bit, and it seemed to work, but I was always within a hair's width of digging in and screwing it all up. Is there an easier way, or is it just a "feel thing" that I'll get happier with later? In general, I think I understand why watch/clockmakers use this method rather than the "machinist's" way with a crossslide and fixed bits - for small shafts, it's actually a lot faster with a graver, and there's not a lot of loss of accuracy. (I was aiming for .1875 long .050 diameter pivots on a .125 arbor - I was hitting that within .002 and straight to within .0005 within an day of practice - call it 6 or 7 attempts.) Most of my time was taken up with sharpening, but even that got easier as the day went on. (Plus, it helps to have multiple gravers ready to go during the job - far easier that way.) Next project - to build mandrels for cutting wheels on. Regards, Richard T. Perry perryrtx~xxhotmail.com -------------------------------------- Date: Tue, 15 Jul 2003 04:13:47 -0000 From: "Jim Knighton" Subject: Re: Graver technique? Richard, I'm not a clock or watch maker but I do quite a bit of turning using handheld gravers. I suppose you would call my work ornamental turning in metal. I've done turnings from steel, aluminum, and brass using gravers built to W.R. Smith's instructions. I am aware that 1/8" stock is probably normal in your world, but I've approached this technique from a more general purpose perspective. My turnings are most frequently from 3/4" or 1" round stock. The largest is about 2 1/2" in diameter. I've done quite a few freeform experimental shapes that I polish and give away to family members as knick-knacks. I've also with great success taught numerous teenagers, boys and girls alike, to do this kind of turning. It's become something of a "must do" activity when neices, nephews, etc. come for a visit, and I am frequently dragged into the shop by these enthusiastic young house guests for this very purpose. I also use the gravers in my own projects whenever I need a non-critical roundover or bevel. I can most often turn the shape faster by hand than it would take me to set up the appropriate radius jig or the compound. I've found old books and magazine articles suggesting that ornamental turnings in metal were done with handheld tools apparently right from the invention of the modern lathe in the late 18th century, and probably earlier. It has been an interesting journey of discovery to figure out what can be done with this kind of turning and just how easy it really is. The literature I've found suggests that in addition to the symetrical diamond gravers that W.R. Smith describes there were numerous other tool shapes in common use. I'm still trying to figure out which of these are useful in the small scale Sherline world. I'm also finding out that the diamond shaped gravers are remarkably adaptable. With that geometry I can turn in metal just about any shape I can visualize. In spite of the fact that I frequently use these hand-held tools I don't consider myself an expert, not by a long shot. I think of myself as more of an advanced novice still learning as I go. Please take my comments with a very large grain of salt. Ornamental shapes such as I turn are undoutedly easy on a CNC lathe. I've discovered for myself that they are easy on a manual lathe as well. I guess the bottom line is that turning these shapes is just plain easy. While I bow to the inevitable observation that hand-held techniques might not be optimal or even appropriate when critical tolerances are necessary, very little of what I do meets this criteria. I suspect that a good many other hobby machinsts are in the same camp, for what its worth. Perhaps the "experts" will take umbrage at this, but from my experience I've come to view the diamond shaped graver as a tool with four cutting edges that can be used with both a left and right handed orientation. I orient the graver to the work as seems "natural" for the shape I'm cutting at the moment, be it concave, convex, a flat, or a taper. I really can't explain how it happens, its something gained by trial and error, and experience. More often than not the graver rests on one of the bit's flats, not on the edge, with the tip pointing away from the direction of the cut. By positioning the tool rest far enough away from the workpiece so that the square portion of the bit is being supported just behind the diamond face, the graver's cutting edge can be oriented so that it is perpendicular to the workpiece. Used in that manner you will be able to obtain the shoulder you desire. If you have a steady hand and sharp gravers it is possible to go beyond perpendicular and cut a shallow undercut. I've done it many times without difficulty, albeit in larger stock. I read somewhere that if the graver cuts, its properly oriented. If it doesn't, its not. Using these words of wisdom I just started playing around and experimenting. No doubt you've already figured out that this kind of turning is done largely by feel and while some will espouse this technique or that, I really don't think there is a "right" way. It's all about what works. In the absence of a teacher or detailed instructions, I just experimented with different orientations until I discovered how to control the graver and get the shape I wanted. For what its worth, it didn't take long to figure out how to cut a shoulder. I suggest using a bit of aluminum or brass for practice pieces since they are so easy to shape and the graver orientations that work with the soft metals work equally well when I'm working with a hard steel. I hope this helps, Jim Knighton jimknightonx~xxworldnet.att.net ----------------------------------------- Date: Thu, 17 Jul 2003 06:09:46 -0000 From: "Jim Knighton" Subject: Re: Graver technique? Dave, as per your request, I've uploaded a writeup including photos describing how I use gravers and why. Its in the files section - look for "turning with hand-held gravers," or words to that effect. To make room for it I deleted my earlier document, "JBK's Lathe Modifications." That article is still available on the Sherline web site. For anyone who might be interested, go to the Sherline Workshop page and check out item 20. I'll be sending Craig a copy of this most recent writeup in case he wants to add it as an addendum to the earlier document. By the way, Dave, I like your power feed setup particularly on the mill. [NOTE TO FILE: SEE TEXT FILE "Sherline Mods General"] While I'm not pursuing mill upgrades right at the moment I'll be keeping your approach in mind and may want to discuss it with you down the road a bit, if you don't mind? I'm not an EE by any stretch, but I'm moderately comfortable with electrics/electronics as long as I have a resource to turn to. Regards, Jim --------------------------- Date: Tue, 19 Aug 2003 02:48:46 -0000 From: "mitchash17" Subject: Cutting Snap Ring Grooves When I do get my Sears 101.07301 going I have some axle shafts to make for my small dozer. The axles are 7/8" od by 8 3/4" long. I need to cut snap ring grooves and drill a grease hole through the center 3" deep and tap end for grease fitting. The grooves need to be .056" wide and turned down to .675" deep. What would be a good speed for this? What do I use for a cutter, can I make one or should I buy one? Any other tips? The steel is CRS, the book I have on making the axles say to harden the surface in the area of the bushings Rc 58Min. what does that mean and how do I do it? Also anyone have a good way of getting old brass bushings out of a tube (sprocket and track idler) there is no way to get behind them to drive them out. Thanks, Ash ------------------------------ Date: Mon, 18 Aug 2003 23:07:55 EDT From: cmiller231x~xxaol.com Subject: Re: Cutting Snap Ring Grooves Ash you will have to carbarize and harden the crs . you should be able to fill the hole with grease and put a shaft in that fits tightly to id of bush, this will hyd the bush out chris -------------------------- Date: Tue, 19 Aug 2003 02:14:23 EDT From: n8as1x~xxaol.com Subject: Re: Cutting Snap Ring Grooves > of getting old brass bushings out of a tube (sprocket and track hydraulic ...turn up a close sliding fit to tube ,fill w/ h2o , & drive it out by tapping plunger in , ....may have to use grease if fit is loose.....#2 tap the bushing , thread a bolt in & use a slide hammer ...or drive the tube off ,holding bolt in vise > axles say to harden the surface in the area of the bushings Rc 58Min. > >what does that mean and how do I do it? u will have to case harden w/ " Kasenit" or similar carbon powder ,heating to cherry red & dipping in powder , reheating to cherry red & quenching in brine will be abt rockwell 62/63.....polish & reheat to dark straw(?) ( dont see why 63 is not perfectly acceptable (better).....purple & blue is spring temper & softer than 58 best wishes docn8as ------------------------- Date: Tue, 19 Aug 2003 11:36:04 -0700 From: "Bob May" Subject: Re: Cutting Snap Ring Grooves Blind holes have an easy job of it by making a piston to go into the bearing and packing grease into the hole and hammering the bearing out by hydraulic pressure acting on the back of the bearing surface. Trick from removing pilot bushings in crankshafts for autos. Then there is also the pilot bushing pullers which are three arms with a little ledge at the end that get behind the bearing and pull it out. Lastly, there is always the peel it out crowd that will take a chisel and gradually chisel down the bushing, peeling one side of the cut into the hole and thus relieving the stress that is holding the bushing in place. Bob May http://nav.to/bobmay bobmayx~xxnethere.com NEW! http://bobmay.astronomy.net ----------------------------- Date: Wed, 20 Aug 2003 23:34:18 EDT From: catboat15x~xxaol.com Subject: Re: Digest Number 1595 > What do I use for a cutter, can I make one or should I buy one? You can grind your own cutter from a HSS tool bit. I have even made a tool from a short section of hacksaw blade to cut a really narrow groove. That takes some fiddling with shims and blocks to hold the blade vertical and allow it to cut, but it does work for snap ring grooves which are much more narrow than normal cut off tools. ------------------------- Date: Tue, 26 Aug 2003 10:29:16 -0400 From: Jim Ash Subject: Re: Lathe dog question >Why is it referenced in most books to use a lathe dog when straight >turning between centers. I have always just used the chuck and a live >center. Have I been doing it wrong all these years? What is this >novice missing here hehheh? If your chuck isn't on center with your live center, either the work will flex, or it will move under the chuck jaws, or both. Working between centers, you're supporting the work positively between two points, and the dog floats in the faceplate slot. A quick experiment: Put a center-drilled scrap in your chuck, without using the live center on the other end. Now slide the tailstock and center up to the piece. If they don't line up, ask yourself where that offset goes once you cinch up the live center in the hole. I ran into this when I first got my lathe. The work would slip in the chuck and walk toward the headstock, then loosen up on the live center side so badly I couldn't get a straight cut. Very frustrating. I still do it sometimes, but now I have a well-used button of scrap sheet brass that I shove underneath the chuck jaws against the spindle. I sandwich the button so the work bottoms-out against it by moving the tailstock in, then I tighten the chuck. Jim Ash --------------------------- Date: Tue, 26 Aug 2003 12:19:25 -0400 From: "Ron Ginger" Subject: Re: Lathe dog question A chuck will not hold a part truely on center. Using a chuck for a long straight part will make a long tapered part with a taper determined by the eccentricity of the chuck. If you want really accurate work, that can be removed from the lathe and returned you must use centers. If you needed to do something like work on both ends of the part and reversed one in end the chuck the part would be non-concentric. If you are making a part complete in one operation and the tailstock center is just being used to provide some extra support for a long part it might be OK to use a chuck. ron ginger ----------------------------- Date: Tue, 26 Aug 2003 17:50:00 -0700 From: "keith green" Subject: Re: Lathe dog question I often have to turn between centers at work. All the machines have chucks on them all the time and we don't usually remove tham for center work. Just take a short piece of steel, turn a hub and shoulder on one end. turn it around and grab it on the hub, shoulder against the jaws. Turn a 60 deg. point on the other end and you'll have a dummy-center that will turn true as long as you leave it in the chuck. Set up the dog so one of the jaws drives it. When I have to do both ends, I accurately center and re-center both ends (using a steady) and, if the chuck doesn't hold true, put in soft-jaws and bore them using a spider to put pressure on the jaws. keith Vancouver, BC ----------------------------- Date: Thu, 28 Aug 2003 10:46:41 +1200 From: "Richard T. Perry" Subject: Lathe Centering Buttons Since there's been much talk recently about lathe centering, I thought I would add in a product review, of sorts. Brownell's sells a pair of "Lathe Centering Buttons" for about $28 - I got a set last weekend. They're really kinda handy for setting the headstock and tailstock true to each other. Essentially, they're two small disks, .900 in diameter,with precision ground faces and 60 deg female centers in the back. Set up is simple - put centers in both head and tailstock, then hold the buttons with the faces touching against the headstock center, then bring the tailstock up to touch (don't "star torque" them, just use enough pressure to seat them.) Now just measure with a micrometer. If the tail and headstock centers aren't right on, the measurement will be more than 0.900 - and adjust as needed (like you would a 4-jaw chuck). (I should mention that I use the adjustable live center in the tailstock). Limitations of this system - 1) I could see that errors could cancel each other out : say the headstock is 0.1 deg rotated away from the operator, but the tailstock has the same problem - theoretically, I think you'd see a match at the buttons (the buttons wouldn't be seating quite right in the centers, but there's really no way to see that unless it's grossly out.) So, I would say the first thing to do is run out the spindle to the lathe bed, to ensure the headstock is square and true. 2) It's a little physically tricky to get the micrometer in and out of the area with the crosslide underneath, but that's nothing unusual for the Sherline. 3) Since you're just getting a measurement, rather than a deflection (a la dial indicators) it's impossible to tell if the tailstock is (say) left or right of the headstock, but just that the "left-right alignment" is off by .003. So, it takes at least two tries on each axis minimum (make a small tap in one direction, then remeasure - did it go up, or down?) I think it would also be easy to chase your tail doing this (you could oscillate back and forth on either side of the ideal center point until it was time to start drinking heavily.) The above all being noted, I got my alignment within 0.0015 in about 10 minutes, then went on to other things. Since I was turning between centers on a non-critical part, I figured that was plenty close enough. Bottom line - they're worth the money, I think. Worth having in the tool box. If anyone wants a part number, email me off line - I'll dig it up. As always, no connection to Brownell's, etc, etc. Regards, Richard T. Perry perryrtx~xxhotmail.com --------------------------- Date: Tue, 02 Sep 2003 20:08:05 -0000 From: "Joe Shaughnessy" Subject: Newbie question Hi to the group, Please excuse what might be a very basic question. My first project on my Craftsman 101.07301 is to cut a new tailstock center. (The current center is pretty nasty.) Am using Lindsay reprints of South Bend books for instructions and simple projects to teach myself this craft. In the instructions to face the ends of the stock on centers, there is a footnote: "A relieved center would simplify the facing operation." I can't find any other reference to a "relieved" center, so I thought I'd get a definition from your collective knowledge. Thanks so much for your help, Joe P.S. I found instructions in another book to face the ends using the 3-jaw chuck, so I did that before turning the piece on centers. :-) ----------------------- Date: Tue, 02 Sep 2003 16:35:52 -0400 From: HUNLEY31x~xxaol.com Subject: Re: Newbie question Joe, You didn't state how much experence you have had, so I hope I'm not out of line with this suggestion. BUY a new dead center to start with. You're going to have your hands full just learning how to grind cutters, figure RPM's and feed rates to start. Dead centers are very inexpensive and cutting tapers and achiving a good enough finish to use may be a bit frustrating for a first job. Is for me anyway. "relieved" center no idea other than drilled, but I'm a newbe too. Larry ------------------------ Date: Tue, 02 Sep 2003 16:54:27 -0500 From: xlch58x~xxswbell.net Subject: Re: Newbie question The business end of a relieved center is cut away on the center line (i.e. cut in half along the axis). It works for facing cuts, since it doesn't carry a lot of load, but not very well for cuts on the circumference since the center becomes a reamer with much side pressure. Charles ----------------------- Date: Tue, 02 Sep 2003 18:13:04 -0400 From: Stan Stocker Subject: Re: Newbie question Hi Joe, A relieved center is one with 50 percent of the tip ground away. This allows the cutter to access the center drilled face. It isn't the center hole in the work, but the center mounted in the tailstock ram that is "relieved". A protected center on the other hand is a center hole in the workpiece that is places in a relieved area on the end. Commonly used where you want the center hole to remain in good condition for subsequent remounting of the work at some later date. A common place to see these is on the cylindrical squares or other precision tooling that may require maintainance grinding after a few years work. Now for a gentle discouragement: MT2 dead centers are quite inexpensive. Purchased centers from a good manufacturer (Bison or better) will be well ground, precise, and correctly hardened. You can also get carbide tipped dead centers for not much increase in price. Making centers is fiddly work. Making a headstock center isn't too bad, as the center doesn't have to be hardened. A tailstock center needs to be hardened, so you make the entire thing a tad oversized (a few thou), heat treat, then grind the MT taper. Mount the ground taper in a MT2 to MT3 sleeve in the headstock and grind the 60 degree working end. Skoda live centers are quite affordable in MT2 sizes, and do very nicely for 95 percent of the work in the small shop. Dead centers are really only required for critically accurate work, when you really are chasing much better than a thou. Why the instructions want you to face the work between centers in a mystery to me, I'd do it in a collet chuck, three jaw, or whatever chuck is handy. Drill the center hole after facing so you can use tailstock support while turning the MT taper. Turning between centers is the most precise means of work in many cases, but is nowhere near as prevelant as in older times. In the early 1900's a faceplate, or a drive plate and drive dog where often the only options. The widespead availability of three and four jaw chucks make turning between centers a special method reserved for the occasions when the hassle was justified by the requirements. If you need to make specialty centers, consider using a MT2 end mill holder. I use 1/2 inch and 3/8 inch ones with bits of drill rod installed that have been cut and hardened for the job on the rare occasions such stuff is required - which is quite rare. Final grinding is done with the EM holder in a MT2 - MT3 sleeve in the headstock with the hardened drill rod insert in place. Once the drill rod "point" is removed, it has to be reground in the headstock each time it is remounted for ultimate accuracy. Not required when being within half a thou or so is sufficient, but critical is chasing tenths. For certain tasks, you can also use bits of bronze or brass ron in an end mill holder. Turning armatures in one example, as most of us aren't lucky enough to have the brass jawed Jacobs chuck made for this task. Cheers, Stan --------------------- Date: Wed, 03 Sep 2003 06:10:07 -0000 From: "Joe Shaughnessy" Subject: Re: Newbie question Hi Stan, thanks so much for your answer. You and Charles provided great descriptions and it makes a lot of sense. Figured out the tailstock setover and turned the taper for MT1 between centers. (It measures damn close and fits the tailstock with no wiggle, or binding.) I will be ordering some extra parts as I can see that some things would definitely be considered comsumables. I learned a lot in this exercise. Think I'll have to stop by the local trade colleges and find some more current project examples. Most of the Lindsay books I've purchased are reprints of pre WWII articles. They're basic and simple, and that works for me right now. Thanks again for your wisdom, a lot of things just aren't covered in books. Laterdays, Joe -------------------- Date: Wed, 3 Sep 2003 06:53:37 -0400 From: "mertbaker" Subject: Re: Re: Newbie question If one has the TS set over for MTs, a smart operator will turn several, so as to have one handy when the TS is back where it belongs. This advice is gratuitous, as I did the setover only the one time I had to do it in shop class, and have used the compound to do this ever since, and many times. Mert MertBakerx~xxprodigy.net --------------------- Date: Wed, 03 Sep 2003 09:13:23 -0500 From: xlch58x~xxswbell.net Subject: Re: Re: Newbie question You can also put a witness mark on the tailstock base to make it easier to set up next time. I agree dead centers are easier to buy, but the skills employed to make one are worth the effort. After sixteen years in this hobby, tapers are still my most dreaded task. Dead centers are cheap to buy, but MT2 collets, tailstock die holders, pipe centers etc are not cheap, so dead centers are great practice. I think the ready availability of cheap tooling (relative) these days can complicate building basic skills in the shop. I think the Gingery guys are on to something. Charles -------------------------------- Date: Sun, 07 Sep 2003 16:05:18 -0000 From: "tresark" Subject: Machining Allthread I need to machine the ends of a length of allthread rod. I took a hacksaw and split a hexnut and threaded the split nut onto the rod. Chucked up the hexnut in the 3-jaw, tighted down pretty tight and tried to machine the threads off and turn down the diameter. Well the allthread just continued to screw into the nut until it was unreachable. I split the nut because I remember having seen it where someone was using that to turn down brass allthread. I'm using steel allthread, actually its a length of ACME screw. How can I hold the allthread to machine the ends without damaging the remaining threads? Two nuts? One in the chuck, one outside and jammed against the chucked one? Is this one of those questions that everyone but me knows the answer? Thanks, Doug ---------------------- Date: Sun, 7 Sep 2003 09:33:17 -0700 From: "keith green" Subject: Re: Machining Allthread You probably will need to either split the nut completely in thirds to hold it in the 3-jaw as the little chuck doesn't have the clamping force to collapse the nut. Sometimes you can get away with splitting the nut almost all the way through one one or two sides and all the way through on one side. I made a good one by tapping a piece of hex rod to the correct size, grooving it near one end for an o-ring (to hold it together), then split it in 3 pieces. Make the hex rod long enough to engage the full length of the chuck jaws. Good luck. keith ----------------------- Date: Sun, 7 Sep 2003 10:58:50 -0700 From: "Dave Hylands" Subject: RE: Machining Allthread Hi Doug, Here's some pictures of what I did: http://tinyurl.com/mjpj http://tinyurl.com/mjpl http://tinyurl.com/mjpn I found that after cutting the slit with the hacksaw, I squeezed the nut smaller (before putting it on the allthread) using a pair of vice-grips. After squeezing them, you could feel the extra resistance when trying to thread the nut on. It's this initial squeeze that the small Sherline chuck isn't really capable of delivering. After that I had no troubles with the allthread moving in or out. I used two nut to keep the allthread aligned on center with the spindle axis. A single nut would allow the allthread to deflect too easily. Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ----------------------- Date: Sun, 7 Sep 2003 15:00:39 -0400 From: "JERRY G" Subject: Re: Machining Allthread Doug, The counter nut idea will work.Or, you can take a piece of square nylon, drill and tap two adjacent sides for setscrews to lock the thread in place. Put the piece in a four jaw chuck.Now drill and bore a hole for threading the Acme Thread. Then put nylon plugs the size of the ID of the setscrew holes and follow with the set screws. Screw the Acme threaded rod in until you have it where you want it. Lock the set screws. Turn down the diameter. Light cuts. Safety Goggles. Regards, Jerry G (Glickstein) ----------------------- Date: Sun, 19 Oct 2003 22:59:18 -0000 From: "John Williams" Subject: Gunsmithing - need to adjust barrel shoulders Newbie alert - I have progressed far enough to attempt my first barrel fitting. I am using a large Ring Mauser, and purchased a pre- threaded barrel on e-bay. I know most of the steps of fitting it up, using Kunnhausen (sp?), but one aspect eludes me. He shows chucking the barrel in a 4 jaw to face the barrel. I have a 12x36 Craftsman with the MT3 spindle, so this is out of the question. Is it possible to face the barrel between centers or do I have to aquire a steady rest? I think I know the question to this, by the way...steady rest... Any other way to take a bit off of the barrel face without the steady rest? ------------------------------ Date: Sun, 19 Oct 2003 21:09:48 EDT From: n8as1x~xxaol.com Subject: Re: Gunsmithing - need to adjust barrel shoulders as soon as u put a barrel on centers , u do damage to crown ..& will need a stdy to re crown by machine ...........if u have problems (read that as errors) fitting ,u will need a stdy to ream the chamber.........& yes , u can face w/out a stdy by using a center w/ a portion ground away to let the tool in ..............or just releiving the t/stock slightly will allow the barrel to ride out a tad & the tool willface the remaining material off ..u can also turn up a centered mandrel & put it in chamber & make ur cuts sacrifially into the mandrel..........u could finish w/ a file if not to ur liking ...BUT.U NEED TO make /buy/borrow a stdy if ur going to do barrel work on an atlas /crftsmn........i have used my current one for 30 yrs & have fitted more than a few match winners between centers...... best wishes docn8as --------------------------- Date: Tue, 18 Nov 2003 12:21:36 -1000 (HST) From: Tom Benedict Subject: Re: Machining Silver Steel Rod [TAIGTOOLS GROUP] On Tue, 18 Nov 2003, Alan Smith wrote: > Although I am not a regular contributor I do read, and absorb the various > bits of information. I thank you for that. > May I ask if anyone can advise on the best technique > for turning down a 2" length of 3/16" Silver steel rod. What sort of tool, > advised speed, any ideas to make life easier! Even a short protrusion from > the chuck allows some 'springing' but the rod seems to need quite a bit of > pressure to cut into it. I've had several tries and the result looks more > like a ploughed field than a smooth surface! > Any help gratefully appreciated, I've had ok luck using atom-splitting sharp HSS tooling with a VERY slight tip radius. Keep protrusion from the collet to a bare minimum and use a pretty slow feed. The Speeds & Feeds PDF in the Files area should have spindle speeds for various diameters of O1 tool steel. I don't know if other silver steel alloys have similar speeds, but it's a start. Tom ----------------------------- Date: Thu, 20 Nov 2003 09:41:02 -0500 From: HUNLEY31x~xxaol.com Subject: Re: AA 6 inch Craftsman metal lathe gears [SMOOTHING TURNING CUT TO MINIMIZE RIDGES] Harold, I don't have your model machine, but try tightening all the gibs and using a good (cobalt), sharp, HSS cutter and see what happens. My 12 " Atlas gave me a fit till I learned what IT liked. BTW, my Atlas likes a cutter angled AWAY from the direction of cut (more then what I consider normal). Lessen feed rate some? Try some leaded steel, It's real nice to machine. Light weight machines are a bit 'unforgiving' at times. Most important- Take the clock out of your shop. You don't want to know....... Larry ----------------------------- Date: Tue, 20 Jan 2004 16:47:49 -0800 From: Rick Voegelin Subject: Armature Turning Questions All, I have recently acquired a Taig lathe that I would like to use to turn and true armatures used in model electric cars. My experience and machining skills are limited, so I am seeking advice from the members of this group. The armature shaft is nominal .0625" O.D., and the O.D. of the three laminations is approximately .675". Since Taig does not offer a 1/16" collet, I have to figure out how to hold the armature securely. I have purchased blank collets from Taig, but lack the equipment to slit them. So the first question: Does anyone know of a source for 1/16" Taig collets? It has also been suggested that I make a slit reducer bushing to hold the armature in a 1/4" collet - or that I use a collet inside a collet. Any comments or suggestions on the practicality and accuracy of these methods? Next is the problem of the interrupted cut on the armature laminations. There is a gap of approximately .250" between each of the three sections. I would appreciate advice on spindle speed, preferred cutting tool and feed rate for this job to prevent damaging either the armature or the lathe. Or should I give up on the idea of machining the armatures and look at a way to grind the O.D. instead? I've found photos of grinding wheels powered by Dremel and Foredom flexshafts on Nick Carter's site. Apologies in advance if these newbie questions have already been discussed. I've found some similar threads in the archives, but not specific answers to my questions. Thank you, Rick Voegelin ---------------------- Date: Tue, 20 Jan 2004 15:00:20 -1000 (HST) From: Tom Benedict Subject: Re: Armature Turning Questions Fraid I don't have answers for you, but I've got similar questions. Are you doing this on 130 size motors? Maybe you can answer a question for me: Have you ever trued up the copper contacts on an armature? What kind of tool would one use for that? I'm guessing it's dead-soft copper. I've mangled enough soft copper I'd rather go into this with slightly more clue than I've got at the moment. Tom ---------------------- Date: Tue, 20 Jan 2004 17:38:59 -0800 From: "Chet R Biggerstaff" Subject: RE: Armature Turning Questions Just drill one with the size you need. You can buy blank collets from Nick Carter or Taig (and many other places) at a reasonable price. --------------------- Date: Tue, 20 Jan 2004 22:15:11 -0500 From: Stan Stocker Subject: Re: Armature Turning Questions Hi Rick, I've done armatures for things like ATVs and auto starters, and a few on fractional HP and up electric motors, but never on RC car size. Just a disclaimer. I've had good results with a very sharp round nose tool, using half and half for cutting lube. Dairy products are the best lube I know of for cutting copper. Undercutting can be done with a hook tool or using a bit of hacksaw blade, ground to be just shy of the slot width. You can slit collets with a jewelers saw, probably with a Zona brand razor saw, or using fancier tools. You can make a simple split sleeve easily, just secure a piece of 3/16 or 1/4 inch brass rod in a standard collet and drill to size. Slit lengthwise with a fine hacksaw. You'll need the tailstock well aligned to do this well. Take a look at Nicks tips section, or the archives and search on my addy. I use split collets for oddball work a lot, and posted a pretty long piece on the how and why of makig and using them sometime in the last few years. You could make a brass cup center to hold the end of the armature using the tailstock drill chuck. You could use a headstock mounted drill chuck in lieu of special collets. The adapter is standard Taig stuff. You could polish the cut surfaces with a burnisher, do a search on Clock Pivot Polishing for some links that might give some useful ideas. Grinding copper is tough, grit tends to bed into the soft copper and turn the commutator into a lap that eats brushes fast. I'd take a look at some of the commercial armature tools that are advertised in the RC Car mags, a few pictures or a hands on touch and feel session at a hobby store might sort out lots of details. Hopefully someone on the list has done exactly what you are after and will post. I've done what you want, but not on your scale :-) Cheers, Stan --------------------- Date: Wed, 21 Jan 2004 10:44:49 -0800 From: Don Rogers Subject: Re:Armature Turning Questions >I've had good results with a very sharp round nose tool, using half and >half for cutting lube. Dairy products are the best lube I know of for >cutting copper A question about the copper. Is it perhaps beryllium copper? >You could use a headstock mounted drill chuck in lieu of special >collets. The adapter is standard Taig stuff. I second this motion. Use as small a chuck as you can get as they usually run more accurately on small stock. I recommend a ROHM keyless that will close to "0". It is a very accurate chuck. Finding one with a 3/8"-24 mount may be a bit of a problem as they are not listed in my Enco catalog, but I know they make them, as I have one. One thing to watch for though is not spinning the shaft in the chuck as the chuck will eat the shaft. Don ----------------- Date: Wed, 21 Jan 2004 15:55:15 -0500 From: Jimmy Weierich Subject: Re: Armature Turning Questions I have had some experience turning commutators (the copper contacts) on small electric motors. In fact, when I bought my Taig lathe, about twelve years ago, one of the intended uses was just this. The motors involved are those used in 1/10 and 1/12 scale radio controlled cars, in my case for racing applications. These motors are in a "can" about 2" long and a little less than 1.5" in diameter. I believe they are called a size "540" motor. The armature has a 1/8" shaft and the laminations are about 7/8" in diameter. The commutator is about 5/16" in diameter and about 1/4" wide. The shaft extends about 1/4" beyond the commutator and about 5/8" beyond the armature on the other end. The commutator, as you guessed, is dead soft copper. These motors are powered with six cell nicad battery packs of a nominal 7.2 volts and current draw of 30-40 amps or more on initial acceleration. Average current draw is around 20 amps in a four minute race with the 1/10 scale dirt oval cars. The brushes used are softer than the commutator so that they will wear rather than the commutator and are replaceable. The contact patch of the brushes is about 1/8" square, so the current transmission is concentrated in a small area. This high current causes arcing when the brushes cross the longitudinal interruptions in the commutator and "burns" the soft copper. Every half dozen or so races the commutator needs to be trued. The goal in truing the commutator is is to get it perfectly concentric to the shaft with a dead flat mirrored finish. This is to ensure maximum contact with the brushes for the least resistance to current transmission. The first problem with truing them on the Taig is supporting them. The shaft is easily supported in a 1/8" collet. However, the narrow width of the commutator between the laminations/windings and the shaft precludes turning between the laminations and the headstock. It was necessary to make an extension to the shaft that would allow the commutator end to be supported in a steady rest and allow room for the toolbit. This was accomplished with a piece of 1/4" rod bored for a press fit on the shaft, just long enough for clearance for a toolbit between the armature laminations and the steady rest. The second problem proved to be insurmountable (at least for me). With the rack and pinion feed of the carriage I couldn't achieve a slow and smooth enough feed to get the mirrored finish desired. Perhaps a power fed leadscrew would solve the problem, but I didn't know anything about that at the time. I had some success with smoothing the commutator with emery cloth after turning, but I was afraid I wasn't holding the tolerance desired with that method. Perhaps if this group had existed at that time you folks could have helped me overcome my inexperience and get it to work. I ended up buying a purpose built commutator lathe specifically for these motors. It uses another motor of the same size and a large o-ring for a belt to turn the armature. Both axis of the tool feed use 1/4-20 screws and nuts with hand wheels. The screws are loaded with heavy silicone grease to fill the threads and eliminate any play/backlash as well as providing smooth movement. The lathe came with a 1/4" square carbide toolbit of the same type and size used on the Taig. I was unhappy with the finish this created and replaced it with a similar diamond bit sold by the lathe manufacturer which produces the desired mirror like finish. The manufacturer recommended using both bits dry and taking as small a cut and feeding as slowly as possible. I no longer have the carbide toolbit and don't recall it's shape. The diamond bit has a VERY small tip radius. I can measure its geometry if you are interested. The toolbits were not made by the lathe manufacturer. I think I still have the tube the diamond bit came in with the manufacturer's name and part number, somewhere. You can see these lathes and toobits at www.towerhobbies.com by searching for "lathe". They ain't cheap! If your needs are less exacting, you may be satisfied with the finish produced by the Taig. Or your experience may allow you to do a better job than I was capable of doing. Sorry if I have been too long winded, but I felt I had to put my response in context. Jimmy --------------------- Date: Thu, 22 Jan 2004 22:35:59 -0500 From: Jimmy Weierich Subject: Re: Armature Turning Questions On Wed, 21 Jan 2004, Tom Benedict wrote: >I'd be interested in the manufacturer's name for that diamond bit. I'm >guessing I can pick one up from Tower, minus the lathe (I hope, anyway.) I found the tube for the diamond bit. The manufacturer is "Carter Diamond Tool Company". The part number is gone from the oil soaked sticker, but the price is still there - $67. This was about 12 years ago. Googled Carter... and found: http://carterdiamond.com/ They have a button for "RC COMM-TOOLS" at the top of the page. They list both LH and RH cut tools that look just like mine for $79.50. Nice to see they are still around and the price has gone up less than 20% in 12 years! They also offer a relapping service for $24. I've actually got two of these - I dropped one and chipped the nose. I'll have to see if they can fix it. I've never tried to true the laminations. The clearance on the motors we use looks to be about .010", seems like that should be close enough. And I've never seen after-market magnets for these motors, plus the stock magnets are glued (epoxy?) to the inside of the can. The better motors already use rare earth magnets. Also, these motors get VERY hot, you can burn your finger on one right after a run. A tighter clearance may cut down what little air flow there is. The magnets will gradually lose flux due to the high heat. There are remagnetizers sold to restore them. I have rewound a couple motors. After winding and gluing the wires it's essential to rebalance the rotor. The less expensive motors appear to be static balanced at the factory with one drilling on the heavy side. The better motors appear to be dynamic balanced with a couple drillings on the laminations spaced circumferentially and occasionally some on one end or the other. I used a model airplane propeller balancer, but never got one to run as vibration free as the factory ones. There are now prop balancers that suspend the shaft magnetically, they would probably do a better job than the one I have (see Tower Hobbies). You can buy motors and replacement rotors with practically any wind you want, so I gave up on this idea. I don't know if this would be an issue if you turn the laminations. You may be removing material evenly enough to maintain the balance. Let us know how you make out. ------------------------------ Date: Thu, 22 Jan 2004 08:08:04 -0800 From: Rick Voegelin Subject: Re: Armature Turning Questions My thanks to all who responded to my questions about turning electric motor armatures on a Taig lathe. The motors I am modifying are used in Aurora Thunderjet HO slot cars, originally made during the '70s (old and slow, much like my driving style ). These are an unsual "pancake" design with the commutator perpendicular to the armature shaft rather than parallel to it as in modern can-style motors used in RC and serious slot cars. Here is a link to photos of the armatures I am turning: http://www.scaleracers.com/HopUp/ArmaturesAFX.asp The commutators on these motors are thin copper plating, so about all you can do is polish them with jeweler's rouge or 1000-grit paper. My objective was to turn and true the OD of the armature laminations, which are crudely stamped and then clipped together (these little gems were manufactured as $3 toy cars, after all). Truing the OD is an essential first step in balancing the arms, and as Tom Benedict noted, after the armature is running true, you can shim the magnets closer to the arm to improve performance. Yesterday I plunged ahead and made a proof-of-concept setup. Following Nick Carter's advice, I made an aluminum reducer bushing that fits inside the 1/4" Taig collet. The bushing has a single slit (broke a few jeweler saw blades cutting it) and when the collet is tightened, it holds the 1/16" arm shaft securely and reasonably concentrically. To support the other end of the armature shaft, I made a bushing that tightly fits the arm shaft and runs in the Taig live center. I spun the armature on the second highest speed setting, and just shaved the OD with .005"-or-so passes to minimize the chances of grabbing one of the three armature laminations during the interrupted cut. Eureka! It all worked amazingly well. My first few attempts produced exactly the result I was looking for. The reducer bushing actually worked as a safety valve; on one pass when I was too aggressive on the cut and the tool caught on one of the armature laminations, the arm shaft just spun in the bushing without damaging either the arm or the tool bit. A friend who is an experienced machinist walked me through the project, and he was very impressed with the accuracy and quality of the Taig lathe. After my first serious project, so was I. I think this could be the start of a beautiful relationship . Thanks, Rick Voegelin ---------------------- Date: Fri, 05 Mar 2004 07:25:41 -0800 From: Rick Voegelin Subject: Re: armature turning [taigtools group] > I want to use my Taig lathe to turn and true the armatures for some > HO slot cars. Anyone have any suggestions on the best method to hold > these little guys and the best tool to use to accurately true the > armatures? Roger Petrella Franktown, CO Roger, I use my Taig for truing T-jet armatures, thanks to guidance and input from this group. Here's the technique I've evolved: I hold the arm in the 1/4" Taig collet. I made a reducer bushing from 1/4" 6061 aluminum rod with a reamed 1/16" hole. I split the bushing with a jeweler's saw so that it compresses on the arm shaft when the collet is tightened. To support the arm on the tailstock end, I made an aluminum bushing that fits on the end of the arm and engages the Taig live tailstock. I spin the arm at the second fastest speed, and take very light (.0005") cuts per pass with cheapo Harbor Freight right-hand bits with carbide inserts. Problems: If you catch one of the arm laminations on the interrupted cut and the arm spins in the reducer bushing, you lose the clamping force because it wallows out the soft aluminum (highly technical term). My next step is to make the reducer out of brass, and slit it crossways (four "fingers") so that it can hold the arm shaft more securely. Actually, having the arm spin in the bushing is a safety valve, because it prevents you from spinning the commutator on the shaft and totally trashing the armature. The other problem is that the live tailstock doesn't turn at the spindle speed; even with only a light preload, there is too much drag. To prevent galling the aluminum support bushing on that end, I put a dab of synthetic grease on the arm shaft. That's cured that problem. After doing a dozen or so arms, I've decided that grinding the OD is probably a better solution than machining it. I've built a fixture to hold a Foredom flex shaft grinder handpiece on the cross slide (there are several examples on Nick Carter's website) -- sort of an imitation tool post grinder. On Tom Benedict's advice, I bought the reversible Foredom so that I can countergrind the arm; most grinders (Dremel, non-reversible Foredom, Harbor Freight, etc.) rotate "with" the spindle. I'm going to sacrifice a few arms this weekend to see whether or not this setup works. Good luck! Hope this helps, Rick Voegelin (still playing with toy cars) ------------ Date: Fri, 05 Mar 2004 17:27:56 +0000 From: Steve Blackmore Subject: Re: Re: armature turning >I hold the arm in the 1/4" Taig collet. I made a reducer bushing from >1/4" 6061 aluminum rod with a reamed 1/16" hole. I split the bushing >with a jeweler's saw so that it compresses on the arm shaft when the >collet is tightened. Why hold a collet in a collet? Surely this multiplies any error by a factor of two? Why not use or make a 1/16" collet? Steve Blackmore ------------ Date: Sat, 06 Mar 2004 07:38:17 -0800 From: Rick Voegelin Subject: Re: armature turning You're right; in a perfect world, I'd use a 1/16" collet. Unfortunately Taig doesn't offer a 1/16" collet, and so far my limited skill and equipment have prevented me from making a proper 1/16" collet from the blank collet that Taig does sell. The drilling's easy, but the slitting has me baffled. (Note to group: Anyone willing to make a 1/16" collet for me, I'm an eager customer ). The reducer bushing is an expedient solution that seems to work well enough for the purpose. (After all, these are just toy cars.) After turning, I static balance the armature on a poising tool, which usually requires grinding a bit of material off the end of the heavier laminations by hand. While far from perfect, the turned and balanced armatures are a country mile better than the original $2 parts. Regards, Rick Voegelin --------------------- Date: Wed, 03 Mar 2004 22:43:08 -0000 From: "kggsystem" Subject: Grooving Technique for Snap Rings or E-Clips I am using my Sherline Lathe to prepare some shafts for a gearing mechanism. I need to put snap-rings at the ends of the shafts for axial fixturing and alignment, etc. However, I am in a bit of a conundrum on the best way to cut a groove for the snap-rings. The Sherline parting tool cuts too wide a groove, and the tip of a standard cutting tool imparts a triangular groove, whereas I need a small width (and depth) rectangular groove. Any ideas? Thanks Kggsystem ------------ Date: Wed, 3 Mar 2004 16:55:04 -0800 (PST) From: Henry Flymo Subject: Re: Grooving Technique for Snap Rings or E-Clips Just use a tool blank and grind your own. Have cold water on hand to cool the tool as you go.Don't grind it to hot that it turns blue, dip it more frequently the thiner it gets. also start with the smallest blank say 1/8" or 3/16", less material to remove. Put clearance angle on both sides and front about 3 to 5 degrees, 0 rake(leave the top flat.)Shim it just a hair below center. Use low RPM and cutting oil. ----------- Date: Wed, 3 Mar 2004 17:04:36 -0800 From: "Dave Hylands" Subject: RE: Grooving Technique for Snap Rings or E-Clips Or perhaps this [for thinbits]: http://www.kaisertool.com/catalog/Catalog.htm ------------ Date: Thu, 04 Mar 2004 05:53:54 -0000 From: "mileagemayvary" Subject: Re: Grooving Technique for Snap Rings or E-Clips I had the same problem with some things I manufacture. I made up (welded but maybe other ways) a "C" shape out of 10mm square steel. Top to bottom is 40 mm outside dimension. Front to back is 35mm. There is a 10mm square piece at the back of the "C" that mounts this into the toolpost so that the "C" sits vertically. Hacksaw a vertical slit at the top and bottom of the C. Tap a hole into the side of each slit so 2 small setscrews can then hold a vertical blade. The cutting part is a piece of one of those small hacksaw blades about 5 mm wide X 0.6 mm thick. Break off a length of about 60 mm and clamp in the C. Teeth point up. Mount device in toolpost. Use cross slide to feed this onto the work piece and it cuts a nice narrow groove. Also can cut a groove on a threaded rod such as a bolt. A single point cutter will try to follow the thread. Use lube. Need to keep moving to a new piece of blade. These blades are usually poor quality. Want wider slot... use wider blade or 2 blades. Warning: ASCII art attempt ----------- : :-------o- < tapped hole so a screw can : : :/ clamp blade top and bottom : : :/ : : :/ <<< piece of mini hacksaw blade ------: : :/ : : :/ ------: : :? >>FEED BLADE THIS WAY INTO WORK ^ : :-------o- TO CUT A GROOVE>> ^ ----------- ^10mm sq mounts in toolpost Rob ------------------ Date: Thu, 08 Apr 2004 18:12:58 +0000 From: "Del Stanton" Subject: RE: More questions > Now, my biggest challenge was some EMT pipe I was turning and boring > to dimension. Even at the slowest speed it was squealing so I applied > WD-40 (all I have at the moment) to try and cool/lubricate. Often when turning tubing the tube will start to vibrate. The vibrations be damped by stuffing the tubing tightly with a rag. Del Stanton ----------------- Date: Tue, 13 Apr 2004 From: "jerdal" Subject: Re: dead centers, live centers, soft, hardened,????? > Centers... If your lathe has a MT3 bore in the spindle, get a sleeve > that reduces from MT3 to MT2. Use the dead center in the spindle > (it becomes "live" when the spindle is turning). The work is driven by > a "dog" and turns at the same rate as the spindle. Yes, the MT2 and sleeve will take up less axial room than an MT3. It is a common way to operate, despite the potentially lessened precision. The MT3 often takes a very long-tailed dog. A slick trick is to turn a small collar on a short piece of 1" or 3/4" round stock in a chuck, then turn a 60 deg point on it with the collar against the jaws. It's dead true to your spindle until removed. It's cheap and can be turned to dead-true again next time. And you don't have to remove the chuck, plus the chuck jaws function as the dog driver. Otherwise you have to pull the chuck, put on a dog-driver and center. For many operations, the turned center is quicker and more accurate. Jerrold ------- Date: Sat, 12 Jun 2004 From: "David" Subject: True Turning [taigtools group] I know it is sometimes not so easy to get a pre made part to chuck true, then do work true to the pre formed surface. My question is when you chuck a rod, and it is off by a .001 or so, will the surfaces you turn be true to each other? Like a shaft adapter. It will have an inner bore and an outer surface that should turn the same. It seems that as long as you don't remove it from the chuck, they should be true and you can part it and loose the reference to the chuck. ------- Date: Sat, 12 Jun 2004 22:21:37 -0000 From: "Robin S." Subject: Re: True Turning You're right. An important skill in turning is how to make a piece in one setup without painting (turning?) yourself into a corner. Other than turning a part in one setup, you can turn it between centers, use a four jaw independant chuck, or if you're lucky you can redesign the part/assembly such that it isn't such a big deal (not easy). Regards, Robin ------- Date: Tue, 22 Jun 2004 From: catboat15x~xxaol.com [atlas_craftsman group] Subject: Re: cutting work to size In a message dated 6/22/2004, atlas_craftsmanx~xxyahoogroups.com writes: >if you have your feeds and speeds set right and the cut is not too long >a travel, cutting it would take less time than explaining it this way. That is why I keep a black board over my lathe never was good at mental arithmatic. You are right, but I think the person asking the question is a beginner in lathe operations and he (or she) may have other problems in making a controlled cut to size. One of the problems that a beginner has (I know it grabbed me at first) is trying to take that final .001 off when the gibs were not set right and kept getting skipped cuts. It seems as if I learn something new every time I go out to the shed and start up the lathe (after oiling, of course). Oh well, I usually have a good supply of scrap to practice on since I toss a lot of my attempts. It seems some people expect their old half worn out lathe to give tolerances that even in big shops are done by centerless grinding at the least and lapping and/or hones on the finest work. I supervised engineers and more than once have seen some young engineer specify a tolerance on something like a picture hanger to 0.0001 inch when a realistic tolerance would be + or - 1/4 inch. Good leaded brass screw machine stock can be cut to fairly good tolerance the same for good cast iron (messy though) but if a newby practices on the CRS from the hardware store he will not be able to turn to close diameters (I have picked up stuff at the local DIY store for metal and it even had a closure seam down one side. Impossible to turn anything to a set dimension as every revolution that seam would start a tear. (Also put a tear in my eye) John ------- Date: Tue, 29 Jun 2004 From: catboat15x~xxaol.com Subject: Re: Turning between centers > When drilling your center, what size of center drill would you recommend > for some given size of stock? Matter of judgement I guess, I have never seen any rules regarding this, large center drill for larger work is all I can say. Don't drill too deep just enough to get the nice 60 degree tapered hole in the work. Next, lube the center with grease not oil. The old way was to use white lead, but since lead is now a nasty word use some grease with teflon or Moly for the high pressures. If the tailstock center moved out are you sure you locked the tailstock to the ways and the ram to the tail stock? That should not happen! A quarter turn of the feed dial would be about 25 thou, maybe too much, try 10 thou till you get a feel for the lathe. Also remember that cutting makes heat, heat makes your work expand so you should do one cut and check the tailstock; if it is getting too hot slack it off a bit. John Meacham in the high desert of California ------- Date: Fri, 30 Jul 2004 From: n8as1x~xxaol.com Subject: Re: Spring Tool...HAND TURNING [atlas_craftsman group] hand turning ...oldest method of lathe turning metal ...pics from 16th cent. showing LARGE metal tools w/ handle under the arm for leverage......until maybe middle 18th cent w/ Maudsly & the screw cutting lathe & carriage came on the scene.... havent done a lot of wood turning, but think the method is near same...when i first went into the shop in 1945, they were still using old file scrapers to round up the radii on pulleys they were turning ........one of the more difficult concepts for a new hsm , is to realize that w/ the 12 in home machines that weigh 1/10 of a 4500 # monarch 12, the technology instruction shud start w/ 1920's texts/techniques, or earlier ,when an industrial 12 in lathe weighed 1200lbs( still, 2 to 3 x the home shop machine) caveats....keep tool clear of chuck jaws .....&.centrifugal force CAN cause a jam up if u are careless ,much like a grinding wheel can catch & drag ....go slo & firm old files work fine ,WITH HANDLES !!!.( open tang can do a job on u if tool gets loose)....# ! - take a 1/2 round file & grind the end to abt a 60deg. point w/ maybe a 1/16 radius on end..now grind off all teeth for abt 1 1/4 back .turn it so flat surface is up & grind a 6-10 deg clearance all around (sides & radius of cleared area....u now have a zero rake tool w/ clearance .,which will work better if stoned.......just to get started , put the rear end of a tool holder in the lantern tool[post that u DIDNT throw away when u got the Q.C. chck up a 3/4 bar sticking out a couple inches... bring the end of holder up w/ in maybe 1 1/4 .of bar ....this is carbon steel ,so cut ur sfm's in 1/2 (IMPORTANT ) ...w/ flat side up & held w/ point de[ressed abt 10 deg put the point to the work using holder as a fulcrum w/rt hand on handle & left on top of file at fulcrum ( fingers out of way for now.) by pushing down on handle, point will rotate into work taking a scrape cutw/ NEGATIVE rake..as you bear down groove appears ...u can widen groove by angling file rt /lftpractice a few radii of various sizes....#2..now take 2 flat mill files & grind the end so it is angled abt abt 45 deg..(like a wood skew)one rt. and one left. now, grind the teeth off & grind a 6-10 deg. clearance on end (zero rake) ...u can use same technique to widen out the radius to a wide v , or a taper or a CHAMFER .... angles are not critical & may want to vary w/ material ......these are close to what i made up near 50 yrs ago & they worked ok on steel for occaiional use........#3....take a round file& gring an inch or so teeth off ....grind a radius on end of desired size.... now grind a 10deg. slope from the end back.....turn file over so the slope is now clearance & put the tool to work w/point depressed abt10deg ,bear down on handle & scrape ur radius #4 take a 4 square file & grind the teeth on end ...orient it w. corner vertical (centered) &.grind a 10+ deg. slope from end back to nothing , like the round file ..turn tool over w/ corner in center & u have a "graver " for lines .(sharpen the corner to suit ...... when used properly , the zero rake becomes slightly neg. , & a scrape cut ,rather than a dig in occurs ...if u get above center line, it will want to kick back ................ to make a ball,scrape in the 1/2 round file an appropriate distance from end , & use the skews to shape up .... old tymers have been known to chalk some lines & scrape in a coarse (4 pitch ) thread on large (12 in d.) bars when the lathes was not equipped for thrdng..... i will attempt to describe my shop bilt spring tool as best i can (w/out the ability to draw or post a drwing ,) later this weekend... hope there is value here for some !!!! best wishes docn8as ------- Date: Fri, 30 Jul 2004 From: n8as1x~xxaol.com Subject: Re: spring tool holder In a message dated 7/30/2004, flasksx~xxcsonline.net writes: >>bit holder that was adjustable. Most all replies and references show a tool totally unlike the one I originally asked about. My tool has the "spring" portion in a high arc (goose neck) as opposed to most spring tools that have a low arc ending a single recess << u have a gooseneck threading bit holder for olde tyme crossfeed threading rather than compound threading to quickly hog out the rough cut( the compound was still just coming into general use as late as turn of century ......mine came w/a thrd & extended socket to go between the turret & shank to lock in a specific position w/variable tension if desired....the gooseneck spring allows for heavier cuts w/less chatter than a solid cutter ...... u must have missed my previous post which i repeat .....i have an S 51 , & S 52 threading bit holder in use !!!!!!! best wishes docn8as ------- Date: Sat, 31 Jul 2004 From: n8as1x~xxaol.com Subject: Re: hsm Spring Tool In a message dated 7/29/2004, HUNLEY31x~xxaol.com writes: > . Please share description follows of shop made spring tool stumbled on 45 yrs ago made w/out forging ( well. maybe the bend was heated) start w/ 1/2x 1 5/8 x 6 bar, narrower/thinner for crftsmn/atlas ....1 1/2 will do if u need ....... mill/shape down to 1 inch , from front to back for an inch ...leave full width for 1 1/2 & then mill down again to one inch for rest of shank ( 15/16 for crftsmn)......u now have a hump near near 1 in from front which becomes a gooseneck ....now a 1/2in slot is milled from the bottom ,up into g/neck leaving near 1/4 in remaining at the top to allow spring ( commercial tools have abt .050 slot ,but this tool flexes more & chatters less ...reckon the gooseneck cud be 1/2 as wide with a 1/8 in slot & still work well.......if too stiff , shape off the top ,leaving 3/16 space to flex...) now bendshank just back of g/neck in manner of an armstrong left hand tool holder ( get heat as u can)....u can mill/ shape/file a slot for bit & hold it w/ 2 set scrws ,or use the method that follows ....mill the bit slot & drill a 1/2 to 9/16 hole abt midway in the slot ( be accurate)...turn up a stud w/ a few thrds on end ...on other end drill a hole thru the diameter 1/32 larger than ur intended bit & lightly champher it ( again, be careful w/ placement )....now square up the end of ur bit sharp , ( no clearance/relief needed) & drive bit thru w/ heavy hammer .....finish driving thru on the sllghtly opened jaws of ur worst ,crummy , beat up heavy vise ( or the one which now becomes ur beat up crummy heavy vise)....last bit i drove thru was a 1/2 in for a chuck wrench i made , (actually .450 ) didnt partially drive & remove burrs., just drove thru w/ a 3 lb hammer..(.sure, u can use a press, if u have one ) bit may chip a tad on end when driving ......insert cutting bit in stud, place stud thru hole ,the slot & washer/nut on opposite side securing bit.... use a nut /thrd that fits ur lathe wrench ........neat & easy ,huh?...........thinning the g/neck increases spring, jamming leather into slot ,decreases ...no reason why u cannot run a screw diagonal thru gooseneck to adjust spring ....w/ the spring point up high , the tool bit rotates AWAY from work when needed ....w/ a low spring point, it will dig in to work & hog , therefore just cutting a slot in a regular holder" dont get it "( course u cud separate holder & weld on the g/neck ........if ur inclined towards any hardening ,be sure to draw the g/neck spring point to spring temper ( blue / +/- 580 F ) grind a radius into end of a bit , w/ clearance & rake ...........start w/ a 1/2 + bar & 1st/2nd open belt speed . ( 1/3 to 1/4 sfm ) ..aggresive hand feed, & either increase speed or decrease as needed..or material demands .......anybodys guess w/ alum/brass ......... keep in touch best wishes docn8as ------- Date: Sat, 31 Jul 2004 From: n8as1x~xxaol.com Subject: Re: Spring Tool In a message dated 7/29/2004, HUNLEY31x~xxaol.com writes: >> I'm self taught on lathe operations and have yet to find a way to use a form tool or any wide cutter without chatter. Please share. If your ever in north Maryland I'll buy you a beer or two. Larry << larry . FWIW ....after last post ,i took the holder back down to shop & noticed a .650 nubbin chucked up in wards/logan 10 " ......put the 3/8 flat to it at a 30 deg. angle ( not enuf nubbin to do anything else ) at 2nd speed .abt 250 , & put a 1/4 in flat on it w/out chatter ..........it deflected maybe 1/8 in w/ heavy feed .....light feed of a couple thou & no visible deflection .......12in crftsmn may or may not act same wer weist ? will try it next time i have a chuck on it .......FWIW ...my china chucks are light years better than the junky union 5 in on most crftsmn /wards ...they are around .001 to .0015 runout & look almost as good as bison (3 jaws DO look as gud ) ..are hardened ,but who knows how long they will hold up ................ best wishes docn8as ------- Date: Sun, 1 Aug 2004 From: n8as1x~xxaol.com Subject: Re: Spring Tool (docn8as) In a message dated 8/1/2004, HUNLEY31x~xxaol.com writes: > Right now the picture is just not coming to me, must be the gooseneck really is descriptive w/ the bill being the tool bit in front inch of holder (head) ,then up the inverted u being the neck & down again ,continuing on for the shank(back) .......if all else fails an address gets u a tracing ........if a bunch want them ,will need a SASE ...... best wishes docn8as ps think someone (brian) ?? posted some pics of commercial ones in files??,or somewhere ..maybe logan ? ........ ps ...need to run some tests on crftsmn 12x36 ......have used the tool on 14 in reed & wards logan & it is efficient ...... crftsmn is late model w/ 1/2 in ways ,so shud be near the same ... u may have to drop speed a but w/ 3/8 ways .......just for heck of it, think i will clamp it on compound of 6 x 18 crftsmn & see ....it is a pretty stout little thing , having taken .030 full cuts w/ 3/8 mill in crftsmn mill attach...IN STEEL ..w/ a little support under vise , bet i can take .100 ..........since i am on the clamping subject , when guru , doug king was visiting from canada , & fabbed a 1 1/4 BXS 9 arbor on my 1895 14 in (which had zero runout, true,still havent gotten over it! call it luck , but i have noticed ,the better one is , the luckier he seems to be) ..he wanted to cut off the 2 in nut he just made on the crftsmn, so grabbed an 1/8 in cutoff tool from the 14 in lathe ...i said , u can get in trouble w/ the .093 that i use , never mind an 1/8 in .....he muttered something derogatory & clamped w/ a shim right down on compound ... proceeded to cut off like he was working on a monarch !!! & not in back gear either. used his favorite thrd comjpound which was a runny as water rinstead of my lard witches brew ( which i think is as gud & certainly ,the price was right ,..he did grind a slight back rake on cutoff bit abt the radius of a 5 in grinding whee& HONED it w/ a med arkansas..........this may cause us to rethink the "english way" of taking ur time & clamping direct on compound .....have found their method of cutting square & acme thrds also easier, to grind a bit since it is undersize , & to acheive a serious fit ...... best wishes docn8as ------- Date: Wed, 04 Aug 2004 From: Donald H Locker Subject: Re: V8 Crankshaft turning question? [Min_Int_Comb_Eng group] John D. Guenther wrote: >> What is the best method of producing a crankshaft for a V8 or V12 engine? Is there any good documentation on how to turn a multi cylinder multi throw crankshaft? I am looking at a 4 throw, 5 main bearing crankshaft with the throws at 90 degree spacing. I am thinking of making it from a piece of 2" diameter stock, such as 12L14 or maybe even a stress proof steel. I know that in the end, the throw's and bearing journals will need to be ground and polished for the best finish. I assume I will need a crankshaft grinder for that part of the operation. My main problem is figuring out the best method of turning the initial shape of the crankshaft. I assume that it would be necessary to center drill both ends of the blank in line with each of the journal locations and the center of the crank, and then turn each successive throw using the appropriate set offset locations for each one. How do I manage to line up the offset center locations on each end of the blank? Is there a simple way to do this, or am I doomed to making the crank as a built up assembly? Any help or suggestions on where to find this information will be greatly appreciated. Thanks John Guenther 'Ye Olde Pen Maker' Sterling, Virginia << Accurately locate centre of round stock and mount the round in a vee block. With vee block flat, scribe horizontal line through centre on both ends of the stock. Turn vee block on its side and scribe another horizontal line through the centre. Scribe circle of radius half the stroke, centred on stock center and you now have located the centre of the mains and the centres of the throws. Centre punch and drill all marks. HTH, Donald. ------- Date: Thu, 5 Aug 2004 From: BPer311742x~xxaol.com Subject: Re: Re: V8 Crankshaft turning question? Les, be careful using square bare particularly if it is bright, cold drawn as there are tremendous stresses locked up in the material which can cause the bar to take on the appearance of a banana when you take the first cuts if you do not stress relieve it first. I would always prefer to start off with round bar even if it is more difficult, but not impossible, to set out the centres. Brian Perkins Bristol England ------- Date: Thu, 5 Aug 2004 From: "Russ Tully" Subject: Re: V8 Crankshaft turning question? John: When I made my V-8 engine (my own design) the same problem arose. In my case the stroke was 1" and the crank throws were four at 90Deg. I made up a jig consisting of an outer ring and four discs that fitted inside the ring with each disc having a hole at its center to start the center drill accurately for the crank pins. The assembly I made was 1/4" thick so the discs were quite stable and allowed for accurate work. The calculations are simple and for the 1" stroke were as follows: 1) For the four discs the diameter of each = 1" x 0.707 = 0.707" ( i.e. stroke x cos 45). 2) For the outer ring the I.D. = 1" + 0.707" = 1.707" (i.e. stroke + disc dia.). Make the O.D. of the ring a convenient size, in my case I used 2 1/4" stock. 3) Make a small disc with a concentric hole for the center drill, to fit in the center of the four 0.707" dia. disc group to locate the center of the crankshaft. Diameter = 1" - 0.707" = 0.293" (i.e. stroke - stroke x cos 45) Make the assembly with a snug push fit (with your fingers). 4) Turn a short (1/16" +-) length on each end of your crankshaft blank for a push fit with the I.D. of the outer ring. 5) With the assembly fitted to your crankshaft blank you can then accurately center the four throw centers at each end as well as the crankshaft center. When you come to do the second end use a surface gage (or other means) to align the centers as closely as possible with the first end. Absolute accuracy in this alignment isn't too critical as you will true up the outside diameter of the crankshaft in any case. The important consideration is that you now have the crank throw centers accurately aligned! A similar math process will work for other crank patterns. For the material I would go with an alloy such as the 4340 steel which will stand up to fatigue stress better than the 12L14. To grind the journals on my crankshaft I used my tool post grinder quite successfully as my shop machinery selection was limited and had no other means to do the job. I radiused the corners of the grinding wheel to that required for the cranks and mains and ended up with a very good finish. Good luck! Russ Tully ------- Date: Fri, 31 Dec 2004 From: "gmh45345" Subject: machinist question [atlas618lathe group] I want to make a sleeve for a 1" steel shaft that when I put them together the sleeve will stay put. I know that the sleeve needs to be heated (oven} and the shaft cooled(freezer}how much undersize should the sleeve be? Thanks in adavance and Happy New Year Everyone. This is a great site. Gary ------- Date: Fri, 31 Dec 2004 From: "drifter1951" Subject: Re: machinist question - .00025" to -.0005" ( that's minus) on the sleeve ID should work fine for a press fit, unless it's going to be in a heavy duty application, then -.0005" to -.001". Heat the sleeve with a torch to easy assembly. Drifter ------- Date: Thu, 10 Feb 2005 From: n8as1x~xxaol.com Subject: Re: Steady rest k3hxx~xxjuno.com writes: > I'd like to build a roller-style steady rest. > does anyone know of a website with plans? just in case u are doing this for finished surfaces on rifle barrels, be advised that it still takes the blueing off & the burnishing effect of hardened steel makes repolishing more of a problem than brass ever did ....hardwood doesn't solve the problem either i simply tooksome bar stock to replace the brass fingers on the original stdy & bolted on 3 small ball bearings ......if starting from scatch ,wud use 1x2 bar stock & braze ,slot for fingers held by clamp screw, a nut brazed on back holds the adjusting screw., tongued hinge & brazed plates for toggle opening ..sized for abt 3-4 in d. pieces, double T braced gib underneath bed prevents flexing (thots way down in the job jar for my wards/logan10in.) .....there is some info out there on using a LARGE ball bearing as the housing , inner race shrunk on to a short sleeve w/ adjusting screws , outer race welded to a frame..also some complaints of chips hanging up bearings...i am still using brass tips on 4 lathes after 50 + years.....but there are happy campers out there w/ single LARGE ball bearing.as a stdy... best wishes docn8as ------- Date: Tue, 22 Mar 2005 From: "boaternh" Subject: speaking of backlash [atlas_craftsman group] Hello I have a 10" X 42" QC, The saddle handwheel for longitudinal travel has always had backlash. The manual gives a brief but nondescript method of adjusting this out of which I have had no luck. In looking closely there seems to be several areas of play. 1. the shaft through the apron seems slightly enlarged although not elongated, should I ream and sleeve with bronze?. 2. the two small drive gears which transmit from the handwheel to the rack have play before applying force to the rack, the gears though are in great shape. any ideas or is this the nature of the beast??? ------- Date: Tue, 22 Mar 2005 From: "mertbaker" Subject: Re: speaking of backlash You have the rack/ gear lash, the gear/gear lash, and the sideplay in the handwheel all contributing to the "problem". There is always some lash in any gearset, and the wheel axis sidplay increqases it, however, unless you have a great deal of side rake on your toolbit, it will make no difference when turning. The forward pressure on the handwheel against the backward force on the tool remove all the slop, and you have control. With too much side rake on the toolbit, it can self feed into the work, removing the back pressure, and pulling the whole works to the limit of the lash in the other direction. This is sometimes called "hogging in". When it happens, it can stall the machine, and/or break tooling. The way out of this is don't go in. So long as pressure with the feed train or handwheel is required to make the tool cut, the lash or slop is like, as the pilots say, "runway behind you or altitude above you", Mert ------- Date: Tue, 22 Mar 2005 From: "boaternh" Subject: Re: speaking of backlash Thanks Mert, you're right, once I take up the slack to move towards the headstock or towards the tailstock there is no effect it just kind of bugs me cuz Ive got everything else nice and tight/smooth. Thanks again Tim ------- Date: Tue, 22 Mar 2005 From: xlch58x~xxswbell.net Subject: Re: Re: speaking of backlash I have a number of lathes. All of them have this backlash in the carriage traverse. I expect that a zero backlash solution would necessarily increase friction and therefore increase wear on the leadscrew/halfnut combo. The rack is not a precision positioning mechanism on a lathe, the lead screw is, so even if you could accomplish zero backlash, it would be ill advised. Even the leadscrew will have some backlash new, but considerably less than the rack. For precision longitudinal movements the crosslide is used. If you need longer motion than it affords, there is a common mod to the right side of the leadscrew to mount a graduated dial and a hadwheel to it so that the leadscrew can be used for precision movements. Charles ------- Date: Wed, 23 Mar 2005 From: catboat15x~xxaol.com Subject: Re: Digest Number 2280 [atlas_craftsman group] >> But, a DRO will allow you to work much more conveniently with setting the reference position where you want it, and do a lot of other good things. << I will agree with that, Setting the reference point to zero, or as I said converting between inches and mm an electronic DRO is great. But, again I would not recommend a beginner to be misled into thinking a DRO will solve all the problems in making part B to fit part A. Some day I may add the scales and read outs to my tools, but not until I can afford the luxury and time to do it right. I don't know what a DRO may do on my HF mini mill, that is so flexible I don't really know if knowing the table position is going to do me any good. Another subject on here often is the QC tool post. Again nice but not a necessity. I have both the lantern and QC posts available to my set up. The QC is much more rigid and I use it with my parting tools. The QC also sets the top of the bit to the same position every time, but since a lot of my tooling is from yard sales, surplus shops etc not all cutting edges are at the top of the bit so I have to adjust those each time. (In other words I still keep that 6 inch thin rule handy to show me where on the work the tool bit is hitting.) A lot of my comments are probably from the "Old dog, new tricks" category so you can ignore them as what the old foggy says "That is the way I learned and it is the only way." Heck, given my choice I would still be using my slide rule instead of a computer, but can't figure out how to send Email with my slide rule. I had to learn all my machine work by reading and trying. There are no schools here, even the trade school nearby that give any courses in machine work. Made a lot of errors, produced a lot of scrap too. When I took my locomotive apart for overhaul I was ashamed of what I thought those many years ago as workmanship. (Hadn't even de-burred around the tapped holes in the bronze cylinders for the steam chest or the clearance holes for the machine screws and always wondered why I had steam leaks there. My books never told me on some materials a drilled or tapped hole pulls up a slight burr at the hole.. Learned that by the steam leaks and wondering why. One of my first projects was to try to set up the change gears to cut some threads, read the books, got the gears set according to the table and ended up with what I called my universal thread as some place along that 1/2 inch shaft the thread would fit any nut I had coarse, fine you name it there was someplace along there where a nut would fit. No book ever told me that you don't disengage the lead screw at the tumbler gears during the threading operation. The best thing is I am still learning and some day expect to be a fair country boy machinist, but not there yet. (although I can tell a whole lot of wrong ways to do things.) ------- Date: Sun, 10 Jul 2005 14:14:04 -0000 From: "azbruno" Subject: Re: nontool projects [atlas618lathe] Yesterday I was making a replacement "section" for a 100 year old fountain pen. The section is the piece that the nib fits in and it screws into the barrel. It's just over 1" OAL made from 1/2" hard rubber rod stock. For the first time, I got to use the indexing pin on my lathe. I made an edge for the middle of the section like the edge of a coin. I used a threading tool sideways, set the depth and just ran a cut for each of the 60 positions. Above that area, I had to create a convex curve. Without a radius cutter, I ended up hand shaping it by starting with a rounded tool and then using a half round swiss file. This piece also required work on both ends so for the threaded end I had to turn it around and dial it in with the 4 jaw chuck. I got down to the very last pass on the thread and my thread dial apparently slipped a tooth on the leadscrew. That ruined the threads and the part - - probably about 5 hours of work ruined. Shouted a few things, slammed a door, blew off some steam, and set about to make another one. This time it was about 2:45 to get to the point where I'm ready to cut the threads again. That'll take about 15 minutes and it will be done. And I will pay more attention!!! ------ Date: Sun, 10 Jul 2005 09:21:36 -0700 (PDT) From: john p Subject: Re: Re: nontool projects Well at least you have it figured out what went wrong. Several years ago a friend who was into restoring old tractors had one sold but it needed king pins, and the fellow was to pick it up in two days. I got in a rush and the first set I gave him was way to small when he installed them. I thought I had just messed up in my measuring, so stayed up half the night making a new set. And damn if they were to small also. I had enough of the good steel for one more set. After sitting and looking at the old pins for a couple hours it dawned on me I was cutting too fast and not letting the pins cool down for the finishing cut. ------- Date: Fri, 19 Aug 2005 20:16:29 +0100 From: Clive Foster Subject: Re: Turning W-1 Drill Rod [taigtools] > Ok, I'm perplexed enough at this, and would dearly like some advise > to get me back on track. > I'm making some punches, and I got some water hardening drill rod to > make the with. I was a little afraid of it at first, but soon found > that with a sharp HSS bit, it cuts easy and the finish is beyond > anything I thought. Sooooo nice and smooth. > That is, it was whilst I was taking 5 - 10 thou off at a time. When > I got down to within 3 thou of final size, I began to backoff. Since > I need this punch to fit closely inside a reamed hole, I wanted > to "sneak" up on the final dia. > I then found I don't have the where-with-all to do it. I literally > ruined the piece. Whenever I try to cut 1 thou or less, I CAN'T get > it to cut at all. It's more like rubbing, and it makes an awful mess > that has high and low spots (banding?) all down the lenghth. > It's a 4in long piece, held in the 3jaw and live centered on the > other end, cutting to 2in back from the centered end. > I tried resharpning the bit, with stonening even, and all for nought. > Soooooooooo, where am I going wrong? Can you not cut that small > amount off of drill rod, or more likely is it my skills? > BTW, when I was getting a good cut, the waste came off in one very, > very long strand from start to finish. Is this typical with drill > rod? It seemed okay to me, but it had a nasty habit of trying to > curl up in the palm of my hand, very time my palms were turned up > while I was "two handing" the pinion wheel. Man, that wire gets hot! > Just to add in case it makes a difference, I was using lube/coolant > judiciously. Thanks for any advise and help, Lynn This inability to take really fine cuts is quite a common characteristic of "tough" and non free machining materials. Unless a mechanical or alignment error is the cause, which I frankly doubt, you are going to have to live with the problem and work out how to get true to size from a larger cut. Ultra-fine cuts, especially with conventional tools, are, in any case, bad machining practice for all sort of reasons and strictly amateur. As I understand things the problem is due to the geometry and energy requirements of the shearing action whereby a tool removes metal from the surface. Considering the cutting geometry its fairly easy to see that a lathe tool has to dig in below the surface of the material and lift the chips or turnings off to flow back over the tool. As the top rake angle is fairly small the turnings have to be bent back by nearly 90 degrees to flow over the tool. Consider the actual cutting edge. Even though its sharp it will have a finite radius. If the radius is too large in relation to the cut the dig action won't work properly and a clean cut is impossible. If the edge radius is more than about half the depth of cut things start getting iffy. Especially for hard materials. Indeed for very fine cuts its a radius of less than one quarter of the depth of cut is more prudent. Clearly for cuts of a few thou or more the edge radius is not a problem (tho' carbide tooling typically has large radii in factory supplied condition which can catch you out giving smallest cuts depths of tens of thous) but for very fine cuts its all much harder. To make matters worse an ultra-sharp edge is delicate and easily worn away. Any material build up on the cutting edge will spoil thing very quickly too. To remove the turnings or chips energy has to be supplied to the material via the cutting edge. The tool feed system is not perfectly rigid so effectively the tool is presented to the work by an exceedingly stiff spring. By turning the feed handle you compress this notational spring sufficiently to apply enough force to remove the desired amount of metal. You are putting energy into the system which is absorbed by the work of fracture of the material (among various other sinks). Everything goes swimmingly when a nice clean turning comes off in a continuous process. However if the chip breaks at the point of removal things will go awry. Firstly breaking the chip absorbs some of the energy which should be going into fracturing off the chips so the cut will, at best, get a bit thinner momentarily before things come back into balance. Unfortunately with a very fine cut "a bit thinner" adds up to no cut at all and the tool merely rubs on the face. Now it take more energy to start a cut as to keep it going. This extra energy has to be supplied by applying a bit more feed, hence a bit more pressure via the "spring", but once the cut has re-started the extra pressure pushes more energy into the system which has to be absorbed by a taking a deeper bite. If you don't supply the extra feed force the tool rubs, if you do it cuts too deep, and when you try to control the effects it all goes into a classic delayed feedback mess (also known as PIO, Pilot induced Oscillation). Sound familiar? So much for theory, how about cures. Taking a bigger cut obviously moves your work out of the area where this sort of thing is a mega problem. Lubrication may also help but it needs to be the right type. I suspect the dark threading oils used on powered pipe threaders may be better than conventional cutting oils here. Good lubrication helps the chip flow back over the tool but may also make it much harder to restart the cut. I'm told that the geometry of tangential or diamond tool holders is better when making fine cuts as the effective top rake angle is much greater so the chip bends away from the parent surface less on removal which is good from the energy balance side of things. Tangential tools work like peeling an apple, conventional ones are more like scraping potatoes. If a pro machine shop has to do a fine cut fine finish job on a lathe they will use a tool with a long edge passing under the work with the edge set at an angle to the axis. I've hear these called "scurfing tools" and seen it work very effectively. HTH. Clive ------- Date: Fri, 19 Aug 2005 23:29:17 -0000 From: "Ed Chesnut" Subject: Re: Turning W-1 Drill Rod I don't remember where I read it, but somewhere I read some machining advice which definitely recommended NOT "sneaking up" on the final dimension with lighter cuts. He recommended something along the following lines. 1. Identify a good comfortable depth of cut which results in a good finish. 2. Use that depth of cut to reduce the item to a diameter which is approximately 3 or 4 "cuts" from final diameter - measure the part accurately and calculate the diameter reduction still to go and divide by 2 to obtain the total tool movement (radius reduction) still to go. For this example, where you have reported that .005" cuts look beautiful, lets imagine your diameter is .038" too large. Divide by 2 and you see that you have .019" of tool movement left to bring the piece to finish diameter. That would be 1 cut of .004" and three cuts of .005". 3. The author recommended using repeated cuts of very near the same depth of cut because the stresses on the tool/lathe/workpiece are constant (or nearly so) with each cut - which leads to consistent cutting performance. So, getting back to the example, take a .004" cut and "mike" the part again and run the calculations. You should find that you have .015" to go - 3 cuts of .005". 4. Take another cut x~xx .005". "Mike" the part. Hmmm...0105" to go. That's OK. Take a cut of .0055" (ah yes, the lovely "half a mark" cut!) 5. "Mike" the part again. Calculate the final cut depth. Is it .005"? .0045"? .0055"? Set for that depth and take the cut. It will end up "spot on" and with the beautiful finish you've already gotten used to. Yes, there is a bit of tapping on the calculator, which is time spent NOT cutting. On the other hand, the finished part will have the finish you want and it will be the proper size with very tight precision (even for a squid like me). Have fun, Ed ------- Date: Sat, 20 Aug 2005 10:22:56 +0100 From: Steve Blackmore Subject: Re: Re: Turning W-1 Drill Rod >I don't remember where I read it, but somewhere I read some >machining advice which definitely recommended NOT "sneaking up" on >the final dimension with lighter cuts. Hi Ed - virtually all my turning is CNC these days and sneaking up is not really an option All perfectly true what you say! In my case by experience, or experiment, I know what feeds/speeds give me a good finish on a particular material. Tables give me a starting point for stuff I'm not familiar with, but I won't aim to take off less than 10 thou, except when boring where a "spring cut" is usual because of tool flexing or when threading where a final pass either gives a nicer finish or fit. In a production environment the normal procedure is to make a part from the initial code, then measure it and adjust the program/machine accordingly. The first one is virtually always scrap. A good shop/machinist will get it right second time and can make another thousand without having to worry about anything other than tool wear. We normally don't have that luxury making "one off's" and it's often necessary to pause with a couple of passes to go and measure the part and adjust the tool wear offset to compensate for the remaining cuts. It's never done by finishing then taking a tiny cut or cuts to compensate. My excuse why "one off" CNC jobs are often expensive Steve Blackmore ------- Date: Fri, 19 Aug 2005 23:44:42 -0000 From: "Robin S." Subject: Re: Turning W-1 Drill Rod Lynn: If you're getting chatter, reduce speed and increase feed, period. If you want to reduce the cutting forces on your part, reduce the length of the cut on the cutter. This means reducing the nose radius of the tool (to virtually zero if needed). Also, try to grind and position your tool such that the position of the nose of the tool, when projected back towards the operator, intersects with a portion of the toolbit which is supported by the toolholder. This seem to prevent the tool for flexing away from the material. While this sounds like it would have virtually no affect on the cut, you will probably notice a difference. The only really good reasons to reduce feed is because your tool is melting, or your spindle is stalling. While HSS is forgiving, you'll notice with carbide that you have to feed almost scary fast in order to get it to work correctly (without stalling or breaking the cutter). If you're having trouble with stringy chips, grind a chipbreaker on to your tool. Basically, you just grind the top face of the tool from the nose perhaps 0.5mm in the opposite direction of feed, and leave a step for the chips to hit. Don't try to grind some elaborate scoop form or something. This weakens the cutter and is likely to result in a broken off nose. Roughly neutral rake should be fine for what you're doing, perhaps slightly positive. Lastly, if you are getting a good finish with a heavier cut, use that heavier cut as your finish pass - this method is preferred. You have to learn to take roughing cuts (and NOT measure them!) and then a repeatable finishing cut which you can measure. Always: rough, finish, measure - then keep roughing until you can take that finishing cut to obtain your finished size. Never rough, measure, finish. Your part and cutter will always flex in any cut worthy of being called "roughing." The finishing cut should be the same or close in depth every time. You should have no trouble achieving repeatable results with this technique. Carbide tooling does not usually allow a cut below perhaps .003" and really likes .010"+, so one must use this technique when using carbide anyway. HTH. Let us know how you make out. Regards, Robin ------- Date: Sat, 20 Aug 2005 17:22:25 -0000 From: "Geoff Kingma" Subject: Re: Turning W-1 Drill Rod In the beginning I always found that getting a good finish cut was a hit and miss affair - even after all the tuning mentioned in this thread. One of the best purchases I made early on was a Diamond Tool Holder from Baycom. (http://www.bay-com.com/). I got the T6 for the Taig. The price seems a bit steep but, as with all "good" buys, you don't remember the cost once you use it. The steep angles (back and side rake) enable one to easily handle a fine cut in W1. I am convinced that this is the secret with the Taig. The supplied grinding jig makes the sharpening of bits a breeze. I use this tool on nearly all my machining - it even cuts brass with no digging in. I believe there are links to a home built design of this type of toolholder but am not sure where - maybe a search for a "tangential toolholder" would bear fruit. Another approach may be to make a large radius tool (say 1/2") on a blank 1/4" square toolbit. Then grind a 20 degree side rake (low side to the headstock) and finally a 10 degree back rake. Apparently this configuration can take fine shaving cuts. I have used this on my 6" shaper with great success. It looks as if the surface has been ground. The key is to stone the edge after grinding. Good luck. Geoff ------- Date: Mon, 22 Aug 2005 22:48:54 -0000 From: "Lynn Livingston" Subject: Turning W-1 Drill Rod (Wrap-Up) Well, I posted this msg last nite, but I guess Yahoo ate it. So, I'll take the opportunity to condense it down even more. First of all, thanks to ALL who took the time and effort to help with advise, tips, links, etc. Got a lot of responses, and a lot of great info to study and contemplate. It certainly made my task accomplishable, which it wasn't before I originally posted. I did get the drill rod turned and the project finished. Although there could have been several factors combining to foil my attempts at taking shallow 1 - 2 thous cuts, I have come to believe the main factor was a lack of rigidity. I say this because of the following: I chucked up a fresh 5/8" W-1 drill rod 4" long in the four jaw and live centered on the other end. The first thing I did was try to cut shallow passes. It worked great and I could even shave off 1/2 thou or so at high speed and got a real nice finish. This really was weird, but as we'll see, there is a reason why I could cut a fresh piece this way. I went ahead then and started taking 6 - 10 thou cuts, on the way to to 3/8" dia, and stopped when I got to within 5 thou. I again began to take light cuts to final, and again I could not. All I could do was chew and gall the shaft. I was really getting frustrated, because I had just previously made several passes at such depth easily. I know I could have at this point tried to heavy cut my way to final, but I really wanted to know why I couldn't bring it down a thou or so at a time if I needed to do so. So, I replaced the HSS bit with a new carbide bit and tried to take a 1 thou cut. It did the same thing the HSS did, which was just kinda' chew and gall the shaft. I then setup the steadyrest, which only left me able to traverse about 2", but there was no perceivable difference as far as I could tell. I then replaced the live center with the dead, and THAT did make a positive difference. I still couldn't cut 1 thou well, but I could cut 2 thou more realiably than before. So, I removed the steady rest and tried cutting the whole length. Back to ground zero, even going back to HSS. Something tells me this thing has got to be flexing, although I couldn't see it. So, I put a DI about midways down the shaft in the rear, and pushed toward the DI with my thumb. I couldn't make it move. I then pushed up the tool bit, and with very little pressure, could deflect the drill rod at will almost to each end. Okay, lesson learned. I then did what I should have done to begin with, and set the shaft back into the chuck until it bottomed out, reset the dead center and proceeded to cut 1 and 2 thou passes. Worked out fine and I got two shafts turned before I knew it. So, ignorance was all that was standing in my way, and I'm very familiar with him! ;-) He does pop in from time to time, and he always looks like a stranger, at first! ;-0 Yeap, I'm a bonified amature, even a green amature at that, but I'll have to settle for that until I get more time and grade under my belt! While I was feeling so enthused, I went ahead and banged out one of those optical center punches that was talked about earlier, using the drill rod for the punch. I even got the heat treatment right, uhhh, I think! ;-) A real treat was cutting the acrylic at any speed, feed or depth I choose! :-) I felt like Tarzan working with that stuff! Seriously, I do appreciate all who contributed, I hope to be able some day to do the same. Lynn Livingston ------- Date: Sat, 20 Aug 2005 20:03:53 -0000 From: "Lynn Livingston" Subject: Re: Drill Rod/Freeby Diamond Toolholder > > I believe there are links to a home built design of this type of > > toolholder but am not sure where - maybe a search for a "tangential > > toolholder" would bear fruit. I knew I had seen it: http://homepage.mac.com/bhagenbuch/machine/projects.html Also from the photo section: http://photos.groups.yahoo.com/group/taigtools/vwp?.dir=/Richard% 27s+collection&.src=gr&.dnm=Special+tool+setup.jpg&.view=t&.done=http% 3a//photos.groups.yahoo.com/group/taigtools/lst%3f%26.dir=/Richard% 2527s%2bcollection%26.src=gr%26.view=t Also in Taigfiles ng photo section: http://photos.groups.yahoo.com/group/taigfiles/lst?.dir=/Richard% 27s+collection&.src=gr&.order=&.view=t&.done=http% 3a//briefcase.yahoo.com/ Lynn ------- Date: Mon, 26 Sep 2005 19:29:42 -0400 From: Kuechenmeister Subject: Fitting Thin Work in Large Chucks I've got one three jaw chuck. It's an 8 in. Bison that runs really well. I've also got a few pieces to face that are about 2 1/2 in. OD and about 1/2 in. thick. These are the A3 tender wheels. I'm trying to figure out how to chuck these up in this big chuck. I can't let them rest on the jaws because that recesses them into the chuck too far. What is the typical way of fitting these kinds of pieces in a large chuck? Parallels? Thanks, Dave K. Lawrenceville, GA ------- Date: Mon, 26 Sep 2005 20:11:04 -0400 From: "John D.L. Johnson" Subject: Re: Fitting Thin Work in Large Chucks Dave, I would chuck the wheel banks all the way into the 3-jaw chuck and bore out the axle hole first in all eight. You can also do a partial facing on one side out from the center hole to create a datum surface. Then I would make a mandrel/fixture to be held in the chuck that would hold the wheel blanks out far enough to work on them. This could be made from a piece of 1" round bar stock. The shaft should stick out an inch or two. Then turn the end down to a snug fit on the axle holes and long enough to go through the wheel blanks. Drill and tap the end for a bolt to hold on the wheel with a washer. Then mount each wheel on the fixture with the datum surface back against the shoulder of the fixture and turn them to the final shape. You can also take the wheel off and turn end for end to finish the back side. Don't take the fixture out of the chuck until all wheels are done because you might lose center if you remove the fixture. John D.L. Johnson 3879 Woods Walk Blvd. Lake Worth, FL 33467-2359 www.LocoGear.com ------- Date: Sun, 9 Oct 2005 20:29:08 -0500 From: "jerdal" Subject: Re: machining aluminum [atlas_craftsman] > wow. Talk about cutting like butter. The only problem is my lathe > sounds as if it is about to come apart at those high speeds. What can > I do to quiet down the gear train on the left side of the headstock? Don't use 'em. Your machine only has "power feed" if you use the threading leadscrew, set up for a very fine thread. That gets a lot of wear on the leadscrew and half-nuts, which will then be inaccurate when you want to cut a thread. Just use manual feed, and disengage the gearing with the forward/reverse lever. JT ------- Date: Sun, 09 Oct 2005 19:19:51 -0700 From: William Abernathy Subject: Re: machining aluminum I disagree. I use the feed on either axis when I want a good clean finish, not only for threading. You should, too. The gears are perfectly happy engaging at normal turning speeds. If lubrication does not quell the racket, consider spinning a little slower. Nobody ever ruined a piece by going too slow. William A ------- Date: Mon, 24 Oct 2005 09:10:09 -0400 From: hhelmenx~xxaol.com Subject: Re: Crankshaft Making [Min_Int_Comb_Eng] Colin Heath wrote: >> Well I have started my engine with the cylinder so far, but have a question regarding crankshafts. My engine is going to be closed crankcase 4 stroke (cycle) petrol engine. << Colin: I have used Philip Duclos' method of making crank shafts for several engines. It is straightforward and works well. Duclos uses a flat bar of steel. Marks and center drills the end with the center of the shaft and the throw one each end, then Saws it to rough shape with a hack saw. Next he mounts it in the lathe between centers and turns the throw, and shaft on the different centers. You can see it in the book "The Shop Wisdom of Philip Duclos". It is published by The Home Shop Machinist magazine. The book is pricy! I think 39.00. But there are about 5 different engine projects, with plans in it, and it has a chapter on making piston rings and 7 or 8 home projects also. The pictures are black and white but very high quality. Perhaps your Library has a copy? Hank Helmen ------- NOTE TO FILE: There are a lot of free detailed instructions for making crankshafts and other engine parts on Ron Chernich's site: http://modelenginenews.org/index.html ------- Date: Tue, 01 Nov 2005 19:06:37 -0000 From: "Andrew Carlisle" Subject: Cutting a wide groove in the face of a turning [taigtools] After a couple of making small electric motor parts on my Taig lathe, there's one operation I still haven't come to grips with: What's the best method to cut a wide and deep groove in the face of a turning? ------- Date: Tue, 01 Nov 2005 11:17:53 -0800 From: Nicholas Carter and Felice Luftschein Subject: Re: Cutting a wide groove in the face of a turning You need to grind a trepanning tool. Basically it's a hybrid of a boring bar and a parting tool. The blade has to have clearance so it doesn't rub on the sides of the groove. Let's say the diameter of the outside edge of the groove is 3" and the inside edge is 2.9" (for a .1" wide groove). The tool needs to have a blade that instead of being straight has a radius of 3" Subject: Oops! Cutting a groove in the face of a turing Please ignore my previous mis-post. Hitting the tab key when I was making up the little drawing, I posted before I had finished my messge. Here again, in profile, is what I'm trying to achieve: ___ | _| | | | |_______ | | --------------------- lathe axis | _______| | | | |__ |____| After trying various methods, it occurred to me that perhaps live tooling might be a good method to achieve the result. I can imagine adapting a laminate trimmer or similar to the cross slide and using it to spin a small end mill into the face of the turning. What do you think? Is there a standard solution to this type of cut that I'm not aware of? Regards, Andrew ------- Date: Tue, 01 Nov 2005 11:26:02 -0800 From: Nicholas Carter and Felice Luftschein Subject: Re: Oops! Cutting a groove in the face of a turing Added to my previous answer, live tooling would give a good result although I would turn the spindle by hand, or figure out a way to get the spindle rotation speed down. You could also mount a rotary table on the milling attachment and mount an endmill in the spindle... You would probably get a better finish from turning rather than milling, as well, not sure if you want a square bottom to the groove or not? ------- Date: Tue, 01 Nov 2005 12:00:33 -0800 From: "Paul W. Chamberlain" Subject: Re: Cutting a wide groove in the face of a turning I've been struggling with that concept for awhile trying to make flywheels for model steam engines. I ground custom cutters with the appropriate side relief and square front, but had a lot of trouble with chatter while cutting brass. The side that cuts the inside of the rim needs a radius relief to clear the smallest radius it will be cutting, The side cutting the hub just needs a conventional relief... say 7ø. Same with the facing edge. I think my problem so far has been getting the radius relief "just right". The last flywheel I cut, I used three cutters (all CCMT in my case). The center web was cut with the point of the cutter (80ø) going straight into the material. The outer rim's interior was squared up with a boring bar, and the hub was squared up with a left hand turning tool. All tools held roughly parallel to the bed (Z-axis), with minor adjustment for side angle of the cutting edge. Took very careful setup to get all three cuts to blend across the face of the web. This was all done manually on a Sherline lathe, so my method of using the leadscrew adjustable handwheel would not work on the Taig rack & pinion. The carriage stop could be used, but would take a sensitive hand to set each tool to the same reference point. A shallower angle tool would allow an smaller For deeper cuts, I've seen pictures of cutters that look like a section of pipe... about 20% of the "pipe's" circumference is used... say 6:30 to 9:00 looking at the back of the tool heading towards the material. Of course the radius on the outside of the cutter would have to be less than the smallest inside of rim radius being cut. Paul, Central OR -------- Date: Tue, 01 Nov 2005 20:33:48 -0000 From: "n2562001" Subject: Re: Cutting a wide groove in the face of a turning Andrew, Paul, and all: I struggled with these problems for some time when I first started machining. For the most part chatter in small machines will come from the work piece that is not rigidly mounted and or a larger lathe tool than is needed. I assume your tool is properly profiled and sharp. Sometimes it is difficult to rigidly mount a work piece in a small machine such as a Taig/Sherline to prevent chatter. I resolved these problems by using Micro-100 (And other name brands) right hand and left hand minature solid carbide boring bars for the type of work you are doing if I understand it. One is used for one surface and the other for the opposite surface. This way you are not trying to cut a large surface at once causing stress and chatter. These minature boring bars can be purchased to reach into areas as small as .040" wide. You can first plunge into the work for a short distance and then move the tool back and forth slightly with the cross slide and then plunge again. When maximum depth is reached the work area can be opened up to the desired size with the right/left boring bars. With this proceedure you will only be removing small amounts of metal at any one time preventing chatter. The tips can be ground to the profile needed. Jerry Kieffer -------- Date: Tue, 1 Nov 2005 14:19:18 -0600 From: "Martin Dobbins" Subject: Re: Re: Oops! Cutting a groove in the face of a turing I don't know what material you are working with, or what size the completed motor will be when finished, but John Shadle (link on Nick Carter's site) has some detail on how to make a tiny trepanning tool. You should be able to scale this up or down slightly as required, the cost would be close to zero. Also amongst the goodies are how to make small boring bars. Slightly modified, one of these could alternately produce the square bottom on the outside of the groove and then the spindle side of the groove. I can't help but believe that live tooling would be overkill, unless the project is a lot bigger than I'm envisaging, or you're machining exotic materials. Cheers, Martin ------- Date: Wed, 21 Dec 2005 14:42:56 -0600 From: xlch58x~xxswbell.net Subject: Re: Adjusting backlash? In a message dated 12/21/2005, brianconcordx~xxsbcglobal.net writes: >I have a Atlas 10F. My problem is that there is way too much backlash >in the crossfeed. Is there a way to adjust it or do I need to make a >new nut? I can live with it for now but I can not partoff cleanly. >I'm new to lathe work so I might just be missing something only >experience will bring. Thank you, Brian My suggestion for most newbees is to stop dinkin with the adjustments on the machine and start making chips*. There will always be backlash on every lathe control, nature of the beast, only question is how much. Determining the right amount takes some experience. The backlash may be there due to something being loose, but depending on how much is there, it is probably due to wear, so taking it all out could cause the screw to bind in places and or accellerate the wear. The only place backlash on the crossfeed will bite you that I can think of offhand is in facing operations, and that is only if you haven't learned to set your toolheight correctly( which making chips and closely observing the results will teach you). If you cant partoff cleanly this has nothing to do with backlash but toolheight, the tool grind (yes, you have to grind parting tools too) and the rigidity of the toolpost. Even then all it results in is the little tit on the piece jerking the slide across with a thump for facing. Use the remaining tit to set the tool height properly, if it is set properly, then you have a rigidity problem -- welcome to Atlas machining, do you have a hacksaw? If you must use the parting tool (which even tax my big lathes), put some rake in the tip and make sure you have clearance between the work and the blade below the cutting edge. Also, the cheap chinese parting tools have an annoying habit of letting the parting blade slide back into the toolholder under pressure, this lowering the cutting edge. *Way too many beginners obsess on overcleaning and over adjusting a working lathe rather than learning on how to use it. My personal favorite stunt on an Atlas are the guys that swap out a perfectly good factory installed and aligned babbitt headstock because they have to have the "really much better overall improved extra fancy modern can't make anything without it" timken head stock. Get a good chuck, get a quick change toolpost and make chips.... And when you get the quick change, don't post to this group asking how to make the t-nut fit. If you cant figure out how to do that on your own or you don't have a big file a vise and the patience to get the job done you have no business with a lathe. Charles, who has had too much coffee. Oh yeah Merry Christmas and hope you have many productive and happy years in the hobby.... ------- Date: Wed, 21 Dec 2005 13:32:08 -0800 From: Jay Greer Subject: Re: Adjusting backlash? He Charles: You almost quoted the advice I got from the master craftsman that taught me how to run a metal lathe. My question was: How do you learn how to run a lathe? His answer: "Start using it and it will tell you!" I drink too much coffee too. Jay Greer Common Sense Boat & Tool Co. Inc. ------- NOTE TO FILE: PREVENT TAILSTOCK CENTER SLIPPAGE (MORSE TAPER SLIPPAGE) I recall this topic has been dealt with somewhere else in these files but under what subject wording I forget. So here are a few tips. Morse tapers depend on a perfect friction fit. They should be clean and wiped free of oil before plugging them into the tailstock taper (or into the headstock for that matter). Morse tapers, internal or external, need to be free of raised burrs. Carefully remove any with a fine file or stone applied to the burr only. Small holes or scratches or depressions can be ignored. When a chuck is held on a Morse taper in the tailstock, the tool it is holding still (drill bit for example) may grab within the rotating work held on the headstock, and then spin. Not good as it can ruin the workpiece, damage the tailstock internal taper, and spoil your day. More positively stopping the male Morse taper from slipping/spinning in the tailstock might be accomplished in several ways. - Use a Morse taper with a flat tail that locks it from spinning. This option depends on your tailstock design as to whether there are provisions to lock such a tail, or whether you must add a wedge or setscrew to accomplish the locking. Note that all such locks depend on a rather fragile tailstock casting or sleeve, and breaking that would really ruin your day. - It seems more common in UK writings to help the taper hold by wrapping the dry male taper with one thin layer (no overlapping) of writing paper. Should not be necessary, but it is an option you might try. - Similarly, dry chalk may be applied to the tapers. Might help a bit. - You can leave the chuck key in the drill chuck and support its free end firmly on the lathe carriage. Or substitute a metal rod, plugged into the chuck keyhole, and similarly supported on the carriage. It might be wise to use adequate tape to make sure the chuck key or rod does not fall off. - Clamp locking pliers to the drill bit and firmly support the other end on the carriage. Or similarly use a lathe dog. Some of these ideas came from the Web, and some have been suggested by Roy Moungovan in his indispensible book "Shop Savvy". Buy it. Tons of excellent advice on many metalworking and woodworking topics. You will probably have to find a used version; try Web book search sites. ------- Date: Thu, 22 Dec 2005 15:17:04 -0500 From: "Earl Bower" Subject: Re: Dead centers and lathe dogs [atlas_craftsman] Original Message --- From: "Steve Cox" Sent: Thursday, December 22, 2005 2:11 PM >I have a MT 3 center for the head stock on my lathe. I am turning a > pair of stepped sleeves to go on a mandrill for a friend. > I drilled a 3/8" hole through the stock an I want to use a center in > the head stock and my live center in the tail stock. Then turn the > steps on the sleeves. > The problem is the MT 3 for the head stock sticks out too far for my > lathe dog's leg to reach my face plate. Do they make a #3MT that > doesn't stick out so far? Or do I need to get a dog with a longer leg? > I can weld a rod to the dog I have but don't want to do that if > I don't have to. Steve Steve, I have the same problems at times on my 9" South Bend. My South Bend has a reducing sleeve from 3 to 2 so I can use a #2 morse taper dead center. What I have done a lot of times is the following: Using a 1/2-13 bolt and washer, I use a "T" nut (from my mill/drill) and this usually gets to the drive dog. The "T" nut fits on the front and engages the slot in the drive plate. Most OEM faceplates has 3 or 4 slots in it and is dished in the back. Just be sure that the head of the hex bolt does not hit anything on the headstock. My drive plate, for the south bend, has enough clearance in the back so the bolt head does not hit anything. CAUTION, be sure that everything clears everywhere before engaging power. Earl Bower www.bowermachineandtool.com ------- Date: Thu, 22 Dec 2005 13:30:57 -0800 (PST) From: Jim Ryan Subject: Re: Dead centers and lathe dogs Maybe a carriage bolt in one of the face plate slots cut long enough to engage the dog? Or install a 3 or 4 jaw chuck and let the dog rest against a jaw. #3 MT centers vary a little in length so you could hunt for a shorter one, but if you have one that's not hardened you could just cut it back yourself to where you want it. Also my #2 center with a #3 adapter sets back a little shorter than my #3 by itself. Maybe you have a different combination of stuff already that could get you there. Jim ------- Date: Thu, 22 Dec 2005 20:25:50 -0600 From: Jon Elson Subject: Re: Dead centers and lathe dogs You can turn or grind the point of the dead center down closer to the headstock. I re-point dead centers from time to time, but have never taken that much meat off one before. > Or do I need to get a dog with a longer leg? I have put a large bolt in the slots of the faceplate to drive the dog in this case. On other occasions, when I needed to turn the entire OD of the part, so that I couldn't use a standard dog, I would drill and tap a hole in the face of the part and put a screw there, and use wire hooked to the faceplate to turn the part. I have heard of people putting a C clamp on the faceplate, but I worry about cyclical stresses working it loose. I wouldn't want a C clamp flying off at me. Jon ------- Date: Sun, 15 Jan 2006 17:44:31 -0000 From: "campgems" Subject: Re: Mundane project article > In taigtools, Nicholas Carter wrote: > Here's a mundane home repair done on the Taig lathe this weekend: > http://www.cartertools.com/wmw.html I couldn't live without > machine tools - how do normal people get by in life? Yes, but being "handy" can get you a lot of work sometimes while the guy that chucks stuff to the curb gets to go play. My fix was to the central vacuum "power head", the thing you push around the floor that has a turbine in it to drive the brush. Ours is about 16 years old, and it started to setting up quite a clatter every now and then. At first, I thought it was the little clog belt jumping, but as it turned out, the turbine shaft was worn and the bushing near the turbine blades was totaly shot. There must have been close to 0.040" clearance. The clatter was when the turbine shaft would start running aroun the inside of the bushing vs turing on its axis. No parts to be had, in fact I couldn't even find a brand name on the unit. I pulled it apart and found the shaft was 7mm. Try to find 7mm drill rod at the hardware store. I ordered out a stick from Enco, and while I didn't have a collet to fit, I found a bit of 0.004" brass shim stock cut just long enough to wrap around the 7mm rod let me use the 9/32" collet. I cut the new shaft, and the only problem was that the old shaft had a straight knurl on the step that the little cogg pully pressed onto. I cut that step first and after a couple tries, I found the right diameter that I could then put some micro splines on and get a good fit. I just held the chuck steady and adjusted the cross feed so the tool was biting into the shaft about 2 or 3 thousandths and the Scribed a line along the length of the step, hand rotated and did it again. I but around 20 or so scribes along the length and ended up with an aproximation of a straight knurl. It worked. Bored and bushed the orginal bushing and we now have a usable vacuum head. I thought about leaving it broke, because I hate the sound of it running, but I knew the wife would come up with a fix if I didn't, and it may be worse than the sound. Don ------- Date: Fri, 17 Feb 2006 02:17:34 -0000 From: "Rob Peterson" Subject: Surface finish (oh no, not again....) [atlas_craftsman] I'm turning the spindle nose prior to threading on a new shop-made spindle for my lathe. I'm using HSS cutters, with about 10 degrees rake and clearance angles. A 5 degree chip breaker is ground into the top of the tool. I also stoned the sharp point off and "polished" the ground edges with my diamond stone. Cutter is on centerline. When I was turning the spindle to size I had some really bad/strange stuff happen. It appears as though the steel is galling and work hardening in spots. This turned those areas into rotating file teeth which immediately broke the tip off of my cutting tool. AARGGGHHHH!!! So, WHY did this happen? SFPM was around 2200 (SFPM=RPM*4/Diam) on a 1" diam spindle. I was advancing the carriage manually (no gears yet for the leadscrew) and taking a light cut of about .003"-.004". Spindle was turning at about 550 RPM. No lube because I don't have a drip pan (yet). I finally resorted to using a bastard cut mill file to get rid of the nasty areas. Once I did that, I was able to regrind/stone my cutter and make chips. Checking the tip after each pass and touching up the edge with the stone helped but I should be able to make more than a 3" long cut before my cutter needs reground - shouldn't I? I also have a "phonograph" finish which isn't that important since the nose will be threaded. At this point the spindle nose is about .002" oversize and I was going to gently polish it by hand with emery just because I don't like ugly looking stuff. Any ideas on what I was doing wrong? Rob P. ------- Date: Thu, 16 Feb 2006 22:03:55 -0600 From: Jon Elson Subject: Re: Surface finish (oh no, not again....) >SFPM was around 2200 (SFPM=RPM*4/Diam) on a 1" diam spindle. 2200???? Yikes! Wait a minute. SFPM should be RPM * Pi * D / 12 which I think comes out to 143 SFPM, if I'm correcting the math properly. That is probably a little high for HSS tools, but too slow for carbide. Depending on the material of the new spindle, you might want anywhere from 55 to 100 SFPM. If the spindle is pretty hard, you might want to go with Carbide tooling. Since you seem to be having work hardening, that may be the way to go. Applying some thread cutting oil from the hardware store can be a great help with some materials. Taking very light cuts, and especially taking cuts at very low feedrates makes this problem MUCH worse. Really pushing the feedrate until you get to the last cuts will help prevent work hardening. Jon ------- Date: Sun, 26 Mar 2006 21:55:12 -0000 From: "jdmichael2001" Subject: Re: steady rest setup [atlas_craftsman] markus fitz wrote: > have a question about using the steady rest, is there a quick way to > center a workpiece which does not have a center while avoiding turning > a taper, since I guess it would be possible to be centered but off the > centerline, i.e. offset like turning a taper You'll want to mount an indictor on the carriage, reach around or over the steady rest, and see that your part is parallel, both fore and aft and up and down. If it's parallel front to back you'll eliminate the taper problem, but if it's pointed a little up or down it will be "working" in the chuck jaws and could walk right out of the chuck. If the part lends itself, you can mount the steady temporarily right up next to the chuck and adjust the jaws of the steady rest to contact the part, then move it down the bed to where it needs to be. Check it again with the indicator there, and adjust as necessary to keep it honest. JM ------- From: "Tom Murphy" Date: Tue Apr 4, 2006 9:55 am Subject: GRAVER selection Help [sherline] I've been using my lathe and mill for some time now with good success. I however am finding I need to do specialty cuts/turning (mostly in brass stock) and feel I need some limited graving work to accomplish this. Can you folks suggest some reasonable and good quality gravers? I am not sure what I will really need or to look for in gravers? As an example startinfg point, TIMESAVERS sells several gravers and accessories: 20020: #3 lozenge graver 20023: Bergeon Graver holder 14954: Waller graver (and holder in one) 22926: 6 gravers on wood handles ($20) 14931: 10 gravers on wood handles (66$) They also sell the WR Smith T Rest (for Sherline) which I presume I will also need. Can anyone provide some suggestions/pointers to get me going? I presume any of the "gravers" are specifically only for metal turning. Many thanks! Tom Half Past 6 clocks ------- From: "Charles Fox" Date: Tue Apr 4, 2006 10:04 am Subject: Re: [sherline] GRAVER selection Help First, before blowing tons of money on a rest, I'd suggest turning your tool holder on the lathe to line up whatever tool you have in it parallel with the bed. That will work in a pinch, and get you started. Instead of a set of gravers, pick two -- significantly different in profile -- and start whacking away at something soft for practice. That will tell you faster than anything else what you have and what you lack. If you're like me, it ain't the tool that's lacking. ------- From: Thomas Murphy Date: Tue Apr 4, 2006 10:16 am Subject: Re: [sherline] GRAVER selection Help Charles- thanks. 1) How about removing the tool I have in the holder now and just using a tool blank in it .... will that work? 2) Do you have a suggestion on perhaps which 2 gravers to start with? Do I need to be 'selective' or are they all mostly similar quality etc. Do you have a resource? I have not checked, but I might be able to get some from my local tool supply houses also .. but I use Timesavers alot ... so I was just looking there. If you have a specific suggestion on profile and brand, I'd greatly appreciate that. Tom ------- From: "Charles Fox" Date: Tue Apr 4, 2006 11:18 am Subject: Re: [sherline] GRAVER selection Help >1) How about removing the tool I have in the holder now and just >using a tool blank in it .... will that work? Sure, Tom -- that may be better. Less chance of an inadvertent whacking off of a finger. >2) Do you have a suggestion on perhaps which 2 gravers to start with? >Do I need to be 'selective' or are they all mostly similar quality etc. I got four, but use two. One if very narrow and sharp, the other broad and flat. I find more difference comes from the way I use it than the tool itself. But don't go by me: I am just barely beginning. >Do you have a resource? I honestly don't remember where I got mine, Tom. Sorry. ------- From: "n2562001" Date: Tue Apr 4, 2006 10:45 am Subject: Re: GRAVER selection Help Tom: There is certainly nothing wrong with using a Graver however it is a skill that requires a lot of practice to become proficient. I am curious as to what you feel you can do with a graver that you can not do with creative use of lathe tools? Jerry Kieffer ------- From: Thomas Murphy Date: Tue Apr 4, 2006 11:31 am Subject: Re: [sherline] Re: GRAVER selection Help Jerry- Currently I need to make a post for a small clock door handle/catch in the same shape to match some existing posts on the matching door. The item is French and dates to about 1700-1730. They are on made of round stock (maybe 3/8"OD .. I still need to measure them) and with decorative concave/convex shaping part way up the post ... similar to a baluster on a home's stair rail (an odd analogy ... but one that gives you a sense of the intended result). I was thinking the best way to execute this would be to use "hand skill" and create the shape I needed. I really do not have any tool profiles in these shapes. Alternatively I suppose one could make the profile on a 1/4" tool blank but that seems to be a fair amount of work also. Any ideas? Tom ------- From: "n2562001" Date: Tue Apr 4, 2006 11:49 am Subject: Re: GRAVER selection Help Tom: Since I have not seen the project you're working on I cannot suggest an exact proceedure. However I have done this work as follows. I first remove as much metal as possible with a 60 degree E-4 brazed carbide tool. (Any threading tool will work.) Once I have formed the general shape, the concave/convex surfaces are shaped with flat and round files while the stock is rotating in the lathe. This will require a little practice but far less than with a Graver for the same result. That is, unless you're naturally talented with the Graver making it a better choice. Jerry Kieffer ------- Date: Wed, 05 Apr 2006 From: "Michael Langford" Subject: Newbie: What's the best way to make this cut? [beginnerswkshp] I'm cutting an 1/4" recess 3-1/2" dia. into the face of a piece of 4" 6061T6 round rod. I guess my impatience is kicking in because it's taking over an hour and then some to get that cut; seems like it shouldn't. I want to come up to a square shoulder on the outside and on center there's a 1/4" hole drilled for a subsequent centering operation. Maybe I should enlarge that 1/4" to a 1/2" hole and use a boring bit working from the inside out? Currently I'm using an ordinary cutter mounted in the toolpost parallel to the ways and doing just that but the heaviest cut I'm able to make is about 20 thou or so. Any help would be appreciated. Thanks Mike ------- Date: Wed, 05 Apr 2006 17:40:11 -0600 From: Darald Bantel Subject: Re: Newbie: What's the best way to make this cut? I did a recessed cut up against a shoulder where I was only able to do 5 thou cuts because of vibration problems. It took me almost an hour to make the crazy cut and then they wanted it enlarged 'a little bit'. Welcome to the fun of making molds! Easy does it is usually easier than doing things twice! Darald ------- Date: Wed, 05 Apr 2006 22:45:21 -0400 From: stan stocker Subject: Re: Newbie: What's the best way to make this cut? Hi Mike: You might want to look closely at just what part of your cutting tool is rubbing/cutting and where. In this sort of operation it's easy to have the heel of the cutting tool rubbing instead of clearing the work, preventing any reasonable engagement of the cutting edge. A boring bar usually has far more side and end clearance than a conventional turning tool. If you're working on a lathe larger than a Taig or Sherline you should be able to get through this job a lot quicker! No flames please folks, I DO have a Taig, love it, but do accept it's limits! When doing this sort of job I usually load up a boring bar, hog straight into the work about 30 thou shy of final depth repeatedly (working my way from center to perimeter), then do a few clean up passes to hit final spec and finish. If using a carbide bar I'll usually hone the cutting edge with a small diamond hone if a lot of material was removed. If the power crossfeed worked better on my old Atlas or SB Frankenbeater I'd probably power feed out rather than nibble my way in, but it's just a hobby shop so I work with what I have when possible. Without a boring bar, you need to grind lots of side clearance on your tool to keep the heel from rubbing. If you're regrinding, you may as well grind the side into a rounded shape, and grind around 15 degrees of top rake. 7 to 12 degrees of front clearance is reasonable. A 1/4 inch tool bit works well in this application, less work to grind and easier to get into tight spots. For a 1/4 inch deep pocket in 6061 it should be plenty rigid as long as you don't have too much of the tool waving in the breeze. A bit of kerosene (cheap) or WD40 (smells nicer) will help with finish quality and help reduce material build up on the cutter. Put it on the work with a flux brush, don't squirt it on carbide as thermal shock kills carbide in a rush. If using HSS then just squirt away. Cheers, Stan ------- From: "joep334" joepx~xxformation.com Date: Wed May 17, 2006 2:53pm(PDT) Subject: RC Motor Comm Truing [taigtools] I am new to this thread. I am interested in using a Taig Lathe to true the commutator of a 540 can motor used for RC. I searched the thread and did not find a whole lot of info on this topic. Does anyone have experience doing this with a Taig? If so, what is your setup? Thanks in advance, Joe ------- From: "benedict-listx~xxhawaii.rr.com" Date: Wed May 17, 2006 4:24pm(PDT) Subject: Re: RC Motor Comm Truing I know at least one person on the list has trued motor commutators. I hope they're still reading, and can reply. I've done this a sum total of twice, so take this for what it's worth (not a whole lot): For starters, most commutator lathes use the armature itself as the spindle. It sits in two v-grooves or u-grooves, and is driven by a belt that runs between the armature shaft and a driving motor (usually another RC motor.) This ensures that once you turn the commutator, it will be centered on the motor shaft. This is what you want. I didn't have a commutator lathe, so I used my Taig. As far as tool geometry, feed, speed, coolant, etc., just keep in mind you're turning copper. Any info you find on copper turning will be useful. Most comm lathes use diamond tools. They're fragile, they're sharp, and they do a fantastic job. I didn't have one, so I basically sharpened the everliving daylights out of a normal HSS lathe tool. I wanted it to shave. In hindsight I probably should've bought a diamond tool. Make sure the armature is running dead-true. No matter how you mount it, when you take an indicator reading off either end of the shaft, it should come back with a zero-zero reading end-to-end. If you're off even a smidgen, the commutator won't be concentric with the motor shaft. Mark the entire surface of the commutator with some Dykem, or if you're like me and don't have any at home, use a Magic Marker. Basically you want to be able to tell when you've cut through the existing surface. When all the magic marker ink has been cut away, you're done. Take extremely shallow cuts. There's not much copper there. I set up the compound at a really oblique angle, around 5 degrees from parallel to the lathe bed and used that for in-feed. It gave much finer control than directly moving the cross-slide dial. (Using trig, a 0.001" feed on a compound set 5 degrees off parallel should give an infeed of 0.00008 or so. I was aiming for 0.0001" per pass.) Feed along the lathe bed needs to be as slow as you can make it in order to get a nice finish. This is kinda tough with the Taig, but it's doable. Take your time. The finish was certainly better than when I started, but unfortunately I have no dyno, so I can't tell if what I did helped in the long-run. I seriously hope someone else responds. My own experience is pretty meager on this. Tom ------- From: "Jeffrey Wittman" eyecreatex~xxhotmail.com Date: Wed May 17, 2006 9:43pm(PDT) Subject: Re: RC Motor Comm Truing I have never used a taig lathe to true commutators, but I am sure you can produce decent results (at least better than the condition of the commutator now). I am a factory driver for several R/C companies, so I can answer just about any question you have regarding motors. Your best option (for best performance) is to use a purpose built machine like Tom Benedict explained, as they will produce the best results possible. In my opinion, Tom gave you excellent advice for the machine you are going to work with, and if you follow his process this will be the best you can do. The only thing you can expect is to take many passes if you remove .0001 per pass, as I regularly take off 3-4 thou when I rebuild a motor. We rarely use cutting fluid, as the finish of the cut is more than good enough without. That is not to say you can't, it will just require a thorough cleaning to remove oil in the groves on the commutator. What you are most concerned with is concentricity not finish as the finish will be destroyed in the first 5 seconds you run a motor (because of brush arcing). A commutator that is out of round however will make the brushes bounce excessivelly at high RPM and slow the motor and burn up the commutator prematurely. - Good luck, and have fun. Jeff ------- From: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Wed May 17, 2006 11:01pm(PDT) Subject: Re: RC Motor Comm Truing dkp_design wrote: > never thought about a lathe for truing the comm. how would you hold > the other end? I would assime you would clamp the comm end shaft in > the lathe chuck, but what about the other end? The live ot dead > centers I have always seen are a point, not a centered chuck? I figured the steady rest would be the right tool, that way you could get it running true. See our homepage at www.cartertools.com/nfhome.html ------- From: "Bad Brad" atkinonx~xxhotmail.com Date: Thu May 18, 2006 10:38am(PDT) Subject: Re: RC Motor Comm Truing I have done it and it isn't hard. I built a special tail stock adapter that slipped in place of the ram and placed a bushing with an 1/8" hole in it to support the commutator end. I milled away some of it to allow the bit to clear when the cut was made. I used a diamond bit (what the bit is made of not the shape). You can buy these diamond bits from purpose built lathe manufacturers (they cost $50-$100 but will outcut anything on tough copper). I held the other end with the 1/8 collet and closer. It works great but make sure all of your gibs are tight and you have the most rigid setup you can. Use a Sharpie to coat the com so that you can see that you are just cleaning the com up. FBA ------- From: "benedict-listx~xxhawaii.rr.com" benedict-listx~xxhawaii.rr.com Date: Sun May 21, 2006 3:37pm(PDT) Subject: Re: RC Motor Comm Truing 21 May 2006, joep334 wrote: > Thanks for all of the input. It seems like a single purpose tool > may be the best choice for me now, since I do not own either a Taig > or a comm lathe. For truing comms, I'd say a special purpose tool would probably be a best bet. BUT! Once you have a lathe in the shop with you, it finds its own uses. Nothing like being able to cut custom parts in addition to truing comms. Want a custom set of wheels cut out of solid 6061? ou got it. It's tough to know what'll come up until the thing's sitting in the shop. Tom ------- Re: lead screw speed in relation to spindle speed? [atlas_craftsman] Posted by: "mertbaker" MertBakerx~xxprodigy.net Date: Fri Jul 21, 2006 7:19 am (PDT) > Now remember!!!I haven't touched a lathe in almost 35 years so be > kind.I have a 12 inch craftsman (101.07403)It has a DC motor with a > variable speed control box.The problem I'm encountering is I need the > spindle speed fairly high with a very slow lead screw speed to give a > nice finish.Is what I'm looking for possible?Also does anyone make any > kind of tachometer to read spindle speed? Most lathes with leadscrews have a set of gears that can be arranged to give slow LS speeds, and for really slow ones, a hand crank on the RH end will do this. Some have used a variable speed gearmotor to give a powered version of this. You can rig a $20 cadence counter from a bicycle shop as a fairly good tach. Mert MertBakerx~xxverizon.net ------- Re: lead screw speed in relation to spindle speed? Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Fri Jul 21, 2006 9:38 pm (PDT) A fine finish is achieved by HSbit ground to overlap the feed marks ..viz. take ur rough cut w/ whatever. a finish cut w/ a round nose leaving abt .005 left ...use a knife tool , like a carbide AR tool ,only HS ..set it as flat as machine/material will allow w/out chattering ( maybe 1/2 to 1 degoff of flat & take the cut ...finish is not a function of speed w/these machines & HS ...& HS is what they were designed for .....u can also use a flat point abt .032wide ..LIGHT cuts , a shovel nose (dutch nose) , & a shear grind bit is even better. i only use carbide for very hard stuff ,cast iron etc...i can take a .0005 off w/ HS ,impossible w/ carbide. best wishes docn8as i went thru this when i started using an 1895 lathe w/ 3 fixed feeds...007,.011.& .017....i can get a smooth finish w/out rings/ridges at .007 ....yours & my crftsmn have feeds as low as .0042 or if loose change ,even less......u need more knowledge & skill ....both of which will come .... machine tool operation ....burghardt vol 1 ( get 2 also for shaper/mill )cheap used any edition from 1921 to 43 or maybe later ..... P S ....a shovel nose is ground flat ,full width ,front clearance ,back rake, and side clearance ,w/ sides ground narrower towards the rear leaving the front the widest ...set this at a VERY sl;ight angle ,the apex in the direction of cut ------- Machining a recess? [taigtools] Posted by: "mike_mechanic1" jmpalmer89x~xxhotmail.com Date: Sun Oct 29, 2006 6:54 pm (PST) Hi again. I need to machine a disc and need to machine a recessed section in the face of the disc. What is the best way to do this? I am working with a .785" diameter disc. Do I grind a small tool specifically for this or...? Thanks Mike. ------- Re: Machining a recess? Posted by: "Vlad Krupin" vlad.cncx~xxgmail.com Date: Sun Oct 29, 2006 11:45 pm (PST) That depends on what shape of recess you need. If it's a shallow one, you could probably use the tools you already have. If it's a deeper one, you may need a tool with a pointy tip and more relief. I ended up grinding a couple of tools for similar tasks. Like this one: http://www.krupin.net/serendipity/uploads/pulley_making_groove.jpg (I'm not making a recess in that picture, but I ended up using that tool for a lot of various purposes I never previously envisioned, including making recesses.) Vlad ------- Stopping chatter update [atlas_craftsman] Posted by: "bus444yellow" jverrettex~xxcox.net Date: Sat Jan 6, 2007 4:57 pm ((PST)) I want to mention a few things that I've done to stop chatter and get a smooth cut on my 1930's 12" craftsman lathe. 1. Bought a axa QCTP and installed Still chattering. 2. Removed some shim material on the cross slide to compensate for the worn bed ways (helped). still chattering. 3. Checked the preload on the headstock after rebuilding and new bearing installed and ran under load. Was loose bad .oo8 play. 4. Tightened the Gibs on the tool post Helped more. still not right though. 5. Fine tuned the Tool height on the QCTP. Starting to sound like bacon frying and curly metal shavings. These things have helped a lot and I am close to getting it right. I still have a little harmonic vibration at times, maybe because the bed is not secured; it's just sitting on some rubber pads. Hope this helps others. I did not go into precise details but it gives you an idea. ------- Re: Stopping chatter update Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sat Jan 6, 2007 8:19 pm ((PST)) .008" play is really serious! Of course, the tool should be on centerline. If too low, the work may try to "climb" over the tool; if too high, then the bottom-front of the tool may rub on the work. Anything you can do to damp out vibrations and improve bed stiffness is bound to help. Jon ------- Lubricant on Steady Rest 'Fingers' [atlas_craftsman] Posted by: "Mike Andre" mandrex~xxen.com Date: Mon Mar 12, 2007 4:21 pm ((PDT)) Recently I've been using my steady rest (Craftsman 618 101.21400) quite a bit with large diameter Al (up to 1 1/2") O1 and W1 tool steel up to 1 1/4" and was wondering what the rest of the world uses for lubricant of the brass 'fingers' that actually touch the stock. I've been using white lithium grease but have also read beeswax, oil, and just about everything else has been used. Speeds are relatively slow for the most part, especially when parting off (!!!!) Is there something that's preferred? All the best, Mike ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "Mike Andre" mandrex~xxen.com Date: Tue Mar 13, 2007 2:23 am ((PDT)) "Larry Trotter" wrote: > I use moly engine assembly grease, it is messy but works great. Larry Hello Larry: Thanks for the response. I'm not too enthused about using moly-anything as it really does make a mess! I've ordered some small bearings and hope to convert the steady rest 'fingers' by attaching the bearings and letting them bear on the work surface - should eliminate the need for any lubricant. All the best, Mike ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "Charles Gallo" Charliex~xxTheGallos.com Date: Tue Mar 13, 2007 5:31 am ((PDT)) Ball bearing on your steady have their OWN problem - picture - the steady is supposed to be as close to where the cutting is going on, and the fingers are fairly tight - a nice chip of swarf gets kicked up, lands on your work, and now gets rolled under the bearing. One of 3 things will happen: 1)it somehow gets jammed up, now scratching your work; 2)It rolls under the bearing, getting swaged into the work - denting/deforming it; 3)It jams the work, probably spinning it in the chuck. 73 de KG2V ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "jerdal" jerdalx~xxbrick.net Date: Tue Mar 13, 2007 8:15 pm ((PDT)) "Glenn N" wrote: > While you are at it it might be good to make a couple of "cat's paws" > to go over the stuff you don't want to mar with the steady rest. He probably means cat heads..... A piece of pipe with 1 or 2 sets of 4 centering screws. You can get it clamped onto an irreegular object and still have a round surface for the steady to bear on, namely the outside of the "cat head". Name no doubt comes from the "whiskers" (screws) sticking out. Also made with a large ball bearing having the pipe pressed in, with the screws as before. Then the steady serves to clamp the ball bearing and no sliding at all occurs. I got one like that with my lathe, but gave it to a relative who does gunsmithing. I don't think he appreciated it, and may have sold it with a different lathe... now I'm sorry I gave it away. JT ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "rwp399" rwp399x~xxyahoo.com Date: Wed Mar 14, 2007 5:09 pm ((PDT)) A while back there was a thread on lubricants for the gears and one that was mentioned was "Lucas Heavy Duty Oil Stabilizer" from NAPA. I bought it and it works very well on the gears so I tried it on the steady rest. It works beautifully and really sticks well. Just my 2 cents. Bob Parker ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "james nicoletto" nic8559x~xxyahoo.com Date: Wed Mar 14, 2007 6:38 pm ((PDT)) Here is the method we use in the shop I work in that works really well for steady rests that have fingers not rollers. You wrap the shaft with emery cloth abrasive side out, you want the cloth backing riding on it. Leave a little extra length and clamp the ends in the joint of the rest. Adjust the fingers up until they touch and squirt some oil on the shaft periodically. It works very well. Nic ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Wed Mar 14, 2007 8:54 pm ((PDT)) On 3/14/2007, mandrex~xxen.com writes: > The Bearing sometimes leaves a mark on the part but never a score or > groove. Roller bearing leaves a burnished finish...more difficult to clean up on a polished rifle barrel than brass fingers which is where i ended up after both hardwood & roller tips. For NO marring ,aluminum split sleeve trued up works well w/ any of above fingers. Certainly w/ roller tips if REALLY fussy, put paper under split sleeve ,or solid sleeve ,if u want to drive one on. best wishes docn8as ------- Re: Lubricant on Steady Rest 'Fingers' Posted by: "Al Basham" albashamx~xxnc.rr.com Date: Thu Mar 15, 2007 3:00 am ((PDT)) Just a thought!!!! I have a steady rest on my wood Lathe that uses Roller Blade wheels. They work very well on wood and will probably work well on metal. Thanks Al Basham ------- Steady Rest Posted by: "Glen Lynch" glenco2x~xxnetzero.net Date: Thu Mar 15, 2007 7:59 am ((PDT)) I use ball bearings on homemade steady. I recently had to turn down the ends of a 1 1/4 keyed shaft for an axle for my locomotive. I found a collar that was 1 1/4 id to slip over the shaft and then the steady rollers would not get caught in the keyway. Glen ------- Re: free hand metal turning [taigtools] Posted by: "awolff612000" awemailx~xxcox.net Date: Fri Mar 16, 2007 9:53 am ((PDT)) "mguysmith" wrote: > Anyone out there have any experience with free hand metal turning? I > am interested in learning more about this for clock and watch making > and any information would be greatly appreciated, especially any > information about making gravers and related tools You can rent W.R. Smith's video "Graver Making and Hand Turning" from Smartflix.com or buy the DVD from his website. He also wrote an article on how to make gravers that is available on the Sherline website. Allan ------- Re: free hand metal turning Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Fri Mar 16, 2007 10:06 am ((PDT)) If you wish to learn the use of a graver for reasons of learning/ preserving the traditional methods of watch/clock making, I would suggest the books from WR Smith. WWW.wrsmithclocks.com I would also suggest that you join the National Watch and Clock Collectors if you have not. Learning Graver procedures is not that difficult with practice. However becoming proficient with a graver to the point of producing accurate quality Horological parts is a everyday life long journey. While a few people may have natural talent unfortunately most of us including myself do not. Jewelers' lathes were designed for Graver use and were produced at least 100 years before modern lathes of the same size were available. If your Goal is to produce accurate quality Horological parts requiring the least amount of skill and in a short time frame, I would suggest modern methods on modern Equipment. For example I can teach you to cut a serviceable Balance staff using a quality modern lathe with a Carriage and cross slide/carbide Lathe tools in a couple of hours. I cannot teach you to do it with a Graver; you would need to teach yourself. I could of course show you some procedures but you would need to develop your own methods that produce quality work. For most this will take years and in some cases maybe never. On the other hand, if you're doing this to preserve traditional skills it can be a lot of fun and in some cases eventually very productive. Jerry Kieffer ------- Surface quality of turning's [taigtools] Posted by: "Shane Harris" vtsignsx~xxyahoo.com Date: Wed Mar 21, 2007 9:57 am ((PDT)) Hello all. After reading some of the posts at this group, I'm a little hesitant to post my 'newbie' question. I have owned my taig mini lathe for about two years now and have learned alot by trial and error and by reading. However, I still struggle with finish quality. My turnings, no matter how I fiddle with spindle speed, feed-rate, depth of cut, lubricant, carbide or HSS bits, etc., end up with a finish that equates to a smooth spool of thread (not that exaggerated, but you know what I mean, there is still texture). Aside from the obvious displeasure with my wife's response to my projects - "It still looks homemade", the real problem with the surface quality relates to bearing surfaces and the like. Any helpful hints? Thanks in advance, Shane ------- Re: Surface quality of turning's Posted by: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Wed Mar 21, 2007 12:10 pm ((PDT)) Try using more of a radius on the tool tip, make sure the toolbit is on center. See our homepage at www.cartertools.com/nfhome.html ------- Re: Surface quality of turning's Posted by: "benedict-listx~xxhawaii.rr.com" Date: Wed Mar 21, 2007 4:28 pm ((PDT)) Gotta ask to get the answers. Besides, the "simple" questions are often the best ones and generate the most discussion. One of my faves is to get a room full of physics geeks and ask, "Why's the sky blue?" Don't take the easy answer! Keep asking them to elaborate. Boy, you should see the sweat fly. Got a couple of ideas to throw out there. Likely you've tried these, so let me know how it works out: A couple of things kill my surface finish. First and foremost is tool sharpness. The sharper the tool, the lower the cutting forces. If the cutting forces get high enough to make the tool flex, you get chatter marks. I keep a bench stone near my lathe (near, but not next to, since chips tend to goop up the stone). I'll take the tool out and stone it occasionally to make sure it stays shaving sharp. Next is nose radius on the tool. It's a noxious balance. If the nose of the tool is pointy pointy sharp, it's going to cut threads. Might be very fine threads if your feed rate is slow, but it's still threads. Some radius is necessary. If the nose of the tool has this huge radius on it, there's a lot of cutting area on the tool. The cutting forces go up, the tool flexes, and you're back to getting chatter marks. I've found an ok balance is to take a newly ground and stoned tool and just drag it across the stone, rotating the tool as I go. You don't want to round the cutting edge at all, just the nose of the tool. This puts about a 3-5 thou radius on the tip depending on how much force I use. It's enough to make a visible difference. As long as my feed rate is less than 2 thou per rev, I don't get the threaded look. Next is to check vertical alignment of the tool. If your tool is below the center height of the lathe, you get raggedy cuts. Likewise if it's slightly above. (Slightly above and the tool tends to dig in worse, too, so you can get nastier chatter marks.) This is worth checking often. Dead-on is a good setting to aim for. Next is to check tool overhang past the toolpost. If I could support the tool for its full length, I would. Next best thing is I poke out only enough for the tool to do its job. If my bar stock is 0.5" in diameter, I'll stick out just over a quarter inch, maybe a tad more. The more the tool pokes out, the more succeptible it is to flexure and chattering. Next is to check overhang of the part. A 2:1 ratio is about all I can do out the end of my chuck without taking special precautions. For example, if I've got 0.5" diameter bar stock, I'll let it poke out 1" at the most without doing something like tailstock support, lightening up my cuts, etc. The bar will flex well before the tool will. If in doubt, set up a bar of your material that's barely poking out of the chuck and try your cut on that. If things suddenly improve, it's flexure in the part. Next is coolant. I know a lot of people don't use coolant on aluminum, especially on a larger machine, but on a small one like the Taig it can be night and day. WD40 is used a lot. I use a water soluble coolant. Not as much lubricity as I'd like, but it helps. For steel I use a from-the-bottle cutting oil. Finally, different materials cut differently. Want some instant gratification? Grab some Delrin and use a slow feed. You can get almost a mirror shiny surface on it. If Delrin's a little pricey or hard to get, the PVC at the hardware store is a good second best. The stuff really does cut nice. If you're still getting raggedy cuts, something's fishy. Brass is a good one to move to next. It's stiffer than aluminum so it can handle more overhang. But once it starts to ring, it'll make a chatter pattern that looks like a bad attempt at engine turning. (For a nice version of engine turning, see some of Nick's earlier posts!) If you're cutting brass smoothly, try aluminum. If that cuts smoothly, try some 12L14 leaded steel. If THAT cuts smoothly, try some cold rolled steel from the hardware store. If you can cut that and not have it look like a thread bobbin, TELL ME HOW! I can sometimes get CRS to cut nicely, but usually it winds up looking like rats were chewing on it. Hey, glad you asked! And best of luck. Hope something in there helps. Tom ------- Re: Surface quality of turning's Posted by: "Shane Harris" vtsignsx~xxyahoo.com Date: Wed Mar 21, 2007 5:15 pm ((PDT)) Well after taking the suggestions, and the one that seemed the most obvious (not to me initially, I tend to over complicate things), I ground a radius on one of my toolbits, and whoo-hoo, smooth almost mirror like finish (I know, don't exaggerate!) on aluminum. Thanks again for the info Tom and Nick. Shane ------- Re: Surface quality of turning's Posted by: "Rich Crook" richcrook9418x~xxyahoo.com Date: Thu Mar 22, 2007 1:08 am ((PDT)) Re CRS: it doesn't like tools with a small nose radius, or shallow depth cuts. Put these together, & you'll find that CRS isn't very compatible with small lathes like the Taig. 4140 steel should be easier to get a good finish on. Using a water-soluble cutting oil/coolant may also help. Rich ------- Re: Holding brasss bar [sherline] Posted by: "Bob Ellis" bobx~xxbpellis.idps.co.uk Date: Fri Apr 20, 2007 4:24 pm ((PDT)) Hi Jerry: Perhaps I should have explained myself more fully and clearly in my original posting. I build 1:72 scale model British steam era locomotives from brass and nickel silver, making many of the parts on my lathe. I am trying to make a smokebox door from 0.75 inch round brass bar. I need to drill the centre of the bar to 0.8mm, which I did by starting the hole with a centre drill in the Jacobs chuck held in the tailstock. This worked fine. Then I reversed the bar to thin down the other end to 3/8 inch, but the thinned down end was not concentric with the centre hole. The purpose of thinning this down is so that it will slot into the smokebox of the locomotive and also so that the piece can be reversed and held in the lathe by the thinned end while the front of the smokebox is slimmed down and curved to the appropriate shape. I hope this makes what I am trying to achieve a bit clearer. As I said at the outset, my problem appears to be that the three-jaw chuck will not hold the piece precisely enough to produce a concentric result. Would my best bet be to buy a four-jaw chuck, which I have been led to believe holds pieces more precisely than a three-jaw chuck? It is now 00.20 a.m. in the U.K. so I am going to bed. Tomorrow I am attending one of the premier finescale model railway exhibitions in this country so I shall not be able to respond to any advice members of the group may offer for 24-36 hours. However, I shall be picking up e-mails eagerly when I return to read what machinists with much more experience than me suggest. Best wishes, Bob Ellis ------- Re: Holding brasss bar Posted by: "David Wood" dave.woodx~xxcomcast.net Date: Fri Apr 20, 2007 4:54 pm ((PDT)) Bob: I'm sure someone else has answered this by now, but you need to do this work in a 4-jaw chuck (and bring plenty of setup patience to the job). Remember, when you remove the workpiece from any chuck, whether you reverse it or just do some other work, and return it to the chuck, all the original turning accuracy is gone. That's why everyone advises you to do all the work in a chuck (three- or four-jaw) in the same setup. The work will be as accurate as your turning and measuring skills, and totally concentric, until you remove it and return it to the chuck for more work. Took me two or three ruined workpieces before I learned that, just about the same time as I read it in one of Rudy K's columns. Good luck with your work. Dave Wood PS: Please raise a pint (Gillespie's, if you can find it) at your local for me. My wife and I visited Blighty every two years for over twenty years, and I miss not being able to return. ------- Re: Holding brasss bar Posted by: "Jerry G" chieftoolmakerx~xxearthlink.net Date: Fri Apr 20, 2007 5:22 pm ((PDT)) Hi Bob, enjoy the show. Now I have a better picture of what you want to do. You have a couple of ways to go. Preferred method. 1. Turn the 3/8" "thinned down" end first -- using the three jaw chuck you do have. Then, make a "work adapter" for the three jaw chuck, which shall be clamped in the chuck and then drilled and bored out for a press fit to the 3/8" diameter. Do not use brass; to prevent galling, steel would be good. You would only need an interference fit of .0003- .0005" on diameter. Maximum. Then press the part into the bore, using the tailstock with a wooden block in between. Now you have the means to maintain concentricity when you center drill, and drill to 0.8mm (.031496"). Do you have the adjustable chuck holder P/N 1202? Will help insure your center drill and drill are better centered. After the drilling, do your shaping, profiling, etc. Remove the dedicated work holder from the chuck and press out your smokebox door! A bench block with a .750" hole to support your work holder while you remove your door will be cool! This can be done in a drill press or a mill. Or a few judicious light taps with a wooden drift pin and brass mallet like Dave H. fancies... :) 2. You could do it the other way around, (like you did), but then you would need to make a pretty small mandrel of 0.8 mm ( .031496") diameter to insure concentricity with the added problem of driving your part. Not the way to go, in my opinion. Regards, Jerry G (Glickstein) ------- Finding the center - Not Atlas specific [atlas618lathe] Posted by: "tvipermn" tvipermnx~xxyahoo.com Date: Thu Jun 14, 2007 11:43 am ((PDT)) Hello, I am a newby/hobbyist with a MK2 and having a lot of fun. As part of learning to turn between centers I am practicing on several different types of metal (6061, 1018). The problem I have is finding the true center of the rounds I am using. Everything ends up with a slight taper. I have a 12" HarborFreight combination square with a center head to use but I just can't seem to get on the center. When I use the technique in the Manual of Lathe Operations to see how far off I am, I can visually see the work piece being off center without even needing to use chalk. So I am asking for your help. What is the surest, most accurate way to find the center? Any tips? Tom ------- Re: Finding the center - Not Atlas specific Posted by: "george britnell" gbritnellx~xxyahoo.com Date: Thu Jun 14, 2007 1:05 pm ((PDT)) The idea of turning between centers is not that you necessarily start out with the center drilled holes exactly in the center of the piece. It's that after they are drilled and the stock is mounted between centers you can then turn it true to the centers. As far as the piece ending up with a taper that's because the tailstock is not lined up with the headstock. Mount a dial indicator in your chuck and run your tailstock up close enough to run the indicator around the center in your tailstock. Adjust the tailstock offset screws until you get a -0- reading. If you get a -0- left and right but not up and down then your tailstock is worn on the way surface and there's not much you can do about that. gbritnell ------- NOTE TO FILE: A small vertical misalignment between headstock and tailstock usually introduces a negligible error compared to a horizontal offset. Most often the tailstock is lower because of wear through being slid along the ways. Some lathes when new have even shown a slightly high error at the tailstock, which disappears over the years (probably not an intentional feature by the manufacturer). If a vertical error is big enough to cause a significant (not paranoid) error, the low item could be shimmed, or built up using Moglice or a metal-filled epoxy. ------- Machining an inside curved surface [sherline] Posted by: "Howard Maculsay" maculsayx~xxearthlink.net Date: Sat Sep 29, 2007 8:01 am ((PDT)) I'm a new member here and also a new owner of a 4400 Lathe and 5400 Mill. I'm making a petticoat pipe for the exhaust system on a Class A Climax locomotive I'm building. The petticoat pipe requires a venturi- shape interior surface. I have a compound slide for my Sherline lathe. I'm thinking that short cuts with a boring tool, incrementally changing the angle of the slide while advancing the slide a little at-a-time might work. See my drawing under "Howard's Stuff" in the photos section. Thanks in advance for any ideas. Howard Maculsay ------- Re: Machining an inside curved surface Posted by: "Jerry G" chieftoolmakerx~xxearthlink.net Date: Sat Sep 29, 2007 8:20 am ((PDT)) Hi Howard. What material? Do you know you have to have the toolbit upside down in the Compound Slide? But, there is an option. I looked at the drawing and what comes to mind is: Roughing out as you describe. Finishing with a form cutter you can grind. However, such a large area of contact is prone to chatter. So, I have used the "no power" technique.... Which is simply rotating the spindle by hand, while shaving/scraping the contour. Later, Jerry G (Glickstein) ------- Re: Machining an inside curved surface Posted by: "Marcus" implmexx~xxaxionet.com Date: Sat Sep 29, 2007 9:27 am ((PDT)) Hi Howard: The method you describe will work, and it will work quite well for the roughing stages. However, to get a nice smooth contour will take a bit of fiddling with files and abrasive paper or cloth. There is another way, however, that we used to use in the days before CNC to turn the swoopy contours of bottle molds. Here it is in Step- By -Step: 1) Trace a layout of the curve you want onto a thin sheet of brass, aluminum or plastic that has had one corner milled accurately square. Make your layout as accurate as you can or think you need. You can make either a MALE tracing template to cut a FEMALE shape in the lathe or a FEMALE template, it won't matter except for mounting convenience. 2) Saw out the shape and file it until it looks and feels perfectly smooth and contoured properly. 3) Mount the sheet onto a metal stem that's small enough to fit in the tailstock chuck, by slotting the stem with a saw, forcing the sheet into the slot, drilling a cross hole and bolting the works together. You want the layout to eventually sit mounted in the tailstock chuck in the same orientation as the shape you're going to turn...in this case, the skinny end will be pointing toward the headstock. and the contoured surface will be toward you when you're standing in front of the lathe. 4) Haul out your DTI and grind a round nosed tool that's as close to the same size and shape as the ball tip on the end of the clock as you can make it. This tool will have to go into a boring bar capable of reaching all the way into the hole you're turning out to shape. 5) Rig up a mount that can hold the clock against the template in the tailstock so the tip of the clock is at the widest part of the template when the tool is just touching the face of the workpiece. 6) Rough out your hole with drills. 7) Mount the template in the tailstock with the template horizontal and oriented as I've previously described. 8) Set up your boring tool, and adjust the proper relative position of the clock tip to the tool tip by moving the tailstock in or out for Z axis adjustments and by nudging the clock in its mount for diameter adjustments. (On a larger lathe, the diameter adjustments are made by swinging the compound slide so it's parallel to the cross slide and moving the compound in and out with the clock mounted to it. The bar is mounted separately to the cross slide with a dedicated holder). The idea is that you must be able to move the clock tip independently of the boring bar tip in both X and Z. 9) Begin turning by advancing the tool to just touch the face of the workpiece and just scraping the biggest diameter of the hole. Set the clock to read zero. 10) Advance by moving the CROSS SLIDE INWARD FIRST a few thou so the clock no longer reads zero, then bring the clock back to zero by moving the carriage toward the headstock while watching the clock. 11) Repeat ad nauseum as you trace the template with the clock, ALWAYS MOVING THE TOOL AWAY FROM THE WORK WITH THE FIRST MOVE AND THEN BRINGING IT BACK TO ZERO WITH THE SECOND MOVE. That way you'll avoid gouging into your developing surface. You're making a series of very tiny staircase moves to approximate the shape, and if you make them small enough, you can get a very good approximation indeed. All the form turning that was too wide for a dedicated tool was done in this fashion in countless toolrooms for many decades. If you get really good at eye-hand coordination, you can start out in the inside of the hole, run the lathe in a fine power feed with the carriage moving outward, and just adjust the cross slide on the fly. The trick is to run the lathe slowly, and never overshoot the Zero mark on the clock. It also helps to save the power feed technique for shallow curves so the clock readings don't change too rapidly as the carriage traverses. Hope this helps...even if not for this job, it's an awfully nice tool for your box of tricks. Cheers Marcus ------- Re: Machining an inside curved surface Posted by: "David Clark" dcclark111x~xxcomcast.net Date: Sat Sep 29, 2007 11:39 am ((PDT)) "Jerry G" wrote: > Hi Marcus, You are taking me back many moons.... :) > Would you classify your method as a "duplicator of sorts" ? > Later, Jerry G (Glickstein) I've seen variations called a "tracer attachment". Some even worked off the power feed. The template reacted a cross slide similar to a compound slide without a lead screw. There were also accessories like a pantograph that could scale the part in relation to the template. Largely obviated by CNC, its still a very cool idea. There's a whole world of clever devices like this that people created before they had computers. I love this stuff. If I may just suggest a small clarification Marcus, the use of the word "clock" for the DTI may be confusing to newer hands. Doesn't bear thinking about anyone trying to figure out what their alarm clock has to do with it, especially if its digital. Remember, there's a whole generation now that have never "dialed" a telephone. DC ------- Re: Machining an inside curved surface Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Sat Sep 29, 2007 11:43 am ((PDT)) Howard: In this case, given the size and non critical curved surface, I would suggest the following. Machine the outside and inside of the stack including parallel angle cuts to the major thickness of the angled surface. Next while spinning the stack you can easily freehand form the curved surfaces using a small bur in a dremel tool. The surface can easily be smoothed and polished with emery cloth and steel wool. Considering the size of the item, it should not take more than a couple of minutes. Once you try a method such as this on non function-critical items that are appearance-critical, you will find it to be very fast, practical, and accurate with minimal practice. Jerry Kieffer ------- Re: Machining an inside curved surface Posted by: "Ian Newman" ian_newx~xxyahoo.com Date: Sun Sep 30, 2007 12:24 am ((PDT)) Hi Howard: Remember that you don't have to use tools mounted in a tool holder on the cross slide. Hand turning is just as practical on metal as on wood. I clamp a bar in the toolpost to use as a tool rest and use an old file ground to an edge as the tool -- this will give you sufficient leverage to make the turning easy (altough you can buy ready made gravers for hand turning if you wish). Free hand turn to a template of the shape you want. It is best to use a collet to hold the work so you do not risk touching rotating chuck jaws, but as you are turning an internal shape this issue should not be a problem for you. Use a slow speed and take things slowly. The ability to hand turn small radii and complex profiles is a skill well worth spening time developing, and you will find that it is surprisingly easy to do (the only tricky bit is getting the skill to turn shapes accurately and quickly at the same time!). Ian P.S. If you are interested in high performance from your petticoat you will find the inside profile of a petticoat is more critical than you may think. ------- Re: Machining an inside curved surface Posted by: "Howard Maculsay" maculsayx~xxearthlink.net Date: Sun Sep 30, 2007 5:48 am ((PDT)) Thank you Marcus for a most complete description. You are right, it took quite a bit of work to smooth out the curve using my approach. I will file your method away for future reference, since I can see where it'll produce a more accurate and refined shape than my method. Thanks Jerry....the use of the Dremel Tool would speed up the smoothing of all my incremental cuts. I used a file and emery paper as others here have suggested, but the Dremel would have been an improvement. Thanks again, Howard ------- Re: Machining an inside curved surface Posted by: "Howard Maculsay" maculsayx~xxearthlink.net Date: Fri Oct 12, 2007 12:37 pm ((PDT)) I finished the petticoat pipe and also finished an aluminum/brass diamond stack. Pictures are posted in Howard's Stuff. Howard ------- Atlas 10" With Horrible Finish! [atlas_craftsman] Posted by: "krisa112003" krisax~xxcfl.rr.com Date: Mon Oct 22, 2007 2:20 am ((PDT)) Hi all, I have an Atlas 10x42 that isn't in the best condition. It runs but has an incredibly bad finish. The finish doesn't have a pattern to it, but deep gouges are visible on the surface of any part I turn. I think that it has something to do with the vibration the lathe experiences while running. Honestly it could be anything. Where should I start? Should I examine the spindle? Build a new bench for it? Possibly out of something that doesn't creak back and forth? I'm puzzled. ------- Re: Atlas 10" With Horrible Finish! Posted by: "Joe R" jromasx~xxcolumbus.rr.com Date: Mon Oct 22, 2007 3:48 am ((PDT)) Some patterns are caused by the splices on normal "V" belts as they thump over the pullies and a lot of people use link belts like these. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43771 Another advantage is you don't need to disassemble the head stock to put them on. Also if your bench is flimsy that can cause problems and as you have indicated it's time to check for bearing play. Bad cuts can also be caused by improperly sharpened or incorrectly positions tool bits. I think you know all the suspect areas so just pick one and start :=} Joe ------- Re: Atlas 10" With Horrible Finish! Posted by: "krisa112003" krisax~xxcfl.rr.com Date: Mon Oct 22, 2007 4:34 am ((PDT)) I just put the lathe on another bench that I welded together and it made a huge difference. I'll admit that I've seen better finishes on other lathes I've used, but it's nothing that I can't sand out now. I gotta admit that these Atlas Lathes are awesome. Mine's 60 years old and largely unimproved from the time it was gifted to me from its dirt road grave. I mean that literally, it was sitting on a dirt road for years. Now that the vibration is gone from the bench it's much improved! Thanks Joe for your reply. It's good to know that there's someplace I can go with questions. ------- Re: Atlas 10" With Horrible Finish! Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Mon Oct 22, 2007 10:21 am ((PDT)) There are many reasons for poor surface finish. The shape, sharpness and angle of the cutting tool can make a huge difference. Some materials simply don't cut worth a darn, too. You want to turn at a pretty high speed on small parts. I have moved up to a 15" Sheldon lathe, which I have completely rebuilt. A new machine in this class would probably sell for over $25,000 today. Its stiffness is totally beyond belief; I was able to make a 1 inch ball socket with a form tool cut to a quarter circle. There was no sound from the lathe except the crinkling of the chips of 1018 steel! I was also able to thread 1"-20 in a single pass, although I got a better surface finish by doing in in 3 passes. All the above is to say that there is NOTHING wrong with that lathe! Yet, I can STILL get a rotten surface finish if I'm turning at the wrong speed, using the wrong tool shape or setting it at the wrong angle. I have eliminated some of the awful mystery metal from my shop, too, so I don't try to machine that stuff again. Jon ------- Re: Atlas 10" With Horrible Finish! Posted by: "Lucas Thompson" lucas.thompsonx~xxgmail.com Date: Mon Oct 22, 2007 10:55 am ((PDT)) There are a lot of things to check of course, but I'll share what helped me. I have two lathes, a 10F and a 4800. I was having problems with terrible surface finish and random gouges on the 4800. After someone showed me how to correctly grind tools, I would take the exact same HSS bit and move it from one to the other and the finish was always awful on the 4800. I took an indicator to the 4800 spindle and it seemed like there was about .003-.004 wobble, but it wasn't consistent; there was no "high side" and "low side"; it would just wander around as the spindle turned, even after tightening it up. I took the spindle all apart and found that the bearings were pretty badly messed up. They didn't sound bad though. After replacing them, the wobble went away and the surface finish is now fine. This lathe had been probably been crashed a few times in it's life because there are some gears with repaired teeth and a broken headstock-to-bed clamp that I had to repair when I got it. I can also see bad finish at times when I don't have the angle set right or the tool is dull or I try to use a tool that has a cutting point that's too big. ------- Re: Atlas 10" With Horrible Finish! Posted by: "Steve" skadsmx~xxpeoplepc.com Date: Tue Oct 23, 2007 9:06 am ((PDT)) For some real good information on grinding high-speed steel cutting tools, go to: http://www.chaski.org/homemachinist/viewtopic.php?t=77187&highlight= and download the file "Tool Grinding by Harold V". Harold is a machinist who has helped a lot on grinding HSS, especially grinding chipbreakers, which are a great help on out light-duty machines. Another member, gadgetbuilder, compiled a lot of Harold's posts into one document. Steve ------- NOTE TO FILE: There are other tips on reducing chatter or improving finish earlier in this file. Additional useful ideas can be found in the "Atlas Repair or Fitting" file even if you have another brand of lathe. The file "Cutters, Collets, and Arbors" may help with cutter issues. ------- Re: Cutting springs [sherline] Posted by: "Pierre Coueffin" pcoueffinx~xxgmail.com Date: Wed Dec 26, 2007 3:39 am ((PST)) On Dec 25, 2007, ferdurkel wrote: > I am new to this group, so please bear with me. Can a person cut > springs on a Sherline lathe? I believe that one usually coils springs rather than cut them... You can do so under power on a lathe, though a sherline will tend to run a little short on torque for this process. For most springs, you want to wind them by hand though. If a spring gets away from you on the lathe, the probability of getting injured is very high. I'd recommend that you start by reading this article if you want to make springs: http://home.earthlink.net/~bazillion/safety.html ------- Re: Cutting springs Posted by: "shipmodelmaker1931" chieftoolmakerx~xxearthlink.net Date: Wed Dec 26, 2007 5:19 am ((PST)) If one wants to indeed "cut" springs on the Sherline. I do not advocate the use of any abrasives on the Sherline lathe. The particles will find their way where they don't belong. However, if you MUST... First, cover the bed thoroughly to prevent the debris from infiltrating. Next, Take a good pair of safety goggles. Use them! Mount a cut off abrasive disc on an arbor and run it in a collet. Use the top speed. If you are cutting a compression spring, it will have spaces between the coils, so cut it where you need to. Running a vacuum while cutting is good. If you are cutting an extension spring, you will have to slightly stretch the coils apart where you need to make the cut. Personally, I believe a bench grinder is the way to go, or a handheld Dremel type unit. Jerry G (Glickstein) ------- Re: Cutting springs Posted by: "Marcus" implmexx~xxaxionet.com Date: Wed Dec 26, 2007 8:33 pm ((PST)) Hi Jerry: As I'm sure you know, but as a reminder and as a safety warning to others; cutting springs held freehand is quite a bit more dangerous than it looks. The reason is the flexibility of the spring and its tendency to collapse and grab on the spinning cutoff disc. The resulting jam often sucks the unwary operators fingers into the cutoff disc, or breaks the disc or trashes the spring. The safest way for a beginner to cut a compression spring is to squeeze the spring in a vise, and cut most of the way through the coil with a Dremel cutoff disc, or, in a pinch, with an old file. Once the cut is complete, the spring can be snapped off to length by twisting (like wringing out a wet rag) at the point where it was nicked. Extension springs are more dangerous than compression springs...my favourite way, is to mark the cut point and then flex the spring into a "U" shape, holding it in that shape with a bit of heavy wire also bent into a "U" shape and stuffed into the free ends of the spring so the whole works looks like a goofy "O". The whole shebang can then be squeezed in a vise with the marked point uppermost and the desired coil nicked as before without trashing the adjacent coils. Exension springs need to be nicked almost all the way through, then they can be twisted as before to snap them in half safely. If you just cheerfully barrel all the way through a stressed extension spring coil with a Dremel wheel, you'll almost always end up with a jam and a broken disc, even if you've clamped the spring in the vise as I described. Now I know, you've cut lots of springs in your time...every toolbreaker has, but this comment is directed at people who've never done it before, and it's far safer than any other method I know. So I thought I'd pass it along, attached to your comments. Cheers and Merry Christmas Marcus ------- Re: Cutting springs Posted by: "Marcus" implmexx~xxaxionet.com Date: Wed Dec 26, 2007 9:20 pm ((PST)) Hi All: I just looked over my post on this subject and realized I was unclear on one point. Here's what I said: "The safest way for a beginner to cut a compression spring is to squeeze the spring in a vise". What I should have made clear is that you do NOT want to compress the spring between the vise jaws...you are clamping it on the outer diameter. Also, I like to clamp the whole spring in the jaws...nothing is hanging out the sides of the vise unless the spring is longer than the vise jaws. That way both ends of the spring are supported by the jaws and there is no free end to resonate and flap around as you make the cut. My apologies for any possible confusion. Cheers Marcus ------- Re: Cutting springs Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Wed Dec 26, 2007 8:40 pm ((PST)) Right on, Marcus. "Been there, done that", and obviously you have too. You know I am a bug on safety because of all the industrial accidents I witnessed first hand, so maybe I was kind of simplistic, and your expansion hopefully saved some fingers, and so forth...May I thank you on their behalf? Best Regards, Jerry G (Glickstein) A fellow "toolbreaker" ------- Re: Cutting springs Posted by: "Mike Bauers" mwbauers55x~xxwi.rr.com Date: Thu Dec 27, 2007 6:22 am ((PST)) If you folks are thinking of how best for Newbies to do this... You better mention right at the beginning to wear at least safety glasses, if you don't mind having bits of cut-off disk and hot metal sparks hitting your face while you're using grinding/cutting disks. Or wear a full-face shield like one should always do when power tool grinding on metal. We industrial types are always wearing safety glasses on the job, and sometimes forget that the same is not a constant for a hobbyist. Best to ya' Mike Bauers Milwaukee Wi, USA ------- Speeds and Feeds [taigtools] Posted by: "Ronald Lambier" ronald_41x~xxyahoo.ca Date: Sun Jan 6, 2008 1:46 am ((PST)) Check out www.colinusher.info, there is listed a beautiful little FREE program called Model Engineers Utilities. You'll find that it covers anything that you will ever need in the way of formula's. ------- Re: Working with coins. [sherline] Posted by: "Ron Ginger" rongingerx~xxroadrunner.com Date: Fri Mar 14, 2008 1:44 pm ((PDT)) A variant on the pot chuck that I have used is to make one from a piece of pipe, or heavy wall tube. If I wanted to open the hole in a 1" washer, for example, I'd find a piece of pipe about 1 1/4 dia, and cut off a slice maybe 3/4" long. Then I'd slice the pipe radially on the band saw, making an opening just one saw width wide -- like the cut in a collet, only in just one place so the pipe remains one piece. Chuck that piece into the 3 jaw and then cut a shallow bore on the end to just fit the washer. Slightly ease off the chuck, slip the washer into the bore and re-tighten the chuck. Don't remove the piece from the chuck or you will lose the accuracy. I've made these in lots of sizes, as needed. They really are not re-usable but just put the piece back in the chuck and turn off the old bore to make a new one. ron ginger ------- Hand Turning [atlas_craftsman] Posted by: "indianfourrider" indianfourriderx~xxyahoo.com Date: Mon Mar 17, 2008 8:33 pm ((PDT)) I was inspired by the thread discussing was to make new handles, particularly the off-hand remark that hand-turning metal was common 150 years ago. I needed to make a new knob for the intake manifold heater bypass on my Indian 4. Never mind what happened to the other knob. A rather rough original had been on eBay and I copied the pictures since I knew that some of the "stupid money" on eBay was going to bid the thing out of sight. (It sold for over $150 and, IMHO was good only for a pattern! Never mind that excellent quality repops are out there, for about the same money!) Me, I'm too cheap to buy something if I think I have even half a chance of making it. ANYWAY, I had made one before on my Unimat SL1000 and it was passable. I had found a source of solid aluminum knob 'blanks' at one of the Big Box stores and bought a couple to keep on the shelf. This one I decided to try and turn by hand. I did true up the blank and rough it to size using the carriage and cross slide; and I discovered that a piece of 3/8"x1" cold-rolled about 4" long clamped in the lantern tool post makes a dandy tool rest. I used a 1/4" wood chisel and two of my old Millers Falls woodcarving tools and the swarf was as fine as spun wool. (I got too engrossed in the process to stop and take pictures - it was fun!) The results are in an album called "Hand-turned Project" It's pretty close and I have one more blank... or maybe I can tweak the one I've already got and get it closer. But it's warm enough here to ride so close enough may be close enough! ------- Re: Hand Turning Posted by: "catboat15x~xxaol.com" Date: Tue Mar 18, 2008 8:51 pm ((PDT)) Watch and clock makers turn by hand quite often. They use what is called a "graver"; imagine a square tool with the end ground diagonally and placed in a long handle. They use those to turn steel, brass and whatever they need for a clock or watch. Look up on Google or someplace for "Watch makers lathes" and you can see what they look like and how the tools are used. A skilled clock maker can even cut threads by hand. Also when I first got into this hobby (or compulsion) I used to get old English "Model Engineer" bound magazines from the library and not only did a lot of people use hand held tools, but they did it on lathes that were driven by a foot pedal, kind of like your grandmother's old sewing machine. I would not think a wood chisel would be a good choice for turning metal by hand, that sharp an edge would get caught in the work and result in a lot of pain and a lot of bandages. Take a normal 1/4 inch square tool bit and grind one end on the diagonal and insert it in a handle of some kind (maybe a handle for a wood lathe tool) and give it a try. Who among us has never finished off with a file or hack saw when the chatter gets too fierce to finish off some piece of work. John Meacham from the high deserts of Calif ------- Re: Hand Turning Posted by: "jmartin957x~xxaol.com" Date: Tue Mar 18, 2008 9:06 pm ((PDT)) Another type of tool to try is a round rod - say, a drill blank - ground at a 70-80 degree angle. Rotating the tool to present different angles to the work, you'll find some that result in a nice chip. Especially with something like 12L14. With hand turning, it's important to have the tool rest as close as possible to the work. There is a lot of downward force generated. You don't move the tool along the rest while cutting, but pivot it instead. John Martin ------- Re: Hand Turning Posted by: "n8as1x~xxaol.com" Date: Mon Mar 17, 2008 9:41 pm ((PDT)) >that hand-turning metal was common 150 years ago. and not just alum/brass .....mild steel also ....i simply grind the end teeth off of flat, 1/2 round & round worn out files then grind the flat to a skew, the others to rounded varying points ,maybe 60-70 deg angles & stone....works well when less than PRECISE dimensions are adequate... radius gauges help when picky ....HANDLES always ! best wishes docn8as -------- Re: Hand Turning Posted by: "indianfourrider" indianfourriderx~xxyahoo.com Date: Tue Mar 18, 2008 4:42 am ((PDT)) "davidbradley*123" wrote: > Are you able to say in what "Big Box" store you found the knobs? Just > curious. They look pretty handy to me! Was the price reasonable? The knobs are a Home Depot item: "Knob Hill" #PN0245V-SN-C and I think they are under $3. They are solid aluminum and have some sort of coating on them and are threaded 8-32. ------- Chip Control [atlas_craftsman] Posted by: "indianfourrider" indianfourriderx~xxyahoo.com Date: Wed Mar 19, 2008 10:13 am ((PDT)) Making my first MT #3 arbor on the taper jig presented me with a problem not previously encountered. I have spent the last almost 40 years doing either wood turning or coaxing a Unimat SL1000 into doing what I needed, ranging from HO scale trains and solt-cars to parts for my 1940 Indian 4. The Unimat continues to serve me and offer challenges, but dealing with long chips isn't an issue! Seems that it is on a 'real' lathe. While I have always been kind of hypnotized by the chip coming off of the tool, these got downright dangerous! Eventually I started using a small Allen wrench and manually breaking the chips. I actually recovered one chip that was over 12' (yes, feet!) long. It was an unbroken cut of almost 1" (see the picture "Chip Ahoy" in the "Shop-made Taper Attachment album.) Here are some specifics, albeit in layman/amateur terms: I have no idea what kind of steel I get from the dumpster at the fastener company. Its chief charcteristic is that it's free. It does work-harden pretty easily. Smith Fastener uses it to make industrial bushings/collars/spacers. They mostly drill it longitudinally and chamfer the holes. The stock I used was 2" diameter. I do grind HSS blanks for special cuts but have been using carbide inserts for general purpose cutting for years. I have an abundance of 1/4" brazed carbide bits and insert holders from the Unimat and mostly use a 4-way tool holder as I became accustomes to the "block" style on the Unimat. I do use the lantern/rocker when called for. These inserts are Sandvik 09 02 04 UF. They supposedly have a chipbreaker. Spindle speed: 266; Feed rate: .0057"/rev; depth of cut: .010" Spindle speed was increased after the diameter got under 1.25; feed rate cut to .0043/rev for final pass. Soooo... now to sit back and glean more wisdom from the group! TIA, Jim ------- Re: Chip Control Posted by: "rfmarchix~xxaol.com" Date: Wed Mar 19, 2008 10:12 pm ((PDT)) Jim: I've been a pencil pusher for too many years, but did start life with an apprenticeship in a model shop. I am recently setting up a retirement shop and will be revisiting all that I learned about turning, milling, broaching, grinding, etc. As far as long steel chips go, I recall several issues. First, never grab the chip with your hand while the spindle is turning. A snag and you'll have a nasty cut at best, or a stumpy handshake at worst. A pair of pliers is the only way to grab such a chip, preferably with the spindle stopped. Second, a chip breaker sometimes does the trick. Back in those days carbide was a bit expensive for a small shop and we ground chip breaker steps right behind the cutting edge of a HSS bit. They work in some circumstances. Otherwise, stop the machine periodically and manually pull the ribbon of chip off the work. Good luck. Dick ------- Re: Chip Control Posted by: "Charles Gallo" Charliex~xxTheGallos.com Date: Thu Mar 20, 2008 1:36 am ((PDT)) > Second, a chip breaker sometimes does the trick Another option - try a different feed/speed/depth of cut combination for the part - what doesn't break into chips at one setting often will at a different setting. That said - I almost exclusively use 1 or 2 different types of SMALL, positive rake carbide inserts. If you look at inserts meant for "swiss" machines, you can often find kinds meant for low horsepower less rigid machines. I WILL agree with the critics of carbide - a lot of the older forms, and larger forms are NOT really useful on something like out machines - they are meant to push off the metal, instead of cut, and you need a BIG HEAVY machine for that. The holder I use most these days uses a TINY insert (about 1/4" in the largest direction) has a nice positive rake, and is designed to take cuts less than .040 deep. In fact, the insert style was originally (and is still mostly) used on boring bars - small ones (1/2" shank), and that's a LOT less rigid than turning in out lathe. Why do I like it? Well, I've turned out 5000 of one piece, and I'm still on the same insert (true - small, non interrupted part - each only 3/4 inch long, in Aluminum - but still 5000 of them, and still going strong on the same insert). 73 de KG2V ------- Re: Chip Control Posted by: "davidbradley*123" thumbsdavx~xxhotmail.com Date: Thu Mar 20, 2008 7:52 am ((PDT)) Jim: When I worked in a machine shop, we had made up some chip hooks that looked like small hay hooks. They had a t-handle [generally wood] with a curved end to grab the chips as they were being formed. The hooks were made long enough to reach in to grab the chips without getting your hand too close. You sure needed to stay out of the way, especially when you were turning stainless. Dave ------- True centreing using a Fixed Steady [MyMyford] Posted by: "tr0up" a.troupx~xxemail.com Date: Tue May 20, 2008 6:28 pm ((PDT)) The underlying principle of the method relies on the fact that a steady constrains a cylindrical workpiece to rotate about the long axis of the cylinder. This holds true even when neither the steady nor the tailstock line up with the headstock's axis of rotation. So in spite of small deviations from truth in the machinery, a centre hole drilled in a length of precision ground bar with the outboard end held in the 3 point steady (as close as you can get to the end), will be perfectly true to the bar. To get the fixed steady near enough, I get the work running true at the chuck, then slide the steady as close to the chuck as the gap allows, push it back against the (inside rear) reference shear, clamp it temporarily and bring the jaws up to just touch the work. Now it can be slid back to where it belongs. Don't forget a dab of anti-scuffing paste or similar on the tip of each bronze jaw before offering them up. Replenish it often. Other steady tips: to steady a soft workpiece, such as brass or alu alloy, wrap a strip of card around the work, inside the jaws. Bring the ends out and clamp them between the faces of the steady at the clamping slot. (Provenance: Ian Bradley, the Amateur's Workshop, p22 -- a great book, to my mind, and for some reason an author much maligned on the Internet.) When there is a risk of chips getting into the nip of the jaws and ruining the finish, shroud the steady with a rag. It should be carefully secured in such a way it cannot get wound into the job. Bikini-brief underpants are the ideal shape. If you're gripping on a hardened surface, doing crucial work, you can aim for a small amount of preload by setting the jaws up with the clamp screw loose, then nipping it up judiciously. ------- crank machining [LittleEngines] Posted by: "Mike Miller" mikex~xxmillertwinracing.com Date: Wed Jun 4, 2008 8:55 am ((PDT)) I've made a single, single throw crank, just to see if I could. While it's a conversation piece for certain types of people, it's pretty ugly, and not something I'm particularly proud of. What's the secret for getting a cutting tool down in the throw of the crank to get a good finish? I couldn't seem to get down in there without a lot of chatter due to vibration in the tool/tool holder. ------- Re: crank machining Posted by: "george britnell" gbritnellx~xxyahoo.com Date: Wed Jun 4, 2008 9:09 am ((PDT)) Hi Mike, it's not a matter of getting the tool down to the throw to machine it but more a matter of having the right shape on the end of the tool and taking light cuts. First, your necking tool needs to be no more than 1/2 the width of the journal that you're cutting. Second, you need to split the end of the tool, called bifurcating, so that it doesn't load the tool as much and then you move the tool left and right to clean up the journal. I am including the link to my Photobucket account with pictures of the machining for my Holt crankshaft. http://smg.photobucket.com/albums/v43/gbritnell/HOLT%20crankshaft/ gbritnell ------- Radius machining [mlathemods] Posted by: "Josh" jkb621x~xxyahoo.com Date: Sat Jun 28, 2008 6:36 am ((PDT)) I would like to know if anyone could tell me a good way to put a 12" radius on something with smaller lathe. I have a 9x30 bench top. I am trying to make the lower anvils for a english wheel I am making and the radii have to be correct for the metal to stretch correctly. I have different radii 12", 8 1/2", 6" etc. Thanks for any help. ------- Re: Radius machining Posted by: "Gene Horr" genehorrx~xxgmail.com Date: Sat Jun 28, 2008 6:57 am ((PDT)) Set up the lathe as a mill with a rotary table sitting off to the side. You'll probably want to rig something to move the radius table against the bit in the lathe. You'll also need to mount the rotary table assembly higher than the lathe bed. Gene Horr ------- Quick Gratification [MyMyford] Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Tue Jul 8, 2008 1:31 pm ((PDT)) Day 4 of closeting myself in the basement with the new lathe, wife at cottage and therefore no Evil Eye. I have just made a large female centre inspired from an ME article from the 1920s, time required 40 minutes. This is a 2-MT version of a 1-MT item I have used a lot for a few years. Take a Groz brand 1 inch blank 2-MT arbor for $5.99 or thereabouts. Set in spindle and centre drill deep Set over the top slide and bore a 60 degree cone inside. Chamfer sharp edges as always. No need to case harden. It would porobably distort and you can simply skim it true, like a soft male centre, when it wears. Two main uses. It can guide tooling being hand-fed axially, which is not centre-popped for use on a male centre. I have never found the need however. More useful is quick centring of rod up to 3/4" dia. in the three -point steady, with a view towards centre-drilling etc. a. Head end of rod goes in three-jaw or collet. b. Female centre goes in tailstock. c. Bring up the female centre to capture the tail end of the rod, and adjust the jaws of the steady. NOTE: The female steady is NOT used with spinning work, just for holding while the steady is set. If the rod has a nice faced end, the 60 degree cone will hold it axial enough for you to get the steady set to a thou or less cencentric error. Withdraw the the tailstock and machine the rod as necessary. d. If the end of the rod is burred or rough, the female centre will probably centre it enough to allow you to withdraw the tailstock and face the end of the rod flat, leaving little or no pip. e. Following (d), centre the faced end of the rod in the cone as before, re-adjust the steady, and withdraw tailstock and machine the rod. I too can spend time clocking (etc.) a rod perfectly axial in the steady, and I will if it has to run true on the outside. Usually however we plan to skim the rod true especially since only ground rod is really round, smooth, and straight. This female centre is much quicker and more accurate than using a bell punch and hoping for the best, and even better than the combo square and scriber. It has definitely saved time on the job at hand: a 13" long by 3/4" diameter Myford-dimensioned boring bar. The female centre also makes a Chinese repro steady much easier to use by compensating for the fact that the brass jaws are terribly loose in their slots. When I have milled up steel and bronze jaws the cheap steady will be very serviceable. As a said, they should be considered kits. Now to clean up pizza and beer evidence before wife is back... aw ------- Re: Quick Gratification Posted by: "Bob Minchin" bob.minchinx~xxntlworld.com Date: Tue Jul 8, 2008 1:41 pm ((PDT)) mmm! I like that idea. Must put that on the round-2-it list. Won't get a mt2 blank for that sort of money here in UK. I tend to get set up for MT cutting and make a batch of them. Bob ------- Re: Quick Gratification Posted by: "Bob Minchin" bob.minchinx~xxntlworld.com Date: Tue Jul 8, 2008 1:47 pm ((PDT)) Just looked up a typical UK supplier - about $14cdn for a 28mm diameter MT2 blank!! Bob ------- Re: Quick Gratification Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Tue Jul 8, 2008 2:28 pm ((PDT)) Can't claim originality but can say they're quick to make and damn handy for centring with the steady. I am fortunate to have access to a complete collection of the Model Engineer at the Ottawa science & tech museum. The pre-1940 volumes, especially, are packed with excellent tooling projects. Most inspirational. Anyway, the Groz taper blanks are nicely finished and screwed for a drawbar, and the 1 inch business end is also finely turned, so one or two is handy to have around for small but accurate tooling. They would take a while to manufacture to the same standard. The ones I have here are finished so well they look ground. The tapers are dead on. Unfortunately what costs a dollar in Canada here often costs a pound in the UK, so yes there is good economic reason to turn up a batch. This is my plan too. I must try out the taper attachment and in any case it would be good to have a supply made from different sized rod. Andrew ------- Re: Quick Gratification Posted by: "tr0up" a.troupx~xxemail.com Date: Tue Jul 8, 2008 11:57 pm ((PDT)) Another use for a female centre is to alleviate the misalignment when turning between centres with the tailstock set over to provide a taper. For any angle more than the merest amount (such as you might apply when making a press-fit mandrel) it's not ideal to use conventional centres for support. Ball centres take care of the misalignment inherent to the setup, but are rare and spendy. Female centres, in conjunction with (hardened) small bearing balls trapped between them and conventional centre recesses in the workpiece, are a perfectly acceptable substitute, given that you're not often hogging off metal when turning shallow tapers. (It's usual to rough the workpiece, parallel, beforehand) I've got around this on the rare occasions I use offset taper turning by drilling centre recesses into stubs of MS held in the tailstock chuck and the 3 jaw respectively (if done immediately before needed and not disturbed, they're plenty accurate) but female centres would be classier. One advantage of the loose ball method is it makes the 'gauge length' of the taper very easy to measure: measure longways over the balls when inserted into the workpiece recesses, and subtract one ball diameter. Apply this as the 'adjacent' and the offset as the 'opposite' to the tan (trig) formula to return half the included angle in degrees. If turning multiple items, you'll need to adjust the recess depths so the "across ball" dimensions are maintained similar. Given the other uses mentioned in this thread, I might just put the proper female centre on my 'to do' list. ------- Re: Quick Gratification, Now Grinding Centres Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Wed Jul 9, 2008 6:36 am ((PDT)) "tr0up" wrote: > Given the other uses mentioned in this thread, I might just put the > proper female centre on my 'to do' list. Now I'm thinking the same too, which implies having a big hardened centre. Myford sell a female centre but it is small and costly. The widely available Groz brand Pakistani 2-MT blanks are claimed to have hardened and ground taper. There is SOME truth to this. There must be a little carbon in the steel because, if you nick the backside of the taper with a file, the metal is pretty tough but not hard. Probably evidence of slight induction hardening. However I doubt the business end can be hardened sufficiently for use as a working centre. The idea of making a large hardened centre from tool steel, in one piece, is somewhat frightening. You can make a male centre this way and harden just the tip. There is no measurable distortion. A BIG female centre accepting 3/4" inside is another matter. I'm inclined to bore a cone into a silver steel sleeve that's a close fit on the MT arbor. Then remove, harden and temper, and re-attach with a fixing screw. If this isn't 100% concentric, then grind true. You can make a toolpost grinder from a block of aluminium or steel bolted to the top-slide, drilled (and maybe) bored 1 inch through on the lathe centres, then split with a saw for a clamping screw. Into the hole goes a Foredom flex-shaft handpiece with a little grinding bit. Cover the bed with tinfoil and several very light passes will true the centre. Works on other shapes, anyway. Quick to bodge up. I am lucky - My wife is a goldsmith so I appropriate the Foredom which hangs over my bench for the odd time when I help her with strange jobs requiring engineering type solutions. The Number 30 and 80 handpieces are excellent for precision lathe grinding and there is no drive problem. Just hang the motor over the lathe. Also vastly better than a Dremel or Proxxon etc. for most bench applications. I regularly see used Foredoms for under $100, and a new one is an ideal Christmas present from the wife. Absolutely avoid the Chinese copies now being sold by Grobet USA. Cheap in price and cheap in quality. We received one and sent it back. The real thing is precision and is good for thousands of hours. Andrew Webster ------- Re: Quick Gratification, Now Grinding Centres Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Wed Jul 9, 2008 6:51 am ((PDT)) Errata, not psychosis, is why I'm replying to myself. I described a grinding head I made for another lathe with a slotted toolpost. For a Myford, simply drill a vertical hole in the metal block you are using, so it fits the English pattern toolpost. A much better arrangement than what I built for the other machine. It can be swivelled by loosening the toolpost nut. This sinle point fixing implies that, when I make such a thing for the Myford, I shall use aluminium and take it easy when doing the drilling. aw ------- Re: Re: Quick Gratification Posted by: "John Stevenson" johnx~xxstevenson-engineers.co.uk Date: Tue Jul 8, 2008 3:37 pm ((PDT)) > Just looked up a typical UK supplier - about $14cdn for a 28mm diameter > MT2 blank!! Bob: Just looked on Arc Euro's site, the 1" blank ended No#2 morse are 2.75 UKP each. 1-1/2" and 40mm are 3.75 UKP each The female centres are handy to have. I got a couple of rotating ones some years ago that were supplied with wood lathes. Handy for holding the ends of small armatures that don't have centres in them and steadying taps with no centre hole when tapping from the tailstock. John S. ------- facing something with holes drilled? [atlas_craftsman] Posted by: "mikeyemc" exibarx~xxTHELAIR.COM Date: Sun Nov 16, 2008 10:31 am ((PST)) When you have to face a piece that has holes in it already, like a backplate. Do you just ignore the holes and take small cuts? or do you have to do something special? I'm concerned the cutting tool will catch in one of the holes and cause a huge catastrophic crash. thanks all! Mike B ------- Re: facing something with holes drilled? Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sun Nov 16, 2008 11:17 am ((PST)) Not terribly likely. You may have to reduce the depth of the cut to keep the vibration down, but it is not going to cause a crash. Some cutting tools can chip on these interrupted cuts. But, if the cut is within the range of the machine, then it just is an abrupt start to the cut on each hole. Jon ------- Re: facing something with holes drilled Posted by: "Exibar" exibarx~xxTHELAIR.COM Date: Sun Nov 16, 2008 11:25 am ((PST)) Cool, so as long as I take small cuts, I can pretty much ignore the holes? Perhaps grind a round tip for the cutter to keep any damage to the cutter to a minimum? thanks! Mike B ------- Re: facing something with holes drilled Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sun Nov 16, 2008 1:41 pm ((PST)) Depending on the material, the cutter material, and the stiffness of the lathe, the rounded tip may help or make it worse. Easy enough to try it both ways. Jon ------- Finding home again on the lathe [sherline] Posted by: "Jim Ash" ashcanx~xxearthlink.net Date: Sun Nov 16, 2008 4:22 pm ((PST)) I've got a contoured turning job requiring a lot of stepped cuts on the lathe. Because of the shape of the piece, the cuts are up to 10-12 full dial turns plus the fractional parts on both X and Y, and I have to count them backwards to get back to zero to set up for the next cut. The probability of mis-counting turns is pretty high eventually. Enter, stage right, the steady rest. I took a short piece of welding rod and ground a crude point onto it. I then bolted it clamped underneath two of the three jaw screws so the pointy end stuck out the top by 6 inches or so. I clamped the steady rest to the bed (clear of the cross-slide and the work), then bent the welding rod point over so it fairly accurarely pointed over the right rear corner of the cross-slide in the zero-zero position, but hanging over it a little without touching it. Now I can crank back to zero on either edge confidently by just aligning the point with the edge(s) of the cross-slide without having to worry about counting turns. It's not going to get me down to the mil, but it will let me know if I'm off by a turn, then I can do the rest with the dials. Jim Ash ------- Sizing a part to be heated [sherline] Posted by: "charlesdewen" charlesdewenx~xxyahoo.com Date: Thu Feb 19, 2009 4:04 pm ((PST)) I'd like to change the external threads on an aluminum part. The new threads will have a slightly larger diameter than the old. I'd like to cut the old threads off, then slip on a cylinder with the new threads. I'd like to heat the cylinder, slip it on, and have the cylinder stay in place after cooling. First question: If the outside diameter of the part is 2.250", what size should I make the inside of the cylinder? Second question: If I use one of the 200-series Loctite products, what size would I make it then? TIA Charley ------- Re: Sizing a part to be heated Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Thu Feb 19, 2009 4:46 pm ((PST)) Hi Charlie, I suggest: Bore the cylinder to 2.250" + .0000" - .0002" for a slight press fit. Instead of Loctite, pin it. No heat, no distortion. Regards, Jerry G (Glickstein) ------- Re: Sizing a part to be heated Posted by: "charlesdewen" charlesdewenx~xxyahoo.com Date: Fri Feb 20, 2009 6:20 am ((PST)) Thanks, Jerry, for that solution. It's quite possible that a press fit would be all I needed, in this case. In the past, I've used setscrews, but with the thickness of the cylinder being about 0.150", distortion can be a problem. I've always been curious about the tolerances for press fits. Is +.0000, -.0002 the standard? Do you chamfer the leading edge to help in mounting the part straight? Would you crenellate the leading edge, if you ever wanted to remove the part? Background note: My application here is remounting 100-yr-old "barrel" camera lenses into modern shutters. The typical design is a set of front and rear "cells" containing the glass "elements", separated by a cylinder containing an adjustable aperture (iris). Putting the cells into a shutter allows for control of the amount of time light passes through them. Precision is required to keep the cells parallel and at the same original separation. Charley ------- Re: Sizing a part to be heated Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Fri Feb 20, 2009 7:46 am ((PST)) Hi Charley: How are you doing? Agreed on the use of setscrews. On the press fit tolerances, I am going to send a link here: http://www.engineersedge.com/class_v.htm Press fits vary with the diameters, the material and the application. I just gave you a suggestion for a light interference fit. In the case of press fits, to insure parallelism when assembling, I always turn the first 1/32" or so to a light push fit and a slight chamfer on the leading edge. Polish all sharp edges to prevent any seizing or galling. Please let me know how you make out. Best regards, Jerry G (Glickstein) ------- NOTE TO FILE: If you go too far when lapping or reaming or boring a part for an interference fit and the fit is loose, the following idea may save the part. See my file "Lapping and Reaming" for the message: Re: Problem with an interference fit [sherline] Posted by: "charlesdewen" charlesdewenx~xxyahoo.com Date: Wed Feb 25, 2009 8:11 pm ((PST)) ------- Re: [sherline] Shaft Manufacturing Tolerances - Engineers Edge Posted by: "Ian Newman" ian_newx~xxyahoo.com Date: Fri Feb 20, 2009 11:42 am ((PST)) Further to Jerry's link, the link below is to a PDF document from the SDP/SI website that lists a whole load of ISO standard fits in easily digestible form and compares them to USA, Japanese, Australian, and a handful of the major European standards. NOTE: This is a pdf and best downloaded before opening. www.sdp-si.com/D780/PDF/D780Ref.PDF It covers tolerances for shafts and holes, roller and ball bearings, belts, threads, gears etc. and then goes on to give various conversion tables. A handy little document - a few of the pages are worth printing out and placing along side the number - letter - decimal - SWG tables that we all have nailed to the wall in the workshop. Ian ------- NOTE TO FILE: There was a long discussion (again) in the atlas_craftsman group about levelling a lathe. Actually we are not necessarily trying to make the lathe perfectly horizontal, we want the lathe bed ways to be coplanar. Many discussions on setting up a lathe, including Rollie's Dad's method are already detailed in my file here called "Atlas Repair or Fitting". Such methods are applicable or adaptable to any brand of lathe. Then atlas_craftsman got into an interesting discussion about making your own cheap but accurate level so as to avoid having to purchase an often expensive (you get what you pay for) precision level. You can find that conversation in my "Machine General" file because this device could be useful on many machines. That conversation starts on Feb 20, 2009. Following is a common sense suggestion from Rex as how to get your lathe quickly up and working. ------- Re: to level a lathe [atlas_craftsman] Posted by: "Rexarino" rexarinox~xxgmail.com Date: Sat Feb 21, 2009 5:51 pm ((PST)) snip > > On that note - must I first get the bench perfectly level (to .001" at > > 10" or whatever) before I start to shim the lathe feet? > > Just my thoughts, and maybe I missed something so welcome friendly > > comments back! Ivan Ivan, you could mount your lathe on a basalt boulder at a thirteen point six degree angle in any direction and still turn accurate diameters, as long as the ways are coplanar. A device laid across the ways near the headstock must "read" the same as it reads across the ways at the other (tailstock) end. The common way to do this is to bolt down the headstock on something resembling a flat surface, then bolt down with shims under the mounting feet on the tailstock end so the ways are "flat" (Not twisted, warped, swaybacked, etc.). Whether it's level or not means nothing. Don't waste time on the bench, LEVEL the lathe ONLY because that's the EASY way to make it coplanar. If you devise a different way, use it. Then make little pieces from big pieces until: you are comfortable with the sound and feel of the lathe, you know how to grind a useful tool, you can use the power feeds, you can cut screw threads whether they are useful or not, you can make a smooth turning from good steel, etc. Enjoy making chips! Rex ------- Re: Beginner's questions: Chucking and test work [atlas_craftsman] Posted by: "catboat15x~xxaol.com" Date: Wed Mar 18, 2009 6:53 pm ((PDT)) Sounds as if you are becoming a machinist! Now you can say "Yesterday I couldn't spell it now I are one." First of all on your cast iron experience. There is good cast iron, but also some junk used for weights etc where quality is not important. A good casting might require carbide for the first cut to get under the sand etc that came out of the mold, but after that "skin" is taken off HSS will give a better finish. The waste comes off as a fine black powder that gets into everything; use a magnet to pick it up. Eccentric turning is often done with the four jaw. Find out where you need the new center (an eccentric for a steam engine is often the project.) Lay out where the new center should be, center punch that mark. Put the four jaw on the spindle and center the punch mark by adjusting the jaws to where the mark runs true. A help with the four jaw is to have two chuck wrenches so as you loosen one jaw you can follow up with the opposite jaw. Also a good place to bring in that length of 1/8 to 1/4 dia eight inch length of tool steel that you have carefully centered and cut a 60 degree point on one end and a recess in the other end with a center drill. Put the sharp end in the punch mark and bring up the tail stock to hold your "finder" bar with the ends. Now as you turn the chuck by hand you have a place to put your indicator to center that offset punch mark. About tools, Aluminum uses almost extreme amounts of rake and relief, steel moderate amounts as does cast iron. Watch out for brass as sometimes you want no rake at all as brass can "grab" at your tool and feed itself. You can find books that tell you to turn this material or that with a relief angle of 21 degrees, 6 minutes 9 seconds. Don't worry about that. TLAR is good here (TLAR is "That looks about right"). Those numbers were for production work and a compromise to get the most material made into chips in a given time. If you wanted to make 5000 copies of something in the least amount of time, those angles are important as when you are changing or sharpening tools the lathe is not turning out parts. So studies are made for that situation. You soon learn from the sound and look of a tool if it is doing well or needs some grinding or setting. For HSS tools, have a small oilstone handy to sharpen up the cutting edge; the work reflects the tool so polish up the tool where it meets the work. Oh before I forget, trying to hold a bolt head then turn the shank is pretty iffy. Often heads on bolts are not concentric with the shank. Some high qualilty bolts may be OK in this matter, but the usual bolt from the Home Center may be way off. ------- Re: chatter while turning [atlas618lathe] Posted by: "Uldis Stulpins" u_stulpinsx~xxyahoo.com Date: Mon Apr 6, 2009 11:00 am ((PDT)) On 4/5/09, mike j wrote: >I have a good friend whose not on the web so I told him I would ask the question. we're both novices at this hobby. I'm rebuilding a 618 and he bought a Smithy multi purpose machine. He called yesterday and told me he was getting a lot of chatter while trying to turn steel. The only thing I could think to tell him was to check the turning speed for the material and the length of exposure for his cutting tool. Both being novices, this is like the blind leading the blind. Any other things to check for I need to tell him? < Hi Mike ~ 1. Spindle speed too fast for type of material being cut (lard oil, etc. may help) 2. Depth of cut too aggressive or you've simply exceeded the lathe's capacity 3. Tool bit incorrectly ground for material being cut or just dull 4. Tool bit incorrectly positioned in tool post 5. Drive belt(s) or pulley(s) loose 6. Gibs not snug or ways excessively worn (gibs tight in one area of the ways, but not in another - typical with "high mileage" machines) 7. Tool post loose or bit not securely clamped or material not properly supported or just too loose in chuck 8. Worn or improperly adjusted spindle bearings/spindle 9. Chuck jaws worn at outer ends (no longer grip material along full jaw length - a typical problem on older machines when turning small diameter, short pieces close to the chuck without an additional center for support) 10. Excessive back-lash of feed screws may compound any of above That's at least 10 things that immediately occur to me. When I get chatter, it's usually an excessive speed problem when I'm in a hurry, solved right away by lowering the spindle speed and brushing on the oil. Also, some steels just don't like to be turned on a lathe. Hardware store steel rounds are not what can be called "free machining". If you're both just starting out, it may pay to get some leaded "free machining" stock. I think Cardinal Engineering (309) 342-7474, 2211 155th St., Cameron, IL makes small quantities available to home shop guys that may take some of the frustration out of getting oriented to the craft. The difference in your cuts can be like night and day based only on what you're cutting, assuming everything else is up to snuff. Uldis ------- NOTE TO FILE: The following conversation deals with a fairly simple turning project, with a number of different approaches as to how it could be accomplished. Some interesting ideas that will be useful in future. ------- Strategy for turning a steel disk? [atlas_craftsman] Posted by: "Bruce Freeman" freemab222x~xxgmail.com Date: Sat Jun 27, 2009 3:18 pm ((PDT)) I need to make a steel disk, about 4" in diameter by 1/4" thick. There will be a 5/16" center hole that I will thread to 3/8"-16. At a radius of about 1 3/8" there will be three to five unthreaded holes, 1/4" or 3/8" in diameter. The question is, how to approach making this? I lack a metal bandsaw, so cutting the disk on a bandsaw is out. My best idea so far is to cut a slightly oversized square of steel, drill a 5/16" center hole, and use this hole as a guide for centering the square on the lathe in the 4-jaw chuck. I could then easily mark the outer diameter and the 1 3/8" diameter, and maybe use the holes in the bull gear as an index for marking the positions of the 3 or 5 outer holes. I could then drill these outer holes on the drill press, and use these for mounting the square on the face plate. At this point I could turn the square round, and this is my first major question: How to do this? Should I knock off the corners with the cut-off wheel first, then turn the disk like turning a shaft or cylinder? Or can I cut off the disk as if with a parting tool, but coming in axially, rather than radially? If so, what tool would work for such a cut? When completed, there will be a 3/8" shaft screwed into the center hole. The face opposite this shaft will need to be faced. Should this be the last operation, using the shaft as the center? I'm not sure this will be possible unless I can contrive an odd dog to provide torque between the chuck or faceplate and the disk. Floundering here. Advice would be welcome. Bruce NJ ------- Re: Strategy for turning a steel disk? Posted by: "Charlie Gallo" Charliex~xxTheGallos.com Date: Sat Jun 27, 2009 3:55 pm ((PDT)) Buy a 4" diameter disk of steel from one of the steel houses? 73 de KG2V ------- Re: Strategy for turning a steel disk? Posted by: "ahz" ahzx~xxinsightbb.com Date: Sat Jun 27, 2009 4:12 pm ((PDT)) Get a steel blank that's large enough. Chuck it in the 4-jaw and face it smooth if needed. Then do the other side. Mark the center using a center drill. Verify you have 2" of good radius from that mark. Bore the 5/16 center. Chuck the disk into the spindle using the new 5/16" hole and a mandrel. Turn the outside to diameter. If you can first hacksaw the corners off it would really help. To mark the holes that are 1 3/8" from the center: Using the indexing holes in the bull gear, lightly score radial lines on the face by pulling a sharp pointy cutter across the face using the cross slide. This is an unpowered operation. Lightly score a circle in the disk by placing the cutter against the face 1 3/8" from the center. Turn the workpiece by hand for one revolution to score a circle. Where the circle and the radial lines cross is where you bore those holes. Use an automatic center punch to mark the hole locations. Bore the holes on the drill press. ------- Re: Strategy for turning a steel disk? Posted by: "Brett Jones" brettx~xx5foot2.com Date: Sat Jun 27, 2009 4:21 pm ((PDT)) Buy the material the correct size if you haven't bought material yet. If you have 1/4" on hand, I'd do it this way: 1. cut the blank to rough shape 2. Drill a pilot hole in the "center" of the blank. 3. put some double sided sticky tape on a drive/face plate or a lathe chuck with the jaws removed (something smaller than the OD of the plate) 4. use a dead or live center to position the blank onto the face plate and hold it in place with a good amount of pressure 5. use light cuts with a sharp tool to turn to the final OD. 6. if the math works you can use the bull gear index to mark your hole locations. Do not use a cut off wheel anywhere near your lathe. The abrasive will cover your machine and be a pain to clean off. Brett Jones [Brett wrote this next in a follow-up message.] I just noticed the part about facing one side. You may be able to do this when the blank is taped to the chuck/faceplate. You might have to get creative with a custom ground tool. A lantern tool post may make this an easier task. Don't worry too much about not being able to get all the way to the center of the plate. It'll be drilled out later anyway. ------- Re: Strategy for turning a steel disk? Posted by: "Robert Silas" robert.silasx~xxvideotron.ca Date: Sat Jun 27, 2009 4:39 pm ((PDT)) You may use a jig-saw with a steel cutting blade, cut it close to the diameter, drill a center hole at the center, press the disk to the chuck by the center hole using the live center in the tail stock, take 10 thou cuts on the 1/4" face, no need other holding, no glue, etc. When the disk is made, hold it by the reversed jaws of the chuck, drill and tap the hole using the tail-stock. I have done it many times. Robert ------- Re: Strategy for turning a steel disk? Posted by: "David Beierl" dbeierlx~xxattglobal.net Date: Sat Jun 27, 2009 5:26 pm ((PDT)) At 07:36 PM 6/27/2009, Robert Silas wrote: >diameter, drill a center hole at the center, press the disk >to the chuck by the center hole using the live center in the >tail stock, take 10 thou cuts A paper disk between steel and chuck will help it stay put. David Beierl -- Providence RI USA Atlas 618 6"/3" lathe ca. 1941 ------- Re: Strategy for turning a steel disk? Posted by: "William Abernathy" williamx~xxinch.com Date: Sat Jun 27, 2009 8:43 pm ((PDT)) Drill and tap the center hole first, then take a big chunk of round (or better still, hexagonal) stock, chuck it, face it, and drill and tap it 3/8 x 16 as well. Chamfer and deburr all holes. Leave the big chunk centered in in the chuck, then saw the disk stock to a rough octagon. (Lacking a bandsaw, you might have to do this with a hacksaw, which should have you looking like Popeye after an hour.) And bolt the work through the center to the threaded slug in the chuck. Do an interrupted cut until you knock all the edges off the disk, then close in on your desired OD. Here's where it gets amusing. If you have a mill and a rotary table, you could use that for your bolt circle. I have another trick up my sleeve that enables me to do this without unchucking the work. I have a shop-made boring bar holder that I put aluminum drill guide inserts in. Using this, I can make regular bolt circles on the Atlas by setting the bolt circle radius by measuring with the cross-slide micrometer feed, drilling the first hole, then counting the appropriate number of holes on the bull gear, dropping in the lock pin, and drilling the next. In answer to your question concerning an axial cut, this is possible as well, but you need to relieve the cutter quite a bit to keep the bottom of the tool from dragging in the kerf. You would need to grind it yourself, and it wouldn't be worth the effort. Concerning your apt question regarding driving forces, threading the work and bolting it to a chunk of threaded material will provide all the non-slip driving you could want. I will caution you, though, to consider using a fine-pitch thread, if at all possible. At 1/4" thick, this plate will have at most 4 threads on it with the 16-pitch NC thread. Four threads is pretty much the minimum you can get away with, and if you have to face the work, you may lose thread strength. William A. ------- Re: Strategy for turning a steel disk? Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sat Jun 27, 2009 8:46 pm ((PDT)) Bruce Freeman wrote: > I need to make a steel disk, about 4" in diameter by 1/4" thick. > There will be a 5/16" center hole that I will thread to 3/8"-16. At a > radius of about 1 3/8" there will be three to five unthreaded holes, > 1/4" or 3/8" in dia. I've never done something quite this heavy on the lathe, but I have made a number of discs for various things. I drill a center hole, and then place a bolt and washers through the hole, and bolt down very tightly. I can then grab the bolt in the lathe chuck. If using a bolt with only partial threads, let the bolt head go deep in the chuck, and use two nuts. This way you don't mar the threads with the chuck jaws. Now, the bolt is nowhere as rigid as the lathe chuck, but it does give you access to the OD. Taking gentle cuts at the OD, you should be able to turn it round relatively quickly. Leave it oversize until the points are completely cut away, then make a finish pass with a newly sharpened tool. You will have to make light cuts anyway, as the disc will spin between the nuts, anyway. Jon ------- Re: Strategy for turning a steel disk? Posted by: "L. Garlinghouse" lhghousex~xxsuddenlink.net Date: Sat Jun 27, 2009 8:50 pm ((PDT)) I don't know what all you have access to but here are some quick thoughts: -- Rather than playing with a square, I'd cut out an octagon. -- I'd start with a square and then spray everything with layout dope or some paint. Then I'd find the center by scribing diagonals from each corner. -- I'd center punch at the intersection of the 2 diagonals. Just a big enough center punch to find center with my dividers. -- Then I'd scribe the Bolt Circles and layout the bolt holes. Next I'd drill all of the holes. Probably go one drill size smaller than the tap drill size on the center hole. NOW I'd go to the lathe and make a mandrel maybe 1/2" dia. stock for chucking and a stem that would be a close fit in the center hole. I'd put some threads on this stem [I'd pick some size that I had a die so I don't have to mess with single pointing the threads if I could]. Then I'd put a washer on the stem, my plate, another washer and the nut and tighten it all down and turn the octagon to round chucking the big part of my mandrel and getting the plate as close as I could to the chuck jaws so as to lessen the chance of bending the stem that is not as big as I wish it was. I might even center drill the stem and use a live center and the tail stock for some more support. I would go slow with light cuts. If the too small holding stem gives way, I don't want a lot of speed to cause problems. When it was to my 4" diameter, I now have a good thing to chuck to and I could take the center hole out to size and it will be in the center of my OD. Really, about the only big difference is that I'm laying out the holes with dividers and not using the lathe to locate the holes. Your way would probably work, but I'm not used to having a 4-jaw chuck and I am used to doing layout with dividers. You could lessen the problems of the interrupted cut if you scribed the OD and then eyballed grinding close to the scribe line if you have a grinder. The less severe the interrupted cut the more chance of success. Using dividers you can get very accurate. Machinery's Handbook has a whole section on layout, with some neat tricks. Hope this was helpful. If you could settle for a larger center hole, the chances for easy success go up quite a bit. L.H. Garlinghouse Arkansas USA ------- Re: Strategy for turning a steel disk? Posted by: "carvel webb" carvelwx~xxabsamail.co.za Date: Sat Jun 27, 2009 11:58 pm ((PDT)) All the hints are workable, but if you still need to finally skim the disk for surface finish or precise thickness, I suggest you beg, buy, borrow or steal a magnetic chuck. If the chuck doesn't have a suitable fitting for your lathe, then hold the magnetic chuck in the outside jaws of your 3 or 4 jaw. Magnetic chucks are surprisingly powerful, but light cuts are still the order of the day! Regards, Carvel ------- Re: Strategy for turning a steel disk? Posted by: "Charlie Gallo" Charliex~xxTheGallos.com Date: Sun Jun 28, 2009 3:21 am ((PDT)) Another idea - if you insist on to it from flat plate - first, lay out the part - center hole, use a caliper to mark out the OD, and just as importantly, the bolt circle. Working carefully, you can then use the calipers to lay out the bolt circle. Center punch the location of the 1st hole, and by trial and error, walk the calipers around the now marked circle, when you get that right (sorry typing errors - in a lot of pain this AM - health issues). Once they are laid out, center punch and mark them too. NOW drill out the center hole (you don't need to tap it yet) and at least one of the bolts for the bolt circle. Mount the work to a sacrificial faceplate - wood is OK, so is Al, heck, whatever. The center hole is for the center (duh) and the hole on the bolt circle is for a driver pin! Now, mount the faceplate and work in your lathe, center the work, and turn down the outer edge - one way that I've not seen anyone mention is trepanning the work - aka you cut in from the face till the work parts off. I'm gonna guess you can figure the rest out from there 73 de KG2V ------- Re: Strategy for turning a steel disk? Posted by: "Bruce Freeman" freemab222x~xxgmail.com Date: Sun Jun 28, 2009 3:47 am ((PDT)) These look like a bunch of good ideas. I'm going to have to do this again, so I'll probably keep this thread and review it again. What I actually DID was this: *I used a power hacksaw to rough out a square. This was tedious, but at least it ran largely unattended. *I drilled the center hole and used a 5/16" bolt as a mandrel, tightened down with nuts. *I mounted the bolt and square in the 3-jaw chuck, and using slow speed, scribed the 1 3/8" and ~2" radii with a sharp tool. *At this point I still had no good way to drive the disk in the lathe with any significant torque. I tried using nuts and lock washer to convey torque from chuck to square, and indeed was able to deepen the ~2" radius from either side this way - destroying the lock washer in the process. (I've never seen a split washer open up and back away from a bolt before!) So I was left with a square with circles scribed deeply, but nowhere near a free disk yet. I would NOT try this again. (The suggestion of a larger device to chuck up is a good one, but I suspect I'd still need a pin or something to convey the torque.) *I dismounted the assembly from the chuck and held it in a vise on the bench. *I trimmed the corners to octagon and then "almost round" with a cut-off wheel on an angle grinder. This was very fast. *Next I used the concept of a "driven lathe" (I don't recall the correct term) to round the disk well enough for my purposes. This entailed mounting the rough disk so it could spin and using the angle grinder to drive it while also grinding the edge. This worked well enough to get a reliable OD, but I didn't attempt to go beyond this to any sort of smoothness because it didn't matter for this project. *Again I chucked the disk and bolt in the lathe, this time to use the "divider" on the bull gear to mark angles. This proved quite easy. (I had pre-marked approximate angles with a protractor as a guide.) I scribed these with motion of a sharp tool held in the tool post. *Off the lathe, I center punched and center drilled the five outer holes, and then drilled them to size. *I threaded the center hole and mounted a bolt and jam nut as the shaft of the apparatus. (I may change this later but it will do for now.) What I didn't do was face the disk. This was because I couldn't get enough torque to do that job. I made a judgment that the surface was good enough for this project without facing. I may revisit this later using some of the hints I got on this thread should that judgment prove faulty. Thanks for the help. Bruce NJ ------- NOTE TO FILE: The following problem relates to a Taig lathe user having difficulaty holding a long thin rod for turning. The suggestions are useful for other small (and big) lathes out there. ------- Re: New Lathe User Help [taigtools] Posted by: "kd006" kd006x~xxyahoo.com Date: Sat Jul 25, 2009 11:32 pm ((PDT)) In taigtoolsx~xxyahoogroups.com, "noisillator" wrote: > I'm trying to turn a 1/2" brass rod that's about 8" long. I need to turn it down to about 0.45". My problem is how to support the far end. I've tried the Taig steady rest, but even with oil it mars the material pretty badly and doesn't hold it well. I'm thinking the tailstock center would work, but I can't figure how to drill a dead-center hole in the rod. I do have a large drillpress, but unfortunately, no vise. What's the most straightforward way to get this done? < Steady rest, center drill the end then use the tailstock center? Kristin [and in a further message] Sorry I was assuming you have a chuck that will go on the tail stock, if you are in the US you could probably remove the chuck from your power drill, there is a lefthand thread screw down inside holding it on, remove that and unscrew the chuck CCW off the drill/ or can probably buy a chuck at a hardware supply. In any case since you have .050 to play with you could probably get close enough with a center finder and scribe the rod end and make a dimple with the drill press. Lacking a V type center finder even a compass/divider set close to eyeball center should get close with 3-4, sweeps. Kristin ------- Re: New Lathe User Help Posted by: "pe3hmp" pe3hmpx~xxhotmail.com Date: Sat Jul 25, 2009 11:52 pm ((PDT)) Not only if you live in the US, at first I removed the chuck from my old powerdrill, later I replaced it with a bigger new one. I think the thread inside the chuck is the same everywhere. mark ------- Re: New Lathe User Help Posted by: "noisillator" tech.writerx~xxearthlink.net Date: Sun Jul 26, 2009 1:47 pm ((PDT)) > Sorry I was assuming you have a chuck that will go on the tail stock Yes, I do, but the bed isn't long enough to do this. The rod is 8" long, and at 0.5" D, it won't slide through the headstock. > In any case since you have .050 to play with you could probably get close enough with a center finder and scribe the rod end and make a dimple with the drill press. Lacking a V type center finder even a compass/divider set close to eyeball center should get close with 3-4, sweeps. Not sure I can ding the center very accurately by eyeballing it. Might be my only choice though. Dang, I need more tools. ------- Re: New Lathe User Help Posted by: "David Robertson" davidr415x~xxgmail.com Date: Sun Jul 26, 2009 2:03 pm ((PDT)) If you have a steady rest... mount the piece in the chuck with the outboard end in the steady rest. Then "catch a center" with a graver as shown in the video below: http://www.youtube.com/watch?v=q6-4oyIoku4 Then you can use a center in your tailstock to hold the end for turning. May be a bit awkward but it will work. David ------- Re: New Lathe User Help Posted by: "Bertho Boman" boman01x~xxvinland.com Date: Sun Jul 26, 2009 2:15 pm ((PDT)) Use a caliper set to 0.25" and mark off several lines as you rotate the piece. You will end up with an accurate center mark. With a prick punch you should be able to get very close. If you really need accuracy, put a short rod in the lathe that is larger than the 0.5" and center drill it and then drill a 0.5" diameter hole about an inch deep. Without removing the rod, drill a smaller hole for your desired drill bit or a center drill through the rest of the rod. Remove the rod, slip it over the end of your work piece, and drill through the guide hole. If you really want more accuracy, then ream the 0.5" hole. Bertho ------- Re: New Lathe User Help Posted by: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Sun Jul 26, 2009 2:25 pm ((PDT)) Make a centering thimble. Bore a short piece to slip over the end of the stock with a hole in the center to guide a center drill held in a cordless drill. An old solution from one of my books. See our homepage at www.cartertools.com/nfhome.html ------- Re: New Lathe User Help Posted by: "pe3hmp" pe3hmpx~xxhotmail.com Date: Sun Jul 26, 2009 2:34 pm ((PDT)) That's one I never came across; thinking about that, if you have to do that often you could make use of a drill chuck, tighten the chuck on the end of the workpiece and drilling thru the center of the chuck where it normally is on the drill axle, that should do it. Mark ------- Re: New Lathe User Help Posted by: "noisillator" tech.writerx~xxearthlink.net Date: Mon Jul 27, 2009 6:14 am ((PDT)) "pe3hmp" wrote: > ... you could make use of a drill chuck ... I like this idea, but if I understand correctly, it requires a drill chuck with a hollow mount. I don't think any of mine are made that way. Also, wouldn't the drill bit be limited to the size that exactly fits through the back of the chuck? My question about this generated quite a few interesting techniques. Unfortunately, most require drilling a perfectly centered hole in something else first. I either don't have the other items available to drill, or no way to mark them precisely. That's not the fault of the people who replied - and I do appreciate all the good ideas - I just don't have enough tools for this work yet. In the end, I used a scrap piece of right angle to scribe four parallel/ right angle lines across the workpiece, forming a very small square in the center. Then I dimpled the center of the square with a pin punch while viewing with a 5X loupe. This worked great until I drilled it. I can never seem to drill exact centers with standard twist drills, even when there's a punch mark. The drill nearly always walks a little as it enters the site. Even using my drillpress and ensuring the piece was exactly vertical, it walked a little. I eventually used the other end, but rather than drilling out the punch mark, used a tapered glass cutting bit followed by a multi-flute chamfer tool. That worked much better. This raises another issue that I've been wondering about for some time. What's the best type of drill bit for work like this, one that won't walk as it enters the metal? ------- Re: New Lathe User Help Posted by: "pe3hmp" pe3hmpx~xxhotmail.com Date: Mon Jul 27, 2009 6:29 am ((PDT)) There are center drills for this, using a small normal drillbit always causes movement: http://www.lathemaster.com/images/TN_Center_Drills.jpg And yes there are drillchucks that have a hollow mount and come in all kinds of sizes. I never had to do it with a very long workpiece. Mark ------- But on a serious note... [taigtools] Posted by: "kd006" kd006x~xxyahoo.com Date: Thu Oct 8, 2009 5:00 pm ((PDT)) Just received my order of stuff from MPJA, got some microswitches x~xx under a buck each. Marked MICRO japan v-56150k long arm low force switches with roller, 1/4" QC/solder terms. Going to use them for my limit switches, rated .1A so I suspect they may be gold contacts. The MPJA P/N is 18085SW. they look like good quality switches, time will tell. I also bought a couple of panel meters, 200mv-500V, 5VDC supply; going to use one to monitor the stepper PS, perhaps another to monitor the voltage on my lathe DC motor for relative RPM measurment. My thought was to use a strobe disk on the spindle and a neon lamp (like the old phonograph strobes) to measure RPM and equate it to armature voltage. Should be easy enough to print out some strobe disks with the right # of lines for 100/300/500 RPM and if my logic is not faulty they should also synch at multiples of the base speed i.e. 200/600/1000/3000/5000. I will post the formula for # of lines if anyone is interested in experimenting. Kristin ------- Re: But on a serious note... Posted by: "Will Schmit" anchornmx~xxyahoo.com Date: Thu Oct 8, 2009 7:45 pm ((PDT)) I was fortunate enough to own a REC-O-CUT turntable. That platter weighed 20 pounds and could absorb the drag of a an Ortifon cartridge in a Weathers wooden tonearm. The strobe on that platter was sensitive enough to show changes in speed as simple as mega bass lines. If the drag of an intense passage of music could cause enough drag on a muther massive platter while using state-of-the-art equipment, then I am quite certain that milling metal would be a major drag. I think that monitoring a spindle plowing through metal would drive a person crazy. I would just use enough power for the job, and then monitor how the chips curl. Far more relaxing ------- Re: But on a serious note... Posted by: "kd006" kd006x~xxyahoo.com Date: Thu Oct 8, 2009 8:04 pm ((PDT)) Really it's all relative; if you're facing off a piece, do we really adjust the speed down as we reach the outer edge? Was just a way to get a baseline speed anywhoo. Seems there is too much involved with speeds & feed and worrying about the whole process; life is too short, get a ballpark speed and turn or mill, nothing will be ever perfect as you move through the job, just close enough for "government work" or "good enough for a blndman flying over in an airplane" (or aeroplane as Old Fred used to say). Not too shabby a way to see free running speeds; anyway, I don't need no stinking digital tachometers, I will do it the old ways. Kristin ------- Re: But on a serious note... Posted by: "Pierre Coueffin" pcoueffinx~xxgmail.com Date: Fri Oct 9, 2009 1:06 am ((PDT)) I've been known to literally do this on a Sherline with the nifty speed control knob... More to get higher speed as I get closer to the middle though. On any work piece where I want a nice finish on a facing job, I run as fast as I can without chatter at the edge, and much faster than that at the center. I adjust speed with one hand as I move the cross-slide with the other. I watch the chips coming off through a magnifier with a fluorescent light, and judge the speed by a combination of the sound made and the way the chips peel off the surface. This does not leave any eyes free to watch a strobe wheel and count the pulses on it though. ------- Machining light Alloys [MyMyford] Posted by: "Frank Chadwick" fr4nk.chadwickx~xxtiscali.co.uk Date: Tue Oct 13, 2009 10:49 am ((PDT)) Folks, I'm having a problem getting a good surface finish on some 10 inch diameter traction engine wheel rims cast in light alloy. I also had problems getting them into the gap on my old ML7 bed, but that's another story. I used slowest backgear and a carbide tip to true the rims then went to a hand-ground tool for a better finish. The tool is sharp and has a rounded profile but I seem to get a tearing effect on the surface. If any one has been there with this problem could you suggest suitable speed and top rake? as I feel this is where I'm going wrong. Frank C. ------- Re: Machining light Alloys Posted by: "Alan Moore" a.j.moorex~xxbtinternet.com Date: Tue Oct 13, 2009 11:25 am ((PDT)) Frank: My sixpenn'orth, for what it's worth. Theory suggests that with a 10 inch diameter you should be using 100 - 150 rpm to give 300 ft/min cutting speed. Are you using a cutting fluid? Most people suggest using paraffin, but I've used white spirit succesfully in the past. The fluid is important to lubricate the chips and prevent them building up on the tool tip. The experts suggest grinding your tool to give 25 -30 degrees side rake, but I'm not sure this is worth doing unless you have a lot of aluminium to turn. Is the tearing effect on the surface regular? If so, it could be chatter and you should look at how the rims are clamped and how much overhang there is on the tool. If it is not a regular pattern then suspect buildup on the tool. Hope this helps. Regards, Alan ------- Re: Machining light Alloys Posted by: "Bob Minchin" bob.minchinx~xxntlworld.com Date: Tue Oct 13, 2009 11:48 am ((PDT)) You might be getting aluminium build up on the tool tip? I suggest low speed, razor sharp tool with lots of top and side rake and clearance with a very slight rounding on the nose. Fine feed and paraffin/kerosene/diesel as lubricant. hth Bob ------- Re: Machining light Alloys Posted by: "durnfjmx~xxaol.com" Date: Tue Oct 13, 2009 12:16 pm ((PDT)) FWIW I have had similar problems, and in?frustration turned the speed UP. Very sharp tool, and "turps substitute" flooded on worked. Can't say it's the answer in your circumstances, but don't be afraid to try the unconventional . . . MikeD? ------- Re: Machining light Alloys Posted by: "Ken Strauss" ken.straussx~xxsympatico.ca Date: Tue Oct 13, 2009 2:46 pm ((PDT)) If buildup is the problem a slow drip of 99% isopropyl alcohol (pure rubbing alcohol) is a little less messy than kerosene. Alternatively, WD40 works well. ------- Re: Machining light Alloys Posted by: "C.S.Johnson" csjohnsonx~xxbtinternet.com Date: Wed Oct 14, 2009 5:23 am ((PDT)) Hi Frank: In addition to what the rest of the lads have said, use a sharp HSS tool,with a good surface finish and choose as thick a tool shank as possible say 1/2"+ , with minimum overhang and lubrication. This will reduce vibration and give a good finish. With some alloys, rubbing the tool top face with a wax candle before each cut works. Colin ------- Re: Machining light Alloys Posted by: "ravensworth2674" ravensworth2674x~xxyahoo.co.uk Date: Wed Oct 14, 2009 10:22 am ((PDT)) Adding a bit(?) to Colin's excellent comments, I use lard oil obtainable from most decent oil suppliers in 5 litre drums. However, the second point is that Cleeve raised his ML7 by a .250" and this appeared in ME 113 in 1955. (kind regards from the other side of the river) N ------- centring tip [MyMyford] Posted by: "sardinesarnie" sardinesarniex~xxyahoo.com Date: Sat Nov 21, 2009 1:59 pm ((PST)) Hello all. I came across this youtube tip on centering a component in the lathe. Copy and paste the link to your browser bar: http://www.youtube.com/watch?v=tn7A9PqNftY Simple to make the required tool, and seems to work very well. Thanks to popnstart for posting the video. ------- Pick-O-Matic Thread/Feed gearing [atlas_craftsman] Posted by: "VBrannick" valestreetx~xxstny.rr.com Date: Sun Dec 13, 2009 7:27 am ((PST)) Question: Can elements of the manual change gear arrangements, somehow be used to supplement the P-O-M 'dial-up' (for loss of a better word) lead screw rotation? The lowest feed rate on the P-O-M 'chart' is .004", and requires a 60T gear. The manual change gear arrangement can provide a .001877", as well as a .0035" feed, and none of the thread/feed specs calls for a 60T gear, which incidentally seems to be an uncommon item. It's unlikely that I might ever need to use a 60T gear, but I would like to have a finer feed that .0048", which with the P-O-M qcgb appears to be the lowest feed available. Thanks in advance for any response. Vince B. ------- Re: Pick-O-Matic Thread/Feed gearing Posted by: "doc" n8as1x~xxaol.com docn8as Date: Sun Dec 13, 2009 2:30 pm ((PST)) If eliminating feed marks is the reason for desiring smaller feeds , there are tool bit grinds ( shear grind) & tool placements that eliminate the rings and provide a smooth surface..the smallest of three belt feeds on my 1895 14 in lathe is .007 ...& w/ these grinds, I eliminate feed rings & present a smooth surface...in fact the xtra gear hanger I made to use ½ nut compound geared feeds down to .0015 is still unused 4 yrs later.. Let me know if you want to pursue this. Best wishes Docn8as ------- Re: Pick-O-Matic Thread/Feed gearing Posted by: "VBrannick" valestreetx~xxstny.rr.com Date: Sun Dec 13, 2009 3:46 pm ((PST)) Hello 'Docn8as'. Thank you for your interest and timely response. I do find that the coarser feed tends to produce a less satisfactory finish with the (obviously) higher carbon content steel rod I'm turning. Over .015" depth of cut tends to cause some chatter. I grind my toolbits on a bench grinder, and am usually able to produce a good surface on 1020 steel, but 1095 drill rod or alloy steels cause more of a problem with my 10" Atlas lathe. I am a bit perplexed by your description of belt feeds, and the mention of an an "extra gear hanger". The so-called 'banjo', on the back-side gear system of the P-O-M, does appear to have provision for other gear arrangements, but I don't know if that might (or might not) be used for other thread systems, such as metrics. I've sent for a manual for the Pick-O-Matic, and that may clear up some of my confusion, relative to feed rates. Not knowing if your lathe is comparable to the one I have, and certainly a 7" swing suggests a much heavier machine, it's difficult for me to envision belt feeds. I'm aware that correct spindle speed (sfpm) for any particular material is essential, and that feed is (or should be) correlated. Sometimes to get a better finish, I resort to experimenting with the spindle rpm, and adjust the feed accordingly. Attention to correct grinding angles, of course is also paramount, but a question may be, how does one know other than cut and try? I am truly appreciative of any advice you may be willing to offer, and suggestions you may have. Thanks again for your input. Vince B. ------- Re: Pick-O-Matic Thread/Feed gearing Posted by: "doc" n8as1x~xxaol.com docn8as Date: Sun Dec 13, 2009 8:33 pm ((PST)) Think I will Start at the end. One does know by cut /try .always cutting /trying /learning for a lifetime ..but there is also the accumulated knowledge of innumerable machinists conveyed by example, word of mouth, the written word. for a start .."machine tool operation " by burghardt vol! . any edition ..ebay book sellers abt $10. may as well get vol 2 at same time ...he was the superintendant of industrial ed. In new jersey school system & a plethora of books are out there. vol one is primarily lathe vol 2 is shaper planer miller grinder.. fifty years later I still will refer.....advanced machine work by smith is near a $30 book, in lesson format for undergrads at MIT, & every operation a HSM wud desire is in there by the numbers...for future use.....these were published from late 20's on, & are the technology where one shud start.. many of later books are geared to industrial practice of later technology & much heavier machines .. speeds /feeds are for industrial use.... I have crftsm/atlas 6x18, & 12x36 & others... the antique 14 in reed is a heavy machine from circa 1895, 1700#..i keep a 12 in 4 jaw on it mostly & go to it for heavier work than I want to do on 12x36, or when I need zero runout ...the feeds are driven by belt & 3 step cone pulleys, 3 from spindle & 3 on FEED rod...these fixed feeds are .007, .010 & .016 ...loose change gears, ( we cut nearly 18 of them ) are in train to LEAD screw...by having the feed exclusive of thrd gears, there is much less compounding & gear change .. ususally only one or two gears to change for different pitches, almost as quickly as Q.C. box..the xtra gear hanger I fabbed was to get very small feeds by gears & leadscrew. much as atlas does..still haven't used them. Atlas gear setups for metrics are available .. they don't use 127/100 or 120 & use the factory gears for reasonably close approximations .. a 127 gear, 16 pitch is well over 8 in D..logan uses 47/37 for a 1.2702 ratio.. this times 2 =25.404... now 1.27 X2 =2.5400=mm/inch. & is the 127/100 ratio.. the atlas setups are adequate for all but the most discriminating uses. the thrdng indicator cannot be used for metrics & one must keep the carriage engaged in the train, and reverse it ... which is how all thrdng was done 125+ yrs ago .. .015 max doc ( depth of cut ) w/ a 10 in lathe is unacceptable ..SOMETHING is wrong. tool not locked down. poor grind, ..too wide a point too high SFM ..spindle looseness, carriage GIBS LOOSE, XSLIDE GIBS LOOSE, COMPOUND GIBS LOOSE .. belts loose or xcessive vibration ..w/ a sharp pointed bit, & everything adjusted PROPERLY I can easily take .100 cut on 12x36 on 1018. i usually just take .060. which are no problem on drill rod..leave the belts less tight than max..i cant tell from here what is wrong but, SOMETHING is. sometimes belts take a set & w/ the cogging action of single phase set up vibrations. rubber mounting helps.. an experienced lathe hand wud be a valuable friend here. Now tool bits. we are talking HIGH SPEED BITS here...i use 2 grinds for finish, depending on what I need...well, three. USE FOR .005 OR LESS DOC....first is the knife edge ..like a sheepfoot pocket knife blade ..similar to a carbide brazed bit, type A. this is set w/ front edge as near flush w/ the bar as possible w/ out chatter ..VERY SMALL ANGLE FROM APEX AT LEFT TO RIGHT ...DEPENDS ON DOC & MATERIAL how flat it can be w/ out chatter....you can do same w/ a "dutch nose" bit kinda like a "D chamfer" bit carbide brazed bit grind but tapered back from front slightly as well as clearance in front & sides & w/ some back rake..again set as close to flat as possible. this is also a great bit for in feed facing cuts ..angle it to a 45deg & hog in ....last is best ..a shear cut. bear with me now. visualize a round nose bit 3-4 in radius on front (barely rounded) w/ side /front clearance & maybe 10 deg back rake.. now rotate this bit counter clockwise till it is at abt 60 deg angle ( low at left to high at right ) .. the chip will be forced up due to massive neg side rake as it shears across the feed lines. centering bit not necessary almost any height will work ..NOW turn your fresh bit blank so corners are vertical instead of as ususal, the flats. now put that grind you visualized on it and you will have abt a 45 deg angle when in the holder. which works .. but by rotating just a tad counter clock wise, you will grind a 60 deg angle. now it fits in your holder & you have the correct geometry .. i think this grind is in machine tool operation vol 2 under planer bits....these are for FINISH ..less than .005 doc... Best wishes Docn8as ------- Re: 30-60 triangle./2 [atlas_craftsman] Posted by: "Raymond" mondosmetalsx~xxyahoo.com Date: Tue Jan 19, 2010 8:49 pm ((PST)) Let's say you are getting close to yout final dimension.... you need to hit 1.2520 final diameter for a force fit into a 1.2500 hole. The diameter now mics at 1.2532. So you need to take off 0.0012 on the diameter, or .0006 radius. This is the amount you need to advance the cutting tool. Are you going to be able to hit that with the cross-slide dial? Probably not. So the compund is set at 30° and you advance the compound dial 1 graduation. This provides 0.0005 inches of cut, or 0.0010 reduction in diameter. Assuming there is no error due to vibration (not likely) you end up within 0.0002 diameter oversize. You can take this off with fine crocus cloth and have a nice smooth finish for a nice smooth interference fit. Now all you pundits don't jump on me about dimensions for interference fits... I am only trying to make a mathematical example and I didn't specify the material, nor did I specify the application requiring the interference fit. raymond ------- Re: 30-60 triangle./2 Posted by: "n8as1x~xxaol.com" Date: Tue Jan 19, 2010 10:31 pm ((PST)) yes, but there is more ...first back off the tool bit .....there is most likely flex remaining form previous cut that wud remove MORE than you desired.....next be sure you have a high speed tool & hone it SHARP ...if dull or carbide, you put a cut on & nothing happens, add some more & when it finally cuts, ..OOPS too much ....until you develope a feel for ZERO, you can easily take off a couple thou plus what you put on .... 100 years ago, using inside/outside spring calipers, you left some xtra, took trial cuts till end barely started, then backed off a tad & took a cut, finished w/ emery cloth if necessary ...then removed the xcess & made the 'fit " ...not a bad idea today .... & yes, i can remove a half thou w/ a well honed tool ..but you must know your machine, tools & BE CAREFUL .....unless i need "round", as best i can machine,..if. w/ in a thou, i will ususally finish w/ al oxide cloth ... best wishes docn8as ------- Re: 30-60 triangle./2 Posted by: "catboat15x~xxaol.com" Date: Wed Jan 20, 2010 12:51 pm ((PST)) Doc is right. I can take off a few thous at one shot, but if I try to take off just one thou it is difficult and time for abrasive paper or cloth. If I am trying to hit a given dimension I mike after the first cut (to make sure the work piece is really round). Mike the chunk of metal (after it is at room temp) then take off about half of what is needed to come off. Then one more cut will get me where I want it to end up. But, if I try to creep up onto a dimension and leave about one thou to come off, I often either not cut at all or the part comes out too small. Most of my tooling is HSS in the lantern post tool holder. About the only time I get out the "big block" holder is parting off where the stiffness helps a lot. Make sure you sharpen your HSS cutters well and hone the cutting edge. The final hone is what gives a good finish; you cannot get a good finish with a rough edged tool. ------- Re: 30-60 triangle./2/3 Posted by: "VBrannick" valestreetx~xxstny.rr.com Date: Wed Jan 20, 2010 2:09 pm ((PST)) Yes ~ experience is the great teacher. The last paragraph of 'Catboat's' advice is the most important. Taking very light cuts often has the effect of glazing the material. Unless the cutter is very very sharp, it has a tendency to rub, rather than cut ~ can even cause 'spring' on small diameter stock. Best to back the cutter away and go at it with a good dressing stone for that final final cut. And then, needless to say, is the time to once again 'mike' the work before finishing the cut. (From experience.) Hey fellows, isn't that what a cylindrical grinder is for? Vince B ------- Re: 30-60 triangle./2/3 Posted by: "Glenn N" sleykinx~xxcharter.net Date: Thu Jan 21, 2010 1:10 am ((PST)) lance wrote: > OK.... what is a dressing stone? > Is it different than a stone I use to sharpen my knife? Hopefully it is at least not the same stone :) What I call a dressing stone is about 3" long and 1/2" wide. They come in various shapes for dressing odd shaped blades. I also use a small diamond slipstone for dressing carbide bits. ------- How do I knock the edges off a cube? [atlas_craftsman] Posted by: "crashbone256" wheezer606x~xxverizon.net Date: Tue Jun 1, 2010 4:20 pm ((PDT)) Group, I have a 5 x 5 x 5" cube of steel. I have it center drilled and mounted between centers. What is the safe procedure to make it a cylinder? Spin REAL fast and use a point tool or ???? Thanks lance ------- Re: How do I knock the edges off a cube? Posted by: "Bill Stietenroth" k5ztyx~xxjuno.com Date: Tue Jun 1, 2010 5:07 pm ((PDT)) This is where a hand made HSS tool works best. Positive rake, small radius on the point to withstand shock and disipate heat. HSS withstands the shock of the interrupted cut better than carbide and the short chips from the interrupted cut don't heat up the tool so you can use moderate speed. After you get it rounded up, change to your carbide tip. Bill ------- Re: How do I knock the edges off a cube? Posted by: "Dean" deanwx~xxbmi.net Date: Tue Jun 1, 2010 6:50 pm ((PDT)) The type and shape of the tool Bill mentions is what you want. As for the "REAL fast" part, not too fast. Everyone has their way of doing this kind of thing. When rounding up a square, I run the spindle fast enough that there is not a noticeable thunking sound as the tool cuts the corners. Fast enough to make a slow buzzing sound is how I would describe it. If you have a band saw, you can cut the corners off of the cube and save making a lot of tiny hot chips. It'll get round a lot faster if you can start with an octagon shape. On a piece like this, chips really fly until the corners are cut down a ways. A guard would be nice if you have one. Dean ------- Re: How do I knock the edges off a cube? Posted by: "ahz" ahzx~xxinsightbb.com Date: Tue Jun 1, 2010 7:58 pm ((PDT)) Put it on v-blocks and run it through the bandsaw to remove the corners. Now you have scrap instead of shavings. ------- Re: How do I knock the edges off a cube? Posted by: "azbruno" azbrunox~xxyahoo.com Date: Tue Jun 1, 2010 9:39 pm ((PDT)) I've done smaller rectangular stock to round and I do it in one pass. Instead of interrupted cuts, I get a smooth, continuous peel. In my case I've done that with up to 1" square rectangular and usually in plastic. I'd be interested to know if it's doable that way for this case, with the larger size and steel. Tool size and geometry would be a big factor I'm sure. Bruno ------- Re: How do I knock the edges off a cube? Posted by: "David Beierl" dbeierlx~xxattglobal.net Date: Tue Jun 1, 2010 11:35 pm ((PDT)) I'd think that would be quite a job for an Atlas. You're talking about a cut that's an inch deep (i.e. two inches off the diameter) at the corners. Bandsaw looks pretty attractive to me. Yours, David ------- Re: How do I knock the edges off a cube? Posted by: "jerdalx~xxsbcglobal.net" jtiers Date: Wed Jun 2, 2010 5:18 am ((PDT)) I don't think anyone would try to do that in one pass... However, it's noisy and troublesome to do those interrupted cuts... the nearer to "net shape" you get first, the better and quicker it goes. JT ------- [atlas_craftsman, in response to an observation that turning can generate a great deal of swarf] Re: New hobby Posted by: "James Walther" indianfourriderx~xxyahoo.com Date: Fri Jul 30, 2010 5:50 am ((PDT)) > Nobody's posts that I've read mentioned how much space all that swarf takes up for such a seemingly small amount of solid material. Next project needs to be closer to trash day. Or another trash can is in order. < Aluminum swarf is recyclable. My tail light reflectors generate buckets of it. Literally. I keep a plastic cat litter bucket - 40# size - near the lathe when I"m making reflectors (Album: Machined Reflectors if you're interested) and compact the swarf regularly with a size 9W using 175# pressure... I end up with a 4-5# brick of swarf for which my local recycler pays me the going rate. Just a thought... -------