This is a catch-all file containing users' tips for turning metal on a metal lathe. (There is another file for turning wood on a metal lathe.) In addition you may read other good turning tips in the lathe files 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 - 2008 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 sometime 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 object is to inject as much compliance and damping 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 UScosting $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 is 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 or 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 occured 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 recomends 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 recomend 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 its 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 then 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 countershaft 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 interupted 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. felicex~xxcasco.net is Felice Luftschein and Nicholas Carter. 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 jjohnsonx~xxLocoGear.com 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 untill 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 bobmayx~xxnethere.com 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 tu