This is just one of some 80 files about machining and metalworking and useful workshop subjects that can be read at: http://www.janellestudio.com/metal/index.html ------------------------------------------------------------------ Metal lapping and reaming tips have been put into a common file here. Before beginning this web site, I was already gathering information on subjects like "Drilling Tips" and "Boring" and "Reaming" and "Lapping". They once had separate files on my computer, and originally had their own separate files here. It has become painfully obvious that while lapping is a very useful process, you folks rarely talk about it. And when you do talk about it, you often throw some lapping info into a thread that started as boring or reaming, etc. Consequently the messages from the separate "Lapping" and "Reaming" files have been combined into the "Lapping and Reaming" file. There is still some other lapping and/or reaming info mixed in with the Boring or Drilling Tips messages. Consequently, you should really read the last three files to find good solutions that may involve multiple processes. The "Finish and Polish" file may also be useful for your particular need, as lapping is related to some polishing techniques. Let's just clarify a few terms so that we are all on track here. These are my very simple definitions. "Drilling" most commonly is the act of using a drill bit to make a "round" hole of a specific diameter. The resulting hole is often rough, and rarely of the same diameter as the drill bit, and often not even round, and can end up quite crooked in direction from the path intended. "Boring" is the act of using a boring tool to widen an existing (drilled) hole to a larger diameter. By slowly increasing the diameter of the boring tool's cutting arc in several stages (so as not to bend the tool sideways), the resultant hole is round, and straight (even if the original drill bit had wandered), and fairly smooth. "Reaming" is the act of passing a precision reaming cutter through an existing hole; the reamer is only a small amount larger in diameter than the existing hole. The reamer brings the hole to a perfectly round shape and size appropriate to the size of the reamer. The walls of the reamed hole will be smoother than a drilled or bored hole. If the original hole was straight, the reamed hole will be too. But a reamer will follow a crooked hole if that is what you started with. "Lapping" (a hole's wall) is the act of passing a lap repeatedly through the hole until the wall is smooth and free from minor defects or tool marks. The lap, usually a metal cylinder, is the perfect matching shape for the inside of the hole and is just smaller enough in diameter to allow for a lapping compound's particles to fit between the lap and the wall. The lap itself must be softer than the hole's wall material so that particles of the lapping compound might bed into the lap, but not into the wall. Depending on the smoothness required, lapping may be done with successively finer grit lapping compounds until the desired result is achieved. Lapping, properly done, does not significantly increase the diameter of the hole. Where the hole is now a very slight "interference fit" (an object to be inserted needs force or heating-of-the-hole-part/ cooling-of-the-insert-part), lapping may change that to a precision sliding fit. Bigger hole-size changes are best done with a reamer or careful boring operation first. "Honing" is another process used to improve the finish of a metal surface. One example is a cylinder hone, which has fine stones to polish the interior of an engine's cylinder wall. A flat very fine stone is the last process in refining (honing) the edge of a knife blade during sharpening. Alternatively in the final step of sharpening, a cutting edge may be drawn backwards over a leather strop coated with a fine abrasive compound (this latter process is then called "stropping"). In the absence of a fine stone or a polishing compound, a very fine abrasive cloth or paper backed by something solid might be used. The "something solid" can be a piece of plate glass or marble or a machine table if flatness is needed. An abrasive cloth might be wrapped around a dowel or suitable curved form if the object to be "honed" is concave or hollow. 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 many additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/index.html 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 - 2015 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. ========================================================================= On Wed, 06 Dec 2000 04:16:25 GMT, BillDarby wrote: >Oh Boy!! These parts are just fancy hinges. The spec calls for 1/4" dowel >pins to be used as hinge pins in 1/4" reamed holes. I supply >the holes and the client will supply the pins. :0) Ah! I've made these. Just drill slightly under (nearest size you have -- I'd use a .246" "D" drill -- and then use a chucking reamer in the same setup. When you're running the reamer, run it slower and feed it faster than you do a drill, with liberal cutting fluid. I've made some very sweet hinges that way. I usually ream one part of the hinge .249 and the other part .251 so the pin presses into one part of the hinge and rides freely on the other part. Regards from Foreman, dforemanx~xxgoldengate.net. ------- Thanks Don Good advice. Do you mean a special "D" shape or do you mean D size IE the .246". I am hoping you mean the size. Do you think the fol would work? Use a grinding vise clamped tight on the part to hold it square and held loosely in the big Kurt to allow a little play. I want to make awfully sure that the ream hits the hole. (or it could get exciting) I don't think I'll try for the two different size holes. Its a perfect idea, but the client has had these made before and specifically stated a ream at .250" So! Thanks again, Don. Bill Darby BTW Can you suggest an RPM for that ream????? ------- Subject: Re: Quick question about reaming aluminum Date: 12/06/2000 Author: Don Foreman You did say you want to do the drilling as a batch and the reaming as a subsequent batch. I've had pretty good luck having a chucking reamer follow the hole if the work is a bit free to move during reaming. In such cases, I've just placed the work loosely in the mill vise by hand so the vise would keep it from spinning out if it grabbed, and pulled the quill smartly for the first little ways. You want a square surface below to keep things from cocking, but you want the workpiece to be able to move laterally to follow the reamer. I don't recommmend this practice, merely report that it has worked well for me. Regards Foreman ------- Date: Sun, 28 Jan 2001 06:43:31 -0000 From: lasernerdx~xxhotmail.com Subject: Re: Simple heat-treating Although the cost of a decent reamer may sound a bit high right now, you may come to see that these are very useful precision instruments. Reamers have a number of very specific applications where a hole accurate to a couple ten thousandths is required. You've obviously come upon one of them. Others include doweling applications where it's necessary to locate one part in relation to another to very precise tolerances. For example, I'm working on a laser gantry. Machines that incorporate precision positioning devices require strict tolerances (I'll be using 5/8-5 Saginaw ballscrews and 1/2" Thomson linear ball bearings). When I assemble my gantry, and adjust it such that it works as I need it to, I will drill, ream and dowel all the parts together. This time consuming task is performed for two major reasons: The dowels will prevent the parts from moving out of alignment far better than screws ever could; and, if I ever need to tear down part of, or the entire gantry, I can quickly fit it back together such that it works in a timely fashion. The entire machine will probably take about 2 - 3 days to assemble and tweak using a surface plate, dial indicators, height gages, gage blocks, etc. If you take care of your reamer, you should be able to use it for many years to come. This is one bit of tooling you don't want to be cheap with. I would suggest you NOT buy Chinese reamers, but rather ones made in the USofA, German, England, etc. BTW, it cannot be stressed enough that drill bits are ROUGHING tools! A drill bit will *never* produce a hole of the diameter it's specified to. In precision applications, reamers and boring bars are the only tools for the job (short of EDM, or some other exotic machining technique). Regards, Robin ------- Date: Mon, 05 Feb 2001 19:42:56 -0500 From: Bradford Chaucer Subject: Re: Drill thur vs Ream thru At 07:17 PM 2/5/2001, you wrote: >Please bear with me on this question, but I am a newbie and learning the >art of machining. >I have bought a Oscillating Steam Engine kit from P.M. Research, Model >2A/2B. In the drawing it calls for " 15/64 Drill Thru .249 Ream Thru >for press fit with shaft" and another place it has >" 11/64 Drill Thru 3/16 Ream Thru " Well I know what it mean to "Drill >Thru", It is the Ream Thru I am not sure of. I take it that Reaming >will enlarge the hole to that point. But why would I do that ? Why not >just drill the hole to the correct size in the first place ? What is >the difference between Drill thru vs Ream thru ? Basically a drilled hole is less accurate and more likely out of round than a reamed hole. A reamer however can't pierce through metal it only side cuts, hence to get an accurately sized round hole, you must first drill it undersized then ream to exact size. >I don't have any Reamers, and could use some of the different drill >sizes. What is a good place to obtain good cutting tools in the smaller >sizes ? Flea markets and Ebay are good places to look. If you need a specific size reamer it may be best to take the plunge and buy it at a tool supplier. Look in Home Shop Machinist for some sources. MSC is also highly recommended. they are on line, and will take orders through credit card. Regards, Bradford Chaucer ------- Date: Mon, 5 Feb 2001 16:45:58 -0800 From: "Kory Hamzeh" Subject: RE: Drill thur vs Ream thru Hi Bruce: Reamer produces a much more accurate hole than drilling, both in size and shape. But a reamer can only slightly enlarge an existing hole. As a rule, I always drill 1/64" smaller than the target hole size, and then use a reamer and fairly low speed with lots of oil. I always get superior results. Reaming in an essential part of the machining operation. Kory ------- Date: Mon, 5 Feb 2001 18:48:18 -0600 From: Gordon Couger Subject: Re: Drill thur vs Ream thru Bruce: It is very difficult to get a drill to drill a hole exactly to size for a press fit and the finish of a reamed hole is a great deal better than the finish of a drilled hole. Break down and buy some reamers as you need them. If you stay with small scale machining you will need both of these regularly. Gordon Gordon Couger Stillwater, OK www.couger.com/gcouger ------- Date: Mon, 5 Feb 2001 21:43:59 -0800 From: "Kory Hamzeh" Subject: RE: Drill thur vs Ream thru Hi Eric, the oil is mostly used to get a nice finish. On harder metals, though, the oil may help prolong the life of the reamer. I had the same problem with reamers not fitting in the mill due to their length. So now I shorten the length by cutting them off using my bandsaw. Kory ------- Date: Wed, 07 Feb 2001 06:45:56 -0000 From: ballendox~xxyahoo.com Subject: re:RE: Drill thur vs Ream thru >This brought to mind a question I've had about this process- I have >some reamers that are too big for my sherline mill, so I have been >running them on a standard drill press. I've only been working on >aluminum though, and they haven't seemed to need any oil. Is this >going to damage my reamers? Bradford, It's CERTAINLY NOT 'helping' the reamers! And your accuracy may be 'less than' what it "could be"... Reamers generally like LOTS of lubrication, slow feeds, and FREQUENT clearing of chips... Failure on any one of these details can result in parts that "seem ok", but just don't quite work right... If you are getting good results so far, I would consider you lucky! Ballendo P.S. I just noticed (as I was deleting the 'non-pertinent' part, that the ORIGINAL message may be from someone OTHER than Bradford... I would disagree with clamping down reaming operations in the drill press. You need to prevent rotation, and you need to be sure the work can't be "lifted and spun", causing an accident. But, you want the reamer to "find" the hole and "center itself" within it. Clamping the part down innaccurately in the drill press will result in oval holes, or worse. ------- Date: Wed, 14 Feb 2001 12:08:25 -0800 From: "Kory Hamzeh" Subject: RE: Reamer .249 size Original Message----- > From: Bruce [mailto:bsnowdex~xxibm.net] > I have a kit for a Oscillating Steam Engine Model 2B from P.M. Research, > Inc. The plans for the Crank Casting calls for " 15/16 Drill > Thru .249 Ream Thru for press fit with Shaft " > The crank will be press on a shaft that is 1/4 Dia. C.R.S. The plans > call for a medium stright knurl for the shaft where the crank will be > press on. > I have recently ordered several Reamers, but couldn't find the size > .249. Would I be able to get away with: > (a) Drill thur with a 15/24 and ream thur with a 1/4 (.250), with > the thought that the knurl on the shaft will expand the shaft slightly > allowing a secure fit. ( it is my understanding that knurling a shaft > will expand it slightly) . > (b) Keep looking for a .249 Reamer because they do exist somewhere, > and step (a) will cause the part to never fit correctly. > (c) Keep reading my Machinest book, the answer is there somewhere > after page 985. :-) Other options: (d). Ream with 0.250 and use loctite to glue in place. This may or may not work depending on the temperature of the area and if you need to remove the shaft. (e) Make your own reamer from drill rod. > And, what does C.R.S. mean as in "1/4 Dia. C.R.S." CRS is Cold Rolled Steel. Good luck, Kory ------- Date: Wed, 14 Feb 2001 16:13:21 -0500 From: "Marshall Pharoah" Subject: Re: Reamer .249 size It is common to find reamers such as a .249 in the over/under category. Under for a press fit, over for a loose, sliding fit. They do exist, and you shouldn't have to buy a whole set. I have a couple of 2A kits, but haven't got to the cranks yet. I'll have to see if I have one. CRS is Cold Rolled Steel. Depending on your application, there are several grades which could be good. The HRS (Hot rolled steel) sold in bins in the hardware stores is usually crap to try and machine. Marshall ------- [QUESTION WAS HOW TO REAM NON-STANDARD OVERSIZE HOLE (also one answer suggested was an adjustable reamer)] Date: Tue, 27 Mar 2001 15:35:24 -0000 From: mothx~xxcadvision.com Subject: Re: A round peg in a round hole? > I have a quarter inch (0.250) drill rod and a piece of metal with a > quarter inch hole (made with a 0.250 reamer). My goal is to put the > rod in the hole, position it, and then silver solder it. However, > since both the hole and the rod are the same size, the rod will not > fit into the hole. An accurate fit is important, therefore I want > the size of the hole to be as close to the size of the rod as > possible (maybe a thousandths difference). In the past, I've put > the drill rod in a lathe and used fine sandpaper, but this seems kind > of hit and miss. Also, I can't find a reamer that a thousandth or > so over my quarter inch. > What's a good technique for accurately increasing the size of a > hole, or decreasing the size of the drill rod, very slightly? > Thanks, Jack Hello Jack, My name is Reg Here is an old model engineering trick you might try. Get some pieces of .0005 and .001 shim steel or brass. Cut a small piece about 3/8" wide and a couple of inches long. If the section with the hole can be mounted in the lathe chuck do so and centre the hole. Chuck your 1/4" reamer in the tail stock. Start your lathe and move the reamer up to the hole. Just before the reamer starts in lay the shim stock against the reamer and let it enter the hole with the reamer. Do one pass and check your fit. If it is still too tight; try the .001 stock. Brass shim stock will work, but it does tend to tear up a bit. Let me know if works out. Cheers Reg ------- Date: Tue, 27 Mar 2001 09:00:07 -0800 From: "Marcus & Eva" Subject: Re: A round peg in a round hole? Hi Jack: There are a few ways you can get to where you want to go: 1) 0.001 oversize reamers are available from bigger supply houses. 2) The hole can be bored in 0.0005 icrements until you get the fit you want (tricky but doable for shallow holes) 3) you can lap the hole with valve grinding compound with a lap that's softer than the material surrounding the hole. 4) you can ream with heavy cutting oil. (will make the reamer cut large by a tenth or two) 5) you can ream dry. 6) you can predrill to a smaller size than usual and feed the reamer on the fast side. 7) you can run a piece of carbide along the gashes of the flutes to raise a bur on the reamer and make it cut oversize. 8) you can polish or cylindrical grind the shaft. 9) you can turn the shaft significantly undersize and then knurl the bit that goes into the hole. 10) you can ream to nominal size and then squeeze the snot out of the assembly to force it together. That's about all the ways I can think of right now, but I'm sure there are others. Cheers Marcus ------- Date: Thu, 5 Apr 2001 19:32:09 -0700 From: "Marcus & Eva" Subject: Re: Reaming [sherline] Original Message----- From: csparksx~xxbigfoot.com Date: Thursday, April 05, 2001 9:08 AM >If I have a reamer with a flute length of 1.5" and need to ream a >hole that is 2" long, will the fact that the flutes are not chamfered >on the shaft end cause problems with the finish when the reamer is >pulled back out? Would it be better to just go all the way through >without backing out? Thanks, Chuck Hi Chuck: There are 2 schools of thought on this. Some (usually academic types) say NEVER back a reamer up through a hole that you have just reamed. Of course, these are the same chaps that have never reamed a blind hole! Just run the reamer down the hole and then cheerfully back it out again. If you want to get real persnickety, you can stop the spindle before you back out the reamer, but I have reamed thousands of holes in all kinds of materials, in and out under power, and I can't say that I've ever trashed a reamer or a hole by backing a reamer out of it. Cheers Marcus ------- Date: Thu, 5 Apr 2001 21:10:13 -0700 From: "David Goodfellow" Subject: Re: Reaming For what it's worth, Rudy Kouhoupt in his video on building a steam engine, backs the reamer out of the cylinder at the same rate as it went in, under power. He cautions the viewer to go in at a steady rate and back out at a steady rate, with no pauses during its travel. My take on that was a pause would leave a ring in the reamed hole. Dave Goodfellow Northridge, California ------- Date: Fri, 06 Apr 2001 00:31:54 -0400 From: "Rich D." Subject: Re: Reaming David and all: The no-no with reamers is to never reverse rotation while in a bore. You can plunge them in and out all you want, otherwise. Don't forget the cutting fluid. Rich D. ------- From: Randy Gordon-Gilmore Date: Thu Jul 26, 2001 5:45 pm Subject: Re: [sherline] Reamers 7/26/2001 -0400, Jerry wrote: >I've got some reamers with shafts a little longer than I'd >like for the Sherline mill. Any ideas how I can cut the shafts >down without making a mess of things? Test the shank with a file. It might not be hardened. Hacksaw would work in that case. I've cut a double-ended endmill in half (don't ask why) with a Dremel abrasive cutoff wheel. Heating was pretty localized since I took my time. Best regards, Randy (now why did I cut that endmill anyway...?) ------- From: "Yasmiin Davis" Date: Thu Jul 26, 2001 6:08 pm Subject: RE: [sherline] Reamers Check and see if the shafts are hardened. Many times they are not for just this reason. One way or another a cutoff disk in a Dremel will probably do a nice job unless these are 1/2 shank things. If they aren't hardened then you can either hold them in a chuck and tighten only on the shank or just cut them off with w hack saw -- actually I usually use a jewelers saw as good blades will cut about any thing and then clean up the end with a Dremel tool. Yasmiin ------- From: deanwx~xxv... Date: Fri Jul 27, 2001 10:08 am Subject: Re: Reamers You can use an abrasive cut off saw for the reamer shanks, and then touch up the shaft end on the grinder. I also cut some double end mills in half this way. I had bought a bunch of them at a very low price, knowing that they wouldn't fit in my mill holder (too long). My 1/2 in. reamer was longer than the Z axis travel of my milling machine. Not anymore. 10 seconds in the cutoff saw, and it fits now! Regards Dean W ------- Date: Sat, 1 Sep 2001 06:51:18 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: RE: Sorry I lied - Floating Reamers When I use "chucking reamers" , I chuck them. (in the drill press or tail stock chuck on the lathe) Home made "D" reamers, I hold in a tap holder. (reaming with one of these babies will make you wish "you'd ate your wheaties") 8-) Leo ------- Date: Sat, 1 Sep 2001 08:13:48 -0500 From: "Dana Zimmerman" Subject: RE: Sorry I lied - Floating Reamers I just checked the full archive for 'floating reamer.' The only mention was in #8257 where Bucky mentioned he could not afford one. Is it possible you are confusing this with another group? I have been looking for about 2 years for a drawing of a floating reamer holder both on the net and in whatever books I can find, and struck out. For the record, a floating reamer holder is one that can drive a reamer as in a lathe or mill, but allows the reamer centerline to follow the hole, for both angular and concentric alignment. This is desirable for all reaming, and mandatory for accurate firearms chamber reaming. Unless you are the sort of gent who can hand-ream a .308 chamber, in which case I apologize. Commercial floating reamer holders are rare and expensive, and design drawings are even scarcer, AFAIK. ------- Date: Sat, 1 Sep 2001 08:39:22 -0500 From: "Dana Zimmerman" Subject: RE: Floating Reamers (was Sorry...) Have a look at: http://sommatool.com/catalog/tool.holders/floating.reamer.holders.asp and http://www.mansonreamers.com/New%20Tools.htm Mr. Manson's price is the cheapest I have seen. ------- Date: Tue, 04 Sep 2001 08:06:57 -0400 From: Richard Parker Subject: Re: RE: Sorry I lied - Floating Reamers Dana, >For the record, a floating reamer holder is one that can drive a reamer as in a lathe or mill, but allows the reamer centerline to follow the hole, for both angular and concentric alignment. I was under the impression that a reamer would follow the hole regardless of how it was driven... >This is desirable for all reaming, and mandatory for accurate firearms chamber reaming. Unless you are the sort of gent who can hand-ream a .308 chamber, in which case I apologize. FWIW, I never found that a "floating reamer holder" was mandatory to cut chambers in rifle barrels. The way Master Spann taught us to do them at CST was to first set up the barrel blank between centers, with a dog and driving plate at the headstock. Then, the breech end was held in a steady rest, the thread detail was machined, and the chamber was cut using a reamer held with a T-handle and a dead center in the tailstock. Always worked for me, and the groups have been spectacular! Best, Rich ------- Date: Wed, 05 Sep 2001 From: Richard Parker Subject: Re: RE: Sorry I lied - Floating Reamers >and the chamber was cut using a >reamer held with a T-handle and a dead center in the tailstock. >Holding a reamer in a T-handle *is* a floating reamer. >Things would be much different if you chucked the reamer in the >tailstock and used it that way. Jim, Hmmm....yer right! Apparently, I've been using the "floating" method for years, but never really thought about what it was called. Another application is a small dead center in the spindle on a Bridgeport, useful when tapping small blind holes with a T-handle tap wrench. So, what's with this "floating reamer holder"? When I find out what it is, do you suppose I'll wonder how I ever got along without one for the last 20 years? Best, Rich ------- Date: Wed, 5 Sep 2001 From: "R and J Sport" Subject: Floating Reamer holders Floating holders are readily available from BROWNELLS and MSC. In the Gunsmithing trade theyare used mainly for chambering as they will compensate for any slight (up to 5 thou.) misallignment between the head and tail stock. The holders sell for about$90.00. If your lathe is plumb accurate you don't need one. If you have to get things done now and don't have time to get everything set to the nth degree they help. Jim at R and J ------- Date: Wed, 5 Sep 2001 From: "Bob May" Subject: Re: RE: Sorry I lied - Floating Reamers Technically, using the reamer holder by hand is a floating holder while putting it against the tailstock center really isn't. A minor point but one for when you start working a reamer it does matter. Also, you should minimize the side forces on a reamer when you put it into the hole as this will oval the hole out a bit. Bob May http://nav.to/bobmay ------- Date: Thu, 6 Sep 2001 From: "Wilks, Ronald (Ronald)" Subject: RE: Reamers Daniel writes: >>MSC does indeed sell 0.1880 reamers. You should be aware that some reamers are too long to effectively use in the Sherline mill without cutting the shank down a bit. I seem to remember that being a problem for me when I built that engine a few years ago using a 0.1880 reamer from MSC. I used a Dremel tool to cut off a few inches and then it worked fine. << MSC also has some reamers in a "jobber drill length" - I don't think the range of sizes in this length is as great as in the longer standard length reamers, but it would be worth a look at them to see if they have the size you need in the jobber length, which you might not have to cut down for use on Sherline equipment. Ron ------- Date: Sun, 21 Oct 2001 From: "Randy" Subject: threading and heat treating questions Hi all ... I'm busy at work learning how to use a lathe and surface grinder ... and I have a couple questions. 1. When using O1 drill rod ... making bullet swaging core dies and punches .. how much does the metal change after heat treating and how does it change, if any , dimensionally .. ( obviously it gets harder ) ... i was told to go a few thousands over size then hone / lap / grind off after heat treating ... Comments on this ?? Thoughts ?? 2. The other thing is much more lathe related .. on the punches If I do leave them a couple thousands over , then heat treat, then grind to final dimension ... Which method would be better ... a tool post grinder on the lathe ... or what a friend told me was called a spin fixture on the surface grinder ( which I have access to ) ?? 3. Ooops .. one more ... LAPPING ? ARRRGH ... anyone know some good methods for that ?? I ordered some diamond lapping compound for harder steels and some needle laps ... Need help with techniques. As always ... thanks for all the input. I have learned much from the list watching all the email and from the answers to my questions. Randy ------- Date: Mon, 22 Oct 2001 From: "George" Subject: Re: threading and heat treating questions > 2. The other thing is much more lathe related .. on the punches > If I do leave them a couple thousands over , then heat treat, then > grind to final dimension ... Which method would be better ... > a tool post grinder on the lathe...or what a friend told me was called > a spin fixture on the surface grinder ( which I have access to ) ?? Randy, The spin fixture is the most accurate of the two ! We use them allmost every day in the tool&die shop at the die-casting plant that I work in to make core pins for die's and they do verry verry good work!! The tool post grinder would work allso but you would have to be more carefull and still would not get as good a finish! So if you have one that you can use then thats the way to go! Just rember that if you move the dile on the surface grinder .001 then you will take off .002 dia!(this can be hard to rember when you first start to use this setup) George ------- Date: Sun, 21 Oct 2001 From: catboat15x~xxaol.com Subject: Re: threading and heat treating questions Yes, steel can distort when being hardened. If your projects are cylinders be sure and quench them endways into your water or oil. But there always is some distortion. About grinding I don't know, but have lapped cylinders and pistons for various projects. You make a lap of some softer material, like brass or even lead, brass is better. and make it adjustable. for outside make a split ring with an adjusting screw or clamp, for the inside make a split cylinder with a tapered hole in the end where you can drive a wedge or something to expand it as needed. Adjust the lap for an "easy" fit and charge it with compound. run the lap over your work making sure you go byond your working portion. Tighten the lap till you feel some drag and keep it up till it is "easy" again then check sizes; Ditto samo till you get to where you need to go. Most of my lapping was on cast iron cylinders and pistons for small IC engines without rings. With care you can even make a tapered bore in a cylinder for an IC engine so it is too tight at the head end, but just right when at running temperatures. John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Mon, 22 Oct 2001 From: Jon Elson Subject: Re: threading and heat treating questions Randy wrote: > Hi all ... I'm busy at work learning how to use a lathe and > surface grinder ... and I have a couple questions .. > 1. When using O1 drill rod ... making bullet swaging core > dies and punches .. how much does the metal change after > heat treating and how does it change, if any , dimensionally .. > ( obviously it gets harder ) ... i was told to go a few thousands > over size then hone / lap / grind off after heat treating ... > Comments on this ?? Thoughts ?? The dimensional change is quite small, but just measurable with precision tools. What really happens is that thin sections and long thin bars warp. Things made asymmetric (like cutting a round bar into a D shape) will warp more. > 2. The other thing is much more lathe related .. on the punches > If I do leave them a couple thousands over , then heat treat, then > grind to final dimension ... Which method would be better ... > a tool post grinder on the lathe ... or what a friend told me was > called a spin fixture on the surface grinder(which I have access to)? It depends on the fixture. The cheap Taiwan or Chinese spin index fixtures are not real tight, a $400 Suburban probably has much better bearings. An air bearing fixture would be even better. There are a number of setup alignments that have to be done with great care, or you will grind cones. If you are willing to do that, or if your lathe is worn, then it will work fine. A toolpost grinder should work very well, and allows you to keep a close eye on what is going on. > 3. Ooops .. one more ... LAPPING ? ARRRGH ... anyone know > some good methods for that ?? I ordered some diamond lapping > compound for harder steels and some needle laps ... Need help > with techniques .... Needle laps? For small holes? Well, maybe they go up to the sizes you are talking about. I have done a bit of lapping in various materials. What you generally want is something a bit soft, like brass, to embed the diamond grit in. You roll the lap on the lapping compound, and the tiny diamond particles are partly embedded into the lapping tool. You then spin the part and feed the lap back and forth into the hole, or spin the lap and feed the hole over the lap on the big parts. Then, you pull it out, clean the hole and measure with whatever tools are appropriate, of trial fit the (I'm guessing) punch into the die. Lapping is VERY slow work, you might get .0001" progress per minute on some work, but usually less than that. So, don't ever think of taking off the last .005" by lapping it. It will take all day! The pros use honing equipment, mostly by Sunnen Products. This is an ingenious process using a long, curved stone attached to a tiny mechanism similar to adjustable parallels, all on a spinning arbor. there is a direct- reading dial on the machine, and you can read the hole diameter as you slowly increase the hole size. You hold the part loosely in your hand, so you can feel the amount of work being done, and advance the dial when there is little torque on the part. It can take off .001" every few seconds, at least when all is working well. It pretty much guarantees a straight, round hole of the right size. Jon ------- Date: Mon, 22 Oct 2001 10:31:20 -0400 From: Richard Parker Subject: Re: threading and heat treating questions >1. When using O1 drill rod ... making bullet swaging core >dies and punches .. how much does the metal change after >heat treating and how does it change, if any , dimensionally .. >( obviously it gets harder ) ... i was told to go a few thousands >over size then hone / lap / grind off after heat treating ... >Comments on this ?? Thoughts ?? 01 is pretty stable stuff, although I prefer A2 because the air- hardening stock hardens a bit more consistently throughout the part. However, on smaller dies this usually isn't a problem. Air hardening stock doesn't need to be foil wrapped to prevent the scale that forms when the parts are heated and oil quenched, though. However, unless you have your own furnace, this is a problem for the heat treater - who usually has an inert-environment furnace, anyway. Changes aren't so much dimentional after heat treating (with regard to an increase/decrease in size), warpage is more of a factor. Obviously, if the finish dimention of yer part has an O.D. of 1", and at another feature it drops abruptly to .250", the smaller diameter will tend to warp off the axis of the part a bit. In this case, you'd leave on a bit more stock on the smaller diameter so the part will clean up with the desired concentricity. A good rule of thumb is to machine your work .005" o/s when it is to be finish ground. When I had the luxury of a jig-grinder, I'd leave the I.D. of bores and holes at 1/64th u/s, particularly when there was a close callout for true position. When you don't have jig or I.D. grinding machinery available however, you're obviously left to other means (tool post grinding, abrasive-charged laps, hones, etc.). Experimentation is the only way you'll find out just how close to finished size you can machine your I.D.'s and still have enough material to clean up to finished size, utilizing the methods that you have at hand. >2. The other thing is much more lathe related .. on the punches >If I do leave them a couple thousands over , then heat treat, then >grind to final dimension ... Which method would be better ... >a tool post grinder on the lathe...or what a friend told me was called >a spin fixture on the surface grinder ( which I have access to ) ?? By all means, the "spin" fixture. These come in various flavors, the most common being the standard "collet" type. While these are good for some "quickie" jobs, you're obviously limited in a lot of ways. And, you have to leave your work in the collet until all the grinding is complete, because repeatability is out of the question once you remove your part from the collet. When you start working with tenths, EVERYTHING matters! Better would be the Harig fixtures, such as a Grind-All or, better yet, a Duo-Form. These are the most versatile fixtures going for most die detail and perforator work. However, when yer parts get longer than a couple of inches or so, yer obviously going to need some method of supporting the end of the workpiece. I once built a dandy little fixture that would spin parts betwixt precision centers via an electric motor, I pretty much ripped-off the design for this fixture from a picture of a commercially available one I saw in a book. Mine was better. :-) >3. Ooops .. one more ... LAPPING ? ARRRGH ... anyone know >some good methods for that ?? I ordered some diamond lapping >compound for harder steels and some needle laps ... Need help >with techniques .... Again, technique will come with practice. Whenever lapping tool steels, I made my own laps from brass in gradually increasing sizes. These were hand laps, naturally (for power I.D. lapping, you'd be better off doing the bores on a Sunnen hone). You can charge your brass laps with aluminum oxide abrasive and achieve good results on most tool steels. Charge the lap by rolling it betwixt two steel plates that are ground flat, with a dab of the abrasive on one of the plates (regular old valve grinding compound works good, and can be had in a variety of grits). The diamond compound I'd generally reserve for lapping tungsten carbide die components and really hard, tough steels (like D2 at Rc60, fer instance). Also, diamond tends to become impregnated in tool steel, where Al-Ox abrasives will wash out.Gesswein and similar outfits have hardwood sticks in varying shapes and sizes that can be formed to fit the particular feature that you're working on and charged with diamond compounds. Between diamond-impregnated needle files and laps of this nature, one can accomplish a myriad of tasks on a good lathe with a high spindle speed. A good microscope with a base made up to fit on the lathe bed is invaluable when doing work of this nature. Good luck! Rich ------- Date: Fri, 08 Feb 2002 From: David Beierl Subject: MT finishing reamers Thanks to the model-eng folk for the answers re wavy parallels. Mine, incidentally, are only about .013 thick, so there's no question that they'd compress in a vise! Onward...I finally bit the bullet and got 1MT and 2MT (hand-style) finishing reamers from J&L to clean up the lumps in the middle of my head- and tail-stock tapers. I got the imported ones that were *only* about $25 and $30 respectively. I expected to have to be very careful not to cut too much, but to my surprise I'm having trouble getting them to cut at all (my experience with reamers of any sort is tiny, and with tapered ones nil). Applying enough pressure to make them difficult to turn with a 4"-long wrench results in somewhere between just-barely and not-quite cutting, and only in tiny isolated spots. Even looking at the reamer under a stereo 'scope doesn't show evidence of chips. Is this a function of tapered reamers, i.e. needing *lots* of pressure, or am I doing it wrong, or are they bum reamers? Once again, TIA... David Beierl - Providence, RI USA 6 (or 3)" Atlas Model 618 lathe ca. 1941 ------- Date: Fri, 8 Feb 2002 From: Sagebush9x~xxaol.com Subject: Re: MT finishing reamers Your sockets may have hard spots. I borrowed a #3 reamer to clean up the spindle of my 12" Craftsman, & almost buggered it up on a spot where something hard was embedded in the bore. I have no idea what the former owner did, but evidently galled it enough to create a hard hickey. I bought a #2 (made in Bosnia, of all places), to rework a friend's drill press spindle. I tried it in my lathe tailstock, & literally one turn by hand made so much difference it was scary. My centers & chuck tighten up & come out w/a "pop'" now... ------- Date: Fri, 8 Feb 2002 From: "Ebower" Subject: Re: MT finishing reamers Check the reamer. If you got a right hand reamer then there is something wrong with the reamer. If you got a left hand reamer then you must rotate it in the opposite direction. Also use a little cutting fluid on it when in use. This will lengthen the life of the reamer. For the common home shop you should buy all right hand cutting tools. Earl bower machine ------- Date: Fri, 15 Feb 2002 From: David Beierl Subject: MT Finish reamers -- Update Following Tony Finn's advice I applied a good deal more pressure to the reamers, using the lathe in low back-gear (58 rpm nominal) to turn either the reamer or the spindle. By using enough pressure to noticeably slow the lathe I was able to get both the 1MT and 2MT reamers to cut a bit. Indeed, they cut where the high spots were and then started cutting through a longer distance, so I guess the method works. I still think they ought to cut more easily, but I haven't really got an extra $60 to try a US-made one, since these are actually doing the job. Thanks to everyone for the helpful advice. david ------- Date: Wed, 19 Jun 2002 12:21:06 +1000 From: "Peter Homann" Subject: Most accurate way to ream? Last night I attempted to drill and ream a threaded blank arbour to 3/16" (for a Taig milling bit holder). I progressively drilled to 0.005" under, then reamed with 3/16" chucking reamer held in a drill chuck in the tailstock. I did not tighten the tailstock to the bed, but slid it along the bed to ream the hole. The speed of the Lathe was the 3rd fasted pulley (sorry) and it was reamed dry. I ran the reamer in an then shut of the motor before removing it. The result was not good enough for a mill bit holder. The milling bit was able to be rocked from side to side when inserted. I tried a brand new Taig milling bit and it was a good fit due to the wax or grease on the bit. Is it possible to ream to an exact size? Would I get better results with a hand reamer? I don't think it is practical (for me at least, due to my skill level) to bore the hole as it is too deep. I also need to make some 1/4" holders so that's what I'll use this one for. If I'm unsuccessful at that, I'll use it for a 3/8" holder. If that's unsuccessful, I'll probably give up! For the 1/4" holder, I'm going to use a 6.3mm drill first as it is about 0.002" undersize for 1/4". If I'm really lucky?? it will drill oversize to exactly 1/4". Am I desperate or what. Also, I have a Sherline 2/8" tool holder, and the bit rocks in that holder. I'm hoping its just that my bit is undersize. I know that the subject has been discussed a lot, but this is something I want to crack as I have about a dozen or more tool bits I want to make holders for. Any comments welcome. Cheers, Peter Homann ------- Date: Wed, 19 Jun 2002 From: tadici283x~xxcs.com Subject: Re: Most accurate way to ream? Peter: Why did you not tighten the tailstock to the bed and use the ram? I have found the the tailstock not perfect from the factory but since you do not have a gib on it I would think that it would not slide straight enough, you may want to think about making a boring bit rather than buying one since you can make one cheaper? maybe? I don't know just a few thoughts, the boring bit can (Boring Bar) can be advanced on the lathe table so size (depth of cut) is not a problem and since you bore it on the lathe or mill you are going to use it on, it is machine specific. Chris of Bradenton FLA ------- Date: Wed, 19 Jun 2002 From: "Peter Homann" Subject: RE: Most accurate way to ream? The reason I did not tighten it was of what I read in an earlier post. The theory is that the reamer will self centre in the hole and therefore less likely to ream oversize. As to making a boring bar. I made one to make a 3/8" hole, and it flexed a bit due to the depth of the hole. I don't know if I could make one small enough to bore a 3/16" hole. Cheers, Peter Homann ------- Date: Wed, 19 Jun 2002 From: Steve Blackmore Subject: Re: Most accurate way to ream? A few points - 5 thou is maybe too close, unless it was a brand new sharp one - small diameter reamers work better with bit more, but its a close call, too tight - it jams - too loose it chatters or deforms the hole rather than cutting (the bigger the reamer - the less clearance you leave) - I'd have tried 10 thou. You should have clamped the tailstock. Floating reamer holders allow the reamer to move parallel to the bore but no angular deflection, leaving the tailstock loose will let the reamer tilt as soon as the cutting edge bites. If you drilled it with the tailstock clamped you should have the same alignment for the reamer, in theory ;) You don't say whether it was a hand or machine reamer? Machine reamers should be run at half drilling speed - ran all the way in and out under power - no stopping! Hand reamers used in a machine may need withdrawing to clear chips - again under power, but otherwise the same. Definitely used cutting oil, plenty of it! Steve Blackmore ------- Date: Wed, 19 Jun 2002 From: "Peter Homann" Subject: RE: Most accurate way to ream? Hi Steve: Thanks for the tips. I'll give it another go tonight using your suggestions. As to the reamer, I'm using a chucking reamer. Also, I bevelled the edges of the hole before reaming. As I said, I need to do a few of these at various sizes, so I'm starting with the smallest diameter ones first. The failures will then be used on the larger sizes. Thanks, Peter Homann ------- Date: Wed, 19 Jun 2002 03:47:11 EDT From: tadici283x~xxcs.com Subject: Re: Most accurate way to ream? Peter: Another thing that I do also is mount the arbor on my rotary table via 3/4 x16 table mount, and drill 5 holes in a radial pattern, horizontally so that the setscrews can be adjusted to get great runout. This also allows more screws to hold the endmill in place. Once mounted I never take the endmill out again until it breaks or needs to be replaced. While you have it in the rotary table go ahead and mill a hex to use as a large nut if you might take it off. I started to drill a hole straight through at first to use a tommy bar to get it off, but since then I mill a hex. Chris of Bradenton FLA ------- Date: Thu, 20 Jun 2002 From: Stan Stocker Subject: Re: Most accurate way to ream? > At 14:59 20/06/2002 +1000, you wrote: >>The results from last nights efforts were better but probably not good >>enough. I used cutting fluid throughout the operation, and reamed at the >>slowest speed. I was able to measure 0.0025" on the DTI, which is not >>brilliant. BUT, when I screwed the arbour onto the Mill headstock the >>readout was almost 0.008"! >>What Gives? Does this mean I'm wasting my time, and arbours? Tony Jeffree wrote: > You might get better results by swapping the lathe headstock & mill > headstock to do the machining - i.e., machine the arbour on the spindle > that you intend to use it with. I think what you are seeing is that you > can't expect good repeatability when removing/re-fitting devices to the > spindle nose, and especially when moving from one nose to another. >>I might try to face the mating surface of the arbour to see if that >>helps, but I'm not confident. > That could help - the other thing to check is the register diameter on > the arbour vs the register diameter on the spindle (at the base of the > threads). You need a close fit there to stand any chance of the arbour > being concentric. >>Then I thought about machining an arbour to accept a collet. I was >>thinking of using an arbour that comes with the screw and washer on >>the end. The washer would be used to hold the collet in place. >>With the centre screw holding the washer I could drill and countersink >>3 M3 holes through the washer and into the arbour. >>Then, removing the centre screw and inserting the 3 M3 bolts I could >>drill/bore the hole through the washer. >>Removing the washer, I could drill/bore a 3/8" hole through the arbour. >>Using the cross slide, bore out the taper for the collet (This is the >>difficult part). Insert the 3/16" collet and milling bit. >>Fasten the washer down to hold everything in place. >>Screw the arbour onto the milling machine & measure the runout. >>Is this possible / feasible? > I'm sure it is possible, but I don't think it will change anything, > as I think the fundamental problem is probably the accuracy of the > register, as mentioned above. So I suspect you would be wasting > effort. Why not just use a collet directly in the Taig spindle? > The Taig collets are not super accurate, but they are pretty good. > Regards, Tony As an alternative that follows along with Tony's post, you might consider two additional options: 1) Face the spindle end of the arbor adapter and bore to an exact fit on the register of the MILL, not the lathe, or as an alternative, simply make your own end mill adapters completely from scratch, using 1 1/4 or 1 1/2 inch steel. You'll need a 3/4-16 bottoming tap to go along with the taper or plug tap you start the threading with. Mill wrench flats before you start threading and you'll be able to hold the adapter in a vise, tapping 3/4-16 in steel takes some leverage. 2) Mount the adaptor, drilled but not bored/reamed to final dimension, on the mill. Mount a boring bar vertically in a vice or to a tool holder clamped down on the mill table. Fire up the mill and bore the hole to final dimension, using the table movement to move the boring bar. You'll likely end up with a quite bit better than 8 thou using this approach, and if the register is well mated, you should get better than half a thou repeatability. DISCLAIMER: I've done this sort of thing on larger R8 mills, and have a Taig lathe, but not a Taig mill. I've made tooling that repeats to better than half a thou, but again, not on a Taig mill. There may be a better/different approach that is specific to the smaller mills that lack of familiarity has kept me from thinking off. Cheers, Stan ------- Date: Wed, 14 Aug 2002 23:01:37 -0400 From: RichD Subject: Re: Finishing a bore timxdunn wrote: > I am making a low temperature differential Stirling engine (1/2 size > Miser from Jerry Howell) and I have reached the point where I need to > finish the bore. > I have made the cylinder from brass and currently the bore has been > cut with a boring tool in the mill (lathe boring tool would not fit > in .3" bore). > My understanding is that I need to get a better finish than cutting > tools can provide in order to give a good piston fit with no leaks > and minimal friction. > My question is, how do I get a better finish without messing up the > parallelism of the bore? > I have read a bit about lapping... are laps the sort of thing that > you can buy or do I need to make one? Maybe lapping is overkill? > Anyway, that's enough words I think. I shall be grateful for any and > all advice. -Tim Tim: Lapping will smooth and make a parallel bore easily as well as size it. A simple lap can be made by turning a brass rod to a loose fit in the bore. Slit the rod lengthwise on center about 4 times it's diameter. jam a screwdriver blade into the slot to wedge it apart testing the bulge until it is set to be a snug fit in the bore. Wet with Brasso polish and run the lap thru the bore stroking fully end to end. When it gets slick and the drag gets to nothing stop & measure. Reset the lap again and recharge to grind more. Brasso is a soft non imbedding grit and should clean out nicely. RichD ------- Date: Thu, 15 Aug 2002 16:54:40 EDT From: wlindiii53x~xxaol.com Subject: Re: Finishing a bore I just finished the 1/2 size Miser back in July and did the following... after carefully boring to .300 and seeing that the bore was not near smooth enough. I decided to cheat a bit and used a 5/16 reamer (.3125") and then turned the graphite piston to fit the new bore. Instead of lapping, I used 3M 320 grit wet or dry sanding paper rolled up smaller than the bore and then allowed to relax once inside. The paper can then be worked in the bore carefully both lengthwise and rotated or both...it takes a bit of time but worked for me. Jerry's instructions are good in that the piston should fall of its own weight through the bore unless the end is sealed in which case the piston should fall much more slowly as the trapped air cushions it so to speak. Good luck...hope this helps ------- Date: Tue, 19 Nov 2002 00:34:49 -0000 From: "jeastwoodlm" Subject: Re: Valve lapping compound for steam engine cyclinder honing? In sherlinex~xxy... >>I've finished boring and honing the cylinder for a small model >>steam engine. It's nice and smooth to the touch, and the piston >>slides pretty smoothly in it, but I'd like to reduce the friction even >>more.Would it be reasonable to apply some valve lapping compound to the >>piston and move it back and forth in the cyclinder, say at the time >>when I'm running in the engine? Or is this likely to really do some >>damage and make things worse? "Ron Ginger" wrote: > Not a good idea for a couple reasons. First, valve grinding compound is very coarse, I think about a 160 or 200 grit. For model engine cylinders more like 400 or 600 is better. Second, to properly lap something you use a lappng tool, not the piston. If you use the piston you are simply 'wearing out' the cylinder and/or the piston. A proper lap is made of a material softer than the cylinder- lead was the traditional choice, aluminnum works fine. You embed the compound into the lap and use it as a tool. I have even used a wood dowel for some small cylinders. Before you ask, brake cylinder hones are also a bad idea- they will not make a cylinder round, the spring pressure will follow a lobe shaped bore. They will also 'bell mouth' the cylinder as you pull them in and out. A simple aluminum rod, sawn down the center for a long as the cylinder, then spread apart by a simple set screw into one side makes a fine lap. Once you learn it's quick and works well. ron ginger < Thanks for the info; I assumed valve grining compound was much finer. I honed the cylinder with 600 grit sandpaper, with a tool much as you described. I'm going to build a real sandpaper honer/holder, but for now I've just glued cylinders of sandpaper to a wooden dowel held in the toolpost. Sounds like I'd either better live with what I have (which is actually pretty smooth now; I've got the cylinder put together with piston in place and cylinder heads attached; after a bit of manual working in it's "smoothed up" quite well) or put the cylinder back in the 4 jaw and hone some more, which will also involve making a new cyclinder. Thanks again, ------- Date: Sat, 19 Jul 2003 09:12:42 -0700 From: "Wm. Dubin" Subject: reamer help Can any one help with a stuck ream problem? I'm reaming brass. The step was from .2510 to .2515, and of course I had the lathe on slowest speed and used oil. The ream is stuck fast, won't begin to budge. I don't mind destroying the reamer, nor does it matter if the hole ends up way over-size, but I need to try and save the brass piece if at all possible. Thanks in advance, Wm. ------- Date: Sat, 19 Jul 2003 12:22:02 -0400 From: "Dave Simmons" Subject: Re: reamer help Wm, I assume you can remove the set up from the lathe? If so, and this only something to try, brass expands at a faster rate over tool steels. Try leaving it in the oven for a while at the highest setting. It might come free - but don't burn yourself. Let me know how it goes! Dave S. ------- Date: Sat, 19 Jul 2003 11:05:16 -0700 From: "keith green" Subject: Re: reamer help Pretty sure you're problem stems from a couple things there. First off, it seems like you're trying to ream too little out. If you're saying you're trying to take .0005 out of there, that's too little. Normal practice is to try for .005 to .015. The reamer should be pretty sharp, speed should be half that used for drilling or less, and use kerosene or varsol for lube. The last may be as important as taking a heavier cut. Cutting oil, depending on which one you used, often just lubricates and causes clogging in brass and bronze. Doesn't help cutting all that much. You probably heated up the part and it expanded. When the reamer got stuck, the lathe stalled, the part cooled and shrunk and not the thing is really stuck. As stated in a previous posting, if you heat it up, the reamer should come out with a little persuasion. keith ------- Date: Sat, 19 Jul 2003 12:31:01 -0400 From: RichD Subject: Re: reamer help Wm: If not a blind hole and has an accommodating backside, press it out? RichD ------- Date: Sat, 19 Jul 2003 12:20:30 -0700 From: "Wm. Dubin" Subject: Re: reamer help First, thank you to everyone who wrote suggestions. I tried RichD's suggestion of pressing it out, and fortunately, that worked, it came right out. I had wondered about using the hot/cold, but glad I didn't have to try it. ------- Date: Sat, 13 Sep 2003 22:40:50 -0400 From: RichD Subject: Re: Reamer question... > Can I use a straight reamer in a blind hole......or will the chips > kill me....???? thanks David in san jose ca u.s.a. Yes, clear the chips out then ream again to the bottom. Again if nec. RichD ------- Date: Mon, 22 Sep 2003 22:12:37 -0000 From: "Charles Hixon" Subject: Re: Sherline sized reamers... In sherlinex~xxyahoogroups.com, "Jim Knighton" wrote: > Does anyone know where to obtain stubby chucking reamers? The reamers > I have at present are approx 6-7" long and awkward to use even on my > mill/drill. Mounting them in the Sherline mill is a physical > impossibility. Might be cheaper to buy the standard length and shorten them with an abrasive wet wheel. Charles Hixon ------- Date: Mon, 22 Sep 2003 18:21:35 -0400 From: RichD Subject: Re: Sherline sized reamers... Jim, Cut them to any length you like. The shanks are usually annealed (soft). RichD ------- Date: Mon, 22 Sep 2003 22:21:35 -0700 From: "Carol & Jerry Jankura" Subject: RE: Sherline sized reamers... Hi, Jim: I made some shorter reamers by taking the standard length product and using the parting tool to cut them down. It appears that the outside surface of the reamer shaft may have been a little case hardened, but the center cut quite easily. I'm not sure if all reamers are like this; I bought mine from Campbell Tool in Springfield, Ohio. They've since changed hands so I don't know what they're selling today. Jerry ------- Date: Tue, 23 Sep 2003 20:44:11 -0000 From: "Keith Baddock" Subject: Re: Sherline sized reamers... I cut mine down using an abrasive cutoff wheel on the dremel - they seemed pretty hard to me - the hacksaw just bounced off! Works fine. ------- Date: Wed, 24 Sep 2003 12:38:30 -0000 From: "Charles Hixon" Subject: Re: Sherline sized reamers... So long as you can do it without forming the blue oxide film on the reamer, a Dremel will work. The blueing indicates a temperature of about 600 degrees F and the steel begins to lose its hardness at that temperature. Still, if it is a hardness loss in a noncritical area, then no problem. Charles Hixon ------- Date: Wed, 24 Sep 2003 20:50:04 -0000 From: "Jim Knighton" Subject: Re: Sherline sized reamers... Thanks to all who responded. I cut down 2 reamers last night (3/8 and 1/2). The shanks on my reamers were much harder than I expected from reading these posts. The portable bandsaw just bounced off and wouldn't do much more than make a superficial scratch. The Dremel was just too small and light for this task. I finally dredged out a pneumatic die grinder that I handn't used for ages and chucked up a 3" cutoff disk. That, folks, made short work of those shanks and in the process I gained new respect for this "old" tool. Regards, Jim Knighton ------- Date: Sun, 28 Sep 2003 13:37:09 EDT From: JMartin957x~xxaol.com Subject: Re: Adjustable Reamer with Pilot > >Why not have the pilot REPLACE the nut? Think I may even have seen some > >commercially made pilots like that. In a message dated 9/28/03 jerdalx~xxbrick.net writes: > That would be fine, but given the length of the pilot, the few threads that are engaged at full extension, and the accuracy with which the pilot bar needs to be aligned, I think it would be "iffy". Yeah, the nut face bears on the blade ends, but....I suspect the reamer would "wobble" too much unless the threads were ground very precisely....more so than they would need to be for the regular nut. 0.001 at the end of a 6" extension vs 0.6" pitch diameter would require 0.0001 accuracy in making the threaded end. Jerrold < I checked. C&T do make pilots for their Critchley reamers that way. http://www.chadwickreamers.com/samples3.htm I agree with you, and C&T warn, that the reamers with the removable pilots are not as accurate as the reamers with the solid pilots. I've got a set of Keystone solid pilot reamers which I use where the alignment is absolutely critical. For most work, though, I think that the removable pilot reamers are OK. I don't have a Critchley removable pilot handy to examine, but if you do I think you'll find that the internal threads are cut rather than ground. And, when making a pilot, I assume we're talking about cutting the threads on a lathe rather than tapping them. Lathe cut threads are pretty darn accurate. In use, reamers don't want to cut any more than they have to. Reamers held by hand or in a floating holder tend to reduce any "wabbling" on their own. Especially if you are removing just a small amount. All that said, my first choice for reaming a bushing where the alignment was critical would be a solid pilot reamer, or, if space permits, a regular reamer used with a guide bushing on the shank through the other hole. John Martin ------- Date: Thu, 04 Dec 2003 08:19:19 -0000 From: "Terence T.S. Tam" Subject: Help - tailstock and headstock alignment... reamer advice [sherline group posting] Hi gang, Rebuilding my lab's lathe, and I think the head stock and tailstock is out of alignment. I was trying to ream a piece that was threaded onto the spindle directly with no slop (an end mill holder actually). So, I centerdrilled, then drilled with a #3 screw machine length drill (for rigidity). The hole's at .2130, I reamed it with a .249 reamer. The hole then slip fitted a .250 end mill. (I am reaming undersize and heating the holder up with a propane torch then setting the tool bit into it, to eliminate the hassle of set screws and trying to grind a flat into a carbide end mill!) I noticed that the reamer seemed to have deflected a little bit when it first touched the work. The reamer is a standard length chucking reamer. My questions are: A: How do I check the headstock and tailstock alignment? I noticed the brass gibs are adjustable, how do I adjust? (What do those 2 little set screws do?) B: Am I pre-drilling too small undersized? C: Anyone know of a source of shorter reamers for a more rigid setup on such a small machine? what do people use on the mill where space is much more limited? Or do you guys just ground off most of the shank? Thanks! Terence ------- Date: Thu, 04 Dec 2003 19:24:48 -0000 From: "Jim Knighton" Subject: Re: Help - tailstock and headstock alignment... reamer advice It appears that there is some variability in the hardness of reamer shanks. I found that mine were much to hard to cut with a metal bandsaw and I ruined a blade trying. I've seen posts suggesting that a Dremel or equivalent will work, at least on small diameter reamers. On my 3/8" and 1/2" chucking reamers the Dremel was much too light. I used a pneumatic die grinder with a 3" abrasive cut-off blade to cut them down. Regarding shorter reamers, when I asked the same question a few months ago someone suggested I look for stub length screw machine reamers. I did, and while I haven't purchased any as yet I found that they are out there. Regards, Jim Knighton ------- Date: Fri, 5 Dec 2003 14:13:04 -0500 From: "JERRY G" Subject: Re: Re: Help - tailstock and headstock alignment... reamer advice Another way to "skin a cat" (reamer shank) Notch the shank with the edge of a grinding wheel. (rotate slowly) Make another V notch oppisite the original notch. (create a v-groove around the shank.) Go deep enough to snap the shank off. Dress up with the wheel. If you do not have a grinder, make friends with your local machine shop owner. Regards, Jerry G (Glickstein) ------- Date: Fri, 5 Dec 2003 13:57:08 -0500 From: "JERRY G" Subject: Re: Help - tailstock and headstock alignment... reamer advice A reamer is NOT an accurate way to insure hole geometry and concentricity. The most accurate way, on a lathe, is to single point bore the hole. If it is a through hole, leave it a little undersize and then hone it in. Blind holes can be done, but bellmouth is a common problem. Alignment can be checked by cutting a test bar. The gibs are purely for taking up wear. Normally, the screws contact the gibs directly or through a insert to prevent damage to the gib. Just take up on them evenly and firmly until the slide moves smoothly without jerking or excess play. You can check the play with an indicator. Regards, Jerry G (Glickstein) ------- Date: Mon, 8 Dec 2003 16:21:38 -0800 From: "Marcus and Eva" Subject: Re: Re: Help - tailstock and headstock alignment... reamer advice Original Message From: "Terence T.S. Tam" > To: > > * What is this honing process and what does it entail? The only > > "honing" that I am aware of is using a knife on a fine grit water > > stone to put the final cutting edge onto it. What sort of grit of > > abrasive should I use, the speed etc, how is diameter controlled and > > how is the tool held? I see something called a "flex hone" but it > > only comes in certain diameters and they all seem way too big (at > > least from MSC). > > * Has anyone seen a boring bar that can bore in the 0.100" range? > > The smallest end mill holder I want to make is for the .125" ball > > nose carbides. Thanks! Hi Terence: Sorry it's taken so long for me to respond...but here's the practical dope from my experience. Strictly speaking, honing uses an abrasive block rubbed over a surface to refine its geometry while lapping uses a mixture of grease or oil and loose abrasive grains smeared onto a tool called a lap, which is then applied to the surface to be refined until it's geometry is acceptable. Most people use the terms interchangeably. What you'll be doing is lapping, and the tool you'll use is a round bar of softer material than the hole you wish to lap to size. The reason you use a soft material for the lap, is that you want the abrasive grains to become embedded into the surface of the lap, so they stick out and grind away at the workpiece, a bit like a very fine file. You need a way to expand the lap when it wears down and when it makes the bore bigger...the fit needs to always remain pretty tight. The way to do this is to make the lap expandable, and you do it by one of several methods. On the larger sizes, like 1/4" and up, you can make a brass cylinder, tap for a small screw in the end, and then cut slots in the side, so when you drive the screw in deeper, the lap body bulges in the middle. You can buy these pre made. they're called "barrel laps" For small holes, the most common lap is a bit of wire that's had a slot punched into it that looks like the eye of a sewing needle. A special tool that works just like a screwdriver is used to twist the slot open, expanding the tool diameter. A rude and dirty way to make a workable lap is to get a soft aluminum or copper bar of the right size and just hacksaw a slot into the end (kind of like the slot in a screwhead but much deeper.) Spread the slot a bit, and then turn a shallow taper on the free end. You want to end up with the widest part of the lap a few thousandths oversize and not right at the end of the lap, but a good 1/2" minimum from the end of the lap. The tip and first 1/4" should go into the hole freely, but the lap should be "draggy" to turn when it's in all the way. Get yourself some "Clover" brand valve grinding compound in 320 grit or thereabouts, and smear a dollop onto the lap. With your workpiece held freehand and the lap spinning in the lathe at slow speed (200 RPM or so), you can run the hole over the lap back and forth at a reasonable rate, say 30 strokes per minute. You can feel with exquisite precision, which parts of the hole are tight, so you work over those areas of the hole until everything feels the same. Keep the whole works sloppy with oil as you lap...protect the lathe because it makes a fair mess and you don't want the abrasive on your ways. You can expect a fine bored hole to be opened up 0.001" in about 5 minutes or less. The first 0.001 goes fast because the lap is cutting away the ridges left by the boring tool; the next 0.001 takes a lot longer. When you measure your hole, you must clean the bore out perfectly...if you leave grit in the hole it will pick up on your test pin and seize it in the hole so you can't pound it out with a hammer!!! When the lap doesn't feel like it's cutting anymore (it's really easy to tell...no witchcraft required) pull it out, and spread it open a bit more. Since it's designed to be a bit springy, it's not that critical how much you spread it...just don't go overboard so much that you can't force it into the hole with a light push. Remember, LOTS of oil...make it really sloppy and you can't go wrong. A dab more grit now and again too. It's a tedious process, but extremely accurate. You can lap a hole straight, round and to size within millionths if you've got the patience...0.0005" is duck soup to hit. With regard to boring small holes...I cheat by using a cutter grinder to make custom tools out of broken carbide endmills. It is possible to make similar tools out of HSS round blanks using nothing more than a bench grinder and a steady hand. I've got some pictures somewhere on this list...I think they're in the Files or Photos section. Have a rummage through those sections on Yahoo and see if they're still around. Remember though, these were done on a cutter grinder, but you should get pretty good ideas about what a tool like that should look like. Some people have also reported good results using endmills and reground stubby twist drills as miniature boring bars. HTH. Cheers Marcus ------- Date: Fri, 19 Dec 2003 03:05:21 -0000 From: "Terence T.S. Tam" Subject: Re: Lapping Techniques (was: Re: Help with tailstock and headstock alignment) "JERRY G" wrote: > Terry, Do you know why you use figure eight patterns? The way it was explained to me, is if you used a back and forth motion when you change directions the piece would rock forward and backwards and you end up lapping a curve instead of a flat, and if you used a circular motion you end up with a concave surface (back and forth in both X and Y. A figure eight pattern evens out the rocking, so you will lap a flat surface. The lap here would be a sheet of tin float glass. Actually I think I'll pick up a sheet of it to use as a granite measurement table, since I'm too poor right now to afford the granite slab (and shipping on that is going to be a killer!) Terence ------- Date: Fri, 19 Dec 2003 23:57:47 -0500 From: "JERRY G" Subject: Re: Re: Lapping Techniques (was: Re: Help with tailstock and headstock alignment) Terence, I don't know about lapping curves, or concaves, but the real reason for figure eight patterns is to prevent "dubbing" the edges of the workpiece. Regards, Jerry G (Glickstein) ------- NOTE TO FILE: There is a discussion involving drilling, boring and reaming starting on 8 Aug 2004 (called "Tail Stock") that has been placed in the Drilling Tips file. Worth a read. Don't forget the Boring file. ------- Date: Sat, 02 Oct 2004 17:52:26 -0700 From: Alan Marconett Subject: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Hi Jerry, [SHERLINE GROUP] list, Right now, I'm trying to get the tool marks out of a steam engine cylinder (outside). The outside contour is shaped like a horse shoe, with sides tangent to a half+ round. 1/4" endmill, cutting basically on its end as a rotary table rotates. The flats are fine, but the round contour has a very small ridge in the middle of each tool path. The paths overlap 50%. Just a lot of work with a jeweler's file, and a few progressively finer pieces of sandpaper. A little emery paper and "Mother's Polish" finish things up. Too bad I can't CNC this part of the job! The inside of the cylinder is another matter! I made up a lap out of aluminum, which I charge up with red rouge, and run in and out of the bore while slowly rotating. My lap is a 2"+ length of 3/4" aluminum rod, that has been drilled for a 1/4" drill rod and a 10-32 setscrew to secure it. This lap is solid, although I think I want to split it, and put in secscrews to allow it to be expanded. I can cut it with the bandsaw, or a small saw blade on the Sherline, but I'm not sure which I want to use, or even exactly how to cut it. I'm sure I had a drawing somewhere for one! Alan KM6VV ------- Date: Sat, 2 Oct 2004 21:36:44 -0400 From: "Jerry G" Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Alan, Are you talking about a drawing for a lap? Is the 3/4" bore straight? Is it blind? How long is it? What kind of finish are you looking for? P.S. The best lap is cast iron material. We used to use laps with copper shells and a tool to expand them. For really fine work, Sunnen hones. Worked very well. Regards, Jerry G (Glickstein) ------- Date: Sat, 02 Oct 2004 19:10:55 -0700 From: Alan Marconett Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Hi Jerry, I thought I had a drawing for a lap, probably in with my I.C. stuff. Do you have one? The cylinder is 1.875" long, the lap is about 2.25" long. Could have been a little longer, but it was on hand. Just a simple through bore. Brass cylinder. Smooth cylinder, no cross hatching like on I.C. engines (that I'll need when I start on the Bob Shores Golden Eagle engine, I believe). I'd heard aluminum was good, because it would pick up the grinding bits, hadn't heard anything about cast iron. Why would it be better? I want to be able to expand the lap a little, thus the next two setscrews. I bought a brake cylinder hone some years ago, and played with that on some shorter cylinders. Then I read that there was a tendency to bell-mouth with such a hone. If you expand a simple split lap, then it's not round anymore, which seems like it would grab more. If it grabs, how do you get it out without scoring the cylinder? My solid lap came close to getting stuck while I was only part way in, possibly due to the lap mixture getting too dry. A wet lap mix seems to work best, but I didn't want to get the mill messy. Alan KM6VV ------- Date: Sun, 3 Oct 2004 09:46:27 -0400 From: "Jerry G" Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Alan, I do not have a lap. Cast iron is better because it has a finer molecular structure, holds the grains well, Meehanite is the best. Charges up easy. Expanding the lap is a good idea. Bell-mouthing is common with most hones and/or laps but you can avoid it by the procedure you use. It also depends on how you expand the lap as far as it "grabbing". Usually, it is split in a bandsaw, with a setscrew in the end, tapered of course. The better laps have a tapered rod going up inside the barrel of the lap. And they are split in the center only so when you expand them, the center bellies out. It sounds to me that you are trying to take out too much at a time, and the grains which were loaded (charged) in your lap started seizing with the bore. I was spoiled. Worked in a shop that had a few Sunnen Honing machines. It was a breeze to hone out some holes. On a Sunnen machine, there is a tapered wedge normally spring loaded to extend and cause the honing stone in the holder to remain at the size that you had set with an adjustment wheel. Constant flood of honing oil, a thick black liquid with a distinctive smell. When you wanted to stop to check the size of your bore, you would step on a foot pedal, the spindle would stop turning, the tapered wedge would be retracted and then you washed your piece to clean off the oil and gage the hole. There was an adjustment for the cutting pressure. Truing rings to dress the stone(s). Ahhh! the good old days! Regards, Jerry G (Glickstein) ------- Date: Sun, 03 Oct 2004 13:08:18 -0700 From: Alan Marconett Subject: Re: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Antonius J.M. Groothuizen wrote:> Alan: > My plan to avoid these marks is to machine the cylinder with it > clamped to the rotary table. Machining about the circumference > rather than along the length of the cylinder should do it. Tony Tony, I thought of that, but I don't have any endmills that long (2")! Also, the diameter of the cylinder is reduced between the flanges, so there is no way to get into these areas (I think) without using the end of the endmill. I was curious to see these slight tooling marks on the round areas and not on the flat areas of the "horse shoe" profile. Must be something about the contact the endmill makes with a round surface. Sherline's two flue 1/4" endmill. Alan KM6VV ------- Date: Sun, 03 Oct 2004 14:02:33 -0700 From: Alan Marconett Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Hi Jerry, I've heard of a setscrew in the end, but that sounds like it would cause the lap to be bigger on one end. If the center bellies out, then there would be less chance of grabbing. But that sounds like the work would have to be secured (I did not). Maybe that was part of my problem. I've heard of the Sunnen machines in some old construction articles, must be quite old. A little too much for a hobbyist. The lap size was fixed, and close to hole size, I charged it up and slowly worked it back and forth until I could run it completely through the cylinder. I suppose I could split it near full length, and add a pair of setscrews to force the two sides apart, but that sounds like it would make the lap bigger at one end then the other. I didn't find the drawing I thought I had. The cylinders look better, but I'd like to lap them a little more. My lap is now too small for much action, I think. Alan KM6VV ------- Date: Sun, 3 Oct 2004 19:24:54 -0400 From: "Jerry G" Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Alan, just a thought. If it is just surface finish you are after and not a given size, would you consider "flap polishing?" Regards, Jerry G (Glickstein) ------- Date: Mon, 04 Oct 2004 09:08:17 -0700 From: Alan Marconett Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Hi Jerry, the pistons will be cut to fit, so exact size is not a problem. What is flap polishing? A slotted mandrel with a flap of abrasive material? What is used for the flap? Alan KM6VV ------- Date: Mon, 4 Oct 2004 19:04:36 -0400 From: "Jerry G" Subject: Re: RE: Cylinder finishing, WAS Re: ShopDawg Cam Clamps Exactly right! For aluminum, A good grade of emery cloth. As you clean it up, go to a finer grade, etc. Regards, Jerry G (Glickstein) ------- Date: Thu, 25 Nov 2004 20:36:11 -0500 From: "Jerry G" Subject: Re: Question about dowel pins Dave: Read between the lines..... :) Original Message ----- From: Dave Hylands > I'd like to use some dowel pins for some jigs so I can remove > a part and put it back without losing registration. > When I drill and ream the hole in the jig which contains > the dowel pin, what sizes should I use? Generally the drill is 1/64" smaller than the nominal size. Actually it is determined by the material to be drilled and/or reamed. > I'm planning on using 1/8" dowel pins. What size drill should I use? On 1/8" dowel pins, I would use about .110" diameter. > Should the dowel pin be a press fit in the base? Yes, if you want the part to be removable from the base. > What size reamer should I use for the base hole? In Aluminum, I suggest .1245" for a definite press fit. The pins are .1250" plus .0002" minus .0000" > From the searching I've done, the common sizes > seem to be 0.123, 0.124, and 0.1245 There is no such thing as a "common size". You can get them in any size you want. > Does it matter what the base material is? I was going to use aluminum > plate, and possibly delrin. I guess what I'm asking is how much impact > (if any) does the base material have on choosing the reamed hole size? The base material has a great impact on the right choice of reamed hole size. > The hole in the part needs to be a sliding fit. What size is > appropriate for that? For a .1252" pin, you want to be .1252" plus .0002" Depends how much shake you want to tolerate. > Thanks - I figure I might as well try to get the correct sized > reamers the first time around :) Dave Hylands Bottom line: 1. Select your material. 2. Do your experimenting on scrap parts, for base and part. 3. Remember that the size engraved or written on the reamer is not necessarily the size hole you will end up with. 4. Reamers will pick up material on the cutting edges unless you have a copious coolant flow. Result, oversize hole, "bloop" fit with dowel pin. Regards, Jerry G (Glickstein) ------- Date: Thu, 25 Nov 2004 20:03:50 -0800 From: "Marcus and Eva" Subject: Reaming dowel holes Hi Dave: Jerry's advice is right on. Here's a couple more thoughts though. Nominal size reamers (0.1250") are much cheaper and way easier to get in our industrially challenged part of the world. Here's what I do when I need to get a slip fit on one side and a press fit on the other: I ream through both parts together using oil as the lubricant (water based coolants tend to ream a smaller hole than oil). I drill quite a bit closer to final size than Jerry recommends, but I step drill to get there: 0.110" to start, then up to 0.120" for 1/8" hole. Step drilling tends to make a round hole very close to the drill size if the drill is in good shape and you don't go nuts on the feedrate. Then I kiss it with the reamer. I can usually get a 0.1250 to 0.1251" diameter hole out of a near new 0.1250 reamer. (Brand new out of the box will usually ream the first hole at least 0.0002" oversize even with floods of oil.) I check the holes with a dowel pin...usually it will be a light push fit or a nice slip fit. Just right for the bit that's got to come free but a bit too sloppy for the side that's supposed to be the fixed side. So I dig into the dirty tricks bag, and there's two good ones for this application. #1 is to haul out the handy dandy Loctite and loctite the little buggers into the side you want fixed. Dirty trick #2 is to put a 3/16" or 1/4" dia ball bearing over the hole and give it a good smack with a ball pein hammer. That will raise a nice symmetrical ring burr at the edge of the hole and magically make the dowel nice and tight going in. It's enough to make a Purist wince in horror, but it works well enough that it's surprisingly widely used, but never admitted to. Here's what you save: The higher cost of an undersize reamer. The nuisance factor of having to open out the hole with a second reamer on the slip fit side. The hassle of having to press the dowel pins in with a great bloody press. The big hassle of occasionally pressing a pin in crooked and either bending it or breaking it and certainly scoring the hole so it's good for nothing ever after. The HUGE hassle of having to get the broken or bent pin back out. The overwhelming embarrassment of having to go to the boss and explain why you got too lazy to use the press, and tried to press the pin in with the milling machine quill, thereby stripping the quill pinion or breaking the handle. A couple of other notes: Delrin reams tight...really tight. You can run a 0.125" reamer into a hole and get a 0.124" hole. The problem is that the material expands when hot (while you're reaming) and then collapses again as the material cools. Brand spankin' new reamers help, so does slow speed and rapid feedrate; an air blast and lube (Vaseline is OK) helps a bit too. There is a collection of toolbreaker tricks that you can use to overcome this problem too. One is to create a burr on the reamer flutes by burnishing them up with a carbide pin (something like the method used to form a burr on a cabinetmaker's finishing scraper). This is a trial and error process, and results will vary with your Wheaties intake for that day. Another is to drop a 1/8" endmill down the hole...the collet runout will make a 1/8" endmill cut oversize by about a thou or so. A third is to re-ream the hole by hand with a brand new reamer and a tap wrench after it comes off the machine. A fourth is to retip the reamer so its cutting edges are shaped like a milling cutter (at 90 degrees to the long axis of the reamer rather than at 45 degrees). This will make it cut large as well (but the hole will be rougher). Hope all this helps, cheers Marcus ------- Date: Fri, 26 Nov 2004 00:28:46 -0500 From: "Jerry G" Subject: Re: Reaming dowel holes Marcus, Wow! I ought to report you to the Toolbreaker's Union, if there was one! I don't want to sound flippant, but I can say to ALL your thoughts, "Been there, done that", and then some..........:) I've seen guys go into a cold sweat when they had to ream a hole because they knew the hole would become a "bloop" fit. (My term for an oversize hole, describing the noise the dowel pins makes as it freely drops through what was supposed to be a press fit! :) I have center punched the inside of dowel pin holes to raise material to hold the pin in place when the ball-clopping, ring burr creating did not hold. I have put a piece of copper or brass in reamer teeth to make them cut bigger. Would you believe putting a setscrew in to hold a pin in a bloop fit hole? If I had a long enough hole, reaming a slip fit for the pin at the top of the hole to "square" up the pin as it went in. I have cut off Allen cap screws and put them in counterbored holes (yes, with Locktite!) to hide the fact that there were broken taps underneath! Wait! That is another subject altogether...I'm going to stop here. We do not want people to think we are not precise toolbreakers creating miracles as we go through life, trying to adhere to the sometimes ridiculous requirements of the "engineers", who never stepped foot in a real machine shop, or toolroom. Yeah, Marcus, you have, with a few words () evoked in me a great nostalgia. I miss the smell, the sounds and excitement of the machine shop(s) and toolroom(s) when everyone scrambles to get to the communal sink for the five minute wash up period. Henny, where is my beer? Line up a few, please...Marcus has done it again... :) Regards, Jerry G (Glickstein) P.S. Now I know why my toolbox had a few toolmaker tools and a generous assortment of hammers, and reamers, reamers, reamers..... ------- Date: Wed, 08 Dec 2004 05:39:55 -0600 From: Gordon Couger Subject: lapping? I have been away rebuild my computer after an drive crash caught me in a dismal state of salvation. A real sin for a retired computer professional. I have a microscope stage that is a 3.5 inch round hole with a .20 bearing surface made of ferrous metal. I assume one is steel and one cast iron. The stage graduated in degrees has a flange that supports it in the .20 bearing. The fit is so close that even with the lightest oil I can find turns too tight. It is very difficult to assemble with out binding. I only want it to turn a bit freer. I don't think I can't mount it in a lathe and touch it with a tool and not take off too much. Or do any other operation and not come up too small when I polish it smooth. I am thinking trying lapping it with Lindy A a extremely fine sapphire compound. I am afraid any lapping compound will lock it up solid. It comes apart in three simple prices so cleaning any lapping compound out after I am done is not hard. The proper thing to do is to get a ball bearing stage but I have this just the right size for the job. It is going on an odd Zeiss microscope that is really hard and expensive to find stages for because it is larger than their standard line. All suggestions welcome. Thanks Gordon -------- Date: Wed, 8 Dec 2004 09:07:42 -0500 From: "Jerry G" Subject: Re: lapping? Gordon, first things first. Are there any score marks on either surface? What do you means exactly by ".20 bearing surface"? Which is cast iron, the hole in the stage?. Have you cleaned it thoroughly, and I suggest BEFORE any lapping, try "Kroil" a really fine oil..... At Bulova, we had a really fine oil, ($2000 a gallon). If that does not work. Lapping is critical. Depending on what you tell me, I will explain how to lap it, but first I have to know what you are dealing with. Diamond lapping compounds (not sapphire) are good IF one part is steel....It is possible to cause a worse problem by lapping and "charging" the work instead of the lap. Regards, Jerry G (Glickstein) P.S. Pro trick. It is possible to "lap" it by using "Marvel Mystery Oil" Inject a little after assembly and then work it in. Disassemble, clean thoroughly with "Afta" a great cleaner, but watch the ventilation, Then, a little Kroil and you should be cool! Let me know how you make out. ------- Date: Wed, 8 Dec 2004 08:15:21 -0800 From: "Marcus and Eva" Subject: Re: lapping? Hi Gordon: I second Jerry's suggestions, but I'd like to add a couple more: First, the areas that will get burred and nicked most easily are the corners...inspect them very carefully under magnification and look also for bruising of the machined surfaces as well as damage to the corners. Check the wear marks on the hole to get an idea of its roundness. When you put a large diameter precision plug into a precision hole, it's very hard to avoid cocking it and shearing a little chip from the shaft each time. With a fit this close, you'll need to assemble it in such a way as to avoid this kind of misalignment. Getting one part mounted to the mill spindle and the other loose on the table can help you get them nice and straight as you gently push them together, turning the free part all the time to be sure it's not binding as it goes down. Next...if I understand correctly, this is a large diameter but very shallow bearing surface with a flange on one end and dis-similar materials. Two things here...this assembly may have been intended to run dry, and oil may make it worse rather than better, just because of the hydrodynamic drag of the large wetted surface area. Try reassembling it with a dusting of dry Teflon spray. Second, the part with the bore will have a tendency to warp over time...if you can mount it gently enough, you might be able to spin a tenths clock in it and see if it's still round. Third: I very strongly recommend that you DON'T try lapping the parts together...one of them MUST pick up and embed the grit in order to function as a lap and that part will continue lapping long after you don't want it to anymore. You are just begging for the parts to seize up solid and never move again. If you determine that the part with the bore is out of round, make an expanding lap that you can drop into the hole and expand to size. Your lap MUST move axially as well as radially...this is not a trivial requirement if you want to avoid ring scores in the bore and seizing of the lap. Obviously, moving the lap axially when the bore support is only 0.2" long is not feasible by hand...get the part and the lap mounted in the lathe so you can use the tailstock riding on the bed to help you maintain alignment. If you determine that the stub shaft is dinged up, dress the bruises flush with a white Arkansas stone and then polish the shaft with worn 1000 grit wet and dry paper. You can't take a tenth off in a half hour of polishing SO LONG AS THE PAPER IS ALREADY WORN BEFORE YOU START POLISHING WITH IT, AND SO LONG AS THE PART IS ACTUALLY A REASONABLY HARD GRADE OF STEEL. To precondition the paper, get it sloppy with oil and then polish a half inch dowel pin for a minute or so. You'll need to chuck the part in the lathe for polishing...of course you'll do this gently so you don't squeeze the snot out of it and distort it. More jaws is better...use the 4 jaw and dial it in as carefully as you would if you were turning on it. Your paper strip needs to be narrower than the surface you're polishing, so you don't round over the corners (unless of course, you want to). To finish, get a skinny hard felt stick, and polish the surface with rouge. This is wordy, I know, but sloppy lapping will trash your parts in a heartbeat, and once they're hooped, you can't go back. So take your time with this assembly, especially if you can't easily replace it. Oh yeah...it goes without saying that cleanliness is next to Godliness when reassembling. Cheers Marcus ------- Date: Wed, 08 Dec 2004 22:31:47 -0000 From: "steve" Subject: Another question on lapping A newbie question. I am making a small (old fashioned model airplane style) engine. There are no piston rings. Cast iron piston and cyinder liner both to be lapped. I have read up a bit about how to make laps and do the job but what grade of lapping paste (ie what grit size) should I use? TIA Steve ------- Date: Wed, 8 Dec 2004 20:13:07 -0800 From: "Marcus and Eva" Subject: Re: Another question on lapping Hi Steve: The grit size you use will depend on a bunch of factors: 1) How much material do you need to remove to achieve your size and finish requirements? 2) What is your job made of? 3) What is your lap made of? 4) What is the grit made of? 5) What is the vehicle that the grit is carried in? For non rocket-science type lapping in cast iron, the most readily available and more than adequate lapping compound is ordinary valve lapping compound available at automotive suppliers. A popular brand is Clover compound...I believe it is silicon carbide in grease, but I'm not at the shop right now so I can't check. I use 120 grit for really rough and dirty cutting to correct major geometric errors. I can cut 0.001" out of a half inch hardened steel bore in 5 minutes or so with this coarse grit and a brass lap. 360 grit is a medium grade that's capable of finishing a bore to "tenths" and will give a medium fine crosshatch pattern that seems to be about right for seating piston rings. 10 minutes of work with this grade will take out 0.0002" or so in a 1/2" bore. 600 grit is getting pretty fine and will let you split tenths...it's great for things that you want to get just the right amount of drag on a sliding fit or spinning fit. The bores of my smallest endmill holders are lapped with 600 grit, and will just allow a Garr uncoated endmill shank to slide in smoothly with 0.0001" deflection when I tighten the setscrew. 800 grit is getting into polishing territory where the appearance of the bore is important. The material that the lap is made of greatly influences the outcome: the principle is...soft laps cut aggressively and hard laps cut slowly but are capable of higher accuracy. The lap must always be softer than the job however, to allow the grit to preferentially embed itself in the lap. Otherwise the job starts to behave as if it were a lap, and the lap starts to behave as if it were the job! Copper is good on cast iron, brass and aluminum (6061 not 7075) are OK too. I've never tried cast iron on cast iron...maybe Jerry G can get into the discussion some more with recommendations. Lapping and honing both like really sloppy wet conditions...I augment the grease vehicle of the Clover compound with a light oil...3-in-one is a readily available oil of about the right weight for my kind of work. A really experienced guy can modify the cutting characteristics of the lap quite a bit by varying the viscosity and quantity of the vehicle... I'm not that good, but I don't do it all that much either, so I've never learned the finer points (by the way, the "vehicle" is the kind of goop that the grains are suspended in). So, that's it in a rather wordy nutshell. Hope it helps Cheers Marcus ------- Date: Fri, 17 Dec 2004 18:11:37 -0500 From: Tom Bank Subject: Question about a post on another e-list [now posted to sherline group] Jerry G and others, The following was posted on another e-list. Could you read it over and then tell me whether the advice given is right? I didn't think it was and replied with the message that follows the first one. If I am wrong I need to retract what I said. Thanks, Tom Bank ---> On Tue, 14 Dec 2004 17:42:30 -0800, you wrote: Jim, >>> I sometimes need to make a part, like a wheel or gear, which is to be pressed onto a shaft. I find with the fraction and number drills available that I can't always get a good fit so I have to resort to soldering or loctite to hold things together. I model in O scale so mostly I am working with shafts 1/8" and smaller. Is there some kind of ultra-mini boring bar to get the right size hole? A simple way to modify an existing drill bit? Also, is there a formula to figure just how much smaller a hole should be to hold tight, yet not distort the part as it is being pressed on? I am new to this group and hope some of you might have some good techniques for this type of work. <<< >> Try and get a hand reamer for the size you require. A hand reamer is tapered (a very slight taper) and you can use this taper to get a predictable press fit. Drill the hole a few thou undersize such that you can get the end of the reamer in the hole, then ream the hole until the reamer reaches a certain depth in the hole. You have to find this depth empirically by cutting deeper and deeper with the reamer and trying the axle or shaft in the hole. When you've found the depth of cut that gives you the press fit you require, and you've got more holes to finish, wrap a piece of tape round the taper at the depth you've found so that you can cut to depth quickly for subsequent holes. Make sure you get a hand reamer with a taper. Machine reamers are parallel and you won't get the results. Or the other option is to get a machine reamer that is ground to cut a hole which is the correct size for a press fit on the shafting you are using. You might have to search around to find such an item and you might not be lucky, so you can make your own reamers, or "D" bits, using drill rod. Jim. << No! No! No! Never use a tapered reamer on a gear! You would wind up with one side of the gear too tight and the other side too loose. Tapered reamers are for sheet metal or, if specifically cut for the purpose, for mounting taper pins of specific sizes. The reamer you want is an "undersized" reamer. You see sets of "over and under" reamers, .001" over sized and the same under the various fractional inch sizes of holes for slip fit or press fit, but you don't need the full set. Just get the one you need. Regards, Tom Bank === Who is right??? And by the way, are hand reamers (the ones that look straight) really tapered? ------- Date: Fri, 17 Dec 2004 20:32:03 -0500 From: "Jerry G" Subject: Re: Question about a post on another e-list Tom, I am not going to comment on the advice given [ABOVE]...... You prefaced your e-mail with my name, so I have to respond. My personal preference which might not suit every one, but do work and stood me in good stead for fifty years of toolmaking...... If I have to make a wheel or gear to be pressed on to a shaft, I have to take into consideration the material of the shaft and the wheel/gear. And the dimensions for a press fit or a force fit, etc. Press fits are tricky to attain and maintain. They are really interference fits, where the hole can be smaller than the shaft by as little as .0002". I do not care for reamers, machine or hand. Hand reamers are tapered at the front. Machine reamers or chucking reamers have the nominal size at the front and have a back taper towards the shank. They are NOT finishing tools. They will follow the hole and sometimes give you the right size if you get lucky. Often times they will pick up material on the cutting edges and cut oversize, the result is what I call a "bloop fit, not a press fit. "Bloop" for the sound of the shaft when it falls through the wheel/gear. :) What does work, you say? Single point boring. Whether in the lathe or on a milling machine, or on a Moore Jig boring machine, the action is the same. A boring tool creates a fairly round, accurately sized hole, in the right location IF the operator is skilled enough. I say fairly round because there is a fact of life known as tool deflection. This can and will result in tapered bores even though you take a multitude of "spring cuts". Now, I will tell you about my secret weapon, besides experience, skill and screwing up a lot of wheels/gears on my way to consistent success. There is a company named Truemade Products Inc. in Ronkonkoma, N.Y. They make Truemade boring bars from carbide starting from .027" dia. to .480" dia. the shanks range from 1/8" to 7/16" And adapters to hold the boring bars. And you can also fashion small boring bars from carbide reamers by grinding away the teeth until you get one boring bar with the clearance to do the job. Getting the wheel/gear to run true so you can bore it out is a matter of set up and procedure. Whether in a lathe or on a milling machine or jig borer. In one, the work revolves and the tool is stationary. In the other, the boring bar revolves and the work is stationary. I never put a reamer in a drill press to "ream" anything. There is a reason it is called a "drill" press. You can put "press fit allowances" in Google and be inundated with all kinds of engineering info about press fits, etc. But, sooner or later you are going to have to produce a part... :) Regards, Jerry G (Glickstein) ------- Date: Sat, 18 Dec 2004 16:13:43 -0500 From: "Ron Ginger" Subject: Re:Question about a post on another e-list I thnk there is some misunderstanding of taper. You are correct that a 'taper reamer' would be wrong from a gear, unless of course you were putting it on a tapered shaft. Taper reamers have large tapers, like Morse sizes. A hand reamer has a VERY SMALL taper in its first 1/4-1/2 inch which helps get it started. The advice to use a hand reamer for a thin gear could work if you very carefully opend the gear hole until it fit the shaft. You might be using just the start of the reamer. A machine reamer also has a taper on its start- but its real shrp, more like a chamfer. Its just to get the thing into the hole to start cutting. ron ginger ------- Date: Sun, 28 Aug 2005 17:54:25 -0000 From: "gordonkwhitehead" Subject: Lap and lapping compound [Min_Int_Comb_Eng group] Well, after much delay, I am finally ready to lap my .934 steel cylinder sleeve to my .937 fine grain iron piston. I see that J&L has a .875 barrel lap that expands up to 15%. Is that a good way to go? And what type and grit abrasive do you guys recommend? Would automotive rubbing compound work? Should the lap be mounted in a milling machine? I am clueless. gordon the old phart in Florida ------- Date: Sun, 28 Aug 2005 20:35:13 +0100 (BST) From: David Everett Subject: Re: Lap and lapping compound Gordon: There is an excellent article about lapping cylinders and pistons in the latest issue of Model Engine Builder magazine. Go subscribe and be a happy model engine builder! Dave Saudi-Arabia-On-Sea ------- Date: Sun, 28 Aug 2005 19:36:47 -0000 From: "mrehmus" Subject: Re: Lap and lapping compound Auto rubbing compound is not a good idea and if this is an aircooled engine from which you expect performance, a straight lap isn't a good idea either. Diamond compound is the best possible lapping compound for this application. You need to lap a taper into the cylinder and then lap the piston to just pinch at the top of the stroke. That way, when the engine heats up (more at the firing chamber end) you end up with a good fit all the way up the cylinder. There is good advice to be found on the Internet and a Google search should find them. "Lapping cylinders," should get your started. At the risk of sounding commercial and self-serving, This was also the subject of an article in the second issue of Model Engine Builder. ------- Date: Sun, 28 Aug 2005 13:58:38 -0600 From: "Kory Hamzeh" Subject: RE: Re: Lap and lapping compound I would suggest using Clover Compound (around 200 to 300 grit) over diamond lapping compound. The diamond stuff essentially never breaks down and if it gets into the ways/bearing/leadscrews of any of your equipment, you will regret it. Kory ------- Date: Sun, 28 Aug 2005 22:50:37 +0200 From: "Frank Hasieber" Subject: RE: Re: Lap and lapping compound ANY lapping compound is bad news for ways/bearings etc, every precaution must be taken to stop it getting in anywhere not wanted, a good method is to cover ways etc with damp newspaper. diamond is excellent if used properly, the best way is to make your laps from copper, then take a very small amount of the diamond compound and smear this on a steel plate, then roll the lap over this with hand pressure (olive oil makes a good spreader for the diamond) then wipe any excess off of the lap, diamond dust and copper have a very high affinity for each other and the diamond penetrates and bonds with the surface of the lap. and will last for along time without replenishing, enough for a number of cylinders. Using this method is safer than any other and the chance of any diamond getting where it is not wanted is almost non existant. The saws used for diamond cutting are nothing more than thin bronze discs, and the diamond is mixed with olive oil and is applied to a steel roller which is brought into contact with the edge of the disc, this then cuts through the diamond. Frank ------- Date: Sun, 25 Sep 2005 11:19:31 -0700 From: Don Rogers Subject: Re: Warped Table? [taigtools -- HAND SCRAPE A SURFACE PLATE] At 04:58 PM 9/25/2005 +0000, you wrote: >Hand scraping flat surfaces from scratch was supposed to have been >the initial step in creating the earliest precision machine tools. That is the method used. You can make a perfect flat surface plate, <0.0001" variance, by making three. We made some small ones for one machine that we had that took a lot of wear. The plates were exactly sized for the ram ways. The plates were small, about8 x 10 " and 1 1/2" thick. We made them from cast iron sheet. We had three sheets cut to rough size, and then had them ground to just oversize on all edges. First step was to fully scrape off the ground surface. Then, with the plates numbered 1,2,and 3. You would red lead 1 and blue 2. Mark 1 and scrape the marks. Clean them up and then red lead 2, blue 3, mark 2 and scrape. Then red lead 3 blue 1, mark 2 and scrape. This rotation was repeated until all three plates had 90% blue when marked and not voids over 1/8 x 1/4 in size. The edges were then scraped in to shape in a similar fashion. This time using a flat of one plate and the edges of two, with scraped flats touching. The rotation was followed so each surface was checked against the other two. The trick getting the edges parallel required a fourth plate. We used a brown and sharp ground and matched bars for that. Rest two plates on edge on the third and then check the top edge with the machined bar. Then rotate one plate 180 on its face so the opposite edge was on the base plate and check with the bar again. When all three edge sets checked out in this way, they were square and parallel. Myself and another journeyman worked on this set for a month or so. Not full time, but when we had an hour between breakdowns, we would work on them. I sure wish I had them now. I still have the bars though. And my scrapers. I have been using my big bull scraper a lot over the last couple weeks. Not on surface plates or machine beds, but on my window sills. They are varnished oak, and were in need of re-finishing. I screwed around for a week on the first one trying different ways to get the old varnish off. I finally dug out my old bull scraper and had at them. I did one this morning, and it took me about 15 minutes to scrape down to raw wood, leaving a surface that a bit of sanding will put it ready for stain and varnish. An interesting point is that when I was scraping machine beds and such, I would need to sharpen my scraper about twice per shift. It held a good edge. The same scraper wiped out both edges on the varnish on just one window sill. I'm going to sharpen it up and then do a final clean up of the window sill. If there is any interest in the group, I'll put together a little photo essay on the scrapers and how to make one and how to sharpen one. All of mine were hand made. Don ------- Date: Sun, 25 Sep 2005 13:23:34 -0700 From: "Paul W. Chamberlain" Subject: Re: Re: Warped Table? Larry Richter wrote: >I'd certainly like to see what real scrapers look like. Here's one source: http://www.use-enco.com/CGI/INLMK3?PMK0NO=589470 You might also get one of these: http://www.grizzly.com/products/item.cfm?itemnumber=H2675& http://www.grizzly.com/products/item.cfm?itemnumber=G9644& http://www.grizzly.com/products/item.cfm?itemnumber=G9643& You'll need a reference surface or edge, certified straight, to identify the high spots to be scraped. While you're at it, should probably get a tube of this stuff: http://www.use-enco.com/CGI/INSRIT?PMAKA=505-1387&PMPXNO=942802&PAR TPG=INLMK3 Paul, Central OR ------- Date: Mon, 26 Sep 2005 03:19:20 -0000 From: "campgems" Subject: Re: Warped Table? > aside: do you know, don, if a slab of float glass > would make a decent cheap substitute for a shop grade flat? I'm not sure of the flatness of the stock glass, but you could use the same rule of three to get three of them flat. Rather than scraping, you would use lapping compound and grind one to the others that way. I guess that after a bit, that they would end up flat. The only trouble with glass though is that it is very brittle and an opps with a piece of metal or a tool could render it junk in a wink. Granet is hard and tough so it doesn't chip and break the way glass does. You can probably get some small scrap pieces at your local stone yard for not much. On the other hand, for $26 plus shipping you can get a 12 x 18 toolroom Grade B black granite surface plate from Enco. They are quoting overall accuracy to 0.0001" Not bad. They have a smaller one 9"x12" that is only $16 and the shipping is almost 1/3 the weight of the 12"x18" one. Don ------- Date: Mon, 26 Sep 2005 03:20:59 -0000 From: "campgems" Subject: File Uploaded to TaigFiles I just uploaded a photo essay on scrapers to the Taigfiles group files area. It is called: Scrapers.pdf Hope this answers some of the questions. Don p.s. As far as I know, red lead isn't available today. However, if you check the artist supply stores, real ones, not the Michaels type stores and you may find the pigment. I got mine back in the 1960's when scraping was in vogue. I don't think "Mr Peabody's Way Back Machine" is working now so it's going to be hard to get back to where I got it to get more. I wish it was working because I've got quite a shopping list of things I wish I had from "back when". Also a few things I would like to take back and forget about {:>) ------- NOTE TO FILE: Red lead and similar old time products might be found in stores selling stuff for "real" marine boatbuilding or farming. There are also safer substitutes that might suffice. Experiment. ------- Date: Mon, 26 Sep 2005 03:40:27 -0000 From: "campgems" Subject: Re: Warped Table? > I tried to make one out of an old file, following a very loose > description in a found article somewhere on the net. Obviously I > didn't get it right, because it's too easy to gouge with it. Or, > maybe it's my lack of understanding how to use a scraper. So, to the > back of the tool box it went for a rainy day and more information. Lynn, a file is a great piece of rough for a lot of different scrapers. I made all of my bearing scrapers from files. Tougher than nails and they hold a good edge. It was just too much work though to try and grind flat stock from one, especially by hand. Just be really careful grinding one. I broke the rest off a 10" bench grinder by snagging the edge between the wheel and the rest. Very embarassing for an apprentice. Every one came running to see what they expected was going to be a badly injured kid. Turns out it only stung my hands but broke no skin. I did learn a couple lessons though. Keep the rest almost touching the wheel so there is no chance to snag the work. The second lesson was that the wheel is considered unsafe if something like this happens. The journeyman immediately took the wheel off the grinder and broke it in half with a hammer. There was a good chance I cracked it and further use could have really hurt someone when it let loose. Don ------- From: "JERRY G" Date: Mon Jan 2, 2006 7:25 am Subject: Re: [sherline] Newbie question - Reaming >>Hi, I have to drill and ream a 1/4 inch through hole (3/4 inch long) in piece of aluminium bar in the 3 jaw chuck in my lathe. I have not done this before so :- (a) What size drill do I use? (b) I assume I hold the reamer in the tail stock drill chuck? (c) What lathe speed do I use for the reaming? (d) Do I use a lubricant? I am looking for good finish in the bore but will machine the matching spindle to fit the hole. Thanks in advance for your help, Steve << Steve: If you MUST ream, this is the procedure..... Make sure the part is running true by indicating it. If it is not, put it in a four jaw chuck (if you have one). Or, take a larger piece and then turn it in place to the required diameter. It will then be concentric, but not necessarily straight. i.e., you might have a taper. Correct this by adjusting the headstock, or careful filing and measurement with a "mike" (micrometer). Then, face off the end to provide a square surface. Now, centerdrill to provide a start for your sub drill for the reaming. The centerdrill should be held in the drill chuck in the tailstock. The tailstock may not be aligned to the headstock. There is an adapter to correct this. It is Sherline part number 1202 and called 3/8-24 Drill Chuck holder. (I have no commercial connection). Now, we come to the sub drilling... Most guides suggest a drill about 1/64th smaller than the reamed size. So, for 1/4" (.250") diameter, some people use 15/64" (.2343") Then, they ream... I like to leave less than a 1/64th for reaming... But I bore in order to do that... All too often, due to many factors, the reamed hole will not be satisfactory...The 1/4" reamed hole may be NOT .250", not running true, have a poor finish, etc... I'm not trying to dissuade you, just pointing out the pitfalls... I try to avoid reaming for all of the above reasons... I bore the hole(s) to size. If done properly, you control the diameter and do not need a collection of reamers. You control the finish. The geometry of the bore is usually concentric, straight and can be tapered, but this can be corrected. You say you will "machine the matching spindle to fit the hole". Why not control everything? The RPM of the spindle should be fairly slow when reaming. There are charts available ... Google them... Yes, the reamer is held in the drill chuck. I like "Anchor Lube" for a lubricant. Good luck, Regards, Jerry G (Glickstein) ------- Dowel Pin Installation Questions [taigtools] Posted by: "Rick Voegelin" rickvoegelinx~xxcompuserve.com Date: Tue Aug 15, 2006 6:53 am (PDT) All: I am building a small checking fixture that requires accurate alignment between two parts. I plan to use dowel pins to align the two halves, but I have never installed dowels before and so I am looking for some practical advice to smooth out the learning curve. Material is 6061 aluminum. Dowels are for location only, no loads on them. I will use a small thumbscrew to clamp the fixture together. If I use 1/8" dowels, what size should I drill/ream the holes for proper fit? What is the best method to accomplish this while maintaining alignment? I would like the pins to have an interference fit in the main part of the fixture, with a little clearance in the removable part for easy assembly/disassembly without being sloppy. The holes for the main part are blind, while the holes for the removable part can be drilled through. Should I use Loctite to retain the dowels in the fixed part? All suggestions are greatly appreciated. Thanks in advance, Rick Voegelin ------- Re: Dowel Pin Installation Questions Posted by: "Don Rogers" Donx~xxCampbell-Gemstones.com Date: Tue Aug 15, 2006 8:26 am (PDT) Rick, you need a set of over/under reamers for your 1/8" dowels. One will ream a press fit hole for the dowel and the other a very tight clearance hole. This work can only be done on a drill press that has been trammed and has a very tight spindle, or a mill that is trammed correctly. You want the holes exactly perpendicular to surface or else it will be difficult to remove the halves unless the clearance holes are way oversize. You will position the two halves together on the table and clamp them together very tightly. Position to the location of the first hole (an X-Y table is really in order if you are doing this on a drill press). Spot drill the hole, then drill your pilot hole.Then ream the hole with the under reamer. Lots of lube and very slow revolutions and only one pass through. Now, ream the clearance in the top piece, being careful not to go beyond the seam between halves. Remove the clamps and do a very slight bevel on the holes, and then hand turn the reamer through the holes to remove any burr from the beveling. You can use a 10 thousands undersize hardened pin in the drill chuck for a press, and use the removable half as a guide, push the pin in to the fixed half with the drill press. It may not go all the way in, but you should get enough of a start on the hole to ensure the dowel is going straight into the hole. You want the bevel to ensure there is no push-up around the dowel to hold the top half away from fully seating. Oh yes, if it is a blind hole for the press fit side, you will need to provide an air escape. You can file one very slight flat on the dowel, just one light stroke with a fine file, or drill a very small hole through the bottom of the hole. There are likely other approaches, but this is one I have used that works. Don ------- Re: Dowel Pin Installation Questions Posted by: "benedict-listx~xxhawaii.rr.com" Date: Tue Aug 15, 2006 2:21 pm (PDT) Depending on how close the pins are, you might consider an oval for one of the holes. Arrange the oval so that rotation around the pin in the circular hole will try to push the pin in the oval up against the sides. If the pins are close together I'll just use over/under reamers (under for the press fit, over for the removable parts.) But if the pins are pretty spread out, getting both of them to line up is... challenging. That's when I'll make an oval for one of the holes. I hope this makes sense. Tom ------- Reamers [LittleEngines] Posted by: "Ray Zdan" rayandpoex~xxyahoo.com Date: Tue Apr 3, 2007 6:35 pm ((PDT)) Because I am new to this group and a real novice to machining in general I am in need of suggestions on reamers. I am interested in building small steam and stirling engines and would like to know what would be a reasonable set to buy ( without bankrupting me). It seems that chucking reamers are what is used for the most part, but I am in need of help as to what type. Fractional, decimal, over/under, etc.etc.etc. Also would it be better to buy them as needed, or get a set ? What do the members of this group mostly use and who would be a reliable vendor? Thanks for any input. Ray Zdan ------- Re: Reamers Posted by: "Keith Green" ksggx~xxtelus.net Date: Tue Apr 3, 2007 7:02 pm ((PDT)) I 'd say buy as needed and get good ones from reputable US, European or Japanese makers. -------- Re: Reamers Posted by: "DTollenaarx~xxAOL.COM" Date: Tue Apr 3, 2007 7:19 pm ((PDT)) Hello Ray: Reamers, oh what a wonderful metal cutting tool. For my $0.002 worth, buy as you need them. Maybe from J & L, USA made. Remember, you get what you pay for. Buy cheap, and there is no telling what kind of finish you will get. As for Over and Under. Every shop needs a complete set from 1/8" thru 1/2". Very handy. Remember, a reamer is only used to "Size" a hold. Not for truing the bore of a hole, or an out of round hole. There you need to look closely at the Lathe Boring tools, and a Lap. Good luck, Dirk ------- Re: Reamers Posted by: "Alan KM6VV" KM6VVx~xxSBCglobal.net Date: Tue Apr 3, 2007 7:23 pm ((PDT)) Hi Ray: Pick a little engine (Stuart 10V or 10D for example), buy the taps, reamers and dies for it. OK buy extra taps. Next engine, get the new taps, reamers and dies you'll need. Repeat as necessary! Alan KM6VV ------- Re: Reamers Posted by: "Paul W. Chamberlain" pwcx~xxcapcocons.com Date: Tue Apr 3, 2007 11:54 pm ((PDT)) You can get some high quality reamers on the cheap by watching eBay and other sources. There are a lot of oddball sizes that sell below market. since you're making the part that will fit in the hole, you can vary a little from the blueprints. Same with endmills and drill bits. I use the oddball sizes for metal removal where the width of the tool is not critical... saving my dimensional tools for the jobs that need it. I got a grab bag o' drills from Harbor Freight years ago. They were an American brand parabolic in odd sizes. They work great for quick drilling pilot holes to start a bore. Chips flow right out the flutes. Paul, Central OR ------- Re: Reamers Posted by: "Jim Dunmyer" jdunmyerx~xxtoltbbs.com Date: Wed Apr 4, 2007 8:26 am ((PDT)) Ray, I'm with the others, buy reamers as needed. Jim ------- Re: Reamers Posted by: "Tom Faragher" tfaraghex~xxadelphia.net Date: Wed Apr 4, 2007 8:38 am ((PDT)) If you buy a set of reamers on eBay make sure they are chucking reamers. I bought a set of hand reamers (squared on the end) and they are worthless for reaming blind holes because they are tapered at the front end. The length of the taper is a little more than one diameter. Tom Faragher ------- Reamers Posted by: "Ray Zdan" rayandpoex~xxyahoo.com Date: Wed Apr 4, 2007 11:07 am ((PDT)) [:)] I just want to thank everyone who has given me help and advice concerning reamers. I really appreciate any and all information I can get. Even though I am a fairly new member to this group I feel that everyone is an old friend who is doing their best to guide me along in the world of machining. Thanks again, Ray Zdan ------- NOTE TO FILE: There is a good example in the Boring file here as to how a difficult hole-making operation can use a combination of drilling and boring and reaming to achieve a relatively deep hole while using a small lathe. See "Drilling 3" deep?" starting Feb 4, 2008. ------- Reaming in the lathe [MyMyford] Posted by: "tr0up" tr0upx~xxyahoo.com Date: Mon Feb 18, 2008 4:42 pm ((PST)) "Ken Strauss" wrote: > In my experience, hand reamers have a considerably longer tapered > section than machine reamers. I thought I'd start a new topic, since we've strayed from the title. Ken has put his finger on the key difference: machine reamers are designed to cut essentially with the end chamfer. Although this is the ideal geometry and gives the best chance of correcting deviant holes, even machine reamers are somewhat difficult to get reliable results from. It's hard to generalise what needs to be done as it's quite situational. Floating reamer holders are not really necessary if you've checked and corrected the alignment of the tailstock, both radial and angular, unless the hole is offset, and describes an orbit as the work turns. Because of the limited availability of torque, and the difficulties of maintaining parallel alignment when hand reaming, the cutting geometry of hand reamers is compromised by adding a long lead-in taper. This makes it possible to get good results reaming by hand, but frankly it's more art than science, and it can only correct holes for minor deviations from straightness: it can't correct deviation from perpendicularity (eg to the entry face). For hand reaming I prefer to use an adjustable reamer, because you can tailor the amount taken off in each pass to the machinability and hardness of the material. And by gradual increments to the cutting diameter, you can correct the deviation of an existing hole in a more "overall averaged" way, where machine and hand reamers tend towards a "weighted average", where the entry end of the hole exerts a disproportionate influence on the line of the reamed hole. "Overall averaging" (apologies for the inelegant coinage) is particularly useful in the common case where a hole has been drilled from each end of the workpiece, and you need to remove the joggle or mismatch midway. If you need to stop a reamer chattering, jam toothpicks, matchsticks or chopsticks (depending on size) into the tooth gap on one side. Be aware the reamer will cut slightly too large. To make a reamer cut slightly smaller than nominal size, rub a hardened dowel along the 'land' of each tooth (equivalent to the front of a lathe tool). To revert, rub it along the face corresponding to the top of a lathe tool. This also works for slot drills, but we're not talking much change - maybe 0.01 - 0.02mm at most. [In later message] I forgot to say: if you need to stop chatter without making the reamer cut oversize, try packing all the tooth gaps - or every second tooth gap if there are lots - with wood per the previous post. ------- Re: End mill or Slot drill ? Newbee question Posted by: "Keith New" britfix70054x~xxwaitrose.com Date: Tue Feb 19, 2008 4:43 pm ((PST)) Hand reamers are NOT intended for use under power - hence the square end to go in a tap wrench or similar. I had an expensive hand taper reamer broken by a "friend" who thought he could enlarge a hole in steel sheet by putting it in a power drill. It shattered like glass as soon as it jammed. Not good. Regards Keith ------- Reamer/reaming [atlas_craftsman] Posted by: "VTatlasLathex~xxcs.com" Date: Fri Oct 24, 2008 9:50 am ((PDT)) What would be the best method and tooling to make a 7/32" diameter by 3/4" deep flat bottom blind hole with the smoothest finish? I am inclined to drill 1/64" smaller hole, and use a spiral flute reamer to finish. Will the reamer give me a relativly flat bottom? Would a straight fluted reamer be better? Any suggestions on spindle speeds? I am about to place an order for the tooling and would prefer to order the right tools. This will be done on 642 and 660 slicon bearing bronze. Thank you Dave ------- Re: Reamer/reaming Posted by: "Russ Kepler" russx~xxkepler-eng.com Date: Fri Oct 24, 2008 9:58 am ((PDT)) Define "relatively flat bottom". The drill will determine the bottom of the hole, the reamer won't be cutting on its face. You could grind a flat bottom drill and use it to finish the hole depth and end up with a little chamfer between the bottom of the hole and the side walls; reamers usually have a little chamfer on their front edge to get started in the hole. Definitely do the 642 first, it's tougher than the 660 and you will want sharp tools for it. Both will have a nasty tendency to grab the reamer - you're doing a 3x depth/diameter hole, the perfect place for that problem. You're going to hear some squeeking with the reamer at depth; make sure that the bronze doesn't get warm and grab. ------- Re: Reamer/reaming Posted by: "gene burda" gjburdax~xxyahoo.com Date: Fri Oct 24, 2008 11:02 am ((PDT)) Dave, I would suggest using an end mill of the proper size. This will give you the best finish, and a flat bottom on the hole. ------- Re: Reamer/reaming Posted by: "trotterx~xxzipcon.net" Date: Fri Oct 24, 2008 11:32 am ((PDT)) The reamer will not cut the bottom of the hole at all. Not all end mills will do a plunge cut either, but a reamer is your best bet. Larry ------- Re: Reamer/reaming Posted by: "jo barden" jobarden422x~xxmsn.com Date: Fri Oct 24, 2008 11:34 am ((PDT)) D bit Jon ------- Re: Reamer/reaming Posted by: "VTatlasLathex~xxcs.com" Date: Fri Oct 24, 2008 11:55 am ((PDT)) Endmill- I hadn't considered that. Will an end mill give a better (smoother) finish to the sides of the hole. I can live with a slight chamfer at the hole bottom, but really need a smooth finish. Thanks for all the suggestions. ------- Re: Reamer/reaming Posted by: "Exibar" exibarx~xxTHELAIR.COM Date: Fri Oct 24, 2008 12:16 pm ((PDT)) Yes, an endmill can be perfectly flat on the bottom of a blind hole and would be the tool of choice for this application. Get a 4 flute end-mill for the smoothest finish, if you can find one in that size. M2 cobalt is the metal of choice for the mill too, but if you're only performing this operation twice, HSS should be sufficient. Mike B ------- Re: Reamer/reaming Posted by: "Ron Rupp" ron.ruppx~xxyahoo.com Date: Fri Oct 24, 2008 12:39 pm ((PDT)) If you don't have a center cutting end mill, drill a pilot hole first till the point of the drill is to the required depth. If you can live with a small divot in the center of your flat bottom then you can drill slightly beyond required depth. Then bring in your endmill. Note: In brass, copper, and bronze an endmill can really try to screw itself into the material. Ron ------- Re: Reamer/reaming Posted by: "jerdalx~xxsbcglobal.net" Date: Fri Oct 24, 2008 7:26 pm ((PDT)) A lot of machinists will grind the point off a regular drill, and then grind a shallow edge and relief on the flat end of each flute. The result looks like an end mill, but is a drill. You drill the hole so the point is where the end of hole is to be, then follow with the flat-end drill to square it up. JT ------- Re: Reamer/reaming Posted by: "azbruno" azbrunox~xxyahoo.com Date: Fri Oct 24, 2008 1:18 pm ((PDT)) Nobody's mentioned boring yet, so I'll toss that out as an option. ------- Re: Reamer/reaming Posted by: "rfmarchix~xxaol.com" Date: Fri Oct 24, 2008 1:39 pm ((PDT)) I like the end mill option, too. As an alternative, you can rough out the hole with a drill, then grind up a teeny, weeny boring bar out of a 3/16" or 1/4" tool bit and use it to finish the hole diameter and bottom. You could also make a lapping tool to get the finish you want. Have fun. ------- NOTE TO FILE: If you go too far when lapping or reaming or boring a part for an interference fit and the fit is loose, the following idea may save the part. To read an earlier conversation about interference fits, see my file "Turning Tips for Metal" starting with the message: Sizing a part to be heated [sherline] Posted by: "charlesdewen" charlesdewenx~xxyahoo.com Date: Thu Feb 19, 2009 4:04 pm ((PST)) ------- Re: Problem with an interference fit [sherline] Posted by: "charlesdewen" charlesdewenx~xxyahoo.com Date: Wed Feb 25, 2009 8:11 pm ((PST)) "chieftoolmaker" wrote: > Using a small, fairly sharp center punch (and small hammer), > indent the ID of the ring (after removal from the chuck), at > regular intervals, both radially and along the inner length, as far > as you can reach from each end. > Support the OD whilst doing this..... V block is cool. > This will upset some material, enough to create an interference fit. OK, Jerry, you get credit for inspiration. I took an electric hand engraver to the inside of the ring, while it was turning at a slow speed. The inside surface became covered with thousands of tiny discrete pin-pricks. The part would no longer fit into the ring. I took a light skimming pass with a cutter over the tops of the pin-pricks, and went ahead parting the ring off. As with the first ring, this one came off hot enough to slide on easily, and instantly cooled to a tight fit. Another success, with a new trick learned, too. A good night. Since I didn't exactly use your idea, I think I only owe you a light beer for this one ;-) Thanks! Charley ------- Re: SIMPLE ENGINE [barstockengines] Posted by: "Grif" kgriffitx~xxwolfenet.com Date: Fri Jan 21, 2011 9:13 am ((PST)) 1/21/2011, you wrote: >I have started to build this engine. I am making it all out of steel >as that is what I have. > http://www.machinistblog.com/plans-hmems-ez-build-engine/ >I don't have any reamers so I used a 1/2 end mill for the cylinder >Tom Good looking project. I'm working on a wobbler and just drilled the cylinder and used a hardwood dowel split on the end with various emery paper to smooth it up, then built the piston to fit. Took a couple of tries, but I can put the piston in the cylinder dry and hold it over my hand, the piston takes 15 or 20 seconds to fall out. With a drop of really light oil, it will not fall out of position. (well,,, for several minutes at least ;-) ------- Re: SIMPLE ENGINE Posted by: "Rob" rroll99x~xxyahoo.com Date: Fri Jan 21, 2011 9:27 am ((PST)) I've used the small hardwood dowel method Grif has mentioned with good results. But I've used valve grinding compound instead of emery paper. A screw is screwed into the split end of the dowel to push the halves apart and adjust its diameter. Just keep it moving back and worth so the cylinder is ground/polished evenly. Then make your piston to fit its diameter. ------- lapping [barstockengines] Posted by: "starr8719" rstarrx~xxptd.net Date: Thu Jan 27, 2011 7:46 am ((PST)) I'm building a beng's fire eater engine, does anyone have any ideas for lapping this 5/8 cylinder bore evenly? I was using red rouge on a felt dremel tool mounted on my lathe but the shaft is too flimsy. it did ok until I cranked up the RPM's, then the shaft bent fom running too fast. Ray ------- Re: lapping Posted by: "DA Dossin" danatlx~xxyahoo.com Date: Thu Jan 27, 2011 7:53 am ((PST)) Ray: The shaft bent? How long of a shaft? Perhaps a pic of your set up would answer the questions. Why do you find it necessary to lap at a high (RPM unstated) speed? DanD. ------- Re: lapping Posted by: "brian carter" briankenyn2x~xxyahoo.com Date: Thu Jan 27, 2011 12:22 pm ((PST)) Hi Ray, I haven't built a fire eater engine, but I have lapped cylinders. As a rule, life is simpler if the lapping tool is softer than the cylinder material. The value in that is that the minute particles that are 'ground' away from the cylinder walls have something to imbed themselves into. You may have heard of a wooden dowel being used, or a piece of aluminum roundstock. Slow is better; if the cylinder and the lap overheat, you run the risk of jamming the lap in the cylinder. That could result in the bending that you mentioned. By example, I followed the instructions for one engine using the finished slide-valve as the lap. I decided to set up the procedure in my drill press, running at the slowest speed of 600 rpm. Naturally I had no clearance and in no time at all, the lap jammed in the cylinder and I had one hell of a time getting it out. In that particular situation I ended up lapping it by hand. But with a softer lap material and the ability to machine the piston to the final diameter, you should have no trouble at all. Just don't go too fast. Good luck. brian ------- Re: lapping Posted by: "Thomas A Trikalinos" ttrikalinx~xxgmail.com Date: Thu Jan 27, 2011 2:29 pm ((PST)) I think that Ray is using a 1/8 shaft dremel bit that has a cotton flap in the end. He puts abrasive on the flap and runs it through. I do not think this is going to give the best results. this would resemble "internal grinding" (were you using a stone rather than the flappy thingie) but the dremel has a very bad runout. You would probably have to use the advice that Brian gave. Make a lap that is a close fit to the bore and is of soft material, put the abrasive on it and hone from the bottom of the cylinder or liner and up... Sorry if i misunderstood. Take care, tom in MA ------- Re: lapping Posted by: "raymont starr" rstarrx~xxptd.net Date: Thu Jan 27, 2011 3:39 pm ((PST)) I don't know why, experimenting I guess! here is a few pics of my grinder set up. the finished bore is nice and smooth. I was just wanting to find out how others do it. today I used a wooden dowel with a slit cut in the end and put a piece of anold felt hat in the slot that worked good too. ------- Re: lapping Posted by: "brian carter" briankenyn2x~xxyahoo.com Date: Thu Jan 27, 2011 4:10 pm ((PST)) Getting back to your cylinder, I am sort of wondering about achieving true parallelism in your bore, using just felt. How did you create the bore to begin with? Did you use a boring tool or a drill bit, or both? Brian ------- Re: lapping Posted by: "raymont starr" rstarrx~xxptd.net Date: Thu Jan 27, 2011 4:41 pm ((PST)) I started with a drill bit, then went in with a boring bar, I gauged the bore and it is parallel. ------- [reaming a bearing to fit a spindle] 109 Lathe Bearing Size [atlas_craftsman] Posted by: "Jason Rossitto" jasongetsdownx~xxgmail.com Date: Sat Apr 5, 2014 1:27 pm ((PDT)) Hi folks, I have a Craftsman 109.20630 lathe and I need to replace the bearings on the stepped pulley (A-3106). My plan is to buy a 0.5" ID 0.75" OD Oilite bearing, ream the inside, and turn down the outside. I've never done something like this so before I spend $40 on a reamer, I want to make sure I'm getting the right one. There are two different spindle drawings in the files on the Yahoo group site. One calls the diameter 0.551 and the other 0.550. I'm guessing I should just measure mine and buy a reamer that matches, but should I ream it to the exact size or allow a half thou of clearance? If I can't find one that matches exactly how far over sized is acceptable? Thanks! Jason ------- Re: 109 Lathe Bearing Size Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Sat Apr 5, 2014 1:57 pm ((PDT)) The spindle on my 109 was 0.551"/ Scott G. Henion, Stone Mountain, GA Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 Welding pages and homemade welder: http://shdesigns.org/Welding ------- Re: 109 Lathe Bearing Size Posted by: "Jonathan H Bateman" jhblagx~xxgmail.com Date: Sat Apr 5, 2014 2:03 pm ((PDT)) Check the article (one of the two rebuild articles on the 109 site) which notes .550 as the original size. Do you have a new spindle? Usually necessary. If you expect to use the old one, mic it at several points and check for straightness. Perfect is close enough. This weakly built lathe cannot tolerate any looseness anywhere; one thou os is barely tolerable. I can lend you my primitive change-out tool n/c if needed. Don't use press without internal support......BLJHB ------- Re: 109 Lathe Bearing Size Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sat Apr 5, 2014 2:31 pm ((PDT)) suggest an adjustable hand reamer ...ck enco, wt tool, victor machinery exchange, last price i remember was under #15 for a 1/2 inch +/- one .. nuts at top & bottom push blades on an incline larger & smaller....carbon steel is cheaper & just fine for hand reamimg ..even machine reamimg if CAREFUL ......these are also great for reamimg out shotgun chokes that are too tight ...now at 82, i cud stand having some of that choke BACK. you WILL need clearane....shud be able to keep your hand on headstock comfortably after bearing warms up ...i wud not want more than one thou clearance on my one in spindle crftsmn 6x18 ......my guess is 1/2 thou & w/ adjustable reamer if it runs hot, open some more. best wishes doc FWIW ...handbooks give running clearances for various shafts AND various classes from watches on down ...no need to buy a new one anything later than 1925. shud be fine & also easier to use ......back when a machinist was lucky to have had an 8th grade education. ------- Re: 109 Lathe Bearing Size Posted by: "L. Garlinghouse" lhghousex~xxsuddenlink.net Date: Sun Apr 6, 2014 5:19 am ((PDT)) I think you have the process backwards. Turn the outside, press in place and then ream the ID. The tighter the press fit, the smaller the ID becomes. Maybe this does NOT apply to your situation, but in my experience playing with single thou clearances and bushings pressed in tightly in non-lathe applications the ID sizing the ID is the final step. Go along with what those that have already done what you are talking about, but maybe they missed your sequencing if it is incorrect. Good luck, L.H. in Arkansas US ------- Re: 109 Lathe Bearing Size Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sun Apr 6, 2014 9:26 pm ((PDT)) YES..tnx ..good point ..... i shud have mentioned that ...i wud expect the bushing will need to be reamed to size after insertion ...they almost always are undersized after insertion. doc ------- Re: 109 Lathe Bearing Size Posted by: wa5cabx~xxcs.com wa5cab Date: Sun Apr 6, 2014 9:56 am ((PDT)) Jason, I agree with LH. If you are going to ream or line bore the bushings to fit the spindle, the proper way to do it is to fit the bushings to the spindle first. And then ream them in place. Also, the best way in which to hold the bushings to reduce the OD is with an expanding mandrel or an expanding 5C "collet". Fortunately, there are relatively cheap Chinese made examples of both routinely for sale. Robert D. ------- Re: 109 Lathe Bearing Size Posted by: "Jay Greer" redwitch1x~xxearthlink.net Date: Sun Apr 6, 2014 11:07 am ((PDT)) HI Jason, I am assuming you are speaking of the counter shaft and its cone stepped pulley. I just finished overhauling my own as the shaft was shot and so were the bearings. I used the same Oilite bearings you mention and used a press to put them in. I made up a new shaft to replace the one that was worn beyond redemption. The material was .5" dis ground and polished steel stock that required milling two flats for the driving pulley's setting cap screws to lock against. I ran a long reamer, .550" through and between the two bearings in order to insure alignment of the bore. There are holes drilled on the top surface of the bearing housing on my counter shaft yoke that were not bored through the old bearings. Even though I used Oilite bushings on the yoke, I drilled them through to allow better lubrication of the shaft. It may be overkill but it works very well. I replaced the old drive belt with a 3/8" segmented belt by Fenner Drives. It runs quieter than the old one did. Best Chips, Jay Greer ------- Reamer set from Little Machine Shop [sherline] Posted by: zerodbx~xxbellsouth.net zerodbx~xxbellsouth.net Date: Fri May 1, 2015 6:46 am ((PDT)) I was wondering if anyone has any experience with the LMS Reamer set #3067 ? Thanks for any responses. I was at the NAMES show and bought a PM Research Steam Engine #3. I do not have any reamers at all. I thought about buying just one .375 required, but why not just buy at set in case for future projects. I went to other machining sites and I am just overwhelmed at too many choices. I don't think I need an over-under set. This is why I saw this 29 piece from LMS. Unless it is something "really special", I just can't afford a $350 - $400 reaming set - This set is $199 which is just comfortable for me in budget. Reamers, 29 Piece Chucking HSS 3067 - LittleMachineShop.com http://littlemachineshop.com/products/product_view.php?Produ ctID=3067&category=-1167600499 ------- Re: Reamer set from Little Machine Shop Posted by: "David Clark" dcclark111x~xxcomcast.net a3sigma Date: Fri May 1, 2015 7:11 am ((PDT)) You can save a good deal of money by purchasing such tools as needed rather than complete sets. In building small engines and other mechanisms, you will frequently need “over and under” reamers — a few tenths over for clearance fits, under for press fits. The only drawback is you may not have the needed size immediately to hand, but if you buy sets you may not anyway. The good news is mcmaster.com. When I order from mcmaster online by 10am, the UPS guy is usually handing me the package the following afternoon. That’s quicker than I can usually find time to go to a hardware store that would have the tool, and shipping is comparable to the cost of gasoline to get there and back. David Clark in Southern Maryland ------- Re: Reamer set from Little Machine Shop Posted by: chieftoolmakerx~xxearthlink.net glicker31 Date: Fri May 1, 2015 9:18 am ((PDT)) Hi Donnie, Another way to go. Don't invest in reamers. With a good Boring Head and a few boring bars, you can make any size hole/bore you need. Also you gain experience while doing it. Regards, Jerry G (Glickstein) ------- Re: Reamer set from Little Machine Shop Posted by: "Reid" reidsimx~xxgmail.com rsimonus Date: Fri May 1, 2015 9:37 am ((PDT)) You might want to check #3066 which has 14 piece reamers. I see that #3067 has 29 piece reamers. I am not sure if you need all of them. Reid ------- Re: Reamer set from Little Machine Shop Posted by: "Ian 1" ian_newx~xxyahoo.com ian_new Date: Fri May 1, 2015 10:31 am ((PDT)) Hi ZerodB, I would second the advice you have already received - buy what you need as you need it. If you buy a set of reamers you will find the you will probably never use three quarters of them, and the remaining one quarter you will use, wear out and replace.... It is the same with drills, taps, dies, etc.; get a set and you will find you use a few of them regularly and most of them never get used at all. A final word or advice - if you buy a set of reamers you will probably get them in a nice wooden or plastic box. If you buy individual reamers they usually come in plastic tubes - keep the reamers in the tubes. Never keep them loose in a draw or box - they will bump against each other and the sharp edges will be damaged and little burrs will be raised. These burrs will score the sides of the reamed holes, making the reamer useless. All the best, Ian ------- Re: Reamer set from Little Machine Shop Posted by: zerodbx~xxbellsouth.net zerodbx~xxbellsouth.net Date: Fri May 1, 2015 12:57 pm ((PDT)) Thank you all for the quick responses. The other set from LMS is an over-under set. The 29 pc is as specified size. Well, I don't have a boring tool set up yet. The one each is a good option too. ------- Re: Reamer set from Little Machine Shop Posted by: chieftoolmakerx~xxearthlink.net glicker31 Date: Fri May 1, 2015 1:51 pm ((PDT)) Hi Donnie, take it from my experience. Once you become adept at center drilling, drilling, and boring, you will be able to make any size hole/bore within the capacity of your machine. Lathe or Mill. A drill is not a finishing tool. A reamer ( except for trying to ream to size) is not a finishing tool. Why? A drill and a reamer will follow the existing hole. A boring bar in a boring head is the tool to create it's own geometry. It is called single point boring. All too often, the flutes of a reamer pick up material and ream oversize, I call it a "Bloop Fit! Jerry G (Glickstein) ------- Re: Reamer set from Little Machine Shop Posted by: "Ken Condal" kencondalx~xxyahoo.com kencondal Date: Fri May 1, 2015 5:28 pm ((PDT)) I do a lot of reaming and most of it is 3/8" and below (often less than 1/8"). A boring tool needs to be smaller than the hole and I've never seen any that size. I buy good quality reamers from mcmaster.com as I need them and by now I have a nice set. Keep them in their original plastic boxes and they'll last a long time. Use PLENTY of cutting fluid and low feed and speed. The drilled hole should be small enough so that you're removing sufficient material with the reamer, instead of just scraping off a few thousandths. There are charts on the Internet for how much material to leave behind. A little practice and patience and you'll be reaming perfectly sized holes. ------- Re: Reamer set from Little Machine Shop Posted by: chieftoolmakerx~xxearthlink.net glicker31 Date: Fri May 1, 2015 6:58 pm ((PDT)) Hi Ken, Go to: Truemade Products of Ronkonkoma, NY 11779 They make a full line of products (Solid Carbide Boring Bars and Adapters) starting at .027" diameter. (No commercial connection) Jerry G (Glickstein) When I made Chief Toolmaker (At Bulova), each and every one of my toolmakers were issued a complete (basic) set of boring bars and adapters. My plant manager saw that it was a good investment, and signed his approval. ------- Re: Reamer set from Little Machine Shop Posted by: craigl2x~xxearthlink.net craigl_2 Date: Fri May 1, 2015 9:11 pm ((PDT)) Hi Ken, Goto: http://www.mcmaster.com/#boring-bars/=wzxpcw and checkout: "Small-Diameter Solid-Carbide Boring Tools" (A direct link to that page does not seem possible.) As is typical, they do not give the manufacturer. They are probably Micro 100 brand. You can find other sellers of Micro 100 boring bars, probably with better prices than McMaster-Carr. You can also find great deals on them on eBay, I recently bought one to bore a 0.125" hole 0.6" deep which needed to be absolutely concentric and a press fit. Craig ------- Re: Reamer set from Little Machine Shop Posted by: "Ian Newman" ian_newx~xxyahoo.com ian_new Date: Fri May 1, 2015 11:36 pm ((PDT)) Hi, As others have pointed out, it is possible to buy very small boring bars, but it is also much cheaper to grind your own. Another approach is the grind a "D" bit - this tool is usually considered as a drill bit, but if you look at its form and profile it is actually a boring bit designed and used to bore a hole of a single, specific diameter. All the best, Ian ------- Re: Reamer set from Little Machine Shop Posted by: jlkiefferx~xxcharter.net n2562001 Date: Sat May 2, 2015 6:37 am ((PDT)) I would second the suggestion by others to purchase special tooling as needed. Of course E-Bay and flea markets are good places to stock up on quality tooling when it is available for future use. However, when purchasing tooling, always check the place of manufacture and of course try to avoid places like China and India. Almost all tooling from LMS will be from China and India and is over priced when compared to Harbor Freight For the same Items. Poor quality tooling will be the most expensive tooling you will ever purchase. It is quickly learned when it destroys parts you have spent many hours to construct. Jerry Kieffer ------- Re: Reamer set from Little Machine Shop Posted by: "Ken Condal" kencondalx~xxyahoo.com kencondal Date: Sat May 2, 2015 7:42 am ((PDT)) Thanks Craig and Jerry. Just when you think something doesn’t exist, McMaster has a page full of them! ------- Re: Reamer set from Little Machine Shop Posted by: chieftoolmakerx~xxearthlink.net glicker31 Date: Sat May 2, 2015 11:51 am ((PDT)) Hi Ken, Many, many years ago, while still employed, I always had a weighty green and yellow catalog on my workbench. Yes, it was, (and still is) Mcmaster- Carr. Jerry G Glickstein) ------- Re: Reamer set from Little Machine Shop Posted by: "Sullivan, John" john_sullivanx~xxbmc.com john_grady_sullivan Date: Mon May 4, 2015 7:30 am ((PDT)) Thoughts and opinions about adjustable reamers to get a small amount more or less than a target size, please. Thank you, John G. Sullivan Austin, Texas 512-340-6078 ------- Re: Reamer set from Little Machine Shop Posted by: chieftoolmakerx~xxearthlink.net glicker31 Date: Mon May 4, 2015 8:26 am ((PDT)) Hi John, there are two types of adjustable reamers. One expands the center of the reamer blades by flexing the blades with a screw driven taper. The other has blades mounted parallel in a carrier body. Also expanded by an inclined plane device. More stable than the first. Better control. What are you planning? Jerry G (Glickstein) ------- Re: Reamer set from Little Machine Shop Posted by: dcclark111x~xxcomcast.net a3sigma Date: Mon May 4, 2015 9:53 am ((PDT)) I have a couple of adjustable reamers, of what Jerry refers to as the second type. Have often used them in a professional shop as well. They are very useful for getting a precise class of fit -- with proper technique. As has been pointed out, any reamer tends to follow the hole, so best practices must be used to ensure the hole is straight, true, and correctly located before you final ream. To get that exact size, you should prepare a number of holes in the same material, then ream, check, adjust until you've got the adjustment you need. Use precision gage pins, or ball gages and a micrometer to check the test holes. When you're shooting for micron accuracy, consistency is vital. Speed, feed rate, lubrication, amount of material removed in the final step must be the same. You may be surprised what a difference these factors make. For most home shop work, standard nominal, over, and under HSS reamers will do the job. First quality adjustable reamers are generally more expensive than a set of 3 for a given nominal size -- and take more trouble to use. David Clark in Southern Maryland, USA ------- ------------------------------------------------------------------ This is just one of some 80 files about machining and metalworking and useful workshop subjects that can be read at: http://www.janellestudio.com/metal/index.html ------------------------------------------------------------------