------------------------------------------------------------------ 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 ------------------------------------------------------------------ This file describes acquiring, making, and fitting backing plates for chucks to be mounted on Atlas (and similar) lathes. Along with reading this file, anyone that needs to cut threads in a backing plate will be well advised to read the text file "Threading" and also see the "Atlas Chucks" file. There is a bit of redundancy in some of the postings, as each person describes a technique just a little differently and adds some hints or experiences. If you are new to making or fitting backing plates to chucks, you will be well served by reading the whole file and then writing down your own set of instructions so that the steps you need for your situation are totally clear to you. 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 - 2014 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ========================================================================== From: Gene Sanders Date: Sun Jan 2, 2000 0:16am Subject: Backing plate fitting I have a new 6" three jaw chuck and have ordered a 1 1/2X8 threaded backing plate to fit to it. I plan to machine it on the spindle to match the recess step on the chuck which should be fairly easy. The problem I may have is drilling the three bolt holes in the backing plate to match the threaded holes provided on the outer edge of the chuck. I suppose making a template like a gasket to locate them might work? If anyone has any tips or advice, I would appreciate thehelp. I'm new to this sport. Gene Sanders ------- From: Date: Sun Jan 2, 2000 4:00am Subject: Re: Backing plate fitting One way would be to machine the sholder to fit the recess and then make some studs with sharp points to fit the threaded holes in the back of the chuck. Align the chuck and back plate and give the backplate a sharp whack with a deadblow hammer. You now should have three center punch marks to drill to. If you don't like the idea of hitting your new chuck with a hammer use blueing or a big magic marker and just scratch through the die to leave shiny spots to center your punch on. The points should be very close to flush with the back of the chuck. The holes can be a bit oversize as the shoulder on the backing plate and the register area of the backing plate are what align it. The screws just hold it in place. I like to mount the backplate on backwards first and true the register to the spindle then flip it and take a trueing cut. It would be good to remove and replace it a few times checking true on the face each time to be sure the register is right. Blueing on the register is a good idea to verify uniform contact. Don't turn the sholder till the backplate registers true and the mount re-mount is consistant. Matchmark the chuck to the backplate so you can re-mount it to the same bolt holes. ------- From: Date: Sun Jan 2, 2000 4:19am Subject: Re: Backing plate fitting Gene- I'm not sure if it's the best way (certainly not the only), but here's how I would do it- I've done a lot of drilling/tapping of panels for electrical installations and mounting printed circuit cards. Without a CNC mill or indexing head, you can still drill very precise holes. Some tips- 1. Get a spring-loaded center punch. 2. Get an etched steel rule with 100ths, 1Oths, 64ths and 32nds. Get a thin one. 3. Get a small x-acto knife for use as a scribe. 4. Consider a head-mounted magnifying glass. 5. Get some layout paint, red and blue. Helps to see the marks. 6. an engineer's square is good to have for square pieces. 7. Numbered drill set. Precision Twist drill makes a nice cobalt set. 8. drill press 9. drill press clamp Now for the backplate- 1. Find out what the bolt hole radius is. Ask mfr. or maybe someone else knows. 2. The most critical part of drilling those holes is to make sure they are concentric. Mount the backplate on the spindle. Put a dead ctr in the spindle. Mount a scribe tool in the toolholder and orient it perpendicular to the spindle. You can use a narrow pointed tool. Get the scribe as close as you can to the center of the spindle, using the dead center as a reference. Zero out your cross slide indicator dial. Move the scribe tool out by bolt hole radius, making sure to account for leadscrew backlash. Run the tool up to the backplate and lightly scribe a circle with the same radius as the bolt holes. Check the radius for accuracy. A pair of dividers comes in handy. 2. Take the backplate off the spindle and take to a well-lit workbench. Pretend you are an engraver working in a mint and it will help your accuracy. 3. Scribe a reference point for the first hole. Call this point "A". 4. Imagine a equilateral triangle inscribed within the circle you just scribed. To find the length of each side, using the radius, calculate r * 1.7321 (note- this is a 30/60/90 triangle and the ratios of the sides are hypotenuse=2, opposite=1 and adjacent= sqrt(3)) This is the length of each side of the triangle, and the distance from one bolt hole to any other. 5. Time for the dividers.. Make sure they are sharp. Use the etched rule to set them to the distance calculated in 4. Measure along the circle from the reference point. Make a mark there and call it point "B". Also, since calculators usually output in decimal, the 100th's of an inch feature on the rule comes in real handy. 6. repeat #5, going in the opposite direction. Call this point "C". 7. Check your work by measuring from point B to Point C. You can walk the dividers around the circle. 8. Center punch at each mark. 9. Drill a pilot hole with a small bit. Use the drill press clamp. 10. Drill to final size. 11. Depending upon the fasteners you are using, you may need to countersink/counterbore. This technique can only get you to within a couple of hundredths of accuracy, which is why the fit of the recess step is so important. If the fit on the recess step is sloppy, concentricity of the bolt holes becomes very important. A word on templates- I've made templates with Autocad and sometimes the plotter/printer isn't very accurate when it comes to linear measurements... If you CAD it out, use an accurate rule to verify your printer is accurate. A template is hard to line up with the workpiece. Better to use the workpiece itself as your canvas. best of luck! Charlie Bader Anchorage, AK ------- From: J Tiers Date: Sun Jan 2, 2000 5:48am Subject: Re: Backing plate fitting My suggestion is that it is not that hard or complex. If you realize that the boltholes should not be the locator, then you see that they can be a little larger than absolutely necessary. But you still want them correct. I just made a plate from an unthreaded blank. This had the advantage that I could be sure that the thread axis and the spindle contact surface plane were at 90 degrees to one another, since they were all machined in one setup. I think that is best. But, assuming the fit of the pre-machined plate is good to the spindle face (verify by sighting with light behind spindle) you can machine the fit and use transfer punches to set the bolt holes. Transfer punches are rods of various diameters, each with a center-punch on one end. You put the tightest fitting one (that will still move easily) down the hole with the parts assembled, and give it a rap to mark the matching hole location in the other part. I would do the following: 1) Machine the plate to fit the chuck, with plate screwed on spindle. 2) remove the backplate and place the chuck on the plate, with the whole works sitting on blocks so it won't tip 3) Use the best fitting transfer punch to mark one hole location 4) Remove chuck and drill the plate for that hole, make it as tight as will fit the bolt when installed 5) Reassemble and install that bolt 6) mark the other holes with the transfer punch and drill them comfortably over 7) Redrill the first hole to equal the others if you want You can get a set of transfer punches in 1/64 increments from Victor Machinery Exchange or other supplier for about $12 (import). It is a good investment. Jerry -------- From: Jon Elson Date: Sun Jan 2, 2000 5:48am Subject: Re: Backing plate fitting What you need are transfer punches, but, in this case, you only need one size, so make your own. Turn several inches of a rod down until it is a fairly tight fit into the bolt holes in the new chuck. On one end of the rod, put a point in the center, just a little bump, but make it pointed. Make the turned down length long enough to go all the way through the chuck body. When you have the backing plate set up so the chuck is a tight fit onto the centering shoulder of the backing plate, take the backing plate off the lathe and set it across two 2x4s or some other support, so it doesn't rock. Place the chuck firmly onto the shoulder, so it seats flat on the main seating surface. Drop the rod into one hole and give it a moderate tap with a hammer. Be careful that everything is lined up so that the chuck doesn't turn on the plate when you administer the tap. Repeat for the other 2 holes. Then, with a flashlight or whatever, sight down the holes and make sure all the punch marks look centered, as a check that the chuck didn't turn relative to the plate. If all looks well, separate the chuck and plate, and drill the appropriate tapping holes in the plate. The holes in the chuck are usually drilled a little oversize to accomodate some error in hole placement. In the worst case, where the holes drifted (not unusual, as the grey cast iron can have hard and soft spots) You can just smooth off any raised edges, turn 60 degrees and try again. A drill press or milling machine can be used, if you have one, to drill the holes with less chance of drill wander. Starting the holes with a center drill will also reduce drill wander. Jon ------- From: Date: Sun Jan 2, 2000 10:53am Subject: Re: Backing plate fitting In a message dated 01/01/2000, jmelson writes: > What you need are transfer punches, but, in this case, you only > need one size, so make your own. Turn several inches of a rod down > until it is a fairly tight fit into the bolt holes in the new chuck. The bolt holes don't go all the way through most of the three jaw chucks I have seen?? That was the reason for suggesting to make "Threaded buttons" to make the marks, Glenn ------- From: Date: Mon Jan 3, 2000 4:26am Subject: Re: Backing Plate/Xfer screws You guys are great! Check it out- J&L has transfer screw sets which consist of 6 screws and one handle. Sizes range from #4 to 1" in Coarse Thread and Fine Thread or various metric sizes. Cost is $11/set 800 521 9520. Manufacturer is Heimann Charlie AK ------- From: Date: Sat Mar 25, 2000 4:39am Subject: Re: Wanted-4 jaw chuck for Atlas 6" In a message dated 3/24/00, heyjudex~xxm... writes: > I'm looking for one too. :-) What size spindle do > you have. I have a 1-8, but I see many more "off > the shelf" solutions for 1-10 spindles. I had the same problem but since 1"-8 is a standard tap size, I just got a piece of 1" thick steel plate and rough cut it to a hexagon shape with the bandsaw and drilled and tapped it. Then I mounted it on the lathe and made it round and faced the back side for relief and register then flipped it over and made the proper fit for the chuck. I bought a 4" 3 jaw new for $75 that was really a nice chuck. When all was done I had about .0015 TIR on a chucked bar. Plenty good enough for what you would normally do on a 3 jaw. Good Luck Glenn ------- From: R. Lee Hawkins Date: Thu Apr 6, 2000 10:42pm Subject: Re: 1"x10 backplate or nut In your message dated: Thu, 06 Apr 2000 you write: >I thought I would save some money by making my own chuck backplate, but >when I called my local fastener company to order a 1"x10tpi nut, they You wouldn't want one anyway. Commercially produced fasteners are no where near as accurate as what you want/need. >said they don't exist. :-( Has anyone else found a source? Umm, why not just mount a piece of steel plate on the face plate and turn that down and thread it with your lathe, thus making your own backing plate? Hint: Drill the mounting holes for the chuck in the proper place, then counter bore them to the finished depth. Use bolts through these holes so you can turn the plate down for the part that goes near the headstock (hard to describe, but look at a chuck and you will see what I mean... there is a "flange" that sticks out from the back of the backing plate). Turn the OD, then face off one side... Reverse the plate, and face off the other side, making sure you get the two sides parallel. Flip the plate back around, and turn the exposed face of the plate down, leaving the "flange" discussed above. Finally, drill a hole in the center (using a drill held in the tailstock, center drilling first) large enough for a boring tool. Bore the hole out to the proper size and thread 1"-10. Carefully measure your spindle thread so you can duplicate it on the backing plate (once you start threading, you can't easily take things apart to check how your thread is fitting). >Or... who sells the least expensive 1"x10 rough backplate? I found an Blue Ridge Machinery (www.blueridgemachinery.com) sells one for a 4" chuck for $47.00. Not sure who sells one for a 3" chuck. >old 3" Craftsman 4-jaw chuck at the flea market and I would like to >mount it to my new Atlas 618, but without a chuck, I can't machine a >backplate! Catch-22! Do you have a face plate? Admittedly it will be hard to do on a face plate, but it would work. Don't be as scared of face plates as most folks seem to be. They work great :) Cheers, Lee ------- From: J Tiers Date: Fri Apr 7, 2000 1:20am Subject: Re: 1"x10 backplate or nut Hey, I don't know how to use a chuck to make a chuck backplate! Always have used faceplate. Hint, space the blank plate out from the faceplate whan bolting down. This gives your threading tool somewhere to go as it exits. Ask yourself how I found this out! Victor Machinery sells raw and threaded backplates in very nice cast iron. WWW.victornet.com should be the URL. Look on www.loganact.com and find the "metal web news" area. There is a description of machining a backplate there. I recall it as not being exactly how I did it, but gives the idea OK, may be better than what I did. Jerry ------- From: Jude Miller Date: Sat Apr 8, 2000 3:35am Subject: 4 Jaw Chuck for 6" A/C Lathe Well, I'm getting frustrated trying to find a 4-jaw chuck for my 6" Atlas/Craftsman lathe. I'll summarize the options in case anyone else has the same problem. 1) Buy another lathe with the chuck included. This is probably the most cost effective way to get all your accessories at once, e.g 4-jaw, steady rest, follow rest, threading gears. Of course, now you have another lathe. 2) Buy new/old stock. Campbell tools lists the chuck for $399!!! Unfortunately it's a 1-10 spindle, mine's 1-8. I haven't checked with Clausing or Sears yet. 3) Adapt a 3 1/4 inch Taig 4-jaw. This chuck only costs about $50. It's small, thread is 3/4-16. Perhaps there is enough metal to bore to 7/8" and thread to 1-8 7/8" deep. Anyone know if this is possible? 4) Buy a 5" Bison plainback and make back plate. I'm starting to think this is a good idea. The chuck and backplate will weigh around 11-12 pounds. Anyone think this is too heavy for a one inch spindle? This will cost around $150 to $200 including backplate material. 5) Wait for the right one on eBay. I've been at this for a while, saw one, and it went over $100 IIRC. Plus you never know if it'll be any good. And the vultures will descend on it :-). 6) Find the right one locally. Good luck. Thanks for listening, Jude Miller ------- Date: Wed, 24 Jan 2001 01:35:54 -0000 From: WBurkysrx~xxaol.com Subject: Re: Source for backplates small chucks please "Richard Hansen" wrote: > Please advise best sources for threaded back plates for four inch > Atlas chucks. Thanks ahead Richard Hansen San Diego CA Richard: I just bought a 4" 3jaw plain back chuck from Enco,then made a backplate by turning the OD of a 1.50-12 thread insert from Grizzly to a shrink fit with the ID of a steel ring about 5/8" thick. Then faced the ring and formed a pilot to fit the chuck, drilled the ring for soc.hd. cap screws that came with the chuck, and bolted the parts together for a chuck that mounts directly to the spindle nose of my 12 x 24 Craftsman lathe. bill Burky ------- Date: Wed, 24 Jan 2001 17:50:54 -0800 From: Mark Fraser Subject: Chuck Backplates New England Brass and Metals (somewhere in the FAQ) gave me excellent service on two, 1x10 backplates. They also sell Bison chucks at good prices. If anyone has a desire to thread using a tap, I have a 1x8 HSS NEW tap, for 25.00 plus shipping, unless the original buyer shows up...... mark in sunny (today) Vancouver ------- Date: Thu, 25 Jan 2001 22:17:42 -0000 From: STYSx~xxMINDSPRING.COM Subject: Re: Source for backplates small chucks please Guys, I just ordered a threaded adapter from a company called Central Carolina Supply out of Sanford, NC. I ordered a semi-finished 4" diameter adapter threaded to 1 1/2-8 for my 12X24. It cost me less than $40.00 with shipping! Their catalog has different adapter plates by both diameter and thread sizes. In the catalog,I see a 4" diameter, 1"-10 threaded adapter, but no 1"-8's. The company sells to many of the local manufacturing businesses in the area. Their catalog is similar to McMaster Carr or MSC, but the prices are better. Their phone number is 919-774-8550. They also have rough castings starting at $15.00. Hope this helps. Rick Stys Apex, Nc Craftsman 12X24 ------- Date: Fri, 16 Feb 2001 17:44:26 -0500 From: "S or J" Subject: Internal Thread Finish Problem Hi gang: I have a problem with a prethreaded chuck backplate for an Atlas 618 1 X 10. The part is well machined otherwise but the plate thread v-form is very sharp and not inclined to go onto the lathe spindle freely, and I am not going to force it. And yes, both the plate and the spindle really are 1 X 10. My spindle fits perfectly with its other chuck and faceplates. All my threading references deal with this situation for an OUTSIDE thread by suggesting the sharp tops be removed by lightly passing a single cut file over the rotating thread. They state that sharp thread points are neither necessary nor welcome for a proper fit, contributing virtually nothing to the strength or alignment, but are easily burred to then interfere with proper engagement. Certainly in the case of our lathes, the alignment is based on the register so the threads should fit well but not stiffly. Any suggestions as to how this INTERNAL thread can be unsharpened evenly would be much appreciated. I really don't want to buy a rather expensive special tap in this now uncommon size. Steve in Thunder Bay, Ontario, Canada ------- Date: Fri, 16 Feb 2001 18:26:52 -0600 From: Jon Elson Subject: Re: Internal Thread Finish Problem > I have a problem with a prethreaded chuck backplate for an Atlas > 618 1 X 10. The part is well machined otherwise but the plate > thread v-form is very sharp and not inclined to go onto the > lathe spindle freely, and I am not going to force it. I'd just use a rat-tail file and lightly run it through with a sweeping motion going around the inside of the thread. You can judge the even- ness of the filing by looking at the new flat tops being created on the thread. I think you will find that very little needs to be removed to get the plate to thread on the spindle. Jon ------- Date: Fri, 16 Feb 2001 19:12:33 -0500 From: "keith bolinsky" Subject: Re: Internal Thread Finish Problem The last shop I worked in had what they called "thread chasers" that worked as internal thread files. ------- Date: Sat, 17 Feb 2001 01:20:14 -0000 From: 76761.1407x~xxcompuserve.com Subject: Re: Internal Thread Finish Problem Have you measured the minor diameter of the threads on the backing plate? If the diameter is too small, you could reasonably increase it to that dimension. I would clamp the plate to a face plate, center by indicating on the threads (you have to have the machine in gear with the proper thread pitch selected to do this), and then bore the correct minor diameter. This would certainly take the "sharp" off the internal threads. ------- Date: Fri, 16 Feb 2001 20:53:08 EST From: Area51tatsx~xxaol.com Subject: Re: Internal Thread Finish Problem I would think that chucking the face plate in a four jaw and then using a dremel with a small flapper wheel would give you good control over how much material you remove. Gerald ps hmm sand paper and a wooden dowel might be another suggestion ------- Date: Sat, 17 Feb 2001 09:40:05 -0600 From: "J Tiers" Subject: Re: Internal Thread Finish Problem >I have a problem with a prethreaded chuck backplate for an Atlas >618 1 X 10. The part is well machined otherwise but the plate >thread v-form is very sharp and not inclined to go onto the >lathe spindle freely, and I am not going to force it. I suggest another possibility is that the threads may either have crud on them, or be rough internally where you can't see it. If rough, you can chase them with a threadform tool on a boring bar by hand, simply scraping the threads a bit following the thread. I have had to do this. You won't remove much metal, but you may not need to. If the V thread is the problem, inspect the leading plate threads for burnishing on the peaks of the V. If they are not burnished, the V is not the problem. Both my machines have a nearly complete V form thread, which causes no trouble. It appears to do the bulk of the centering, as registers are very loose on some chucks which still center well. (If the plate was made in India, be prepared for it to be really messed up. Some of the parts from there are so bad you wonder how they could even have been shipped, as the faults are glaring and obvious.) Jerry3 ------- Date: Sat, 17 Feb 2001 13:37:37 EST From: anthrhodesx~xxaol.com Subject: Re: Internal Thread Finish Problem Regarding the message copied below, where did you get your prethreaded backplate? If it came from a UK source the thread *might* be Whitworth form, 55 deg. instead of the 60 deg. thread used for inch threads in the US and Canada and for metric threads throughout the world. Try to determine whether the thread is Whitworth form (55 deg.). If so, see if you can get it replaced with one cut to the S.A.E./Unified standard 60 deg. form. If this is not an option, yes you can take off the peaks of the threads. The Unified standard calls for reducing the peaks on internal threads by 1/4 of full depth of the thread. I'm not certain using a file for this purpose is a good idea, might be better to mount the backplate backwards on a face plate, *carefully centered*, and use a boring bar to knock off the peaks. If you use this method, cut from left to right to avoid having to stop next to an internal shoulder, use a very fine feed so you won't simply follow the original pitch and accomplish nothing, then, without changing the cross-feed setting, reset the longitudinal feed to a different fine feed, wind the boring bar into the bore by hand, and again power feed from left to right. This is all to make certain that you haven't missed any of the peaks where the fine feed happened to place the cutting tool in a thread valley rather than on the peaks. Hope these suggestions are constructive. Anthony Berkeley, Calif. ------- Date: Sun, 18 Feb 2001 21:02:15 -0500 From: "S or J" Subject: Re: Internal Thread Finish Problem Thank you to everyone that responded to this question about a new backing plate with sharp vee threads that resisted going on the spindle. I did not force it and first sought advice here from the group. The suggestions were hard to choose between, so I opted to first take some comparison measurements with the problem backing plate and with my existing Atlas original chuck and original faceplate to see how bad the situation really was. The mystery backplate had an internal distance between thread tops of 0.875 inches. My Atlas chuck was 0.900 and the Atlas faceplate was .911 and both of these had obviously flat thread tops which would account for the rather large difference. All three were within about three thou over the registry so that was not likely to be a problem. (I really have got to get one of those electronic LCD calipers; these old eyes need more magnification than regular reading glasses to see those tiny vernier alignments.) As the new backing plate's thread top to top diameter was larger than the minor diameter of the spindle, it should theoretically go on at that size despite the sharp tops unless the threads had some other problem. Someone here suggested that there could be some crud/roughness hiding in the threads that resisted simple cleaning. I could not see any but there really was no way to see the bottoms of all the threads. So I got out the suggested internal 60 deg V boring bar and jigged the backplate so I could keep the two in alignment while manually rotating the plate. I could certainly feel roughness in the thread hollows and the bar cleared that up within a few passes. The thread tops still concerned me, as being too sharp, they could easily get micro burrs from bumps that could interfere with future fits. My inclination was to favour the suggestion about attaching the backing plate backwards to my faceplate and taking the tops off with an internal boring bar. And I would have done so if the measurements had indicated a need to take a lot off or the following suggestion had not sufficed. I decided to first try the other simple idea of using a fine abrasive cloth (crocus cloth wrapped around a 3/4 inch wood dowel) and making about a dozen careful rotations while again jig aligning the plate square with this manual tool. By this point, the threads looked and felt smooth. After a thorough cleaning to remove any possible abrasive residue, it was time to test fit. It went on smoothly and even better, indicated true. I must admit that I am a reluctant chicken about internal thread or boring work and was relieved to be able to solve this problem with some manual finesse. Someday that internal threading bar will get some use under power :-) All your ideas were thoughtful and I am sure each one will have application somewhere in solving future problems of a similar nature. When you live far away from sources of supply and tools and clubs in a special hobby, this group is a real treasure for assistance. Thanks again for your support, Steve in Thunder Bay, Ontario, Canada ---------------------------------- Date: Sat, 14 Apr 2001 12:47:28 -0000 From: STYSx~xxMINDSPRING.COM Subject: Re: Chuck Backplates --- In atlas_craftsmanx~xxy..., Robert McDonald wrote: > I need to mount my new (to me) 4" 3-jaw chuck. > - Do I just ask for a 1-1/2"x8tpi backplate for a 4" chuck? > - Is it safe to buy the cheapest available? > I realize that I will have to machine the face to true it up and > match the chuck. Rob Rob, Its just that easy! The backer plates that I purchase are inexpensive (around $20.00) and are made in Poland. When I ordered my 4" backer plate, the O.D. is actually 4.10". I used my last one on a salvaged 3" chuck that I use for high speed turning on my 12X24. I left the O.D. at its original diameter because I may use that backer for a larger chuck in the future. I spend a few lunch hours each week at a local metal scrap yard finding and repairing old lathe tools, so I try to stay flexible with my tooling. I don't even need to buy backer plates any more. I have found that discarded cast iron pulley castings, and cast aluminum cart wheels make perfect backer plates after machining. Its good practice for turning and threading skills. If you need a source for backer plates, I posted one early this year on this site. Do a search under my name and you'll find the address and phone number. Happy Turning Rick Stys Apex, NC Craftsman/Atlas ------- Date: Wed, 09 May 2001 15:15:16 -0700 From: S1 Subject: Re: Soliciting opinions It isn't hard to make adapter plates for chucks. I have a 6x12 AA lathe with a 3/4 16 tpi shaft. I bought an 80mm chuck for it, found the bolt circle. I then locked it in my Faceplate, center drilled and tapped the final hole. I put it on the shaft of the lathe, turned it so it fit and drilled the bolt circle on the mill using the x-y coordinates that the math formula gave me for the bolt circle. It wasn't very difficult. ------- Date: Thu, 10 May 2001 14:09:15 -0000 From: n5kzwx~xxiname.com Subject: Re: Soliciting opinions Don, my nephew (Cedar Park) and I (Lake Travis) both have the same lathe as you (with the 1x8 spindle). I have a 1x8 tap that you may borrow if you wish. Note that the center hole in the Buck 1x8 back plate is too large, the tap slips right through. I have one of the Buck plates that I have partially reduced in size for a 4" 3-jaw I got off eBay. It was taking so long that I got tired and grabbed the cast-iron collar off an old barbell set and turned it down to fit the chuck. Since it's hard to find accessories with a 1x8 thread, I bought a length of cored brass rod with a 1.5" OD and a .75" ID. Whenever I need to adapt something to a 1x8 thread I bore it out and turn down a chunk of brass rod to get a shrink fit. (Having first threaded the brass to 1x8 and bored it out to fit the spindle register.) Once the brass sleeve is mated with the other part, I usually pin the two together before touching everything up on the lathe. Good luck with your "new" lathe. Ed ------- Date: Fri, 11 May 2001 05:45:59 -0400 From: Ronald Thibault Subject: Re: Soliciting opinions At 09:43 AM 5/9/01 -0500, you wrote: >> I have a Craftsman 6" lathe I'm trying to get up and running. My problem is twofold. (well, really three as I don't have much experience) 1. It came with no face plate or chuck. 2. it has odd ball 1"-8tip threads on the spindle. I will have two chucks soon. One I already have is for a Sherline. I have thought of buying a second MT2 center or an MT2 to Jacobs adapter and turning down and threading the front of it to fit my Sherline 3/4-16 chuck. I bought a Buck 4" three jaw on Ebay but it will have no back plate. My choices there are to buy the Buck 1-8 back plate which costs more than the chuck or buy a blank and try my hand at threading it. I've seen blanks with a 1" center hole but don't know if the hole has to be less than 1" to be tapped. Apparently these blanks also need to be trued up by doing some cutting on them. Any help or advice would be appreciated. Of course another option would be to trade this old Craftsman in on a Sherline that will fit the tooling I've got. (I bought a used Sherline Mill and about half the stuff that came with it was for a lathe). Don Colbath Austin TX << Don: Grizzly Tools sells spindle adapters for your spindle thread. These screw onto the spindle and then various woodworking chucks are bolted on. I have used the 1 1/2 - 8tpi ones as a basis for a faceplate on my 12" Atlas. You may have to cut the register land, but as you already have a 4-jaw, this should not be hard. I cut the register, then turned down the outside with it installed on the spindle. The faceplate was then bored for a light press fit and secured with high strength Loc-tite and cutoff screws locking the joint. See the wheel arbors section of the loco construction are of my web page (address below). They are only $6.95 each # G3163. They also make good spindle nose protectors. Grizzly has a Web site at http://www.grizzlyimports.com/ Ron Thibault North Augusta, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------- Date: Mon, 27 Aug 2001 13:12:40 -0500 From: "Mario L Vitale" Subject: Re: 3 jaw chuck From: "Louis Tweed" > I have 2 three jaw chucks that need adaptors(?) backing plates(?). > Where would I look for such an item? I also need some tool holders for > my Aloris BXA post, anyone have a supplier they like for this stuff? > Enco pissed me off so I am looking for other suppliers. Louis Louis, I just bought a rough cast back plate for a 6" chuck from Wholesale Tool (www.wttool.com) It cost $17.50 and was actually a casting that had been rough machined...a very nice piece. It was also a fun project. If you are in more of a hurry they have machined threaded back plates in the $40 to $50 range. By the way, if you are not familiar with them, they have a full range of stuff, both domestic and import, and as usual, the import stuff is something of a "crap shoot"...some are real bargains, others a waste of money, but if you use your head and think about what is critical about the tool you are buying, you can usually do very well. For instance, a rough casting that you will machine all over is not dimentionally critical, but you don't want a casting that could could double for a sponge. One thing the Asians seem to do pretty well is make nice, heavy, grey iron castings. Also Wholesale tool has been Excellent regarding returns, not like some other aforementioned distributors. J&L, MSC, and other major tool distributors also have similar offerings so you might want to check with them just to see how prices compare. Good Luck, Mario ------- Date: Mon, 27 Aug 2001 20:34:31 -0400 From: "Matthew King" Subject: Re: 3 jaw chuck I've been quite happy with Traver's - fair prices and PROMPT service. Go to www.travers.com. They've got a great catalog with excellent pictures. Their prices seem to be among the lowest I've seen. I've just placed an order with KBC tools. Their standard prices seem to be a touch higher than Travers, but still considerably lower than MSC or J&L. Their sale prices are astounding on some items. www.kbctools.com is their address. J&L Industrial and MSC both have excellent catalogs, excellent service, excellent selection, and excellent in stock percentage, but they KNOW these things and their prices reflect it! Grainger is great in a pinch, and may have a local outlet nearby, but they are REALLY expensive. Take care, Matt King Columbus, GA ------- Date: Sun, 2 Sep 2001 02:45:10 EDT From: catboat15x~xxaol.com Subject: Re: 109 backplate and chuck The back plate is the coupling between a spindle and chuck. There is an internal thread that screws onto the spindle and the outside is turned to fit closely into the recess in the chuck back and holes drilled to match the threaded holes in the back of the chuck. Sometimes they are available ready made for a particular spindle thread and chuck, or as a partly finished back plate, threaded for your spindle and you turn it to fit your chuck. (more accurate than ready finished as the seating for the chuck is done on the lathe it is to be used on.) Also, you can obtain raw castings and you would have to bore and thread the female portion to your spindle (how to do that without a chuck is a problem,) Then turn the outside to fit the chuck. When I only had a four jaw on my lathe I made a back plate for a "found" three jaw out of an aluminum cutoff I had. Not recommended material, but did the job for several years. After making a "false" spindle end of the same diam, length, thread and step, I chucked the aluminum in the fourjaw, drilled, bored, threaded to fit the false spindle (You need the false spindle nose to try the fit and thread instead of having to remove the chuck, try the blank, re-mount the chuck over and over again.) John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Sun, 02 Sep 2001 19:26:50 +0000 From: Jon Elson Subject: Re: 109 backplate and chuck emailx~xxpierina.com wrote: > First I need to say thanks for all the great info! Here's a tough > one. I would like to get my 109-2063 running but I can't find a > chuck for it. Can someone tell me what the relationship between a > back plate and the chuck is? I'm starting school and would like to > have my lathe available. Any suggestions on where I could aquire a > back plate and chuck. Can I modify something new to work on my old > lathe. Any response would be appreciated. Thanks in advance. There are some one-piece chucks which do not have a backplate. Many chucks for the lathes with threaded spindles use a backplate between the chuck and spindle. If you have a face plate, you can use it to machine a backplate out of any suitable material. if you don't have a faceplate, then you need a backplate that is big enough to mount the chuck, and has the correct spindle thread to mount on the spindle. Then, once the backplate is mounted on the spindle, to face the front off smooth, and cut any register required fro the chuck. Then, you mount the chuck to the backplate and use a transfer punch to mark the holes for the bolts that secure the chuck to the backplate. You drill and tap these holes, and generally use socket head cap screws to mount the chuck to the backplate. If you cannot get a backplate that already has the correct spindle thread, then you will have to cut the thread on the lathe. It is about a 1/2 hour job. Travers, MSC, J&L, KBC, Quad Tool and others sell blank backplate castings for this purpose. Jon ------- Date: Sun, 9 Sep 2001 23:07:32 EDT From: sleykinx~xxaol.com Subject: Finished my backing plate and mounted the new chuck This weekend I finished up the backing plate for the 8" Kitagawa 3 jaw chuck I recently acquired. I made the plate from 1" steel plate that had been flame cut round to about 8.5." I mounted it in the big 4 Jaw on the 12" Atlas and faced, bored and cut the threads and register and relief to clear the indexing pin and backgear lever. Then I removed the chuck and mounted the plate on the lathe and faced and turned it to size. I cut the register for the new chuck and then came the hard part ... drilling holes in my pretty new back plate to fit the holes in the chuck. The mounting holes in the chuck are not through holes so I had to get out Machinery's and study up on bolt circles etc. Calculate the chords made some marks and drilled (10.5 mm for a 10 mm bolt) SHOCK! All three bolts lined up perfectly! First time I got these bolt circle things right Counterbored for the caphead screws, mounted the chuck and screwed it onto the spindle. I can't see movement on the DTI with a 5/8" drillrod chucked up ... what a sweet chuck this is! :) Glenn Neff ------- Date: Wed, 19 Sep 2001 21:31:02 EDT From: LouD31M066x~xxaol.com Subject: Re: (unknown) From: "John Gush" To: "Lathe group" Sent: Wednesday, September 19, 2001 8:29 AM > Hi Group, I am a newcomer to metalworking, I usually play with > that well-known prehistoric material -- wood. > I have just acquired an Atlas 618 for $300 without > having the opportunity to inspect it first, (a long > complicated story)! I have stripped it down, removed decades of > grease and sawdust, but I appear to have a major problem. > > The chuck that came with the lathe is a 4" Westcott > (Oneida, NY) 3 jaw, self centering, and when threaded > onto the spindle it wobbles rather alarmingly. On > closer inspection, it appears that the chuck spigot? > does not snug up to the shoulder on the spindle, but > there is a perceptible gap at one point on the > circumference which corresponds to the wobble in the > whole chuck. The spindle does not appear to have any > runout, either radially or on the face of the > shoulder. A Morse taper arbor in the spindle seems to > run true and I checked? the threads by running a large > flat tip on the dial gauge over the threaded portion. > > I spoke to a helpful chuck repair firm who agreed that > it looked as if the chuck and or lathe had been > dropped on its head and the internal 1"x 10 thread had > been damaged. I was persuaded to buy a Bison 5" four > jaw independent chuck, and a backplate which should > enable me to fit both chucks to the same backplate > after a bit of machining on the threaded body of the > three jaw. So much for the theory. > > The new Bison backplate exhibits exactly the same > behavior as the three jaw chuck! I have two > questions: > 1. Is the rather large 5" 4 jaw too big for my little 618? > 2. What is going on with my spindle/chuck fitting, and > would spending $200 on a new spindle just be throwing > good money after bad? Can anyone help? John Your story is same as mine I did not inspect, inspect and inspect again. If some one will cut a 1 x 10 threaded shaft you might be able to check if threads in chuck are at fault. This may tell you some thing and should not be a serious use of time or material. Look threads on spindle over very carefully sometimes a turned over thread may bind in chuck. Try using layout dye on spindle and turn chuck on see if you can find a spot where it rubs. Try it with both chucks see if it is same spot or spots. Cure may be as simple as a little careful filing of thread or as serious as a new spindle. If some one has a parts lathe out there you may be just as well off to go for replacement headstock. If chuck thread is at fault a 1 X 10 tap (special order oddball size) might "fix" it well enough to use ,but, you don't want to mess up spindle threads. If threads are in a removable backplate solution may be buy oor make an new backplate to fit. I have done some serious thing in this area and due to fact spindle threads were shot I had to start with a new spindle ...ouch! Louis ------- Date: Wed, 19 Sep 2001 20:39:56 -0500 From: "jerdal" Subject: Re: (unknown) I don't think that everything you are saying can be true. You need to check the spindle again, on the shoulder face, the inside of the taper, and on the "register", which is the unthreaded part. When you say "there is a perceptible gap at one point on the circumference which corresponds to the wobble", do you mean a small area like a "ding" or a larger sector of the circumference? If a small portion, there must be a ding in the edge. If a sector, then there must be something hanging it up, such as a bad spot in the threads or a burr on the end of the thread, or a burr raised on the shoulder somewhere. If found and stoned out carefully, you should be fine. The only other problem would be if you did find a runout area right by the area that won't seat. then maybe there could be a bigger problem, but even then you could turn it down flat again. (DON'T do that any time soon, by the way). If the spindle runs true, I see no reason to go after that expensive item first. Nobody's old lathe has a perfect spindle, and darn few new ones do. Bumps are no good, but small lowered areas can usually be ignored. I bet it is something quite simple, a burr, bit of crud, etc. Jerry ------- Date: Sat, 01 Dec 2001 19:45:30 -0000 From: walnut_charliex~xxhotmail.com Subject: Re: Face Plates I've needed backing plates for several of the lathes I've owned. I've found that the easiest place to get the basic blank is to go to a thrift store or sporting goods store and buy bar bell weights. The cast iron ones are cheap and come in a variety of sizes and hole diameters. They are close to the required shape and easy to machine. I usually make a plug that is the same size as the spindle. Using thread wires and a micrometer the plug can be made quite accurately. You then machine the thread in the blank until you have a very good fit to the plug before removing it from the lathe. After that, screw it on the lathe and machine it to fit the chuck to be used on it. Walnut Charlie ------- Date: Thu, 10 Jan 2002 17:39:22 -0000 From: "k3vyl" Subject: Re: face plate In atlas_craftsmanx~xxy..., s2bello... wrote: > Saw some 4" Rigid face plates with 3/4-16 thread on sale. > Question is it worth buying then plugging the center hole and > rethreading to 1/2-20 for my 109? All advice welcome, TIA. SteveB When you go to chase that thread in there dont use a tap, at least to start it. Set the plate up face to face with the faceplate of another lathe, and start the thread with a single point tool on the boring bar. Cut most of the thread then finish it with a tap. That will give you a nice finish on the thread and minimize the amount your going to have to take off the plate to get it trued up on the 109 spindle. A 3/8 diam boring bar with a 1/8 tool is ideal for this stunt,but you'll have to make the bar from stock. Even if your 60deg point isn't perfect the tap will fix the error. If you're real good on the grinder you can make a little boring bar from a good allen wrench, by grinding off most of the short leg and putting the 60deg point on what's left. I found most of this out by making faceplates for a wood lathe with a 1-8 spindle nose. Taps just don't seem to make real straight threads no matter how carefully they are used. You can end up with a serious wobble that requires a lot of truing up. RC ------- Date: Fri, 11 Jan 2002 14:38:36 -0000 From: "lou55954" Subject: Re: face plate I recently made a backplate for a new chuck for my 109 from a 1/2 inch steel plate and the process might be applicable to face plates as well. I cut the plate to roughly an octagonal shape and chucked it in the four jaw chuck. I then took a light facing cut just enough to clean (true)it up. I then drilled and tapped a 1/2-20 thread in the center. Supporting the back end of the tap wrench with a dead center in the tailstock while I advanced the tap by hand assured a pretty straight thread. I then removed the plate from the chuck and removed the chuck from the lathe and threaded the plate on the spindle with the newly trued surface facing the headstock. I then took a light cut or two to true up the face. I finally turned the diameter to a very light press fit in the recess in the chuck. Lastly I drilled the mounting holes (a little oversized) and mounted the chuck. The runout is almost nothing. By truing the working surfaces with the piece mounted on the spindle, any inacuracy in the tapped hole is compensated. If the spindle nose is a little longer than the plate thickness, place a washer or two behind the piece to true up the face all the way to the center. Remove the washers before turning the diameter. When using this procedure to make a faceplate, a hole can be drilled to accept the dog, holes can be tapped to recieve fixtures, or if a mill is available, slots can be milled. This whole process took about three hours and was completed in one evening. Turning the steel plate would have been very difficult without a counter shaft to reduce the spindle speed. with a direct drive, even in back gear, turning steel in the 109 is not very easily done. See the photo section for a picture of a simple, home made counter shaft I made for my lathe. I hope this helps. ------- Date: Fri, 17 May 2002 17:57:18 EDT From: hdetwilersx~xxaol.com Subject: Re: Backing plate I have use ENCO and MSC back plates -- all of which read "Bison Only." Never had a problem. I just order the size I want. Bore out to the minor dia and thread away. Don't forget to turn a gauge first so that you don't get caught having to restart an internal thread. (Not an impossible task but for me it is a real pain.) If you have a problem finding the major and minor dia's let me know and I'll look them up and send you a quick way to figure them yourself. The whole operation is not as bad as every one seems to think it is. Just remember to set over to 29.5 degrees in the direction opposite from the one used for external threads when turning internal threads. (The two biggest mistakes are forgetting to set over for internal threads and getting in too big a hurry.) Use your slowest speed. Take shallow cuts - you are not in a production shop. My first cut would be approx .005" and I would quickly set it back to no more than .002". I ALWAYS run the cut at least twice and ever second or third cut I may run it four to six times. Be sure that the tool is not cutting and that everything is free. If you don't take you time you will get threads that are on an angle. Remember this is supposed to be fun and it is never fun when something doesn't work. Hope this helps ------- Date: Tue, 21 May 2002 02:05:49 EDT From: catboat15x~xxaol.com Subject: Re: Backing plate In a message dated 5/17/2002, newgunsmithx~xxyahoo.com writes: > how do or did you get a backing plate for your chuck? I did one from aluminum and one from cast iron (the correct way) I purchased an unmachined back plate from one of the usual suspects. Then I mounted it in my four jaw to have the cored hole run fairly straight. Then after making some close measurments of the spindle nose (Thread OD, Pitch, Length etc) bored the raw casting and internal thread cut with a threading boring tool to fit the spindle nose. (I found out later it is best and easier to make a "fake spindle" out of some stock to check that fit, lots easier than in place.) After the thread fit and the register on the new plate fit well, I then took it out and screwed it in place on the spindle nose and turned the OD to fit the register in the chuck back. Drilled the mounting holes in the new plate a bit oversize (the register holds everything in line, not the bolts) and assembled the whole thing. Not a hard job, but an interesting one for a learner as you get a lot of practice in some fine turning and single point thread cutting. John Meacham California High Desert 12 inch Atlas, Minimill, rusty file ------- Date: Fri, 24 May 2002 07:21:25 -0400 From: Chabannes Rene N Contr ASC/YCD Subject: RE: backplate material >>From: bill_collins14 [mailto:bill_collins14x~xxyahoo.com] Howdy all.what is the best metal to use for making a backplate.I need to make one for my 109.I have a 4 jaw chuck on it now and would like to make a backplate for a 3 jaw.The 4 jaw is 3" and the 3 jaw is 4" diameter. I would like to use something that doesn't cost a lot. Thanks Bill C. << Ductile iron would be easy to machine. I made a back plate years ago for a small chuck and just used a drop of steel - probably CF C-1018. I had someone else drill a hole for the 1" tap (6" lathe)and tapped the hole. I squared up the ends by screwing it on the spindle and then machined the backplate out of it. ------- Date: Fri, 24 May 2002 06:57:34 -0700 From: Rick Kruger Subject: Re: backplate material Cast iron is what most backplates are made from, helps in reducing vibrations as well as being easy to machine. If a 109.1 is a 6" lathe, you could make it from just about anything available to you. I have a Grizzly 7x12 minilathe for which I've made several backplates from aluminum and they work quite well. On larger machines, I'd stick with CI. I've located a tool steel dealer that sell remnants of all kinds of bar/round steels, including cast iron. I bought a 6" CI round from making backplates. I've not found any CI at the scrap yards in my area. Rick K. Portland, OR ------- Date: Fri, 24 May 2002 15:01:34 -0000 From: "bill_collins14" Subject: Re: backplate material Hello Rick, just wanted to be sure before I head to the scrap yard.I will be making the backplate for a 4"3jaw chuck. I don't have any way of holding the material to turn it down. I will drill a tap hole then thread it and turn it while it is on the spindle. I also need to make a face plate for this machine too. I can't afford to buy one so I will have to make it. The lathe was missing the threading indicator, I made a new one from a piece of motor-cycle crankcase on my little mill. It works perfect. Now maybe I can learn to do thread cutting now. Thanks for the advice. Much appreciated. Bill C. ------- Date: Fri, 24 May 2002 16:06:55 -0500 From: "jerdal" Subject: Re: Re: backplate material Think like a third-world resident...... You can make the faceplate first. I made a backplate for a 109 once by attaching two pieces of 0.375 steel together with short machine screws. I used the smaller for the chuck register section. Then I threaded the thing as straight as I could with a 1/2-20 tap, and counterbored on a drill press for the register. Had to do that on both sides, since I had to flip it once to face off everything squarely. I finally turned them down to suitable dimensions for the chuck. Worked reasonably for a couple years until I got a bigger lathe. You could do that to get a functional faceplate. Using that you can make a better lathe-threaded faceplate, with a bored register. Then finally you are set up to make any backplates or other faceplate work you need. If you have nothing with which to do the job, it is time to make tools. Remember, the folks who made the first 50 foot swing lathe did NOT have a 75 foot one to make it on! Jerry ------- Date: Fri, 24 May 2002 16:41:37 -0700 From: Rick Kruger Subject: Re: Re: backplate material Bill: Sounds like you are well on your way. I think your approach is just fine. Turning the registration shoulder for a plain back chuck right on the spindle is the best way. That is how I've done it for my 7x12 chucks and the 6" 4-jaw I did for my Atlas 10F. I would NOT use a cast iron lifting weight if you can avoid it. Aside from the thru hole issues, the CI in the weights is of less than desirable quality and there have been reports of thick, hard to cut thru skins. For a 6" lathe, I think you can very adequately use alum, or 12l14 steel, or anything else that is reasonable to turn. Here is a thought. Consider making the backplate adjustable, such as in the much higher priced "Set-Tru" or "Adjust-Tru" chucks. I did just this for my Bison 4" 3-jaw on the 7x12. I can dial it in to 0.0001" TIR quite easily. It is actually easier to machine than a snug fit register, in one regard, although it does require additional machining steps (drilling, counter boring, drilling & tapping adjuster set screws, etc.). I used some type of steel for this project, I think 12L14 or 1018. Works great. I don't very often put the 4-jaw on the 7x12 anymore due to how easy it is to dial in the adjustable 3-jaw. Here is a link to what I did: http://warhammer.mcc.virginia.edu/ty/7x10/vault/Lathes/7x10-7x12-Proj ects/SetTruBackplate/ (The URL will be broken into two lines. Rejoin them prior to pasting into the Location Bar in your browser, or copy the second line (highlight it, then copy it), then click on the first line. Your browser will return an error. Put your cursor at the end of the URL line of text and past the copied second line. Make sure there is no blank space between the two. Then hit Return/Enter and it should load.) Rick K. Portland, OR ------- Date: Fri, 24 May 2002 21:09:19 -0500 From: "Mario L Vitale" Subject: Re: Re: backplate material Ron, I bought a rough cast backplate from Wholesale tool about six months ago...because they were "much cheaper than anyone else". The quality of the casting appeared to be very good and the machinability was fine. When I was boring the center hole for the minor diameter of the spindle thread I exposed a small void in the casting. I hoped against hope that as I got closer to the minor diameter it would clean up. It actually got bigger before it got smaller!!! But before you get too concerned, at the minor diameter it was about 3/16 in dia. and when I finished cutting the thread, what was left was about a 1/8"dia void and the backplate works fine. Just to see what they would say, I called Wholesale Tool and explained what had happened. They said that shipping the old casting back to them would probably cost as much as a new one was worth (which is what I suspected) and they sent me a replacement casting free of charge!!! Now I need to go out and buy a new chuck just so I can use my "free" backplate. What I've taken too long to say is that the wholesale tool backplate is a good deal and wouldn't hesitate to buy another! Mario ------- Date: Fri, 24 May 2002 22:38:32 -0700 From: "GSNEFF" Subject: Re: backplate material Couple of thoughts that might not be quite as obvious to some. The material thickness needs to be greater than the length of the spindle threads by enough to true up the back side before you flip it and make the front. The backside needs to be true so the registry coller can hold it with repeatability. Aluminum scrap will cost more than steel but will be much easier to machine. I have made several backplates out of CRS rounds. Some from bar stock cutoffs and some from flamecut scrap. As long as you remove enough material to relieve the surface stress you will not have any problems with warp. Flame cut rounds are way hard on the cut part. If you can set them up and use a hog grinder or similar to remove most of the hard stuff first it will make it a lot easier on the little lathe. My first back plate was made from CRS that I cut on the bandsaw into a hexagon and then drilled and tapped the threads on the drillpress. I then proceeded to wipe out the backgears trying to "power" through the interrupted cut to make a round piece. I have since found that if you spin it up and take small cuts it is better on the machine ... as long as you don't go so fast things start bounding around :) Best of Luck Glenn Neff Medford, OR http://www.superford.org/?vID=1089 ------- Date: Tue, 28 May 2002 22:56:59 EDT From: LouD31M066x~xxaol.com Subject: Re: backplate material Was tearing down small engine for scrap aluminum and found Honda flywheel is cast iron and about right size and shape for 6 inch lathe face plate. Suggest your local small engine fix it shop mechanic might set aside interesting scrap items if a cold six pack of his favorite beverage were mentioned. Louis ------- Date: Thu, 1 Aug 2002 07:49:02 -0500 From: "jerdal" Subject: Re: RE:AA 109.21270 > I bought a 109.21270 at a flea market (7-mile fair, south of Milwaukee) > last summer. It has what I believe to be the original 4-jaw chuck > and its gears, but no centers for the tailstock. If I can't find a > 3-jaw chuck for a reasonable price, I can buy a new Chinese 3-jaw for > $49.00 but will have to have someone make me a mounting plate to fit > it, and thread it for the 1/2-20 spindle. You can do it on the machine, I did. Since you have the gears, if you have a faceplate you can thread the backplate on the lathe. If no faceplate, you can make one. (Purists may now avert their eyes) Mark out a suitable circle and center on a piece of metal about 1/2 inch thick. Drill it and thread 1/2-20, using whatever $10 tap set or better item that you have. Drill out a bit of relief for the unthreaded portion of the spindle. If the metal is less thick than spindle nose is long, you will need to add another piece screwed on (tight fit on screws) in the center to make it up. Saw off as much as you can down to your marked circle. Mount it on the spindle backwards, using a washer to make up for the unthreaded portion of spindle. If it does not fit square, you can pack it up on the loose side, or not. Carefully face the center portion. Turn it around, and now it should screw down OK flat to the spindle shoulder with no washer. Face off the whole surface, take it off and drill whatever mounting holes seem appropriate for the stuff you will work on. Now you can mount a backplate blank (which will look remarkably like the faceplate blank!) and with some spacers away from the faceplate you can do the internal threading with your changegears and a bit ground to the right shape. Mind you, I did mine the way I described for the faceplate, and never went to step 2. Worked fine until I moved on to a different machine. There is always a way to do what you need to do. > I didn't know how hard it is to find centers with a "0" Morse taper, > either. Any of you guys out there have any suggestions beside > "look at E-Bay"?? Yes, Campbell Tools, they have a website. Carbon steel, HSS, or carbide faced 0MT centers Jerry ------- Date: Thu, 01 Aug 2002 12:30:27 -0500 From: Jon Elson Subject: Re: RE:AA 109.21270 > Morse taper, either. Any of you guys out there have any > suggestions besides "look at E-Bay"?? If your 4-jaw has a backplate, remove the chuck from the backplate and bolt a flat piece of iron or steel, or a blank chuck backing plate, to the 4-jaw's backplate. If the 4-jaw is one piece, remove the jaws and screws and bolt or clamp the new plate to the body of the 4-jaw. Now, you can bore and internal thread the new backplate. To check fit of the threads, unscrew the entire assembly from the spindle and reverse it. Keep threading until it fits on the spindle threads. Then, mount the new plate on the spindle and face off the front of it to receive the new 3-jaw chuck. I have done this on a 10" Atlas, and the results were perfect. Jon ------- From: lou55954 [mailto:skykingx~xxcharter.net] Sent: Tuesday, August 27, 2002 11:00 AM To: atlas_craftsmanx~xxyahoogroups.com Subject: [atlas_craftsman] Re: RE:AA 109.21270 I recently made a mounting plate for my 109 lathe to mount a 3 jaw chuck. I took a piece of 1/2 thick mild steel plate and sawed it to an approximate circular shape a little larger than the desired final diameter. I tapped a 1/2-20 hole in the center with a hand tap, and screwed it to the headstock with a washer behind so that the headstock thread didn't quite protrude through the plate. I then faced the plate with a light cut to true it up. Then I reversed the plate, this time without the washer with the newly trued face flat against the head stock face. I then turned the diameter slightly larger than the recess in the chuck. I then faced the piece to true it up. (you don't have to take this cut all the way to the headstock diameter since it dosen't touch anything in the final assembly except on the outer surface) Then finally I turned the diameter to fit the recess in the chuck, using light cuts to carefully produce a fit that takes a light tap to assemble (as the runout of the chuck depends on the accuracy of this fit). The last operation was to mark and drill the mounting holes. These holes were drilled slightly oversize to allow the chuck to center on the diameter of the plate. My final runout was on the order of .001 inch. Since the lathe is pretty light duty, especially when cutting steel, be patient and take light cuts using a sharp bit and you can accurately mount the chuck. The 3 jaw chuck has greatly increased the utility of the lathe in my shop. It is the one that is nearly always on my lathe. If you chose to have someone make the mounting plate, have them leave the diameter a few thousandths oversize, so you can make the final fit on your lathe. Lou ------- Date: Tue, 27 Aug 2002 12:52:43 -0400 From: "Bill Hardin" Subject: RE: Re: RE:AA 109.21270 I had the same problem, and found the only solution in a 3 jaw chuck made specifically for the 109 series is the Sherline Model 1070. It is threaded for the 1/2-20 spindle. Not as cheap as the Chinese, and I tried to find a cheaper solution with no sucess. On sale the Sherline is about $90. Micro Tools was the best source when I bought. For centers, tool holder, boring bar holder, milling table, much more, I have been very happy with both the work and prices of Earl Bower. He has live centers with changeable tips, #0 morse taper, less than $20. The tool holder is built from one piece to the AADOCS drawing, two .550" slots for tools, and the boring bar holder for 3/8" boring bars fits this tool holder. I bought a cheap set of 9 boring bars for about $15. Thought that was good enough to learn with. In any case, an email to Earl at ebowerx~xxlcsys.net will be time well spent. I have enjoyed dealing with him. Bill Hardin (a newbie with days of experience!) ------- Date: Thu, 30 Jan 2003 12:45:59 EST From: JMartin957x~xxaol.com Subject: Re: Advice on chuck mounting petevx~xxair2.com writes: << By final machining do you mean the drilling and tapping of the holes? That's the only steps it didn't sound like he said had to be on the lathe. And if so, it would mean you can't do the drilling and tapping on a drill press? Pete Lafayette, LA >> No. The drilling and tapping is fine on a drill press. The final machining steps that should be done on YOUR lathe are: 1. Boring the backplate (assuming it is already threaded) to fit the register on your lathe spindle. 2. With the backplate mounted on your spindle, facing it (doing a facing cut) so that the face is absolutely flat and perpendicular to the lathe axis. 3. With the backplate still mounted on your spindle, turning a shoulder or step to mate with the shoulder or step on the chuck. Your chuck should have this, to ensure that it is mounted concentric with the spindle. 4. With the backplate still mounted on your spindle, cutting the OD of the backplate to that of the chuck or a bit less. This is really just cosmetic, though. Basically, even the threaded backplates have to be fitted to your spindle and chuck. If it has the register already bored, which most don't, you can skip step 1, but you'll still have to do 2 and 3, and then drill and counterbore or tap for the screws. John Martin ------- Date: Thu, 30 Jan 2003 10:01:56 -0800 From: "Bob May" Subject: Re: Advice on chuck mounting After you have done the registering step on the backplate, you have the necessary stuff done to properly locate the chuck. The screws are just there to hold the chuck onto the backplate and keep it from slipping about. There is no accuracy needed to insure that the chuck is properly centered on the backplate. There is, of course the need to properly make the holes so that the chuck can be bolted to the backplate! Doing a backplate properly is a bit tricky as you want to have a snug fit to the chuck without being too tight or loose. A set of calipers to get close is one way to go with a bunch of fine cuts on the end of the step to get closer with some final cuts (you want to be taking very fine cuts that almost don't take any material off at this point) to get the chuck to fit on the backplate. I also recommend that the final cuts be done after the backplate has cooled down from the heat of the cutting of the step as you can easily have a bit of expansion from the heat and end up with a backplate that is cut too small. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Thu, 30 Jan 2003 13:22:42 -0500 From: "Richard Farris" Subject: Re: Advice on chuck mounting Do you also have to mark the backplate in relation to the chuck before marking and drilling and tapping, so you always put the backplate in the same position or relation to the chuck??( if you ever have to seperate them)?? Second question is about the chuck relationship for a D1-xx setup. Does the chuck have to be axially positioned properly or the same every time when changing from a 4 jaw to a 3 jaw or back. I've just been popping them on and off and locking them in place without giving it much thought. Most of my turning has been practice in setup and in learning how to come into dimension AND have a good finish. Dick ------- Date: Thu, 30 Jan 2003 22:50:41 -0000 From: "Bill Collins " Subject: Re: Advice on chuck mounting Hi John,here is a link with some very good instruction on mounting a backplate to the chuck. http://www.metalwebnews.com/howto/chuckmnt/chuckmnt.html Hope this is of some help. Thanks and God Bless. Bill C. ------- Date: Thu, 30 Jan 2003 22:35:50 -0600 From: "jerdal" Subject: Re: Advice on chuck mounting > What Jon didn't say is that to ensure precision the final machining of > the backplate really has to be done on YOUR spindle, on YOUR lathe. > As to machining the register step, I'll disagree with Jon and say > that you could probably do it with vernier or dial calipers if you > work carefully, but it still has to be done on your lathe. I will agree with both the above statements. Also, decide the depth of protrusion, and turn the depth, leaving the protrusion oversize. Make it about 20 thous less than the depth of the recess in the chuck, which is likely close to 0.100. Then carefully turn down the protrusion. Just get it close but oversize with caliper measurements, then turn down VERY carefully a half thou at a time, make a trial, turn down if required, try again, and proceed like that. Don't get ahead of yourself, and barely touch the crossfeed as you get close. Be sure to use a sharp tool and fine feed, by hand, so as not to fall into the trap of making the burrs the right size and the part undersize! Knock off the front edge a little so that won't bias your fit. A slight undercut where the protrusion meets the backplate surface is very helpful. While the loose fit method of adjustment is OK, I would not do that first. First make it a bare fit , you can always reduce the size later, but its harder to turn the metal back onto the part! Jerrold ------- Date: Fri, 31 Jan 2003 19:14:59 -0000 From: "Charlie Fly " Subject: More advice on chuck mounting I am also fitting a chuck to my Atlas 3950. I bought the chuck and the backing plate from Little Machine Shop. The backing plate is already threaded for the 1x10 thread. However, it threaded all the way thru. So it will not screw on all the way. What I need to do is bore the internal threads out to match the OD of the spindle. Correct? How much diametral clearance is correct here? Is 0.001 too much or too little? As long as the bored out region clears the taper on the final threads on the spindle, that is sufficient. Correct? Thanks Charlie Fly League City, TX ------- Date: Fri, 31 Jan 2003 15:32:08 EST From: JMartin957x~xxaol.com Subject: Re: More advice on chuck mounting Charlie: You get an A for having done your homework before asking questions. You're right on everything. The clearance you bore to at the end of the threads will, more than the fit of the threads, determine the repeatability in mounting your chuck. I'd aim for even less than a thousandth, if you can. Remember to let the backplate cool before you fit it - don't want it to shrink on. Also use oil. If it's a bit snug it will loosen up after you have installed and removed it a few times and the machining marks have worn down. John Martin ------- Date: Fri, 31 Jan 2003 23:28:44 -0600 From: "jerdal" Subject: Re: 4 jaw for Atlas? > I'm in the market for one and wonder if this a good bargan and any > opinions about value? It is a hundred dollar chuck or 50 or 200? Just > looking for informed/considered opinions Well, you can get it for $50, why not. Not for much more........A NEW Bison 6" can often be had for a bit over $100, to which you add $15 to $40 for a backplate, depending on finished or not. Cheap at the price. And it's not made in China. Used chucks are a problem. This guy may be OK, or he may not know squat and be convinced his goose is a swan. Used chucks often are worn in ways that leave the jaws loose, so they cock when tightened. Or the jaws may be gouged/worn/etc. That plain out sucks. You can't do decent work without a little box of shims. Why pay for the privilege of making do? Yeah, you can grind the jaws, but I'd not pay to do it, only for a free chuck... Oh, and fitting a backplate is easy, in case that is bothering you. It was the first thing I ever did with a lathe, other than face the faceplate smooth enough to put the unfinished backplate on it. If I could, you can. Jerrold ------- Date: Mon, 3 Feb 2003 18:36:25 EST From: n8as1x~xxaol.com Subject: Re: Long distance diagnosis In a message dated 2/3/03, elsonx~xxpico-systems.com writes: >But, POSITIVE rake carbide works VERY well on 10 and 12" Atlas 1/4 in & larger brazed carbide bits have been of great value facing off & trueing up many large faceplates /back plates ...instead of having to run at 28 rpm for 5 inches in or keep changing speeds ,i can run carbide in 1st speed open belt ...164( or higher)...would not want to be w/out them ...for routine turning ,i dont even consider them ...i want lots of back & side rake on a sharp HS tool that i can easily put an edge back on. (but then , i am an anachronism & frequently use 0-1 for making special cutters , reamers & sometimes tool bits.).............carbide is obviously better for hardened steel , which i assiduosly attempt to avoid turning.....have not been happy w/ cheap import carbide boring bar sets ,maybe US tool makers do a better job & i am doo cheap to buy them...( perhaps someone will comment on that , not my cheapness , but US carbide ,,,would like to know) best wishes docn8as ------- Date: Tue, 4 Feb 2003 10:11:32 -0800 From: "Bob May" Subject: Re: Re: More advice on chuck mounting One trick is to do if you are afraid is to do a shallow register and get it nice and snug. After that, you can leave that part alone and deepen the depth of the register without touching the good part of the turning. If you accidently go too deep behind, you won't have lost the good part and yet you will have enough depth to fully mount the chuck on the backing plate. If you go too far with that first part, it won't be a problem as you have a second or even third try to get it right. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Wed, 26 Mar 2003 22:37:07 -0000 From: "Ernest Lear" Subject: Re: Large pieces Original Message from: "Brian Squibb" >> I have just been out to the workshop and realized that my 4 jaw chuck will take 1-1/2 inch bar which is enough to make it secure and solid enough for the center. It takes about 2inches of bar down the center. My lathe came with 2x 4inch 3 jaw chucks (one soft jawed) and a 6inch 4jaw (independent). Luckily I also have some extra backplates - are these the same as a Boxford/Sounthbend? I only have a woodworking faceplate, so I will see if I can get a used one somewhere. Brian << Brian: The Boxford backplates are the same as the Atlas. Thread: -National Form 1.5"Dia x 8th'd to the 1" .I have bought backplates for my chucks that were advertised for use on a Boxford and they work fine. Regards Ernest ------- Date: Sun, 30 Mar 2003 22:23:50 +0100 From: "Ernest Lear" Subject: Re: Fwd: Backplate From: "Brian Squibb" > >I have just bought a 160mm 3 jaw Pratt & Burnerd chuck. > >Is it necessary to have a full size 160mm backplate, and any hints > >or tip for fitting it and getting it running true? Thanks Brian Brian The best way to get your new chuck running true is 1st fit a backplate larger than the dia of the recess, you will find in the back of your new chuck, on the spindle of your lathe. 2nd machine the face of the backplate and then the dia down to a size that fit tightly into the chuck recess. Mark out and drill the bolt holes to line up with the 3 or 4 fixing hole inside the recess of the chuck and bolt the two together. Now your chuck will run true. Remember to make sure the backplate after machining is a good push fit into the chuck recess. I have a Pratt chuck that I fitted and it runs true and when I check it with a DTI it was less than .002" which I,m happy with. Ernest ------- Date: Mon, 31 Mar 2003 10:39:40 +0100 From: "Ernest Lear" Subject: Re: Fwd: Backplate >>>From: "Brian Squibb" Ernest, Thanks for that - I have bought the chuck on EBAY - cost me £33. I needed the bigger chuck as I am hitting the limit on my 4 inch in that the central hole only just takes 1 inch stock. How do you like the Pratt - it has a good reputation - does it meet up to it? Brian <<< Brian: I like it a lot but mine does have a slight belling of the jaws and very small objects it grips (by the last 1/4" of the chuck jaws) will fly as soon as the cutter starts to bite. At the moment I'm in the process of making a "Toolpost Grinder" base on the one described in No67 Model Engineers Workshop mag. This when it is made will regrind the jaws and then they will be as good as when Pratt dispatched this chuck from the factory. I bought mine from Mike Kern for £40. By the way I just had another look at mine and the backplate is the same dia as the chuck and the outer part of the face was turned after facing to make the step to push fit into the chuck. You've got to chamfer the edge of the plug to ensure the chuck rear is square and fully butted up against the rear plate as there a radius in the chuck recess. I use an old backplate, that was on an old 3" chuck but was left at 8" dia. as it was never turned down to the chuck outside dia. This chuck I got for nothing as the jaws were missing all the teeth on the back of them and therefore just scrap other than me reusing its backplate. Your second hand Pratt will be very good and will be streets better than what you can buy new today for more than £100. Ernest ------- NOTE TO FILE: On 24 Apr 2003 a question came up about problems turning a cast iron backing plate. The question related more to the difficulties of turning cast iron. See the text file "Metal Types and Tips". ------- Date: Mon, 26 Jan 2004 21:20:13 -0000 From: "mtrsickleman47" Subject: Chuck Runout When I bought my lathe (12X24 Atlas)there was no chucks included. I bought a cheap 3 jaw and a threaded cast iron back plate from Enco. The chuck is really pretty decent and ran true when I first machined the back plate. My spindle is running true with less than a half of 1 thousands runout. But now after a year and a half the backplate,OD of the chuck and a drill rod in the chuck ALL run at 7 thousands of runout. I don't want to replace and remachine back plates every year. But it seems that that the threads are now getting seated in and it has thrown the accuracy of the chuck off. I have checked the threads and they are clean of nicks and metal chips. It appears that my only two alternatives is either buy a new back plate and machine it (again) OR spend $400+ on a Bison Set-Tru chuck and back plate so I can adjust the runout when it needs it. I do have a use for my old chuck if I go this route.I was needing a 3 jaw for my rotary table anyway, I could just use it there. So I would only be out the $45 I paid for the back plate. And even it could be used as a 6" face plate. So, What do you think?? Zort ------- Date: Mon, 26 Jan 2004 14:09:10 -0800 From: William Abernathy Subject: Re: Chuck Runout Sounds like your back plate bent over the year. Castings will do this. Now that you've released the stresses in the back plate, odds are that if you remove the chuck and remachine the back plate, it won't move much more. William A. ------- Date: Mon, 26 Jan 2004 17:42:24 -0500 From: "Dick Farris" Subject: Re: Re: Chuck Runout Zort, I've read the thread from William and agree with his comments. I haven't had it happen to me yet, but I do believe that cast iron has to "age " and stress relieve itself after casting. Also helps on large pieces to machine both sides of a plate. not just one side. Or so I've heard. Dick ------- Date: Mon, 26 Jan 2004 18:57:04 EST From: n8as1x~xxaol.com Subject: Re: Chuck Runout Zort ...i have remachined a faceplate 3 times chasing warpage from improperly handled cast iron ...as above remove the chuck & clock things .if out , turn down the periferee & refit...all u ned is a slight ledge of a shoulder so ,not all has to be removed ...then face off the plate ...if all else fails , u can turn a true shoulder , & cut the spigot undersize ...put plate on chuck,.tighten up lightly & tap till a piece drill rod is true & TIGHTEN ....barring a wreck ,it will hold ....also possible to convert to an adjust true bu adding an intermediate plate, deepening the register if enuff plate ,or by adding studs to chuck & usint b/plate w/ adjust screws added....e mail me if u get there & need more info... best wishes docn8as ------- Date: Mon, 26 Jan 2004 22:04:07 -0500 From: Stan Stocker Subject: Re: Re: Chuck Runout mtrsickleman47 wrote: > Charles:Well that may be it. The register on the spindle measures > 1.4980 and the back plate in the same area measures 1.5120. So I > suppose this means a new back plate. I don't remember opening this > diameter up on the back plate when I machined it but I must have. > Thanks Zort Hi Zort: If you have enough meat on the section of backplate surrounding the spindle, you can bore it even more oversize and press in a thin ring of material (hard brass, 12L14, or the like), then bore the opening to a nice fit on the register. A light facing cut on the flat surface finishes up the spindle side of things. Then mount the backplate to the spindle as clean up the chuck register and mating faces. Cheers, Stan ------- Date: Tue, 27 Jan 2004 00:37:14 EST From: n8as1x~xxaol.com Subject: Re: Re: Chuck Runout > Charles:Well that may be it. The register on the spindle measures > 1.4980 and the back plate in the same area measures 1.5120. So I > suppose this means a new back plate. BUSH the register ....open it up some & make an 1/8 in or so bush & shrink /press it in .(dont thread)...then bore to suit .....have done at least a dozen.....more than likely , plate is warped as well ... best wishes docn8as ------- Date: Tue, 27 Jan 2004 00:23:33 -0600 From: Jon Elson Subject: Re: Re: Chuck Runout >suppose this means a new back plate. I don't remember opening this >diameter up on the back plate when I machined it but I must have. No, crappy backplates have the register and threads cut so large there's no doubt it will fit over any spindle - loosely! That's why I never buy a machined backplate, but just the raw casting. Then I can cut it for a good, secure fit to the machine's very individual thread and register. The thread doesn't need to be a real close fit, but the register should be. You need a mike that reads over 1", and either a good set of telescoping bore gauges or to make a piece of bar stock of exactly the same diameter as the spindle's register first. (Yes, you can do it all on a faceplate, and keep unscrewing the faceplate every pass to check the fit. Ugh!) Jon ------- Date: Thu, 29 Jan 2004 22:23:02 -0800 From: "Spurrs" Subject: Up and running and off with that backplate Finally, the atlas is making swarf in a smooth and quiet manner. My biggest concern with the lathe was that I could not remove the backplate from the spindle, resulting in the only holding device being a rather worn in the jaw 6 inch 3 jaw chuck. SO, first job was to make a protector to allow the spindle to be clamped in a vice whilst serious grunt is given to remove the backplate. Having made the protecting sleeve out of 2 inch hex brass, it was spindle out again and into the protector which is slotted to take the shaft key. Some not too serious grunting resulted in the backplate coming off at long last. Therefore, if anyone has the problem, either borrow my "protector" or bore a 1.5 inch hole in something soft, hex or square, slit it 0.25 wide along the length, then you can remove just about anything stuck to the spindle nose without risk of damage to the spindle or gears. Have fun! Nigel ------- Date: Fri, 30 Jan 2004 10:18:08 -0800 From: "Bob May" Subject: Re: Up and running and off with that backplate I like using the heat wrench for helping with the grunt work. Heating the backing plate with the spindle in the holder will shrink the spindle and expand the backplate and make things a bit easier to remove. It also tends to release any Locktite that somebody may have used to keep things from falling apart in the plus side. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Fri, 30 Jan 2004 17:52:06 EST From: n8as1x~xxaol.com Subject: Re: backplates jobarden422x~xxmsn.com writes: >> I don't know if any of you are interested but I have just downloaded the "Hemingway Kits" catalogue and they do an adjustable backplate kit so that you can get your chuck dead right an it is only £13.85 for a 5" chuck. thought it might help some out. Jo << a really interesting catalog....but for $24 us + shpg., can buy a new 4 in 3 jaw from wholesaletool($36 think still on sale ) have 3 ,only 2 fitted so far ..001& .00125 tir....u do need a b/plate ,either WT , or victor machinery exchange there are several ways to do this w/out an intermediary plate , depending upon b/plate thickness & chuck size ....4 adj screws at 90 deg. are easier to work with ....b/plate register w/ the chuck can be deepened enuff for adj. screws on chuck body, or a disc bolted on plate ,or studs used in back of chuck ,....then open up attaching holes in b/plate abt 1/32... the least projection from spindle u end up with ,the better... best wishes docn8as ------- Date: Sun, 15 Feb 2004 12:12:45 -0800 From: "Spurrs" Subject: Chuck mounting and spindle play Having spent an hour or two finish machining a backplate to fit a new chuck, I am more than pleased to have followed Tony's tips listed on lathes.co.uk because: 1. Heating the new chuck - just hot to touch - means trial fits on a possibly warm from machining backplate means that the chuck will be tight when everything cools down rather than loose. 2. Holding a bar between centres while machining backplate takes out any spindle play. After fitting the chuck then gripping a long bar in the chuck, I found some spindle play. This was not present during backplate machining as there was a bar mounted between centres. So, when checking for spindle play in taper roller headstocks, grip a long bar in the chuck and feel for play at the end of it. Adjust collar then tighten to ensure play is eliminated. Now I can enjoy smoooooth parting. Nigel ------- Date: Fri, 19 Mar 2004 21:30:15 -0000 From: "Steve Forslind" Subject: Accurately locating backing plate bolt holes I've bought a couple of chucks with no backing plate, and a couple of blank backing plates. There are threaded mounting holes in the chucks; three on one, four on the other. How does one *accurately* transfer the mounting bolt holes to the new backing plate? ------- Date: Fri, 19 Mar 2004 16:58:01 -0500 From: "mertbaker" Subject: Re: Accurately locating backing plate bolt holes 1. Screw the back plate on the lathe, & turn the locating shoulder on it very carefully to an exact fit on the chuck. 2. Backplate off the lathe, fit the chuck in place & using a transfer screw, mark one of the holes. 3. Drill the hole with a clearance drill. Use a drill press. 4. Run in the first bolt, loosely, with the transfer bolt in the opposite hole. Drill that one, put in the bolt, & do the next. You can do 'em all at once if you have 3 or 4 transfer screws. No transfer screws? Make 'em by chucking a screw with the proper thread, & turning a 60° point on it. You may have to file a flat on it to enable getting it out of the hole, if it's blind. Do this first, natch. You may have to case harden the point. If you use hardened screws, it shouldn't be necessary, but you may have to grind the point, in that case. Don't leave a lot of the point protruding when you assemble & tap the plate to transfer the hole location. Mert ------- Date: Fri, 19 Mar 2004 16:53:34 -0500 From: "Dr Robert Harms" Subject: Re: Accurately locating backing plate bolt holes I do it with Prussian blue, but in reality exactitude isn't that important as you counterbore the backing plate to the individual chuck and the counterbore is what centers the chuck. The holes in the backing plate for the chuck arent necessarilly that important and can be somewhat oversize. ------- Date: Fri, 19 Mar 2004 17:07:01 EST From: jmartin957x~xxaol.com Subject: Re: Accurately locating backing plate bolt holes Transfer screws are one way. The holes don't have to be extremely accurate, however, as it is the register and not the screws that locate the chuck on the backplate. A little slop in the screw holes and counterbores is needed. It's not as if you were mounting the chuck with shoulder bolts. Some even like to leave a three-jaw chuck a little loose on the register so they can tap it into adjustment at a given jaw setting and then tighten the screws holding the chuck. Sort of a poor man's tru-adjust chuck. John Martin ------- Date: Sat, 20 Mar 2004 14:53:20 -0000 From: "Steve Forslind" Subject: Re: Accurately locating backing plate bolt holes Thank you, gentlemen, for your thoughtful answers. Points well made: The center boss is the most critical part of a good job. The bolt holes are important, but secondary to the boss. Not having any transfer screws, I pointed some studs. I put the studs in the chuck, mounted the chuck in my larger chuck, lined up the point of a 60 degree c.t. cutter with the points of the screws, backed off the carriage, swapped the chucks for the backing plate, and scribed a circle in the backing plate as a double-check measure to be sure the points of the screws were properly located. Worked like a charm. Thank you all again. ------- Date: Wed, 02 Feb 2005 21:08:24 -0000 From: "n5kzw" Subject: Re: How to Finish a Backplate [atlas_craftsman group] In atlas_craftsman, Kuechenmeister wrote: > I thought about turning down some all--thread into something like that. > Actually, it wouldn't be too bad. Find some Allen screws with the right > metric thread. Chuck up the allen head and turn down the threaded part > into a point. Cut off the socket end and clean up the thread. Then > screw them into the chuck, leaving them a little proud of the chuck. > Seems like you'd want to slot the pointed end to screw them in and out, > but then it wouldn't be pointed. I'll have to think about that. Dave > On Feb 1, 2005, at 9:18 PM, Jon Elson wrote: >> kplus13 wrote: >>> I'm certainly a fan of transfer punches and I used them quite >>> successfully on a smaller chuck. I would do that for this backplate, >>> too, except that the tapped holes are in the chuck and they are blind. >> Ahh. There actually are transfer punches that thread into a hole, but >> they are harder to make. All of my chucks, and I've had quite a >> few over the years all had the bolts run through from >> the chuck face, and the thread was in the backplate. Jon Instead of turning down the allen screws, use a Dremel cutoff wheel to whack off a length of tight fitting allen wrench. Chuck the piece of allen wrench in your drill, and spin it against your grinding wheel to make it into a center punch. Make however many punches you need, pop them in your allen screws [the same hole as the allen screws] and adjust the length of the allen screws to make the chuck co-planar with the back plate and have all punches in contact with the back plate. Then tap the chuck at each screw to mark your holes. Regards, Ed ------- Re: updated tool post / chuck / accuracy adjustments [atlas_craftsman] Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Tue Apr 3, 2007 1:34 pm ((PDT)) In a message dated 4/3/2007, brettx~xx5foot2.com writes: >I got the plain back chuck with a pre-threaded Bison backing plate. Cutting the shoulder on the backing plate was simple enough but drilling the mounting holes would have been a pain had I not had a rotary table to space out the 3 holes in the bolt circle. < FWIW w/ out a rotary (i have one but think this might be quicker)...last six or so new chucks i fitted had bolt circle dim.on instructions ....measured off finished b/plate od & scribed a circle w/ lathe tool ...then indexed & marked w/ crftsmn h/stock indexer, ...used bull gear teeth & a file bearing couple places on bed & h/stock casting for 14 in antique ....made an index bar for gear teeth on wards logan ...... best wishes docn8as ------- Re: updated tool post / chuck / accuracy adjustments Posted by: "William Abernathy" williamx~xxinch.com Date: Wed Apr 4, 2007 9:19 am ((PDT)) redsouljoe wrote: > As I understand it, I simply need to mount this plate to the spindle > then face the plate to make it run true for my lathe. After that I > bolt the plate to the chuck and presto. You also need to cut a bit of a recess around the edge. When you look at the "plain back" chuck, you'll see it has a bit of a rim to it. You need to cut enough off the edges that you have a solid connection between the plate (male) and the chuck (female). Pardon my ASCII... | _ | plate > | < chuck | _ | > Since the backplate is made fr a bison chuck, will the chuck have > corresponding bolt holes already drilled in it? The reason I ask is > because I don't have a very accurate drill press or a mill, so I'm > not sure how I would accurately attach the chuck if it doesn't have > holes already. If you can cut the pokey-inny part of the plate accurately with your lathe, then you can cut your bolt holes with a lot of slop. The accuracy of the bolt holes is not critical; the accuracy of the plate is. The only other gotcha with Bison chucks is that they're not always the most convenient size. My 6" Bison chuck requires a 6 1/4" backing plate. YMMV. W ------- Re: 3 jaw chuck [atlas_craftsman] Posted by: "Michael Fagan" woodworker88x~xxgmail.com Date: Thu Jul 5, 2007 10:16 pm ((PDT)) On 7/5/07, Kirk wrote: > Since I have been using my 10100, I have only had use of a 4 jaw chuck. > It took every last ounce of will power to teach myself to set up my > round stock in it....but back to my question, I have purchased a 3" 3 > jaw chuck that is 2 peice, in that it has a seperate backplate, and I > am wondering how to mount the darned thing. The back plate screws on > ok, but how do you attach the actual chuck to it? There are threaded > holes in the chuck, but not the backplate. Thanks Kirk Samuels It depends on setup of the various shoulders, but it should be possible to insert socket head cap screws through the backplate and into the back of the chuck. There should be a close tolerance shoulder on either the backplate or the chuck and a corresponding recess in the opposite member. The screws themselves are likely fairly low tolerance, since they are for fastening only, not locating. The bolts should be tightened evenly, preferably in a star pattern, and torqued if possible so that the forces are even across the chuck. ------- Re: 3 jaw chuck Posted by: "Elton E. (Tony) Clark" eltonclarkx~xxgmail.com Date: Thu Jul 5, 2007 10:36 pm ((PDT)) *I've been there, done that... First I turned down the backplate, which had NO holes, to the same diameter of the Chuck. Then I machined the face of the backplate to nearly match the tapered shoulder on the back of the chuck. Then, I held the chuck against the backplate and rotated the lathe slowly 'til the two surfaces "lapped" together. Then I removed both from the lathe and center-punched through the chuck into the back plate. Then I drilled and threaded the backplate. When I mounted the assembled unit on the lathe, a test shaft dial indicated a runout of less that .001. A "real" machinist friend checked it out -- my method and results and said: "You are one lucky SOB! " Tony in Texas ------- Re: 3 jaw chuck Posted by: "Kirk" kirkx~xxovrccc.com Date: Fri Jul 6, 2007 8:53 am ((PDT)) Thanks Tony, I was hoping there was a much more simple method. I think I will save the money for a bison chuck (over $400.00 w/shipping from MSC), or keep an eye on ebay. That 4 jaw is looking pretty sweet ...lol. Once again thanks Tony. Kirk Samuels ------- Re: 3 jaw chuck Posted by: "Kirk" kirkx~xxovrccc.com wildnwv62 Date: Fri Jul 6, 2007 10:15 am ((PDT)) Thank you Michael. The back plates I hae are "plain", in that I will have to cut the shoulder myself. In reality this is probobly a good project to further my learning, which is what this is all about anyway. As the saying goes, you learn more from your mistakes than your successes. I have learned more in the past couple of days from this group than in a couple of years of cussing......cuddos to the owners/moderators and members Once again thanks Michael ------- Re: 3 jaw chuck Posted by: "Brett Jones" brettx~xx5foot2.com Date: Fri Jul 6, 2007 9:11 am ((PDT)) $400 is pretty steep. Enco has the Bison 5" 3 jaw (2 piece jaws) for $150. The Bison backing plate is another $50. These are on sale at the moment, but they seem to be a sale item quite often. Brett Jones ------- Re: Craftsman 6" backplate for chuck [atlas_craftsman] Posted by: "Glenn N" sleykinx~xxcharter.net Date: Thu Dec 25, 2008 1:16 pm ((PST)) All the back plates I made for the 6" Atlas I had and most of the back- plates for my 12" Craftsman are steel. I made all of them and they all work quite well. Some were made from barstock that had been cut to about 1" thick and some were from flame cut slugs from plate. Some I drilled and tapped on the drill press then turned the register on the lathe, and some I bored and threaded on the lathe. As long as the register lands are true so you get good repeatability then the rest will be turned true to the spindle. The bolt circle can be a bit challenging to get just right but if the chuck registers well with the backplate they can be "fudged". Just don't be tempted to use back gear on an interrupted cut on a 6". I blew mine out that way.. :( ------- Re: Craftsman 6" backplate for chuck Posted by: "carvel webb" carvelwx~xxabsamail.co.za Date: Thu Dec 25, 2008 10:50 pm ((PST)) Hi again Michael: Steel can be used, but CI has advantages. If you are feeling ambitious then one can shape any old piece of CI roughly to shape with a bandsaw, and start turning it down from there. I have made a backplate out of a chunk of washing machine counterweight, but it was a lot of work! With backplates being available at good quality and price (last bought for my Maximat from Little machine shop was $18), one must ask whether the effort is worth it? However I would still advocate machining the bulk of the thread on the lathe first, as cutting an accurate thread of that size from scratch with a tap would be a challenge. Just another thought maybe worth repeating - CI chips/swarf is almost as bad as grinding paste, and steps should be taken to protect the lathe, and/or strip and clean the affected areas afterwards (e.g. cross slide, saddle, etc.). Regards, Carvel ------- How Correct A Back Plate Threads That Fit Too Tight [atlas_craftsman] Posted by: "Wilfred" wrhoafatx~xxverizon.net Date: Sun May 9, 2010 10:49 am ((PDT)) I have a new 1 x 10 TPI backplate with threads that will not fit all the way over the spindle. Is there a simple way to adjust the threads on the backplate without using the lathe's threadcutting feature? I do not have a tap of the correct size, Thanks in anticipation, Wilfred ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Sun May 9, 2010 11:28 am ((PDT)) Are you sure it is the threads, not the register bore, that is tight? In other words doe it just get tighter as it is screwed on or does it just stop when the back edge reaches the smooth part of the spindle. Scott G. Henion http://shdesigns.org/Craftsman12x36 ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "c_h_a_r_t_n_y" mgibsonx~xxstny.rr.com Date: Sun May 9, 2010 12:27 pm ((PDT)) Re to Scott: Good call. Also, might thread it on backwards as the threads go all the way through the plate. If the threads are too tight, there is a problem and hard to fix. The tap is costly. If the thread is OK then one would need to rebore the register bore and that might be a task in itself. If careful you can thread it on backwards and bore it if it has long enough hub to reach the ID bore and not hit the spindle thread. Good Luck chart ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "Wilfred Hoafat" wrhoafatx~xxverizon.net Date: Sun May 9, 2010 5:04 pm ((PDT)) It gets tighter as it is screwed on. ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "William Rutiser" wruyahoo05x~xxcomcast.net Date: Sun May 9, 2010 6:08 pm ((PDT)) I suggest you clean the threads carefully. Examine with a good light and magnification. I have been surprised by how much trouble a very tiny chip can cause. ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "Ron Gerlach" r7734gx~xxhotmail.com Date: Sun May 9, 2010 7:19 pm ((PDT)) William: I agree with you. He should wire brush both the internal threads on the backplate and the external threads on the spindle and see if that helps. Is the thread pitch correct for his lathe? RonG ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "jerdalx~xxsbcglobal.net" jerdalx~xxsbcglobal.net Date: Sun May 9, 2010 8:22 pm ((PDT)) It is perfectly possible to have threads that do not fit, of the same nominal size and pitch. A Southbend faceplate will not screw onto a Logan, unless the Southbend threads are scraped out a bit. It is a slight difference in pitch diameter, or possibly sharp crest vs blunted. I just used a threading tool in a boring bar and hand-scraped the threads a bit, and it fit. It's a known issue. The "register diameter" is a religious belief. It is a sin equal to insulting the Prophet if you do not believe it should be a virtual "wringing fit", but in reality it has some leeway. Not all lathes even have a register; Sherline, for instance, a very nice small lathe, has no register diameter, the threads are undercut. So if that is the issue, bore it out a bit and don't worry that your accuracy is ruined forever. It is not. My chucks with loose ones repeat as well as those with tighter. JT ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "c_h_a_r_t_n_y" mgibsonx~xxstny.rr.com Date: Mon May 10, 2010 8:48 am ((PDT)) Re to jerdal "It is perfectly possible to have threads that do not fit, of the same nominal size and pitch." Yes and it is possible it is a 1"-8. If one is sure it is the correct pitch: You can turn a 1-10 male thread on a soft material like brass, then use lapping compound on that and lap the adapter hub to the sacrificial thread. I would use coarse first, then fine compound. I use Clover, coarse and then fine. I have used this on rusty or poorly fitting nuts and bolts and it works great. Need to clean up the threads well after. Use kerosene then ammonia helps get the final grit out, using a tooth brush and ammonia. (Ammonia is a gas in water and evaporates with no residue.) I have used the lapping master and split it with a hack saw and wedged it a bit to add friction. Just to add a thought. I have used auto paint rubbing compound on threads, but it a wax base and hard to clean off. Goo-Gone is about the best I have found to clean it off. That is only for final SLICK FIT. chart ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "L. Garlinghouse" lhghousex~xxsuddenlink.net Date: Mon May 10, 2010 5:22 pm ((PDT)) Chartney's lapping compound approach seems to me to be sound. But you said you didn't want to mess with cutting threads. Soooo ... think about this. Put layout dope, or blue or red or some other color oil paint on the spindle and screw on the face plate. Take them apart and see where the coloring on the face plate stops. That is your tight place. If it is just a few threads near the tailstock side of the face plate, I would not think twice about removing them with a boring bar [which I think someone just suggested]. Key thing, I think, is that the face plate hits home with the shoulder at the left hand side of the spindle. It doesn't take 100% of the threads to let the face plate function as long as the thrust is taken by the shoulder. Before you do this, let's see what others might think. Later, L.H. Garlinghouse Arkansas USA ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "James Irwin" jirwin1x~xxaustin.rr.com Date: Wed May 12, 2010 10:28 am ((PDT)) The lapping approach will remove metal from both male and female threads. Will likely leave embedded compound in both, too. This could lead to a very "stuck" condition! Lapping or cutting metal is a permanent "solution" that¹s exceedingly difficult to "un-do". Try everything to find the cause of any binding before cutting. "Measure twice; cut once". Jim I ------- Re: How Correct A Back Plate Threads That Fit Too Tight Posted by: "Chris" chris_petersonx~xxtoyota.com Date: Thu May 13, 2010 9:53 am ((PDT)) Triple check the thread pitch!!! I just picked up a 618 Atlas lathe that has a combination 10 tpi and 8 tpi spindle. Didn't know Atlas made one like that? They didn't! Someone tried to thread some 1" x 8 tpi chucks onto a 1" x 10 tpi spindle. They went on about 1/2 way... and really hosed the spindle threads in the process. Chris ------- how to make a backplate for an ADJUST TRU 202-5464 [atlas_craftsman] Posted by: "Don Peterson" donx~xxameridreamhi.com Date: Sat Mar 5, 2011 9:40 am ((PST)) Hi first post here. I bought a ADJUST TRU 8" chuck from shars and i need to make a backplate for it. Shars lists a premachined backplate in the 2010-2011 catalog, but it is not in production right now. So i know the basics of fitting the backplate, but it is the stock that i need help with. The backplate has the register part that protrudes .70-.745 to mate with adjust screws. The total thickness of the backplate would have to be in the 1.25- 1.5 inch range. I have not been able to find any with those specs. I have also thought about screwing welding or gluing the protrusion part onto a semi machined 1 1/2 -8 standard backplate. Would like some feedback and suggestions. Maybe i should make a d1-4 spindle for my A/C 12 x 36 for ease in the future. Thanks Don ------- Re: how to make a backplate for an ADJUST TRU 202-5464 Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sat Mar 5, 2011 10:51 am ((PST)) check WTTOOLS, victor machinery exchange, travers tool, enco, & MSC, for an unmachined BLANK backplate ...an 8 inch one shd be thick enuf. bolting an additional plate to the backplate is acceptable ... fwiw that is how many of us have converted a stndrd 3 jaw to an adjust tru ....made the adjustment screw set up on the intermediate plate. everything is easier & cheaper w/ a screw thrd spindle ... better suited to DIY hsm .... xcept use caution reversing spindle ....i sometimes thrd in reverse after a reasonable bump on of the chuck ......being careful w/ doc / speeds, i have not had a chuck loosen/ come off. they worked well for 150 yrs best wishes docn8as ------- Re: how to make a backplate for an ADJUST TRU 202-5464 Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sat Mar 5, 2011 6:10 pm ((PST)) Years ago I bought an 8" Phase-II adjustable chuck (a fine Buck knock-off) from Travers Tool, and they found me a rough backing plate to go with it. (I had to machine the spindle thread as well as other surfaces.) I cut off a BUNCH of the "spigot" for the spindle thread to reduce the chuck overhang, then machined the rest. I think it cost more to ship the plate than the plate cost itself. I would prefer something like this to be made in one piece. Maybe if you ask for a back plate to fit a Buck or Phase-II adjustable chuck, one of the tool suppliers can find one for you. A D1-4 would be nice, but kind of big and heavy for such a small spindle. My Sheldon 15" lathe has a 2.25" spindle through hole on a D1-6 spindle, for instance. Jon ------- [was: Re: how to make a backplate for an ADJUST TRU 202-5464] Re: adjust tru chuck Posted by: "carl warner" crl_wrnrx~xxyahoo.com Date: Sat Mar 5, 2011 11:32 am ((PST)) Don. I like the adjust tru chuck also. My last job had one on the 11" delta lathe. I used it for over a year, before I figured out that it was adjustable. Well actually I did not figure it out, I found the manual in the desk drawer. I also have a 12X36 atlas, I bought that had a 4 jaw chuck only. I was concerned about weight, most chucks are thicker front to back than the original atlas chucks, so I went with a 5" chuck. I wish I had bought the 6" now. As I had to make a back plate anyway, I set out to find a way to make it adjustable. Researching the subject on the Internet, I came across an English company that sells kits for 4" and 5" adjustable back plates. There are good photographs and drawings, so you should be able to figure it out from there. The English store is "Hemingway Kits". From their home page click on "Hemingway tool room", then select "work holding and positioning", then select "adjustable back plate designed by Mr. E.Riley". Their Kit will not fit your chuck but should show you how to make an adapter plate to go between your chuck and a standard back plate. I have bought a casting for a 4" back plate and will machine it and then make an adapter plate out of 1"steel plate. I hope this helps you. Carl Warner ------- Re: adjust tru chuck Posted by: "jerdalx~xxsbcglobal.net" jtiers Date: Sat Mar 5, 2011 9:12 pm ((PST)) If you look at the backside of the chuck, it should become obvious what you need to do to make a backplate. For a Buck (real adjust-tru brand) there are 4 screws in the chuck, which will push on the sides of a longer "spigot" on the backplate. There are also screws which hold the chuck down to the backplate. You slack the securing screws a bit, and use the 4 side screws to push the chuck into alignment as needed before tightening everything again. The side screws work exactly backwards from the screws on most 4 jaw chucks. So make a one-piece backplate to fit it. You can use cast iron, or steel. As this is the A/C group, you will have a threaded nose spindle. So use a thickish piece, with at least enough material to have the nose of the spindle come to just short of the front of the backplate. Total you want enough to be sure you have a small protrusion or spigot of maybe 0.125" (3 or so mm) on back, plus a section about 0.125" thick plus another 0.125" for every 2" diameter of the chuck to form the solid body, and a spigot just short of the depth of the recess in the adjust-tru chuck to engage the adjust-tru. That is likely to be about 1 1/8" (29mm) for a 6", or about 1 1/4" (32mm) for an 8", plus or minus. If the chuck securing screws go in from the back, increase the allowance for the back spigot to account for the heads and any washers. Drill a half inch or so hole in the middle of the blank, bigger if you can, and clamp it to a faceplate on the lathe*, with hole centered. Bore out and single-point thread the hole to suit the spindle, cut the unthreaded portion, and face the back true. Face off the extra to form the back "spigot". Now mount it to the spindle, rough the outside diameter, and face the front side. Cut the front spigot perhaps 0.040" undersize for the recess in the adjust-tru area, and about 20 thou short of the depth. Finish turn the OD to suit the chuck. Remove from spindle. Now you can put the chuck on it, and mark the holes that will hold the chuck on. Drill out for either threads or clearance, and finish as appropriate. At this point you should be able to mount and use the chuck..... I would NOT add another adapter between a backplate and the chuck. Nor bolt/glue/whatever anything in there either. One-piece is best. JT * if you do NOT have a faceplate, get one.... this is what they are for. if the piece is not clampable, screw it in place with holes from back threaded into the blank.....just be sure they will not fall in places you will need to put a functional mounting hole later. if you don't have a faceplate it IS possible to do this, either with a 4 jaw chuck, or some 3 jaw chucks. Just not as easy, depending on how big the backplate has to be. ------- Re: [atlas_craftsman_projects] Back Plate Bolt Hole Placement Posted by: "Russ Kepler" russx~xxkepler-eng.com Date: Tue Aug 14, 2012 6:43 pm ((PDT)) On Wednesday, August 15, 2012 danolog16 wrote: > I'm making my own backplate for a 4 jaw I just got. When I finish the plate, the last thing I need to do is drill the holes. I plan on doing this on a drill press, but I'm concerned about getting the hole placement accurate. My plan is to use the cross feed to measure out to the radius of the bolt centers, and use the turing spindle to make a ring. Then use some combination of protractors and plumb-bob to get the geometric 90 degree perpendicular lines. These will cross the circular line at the position of the holes. Are there other ways to do this that would be more accurate? < Just turn a locating pin that fits though the front of the chuck and use it to pop a hole with the back in place. Drill that with a small drill that'll easily center on the pop, then step up a couple of times to the final drill (stepping up allows the drill to center in the existing hole). Tap the hole, mount to the chuck and mark another hole. After 2 holes have been done, just pop the last 2 and be done with it. Really, you should be able to pop all 4 but doing them one at a time allows for some error in the process, and this allows for some errors in the hole location in the chuck. (Or do you think the chuck makers never make errors?) ------- NOTE TO FILE: I normally place a conversation into only one file here, the one I think most suitable for the particular topic. But the following discussion involved threading, and making an Atlas backplate [or any other brand's for that matter], and doing it with a boring bar. So it ended up in all three files. ------- Boring bar deflection [atlas_craftsman] Posted by: "geoffrey_in_siam_atlas_12in_3991" lovex~xxcvbt-web.org Date: Fri Mar 1, 2013 9:04 am ((PST)) We're making a backing plate for a 4-jaw chuck that I bought. I have to bore and thread 1.5" 8tpi threads. In making trial cuts on a test piece I've come across some puzzling things: Boring, we dialed in .150 on the cross feed and get .003" Threading, we dialed in on the compound rest .067" and got less than .010" Our boring bar is about 1/2" in diameter and 6" long. We mounted a linear dial indicator on the carriage and put the tip on the boring bar about 2" from the tool post. It seems that the boring bar is deflecting. When we set it up for real then we can grip it shorter. As we cut threads we think that the deflection will become greater. So, how can we measure to know when we have sufficient depth of thread? We don't have a male bolt handy. ------- Re: Boring bar deflection Posted by: jmartin957x~xxaol.com Date: Fri Mar 1, 2013 12:43 pm ((PST)) Use the largest bar that will fit the bore, and choke up on it so that you can cut just as far as you have to. No further. It should be sharp, and cutting. Not rubbing. Set it at center height or a bit above. Even if you do everything right, you'll still have to take a couple of "spring cuts", without changing the cutting depth, to take out the slop and windup in the system. Silly question, but you are taking out the backlash in both cross and compound feed screws in the cutting direction - outward - right? John Martin ------- Re: Boring bar deflection Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Mar 1, 2013 12:45 pm ((PST)) if you are using the lathe that the chuck is intended for, you must EITHER make a copy of the spindle thread to check your thrdng progress, OR mount the back plate on a face plate ..then you can remove the face plate w/ back plate attached to check progress & then replace w/ out needing to pick up the thread...you are threading to fit, and NONE of the current depth of thrd specs will be correct ...you need to cut a V thrd, not some other stndrd.....you thrd to FIT on these spindles & on most home shop items ..if you doubt that, i will GLADLY sell you a 1-1/2 & 8 new tap for $20 + shpg. if you are inexperienced in boring /thrdng, PRACTICE on scrap first ... all boring bars flex ...just a question of how much, (doc, extension, diameter, grind etc) ....use a sharp pointed HIGH speed bit ....carbide cannot be made as sharp & requires more FORCE to cut, hence more flex... books show a rounded point ..forget it ...you want a sharp point w/ back rake & PLENTY side rake .for a real smooth finish; either angle the bit as flat as opossible w/ out chatter OR grind a 1/32 flat & take cuts under 5 thou (real smooth not needed to thread on)..these are light machines (plenty flex w/ using turning tools also) & until you really know where you are, 20 thou doc is plenty ...too fast a feed, & the bar will spring away ......stone your grind, makes a big difference....i use at least a 3/4 bar w/ bit on the end for 1-1/2 thrd.....i assume you are using a 1/2 bar w/ a small tool bit at the end???? you can still make it work, just lite cuts. fifty years ago w/ a 6x18 i bought the catalogue boring tools & cud not figure out for a LONG time why i cud not bore ...turns out the tools were not HARDENED ...experience wud catch that right away ...but as a beginner, it drove me nuts. oh yeah, dont forget to compensate for the back lash on your compound / x feed ....if you have not dialed it out, you can put on 20 thou or so & not move the bit !!!!!!! & just for the record i have cut more than a dozen back/face plates, finally on the last one i made a dummy spindle. best wishes doc ------- Re: Boring bar deflection Posted by: "cliff" kenx~xxucsp.com Date: Fri Mar 1, 2013 1:20 pm ((PST)) Make a male bolt first. You can check it as you make it by using a chuck or other 1.5 x 8 threaded part as go/no go. Then use the bolt as the go/no go for the back plate. The male part is much easier to make (external threads), and I doubt you will have great joy making the internal threads without having a go/no go test method. ------- Chuck back plates [atlas_craftsman] Posted by: thehairsx~xxoptilink.us Date: Fri Jan 31, 2014 10:02 am ((PST)) Has anyone ever used aluminum for a chuck back plate. If so how did it work and did it last well? David Hair Dalton GA ------- Re: Chuck back plates Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Jan 31, 2014 10:47 am ((PST)) NO, but i did make a faceplate from an 83 ford 150 front rotor ....for a Barnes 9 x24 ..bushed the spindle hole w/ a drive fit. re aluminum ...if you have ever snapped & drilled out steel bolts that were CORRODED into aluminum bearing housings on mower decks (not rusted), you might question this...BEEN THERE. SOME types of aluminum approach steel for strength ..but if you have to buy, absolutely not ...double the price of steel & abt equal fo cast iron at "speedy metals". if you have the material, the only thing lost is time, plus you gain the experience of making one...certainly not ideal for vibration damping like cast iron (cast iron is messy, but turns & threads quite easily), but shud be adequate for normal use ?????...no experience, just a guess.....sure wud keep the spindle thrds WELL lubed......interrupted cuts may want to jam the plate worse than cast iron as it "galls". best wishes doc ------- Re: Chuck back plates Posted by: "David Hair" thehairsx~xxoptilink.us Date: Fri Jan 31, 2014 12:39 pm ((PST)) Thanks Doc, I don't think the chuck will be on the lathe long enough to corrode. This will be my 4 jaw chuck. The reason for looking at aluminum is I can cast the back plate and I haven't got to the point I'm willing to go to cast iron temps in casting. If you are talking about the screws that hold the backing plate to the chuck I'll watch that. I want to try a couple ways of making a collar lock and casting in aluminum is the cheap way out for me. I'm also looking at casting a 10 inch faceplate. David Hair Dalton, GA ------- Re: Chuck back plates Posted by: "Eggleston Lance" wheezer606x~xxverizon.net Date: Fri Jan 31, 2014 1:22 pm ((PST)) Along with Doc, I have successfully used cast iron brake rotors as face plates. They are strong, cheap and easily machined for attachments. As to the aluminum back plate, the forces on the mounting bolts are very high, especially in a catch or interrupted cut. I would use 6000 or 7000 series alloy and sleeve the bolt holes with steel. lance ------- Re: back plates/unscrewing in reverse Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Jan 31, 2014 1:30 pm ((PST)) David ....faceplate shud be fine ..been done before & auxiallary faceplates on top of the original are not uncommon. re split clamp for spindle ....the specter of a chuck flying off in reverse has been greatly exaggerated ....seating the chuck w/ a bump, in 50 yrs of LH threading & RH away fron shoulder threading & running in reverse w/ a tool post grinder...., it has never come off,,,,the doc [depthe of cut] is minimal & the speeds for threading are low....the cam action chuck backs came into use when carbide tooling came into general use ...HEAVY cuts & FAST speeds, before that i find no mention of chucks unthreading in all the literature i have read AND in my experience as well ...FWIW. 5 yrs ago, way down on the learning curve, i bought a 3 jaw chuck for my 6X18 ...chuck was 10 TPI spindle was 8 tpi ...not knowing a better way then (drilling out, bushing & rethreading) i recut to 8tpi over the original thrds...i centered a bar in the 4 jaw & grabbed it w/ the jaws of the 3 jaw & proceeded.....it came out w/ 11/4 thou tir ...so i left it alone ...BUT need to be carefull ...at med high speeds as soon as the c/shaft is thrown out it starts to unscrew ..when i forgot, i just caught it in my hand ......still have the lathe, but not in use the last 30 yrs; that is the only instances of chuck unscrewing in my experience & that is when running forward. best wishes doc ------- Re: Chuck back plates Posted by: white5415x~xxyahoo.com Date: Fri Jan 31, 2014 1:37 pm ((PST)) I used a piece of 1/2" thick steel plate to make a face plate. Lopped the corners off with the band saw to get it semi round. drilled a 1" hole in the center and welded in a piece of 1" round stock. Then mounted it in the lathe and cut the face to fit the mounting plate on the lathe, removed the chuck, turned the plate around after drilling the 3 mounting holes. Mounted it to the mounting plate on the lathe, and faced it off and turned the edge to a round disc. Ended up with a 10" face plate. The hardest part was turning the edge, just about all it was to have enough power to turn it at that distance out from the center. John ------- Re: Chuck back plates Posted by: white5415x~xxyahoo.com Date: Fri Jan 31, 2014 1:45 pm ((PST)) Okay I'll ask. How do you use a brake rotor for making a face plate?? I've never seen a brake rotor that is solid across its surface? Usually the hub is at a different plane than the face where the brake pads run. I guess you might just cut the center out and make a small face plate. John ------- Re: Chuck back plates Posted by: "Eggleston Lance" wheezer606x~xxverizon.net Date: Fri Jan 31, 2014 1:57 pm ((PST)) I had a one-time-job to do. The part was larger than the diameter of the rotor. Mounted the rotor concave on an inside 3-jaw. Trued the outside edge and face to the spindle. Bored and threaded mounting holes for clamping bolts through the rotor's pad area. Mounted the part and bolted it to the rotor. Counterbalanced the assembly with weights thru-bolted to the rotor. Turned the part slowly at first, then up to speed for the finish. Rotor worked fine. Have also used it as a mounting table on my mill, which has a very narrow work slide with a single T-slot. lance ------- Re: Chuck back plates Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Jan 31, 2014 2:32 pm ((PST)) made it for a 9X24 Barnes ...faced down the hub, trued up the internal diameter & drive fit a solid bar (abt one thou per inch interference) keyed the joint w/ a 16 pwt nail for insurance ...bored out the inside & threaded it for the lathe. best wishes doc ------- Re: Chuck back plates Posted by: "Donald Lewis" ddean49x~xxyahoo.com Date: Fri Jan 31, 2014 3:11 pm ((PST)) I made mine from the rear hub of a 2000 Subaru. It can be challenging to get the mounting holes to miss the old lug stud holes. Don ------- Re: Chuck back plates Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Fri Jan 31, 2014 3:19 pm ((PST)) Never have I seen an aluminum chuck back plate. It is not recommended; aluminum is too soft. The answer of going cheap is not the answer. GP ------- Re: Chuck back plates Posted by: thehairsx~xxoptilink.us dhlh1984 Date: Fri Jan 31, 2014 4:52 pm ((PST)) GP, I've bought a cheap 6" 4-jaw chuck. $50.00 and I don't really want to invest more in a cheap chuck than the chuck cost. Most of my work I will be using my 3-jaw. This is just for those odd shaped parts. David Hair Dalton GA ------- Re: Chuck back plates Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Fri Jan 31, 2014 4:33 pm ((PST)) I made an ER40 chuck using 6061 aluminum and it worked fine. It is plenty strong enough for the lathe. I did notice the threads have gotten a bit looser. Part of that is the threads were a bit rough (bit of chatter on boring bar.) So, I do make sure to oil the threads. Scott G. Henion, Stone Mountain, GA Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 Welding pages and homemade welder: http://shdesigns.org/Welding ------- Re: Chuck back plates Posted by: "Rexarino" rexarinox~xxgmail.com Date: Fri Jan 31, 2014 11:37 pm ((PST)) David, I've made 3 - 12 inch sanding discs of wheelium less than 3/8" thick and they work very well on wood and metal sanding. You may want to use something to dampen the resonance when facing the plate -- if you actually do hit a resonant frequency at some diameter/speed/feed combo. The next time I have that problem, I'm going to use part of a tube of cheap caulking on the back of my casting to dampen the motor resonance -- but then, I'm also going to install link belts on the headstock, which may improve my surface finish a lot. Oh, and I'll use Doc's shear bit to finish it. We were new to casting wheelium when we made the first one, and we "short cast" it, not enough metal in the pot. :_( Joe and I thought we would just smash it up and remelt it, so we grabbed a 16 pound sledge and some bricks, supported the casting across 2 bricks and proceeded to whale on it. We pulverized 6 or 8 bricks, wore ourselves out..., and put nicks and dents in the casting! A sixteenth inch deep cut would likely have smoothed out all the damage we "didn't" do to it. I had been very suspicious of the strength of aluminum, until I tried to bust that sucker in two! Since that time, I've found that millions of people are driving on aluminum wheels that are less than .200" thick everywhere except the webs, and those wheels don't shatter or fold up even when they get damaged enough for Joe to see them in the auto body shop. Yes, they bend and break, but so does the suspension when the wheels suffer significant damage! I trust A 356 aluminum to be as strong as I can possibly need for the tooling I make from it, especially when I yank it out of the mold as hot as possible and chill it immediately in cold water. I think your back plate will be quite serviceable, especially if you cut the threads carefully (not oversize!) and use a good alloy like wheelium (A356). Rex Bosse Portland, Oregon ------- Re: Chuck back plates Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Sat Feb 1, 2014 2:32 am ((PST)) On wood lathes they use aluminum drive plates, not for machines that are used for machining steel and have high torque. You will find out when you can't get it off the spindle. Don't be so cheap. You can buy a blank and you do all the machining GP ------- Re: Chuck back plates Posted by: "David Hair" thehairsx~xxoptilink.us Date: Sat Feb 1, 2014 5:08 am ((PST)) Rex, about all I use is wheels and bell housings. I'm also thinking of adding a little copper for this casting. Funny, this is the first time I've ever heard 356 called wheelium. David Hair Dalton GA ------- Re: Chuck back plates Posted by: jerdalx~xxsbcglobal.net jtiers Date: Sat Feb 1, 2014 6:56 am ((PST)) What GP said....although I'm less concerned about it sticking in place (although it could if distorted in a crash), but more about it wearing or getting "dinged" to the point it is no longer repeating position. Aluminum is generally soft, although there are hard alloys. And, the lathe cost more than the chuck. Don't think of it being something for the chuck, but rather something for the lathe. Then also, don't think of a 4 jaw as a big pain in the neck that you might HAVE to use sometimes, but rather as the chuck to use "by default" for general turning. It's stronger, and you can always put the part back in after taking it out, and pick up the same concentricity. Not gonna happen with a 3 jaw. JT ------- Re: Chuck back plates Posted by: wa5cabx~xxcs.com Date: Sat Feb 1, 2014 8:42 am ((PST)) David, I have to agree with GP. Although it would be nice to be able to say you made the whole thing from scratch, if even the short term results were going to be even marginally satisfactory, you can bet the Chinese chucks would all come with aluminum back plates. The immediate problem that I see is that unlike face plates and sanding disks, even small chucks are fairly heavy. Too easy to damage the threads during installation. Also, I didn't look the figures up but I would expect that the coefficients of thermal expansion of the cast aluminum versus the chuck will be different. Buy a cast iron or seme-steel blank and finish machine it. Robert Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: Chuck back plates Posted by: "Eggleston Lance" wheezer606x~xxverizon.net Date: Sat Feb 1, 2014 5:42 pm ((PST)) Does anyone KNOW how thermal expansion affects a hole? If an aluminum face plate with threaded hub is warmed, will the hub ID get larger or smaller? lance ------- Re: Chuck back plates Posted by: jerdalx~xxsbcglobal.net jtiers Date: Sat Feb 1, 2014 5:48 pm ((PST)) Bigger, always. The metal expands with heat, making the circumference of the hole bigger. Jerry ------- Re: Chuck back plates Posted by: "James Irwin" jirwin1x~xxaustin.rr.com Date: Sat Feb 1, 2014 6:29 pm ((PST)) Thermal strain (aka expansion) is expressed as ³/deg² Yes, that is correct. Actually it is, for us, mostly expressed as microinches per inch per deg F. Since units of length are the same they cancel out to the more anal ?mathemagicians¹ among us. Unless mechanically constrained, this strain (expansion) proceeds in every direction. For aluminum alloys we¹re talking right at 13uin/in per degF. For steels it is 7-8. Since the length around any circular shape is way longer than the distance from inside to outside, the hole will get bigger. Barrels of big guns have long been made by heating the outer sleeve and chilling an inner sleeve, putting them together and allowing the outer to shrink (and inner to expand) to equilibrium locking them tightly together. Adds greatly to strength! Here¹s some homework http://www.science.gov/topicpages/w/warm+shrink+fitting.html Jim Irwin ------- Re: internal expansion Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sat Feb 1, 2014 6:36 pm ((PST)) it can be dramatic, & was for me .....replaced the ring gear on an 8N ford abt 20 yrs ago, hole drilled & whack w/ a chisel & the old one split ...checked the new one for fit & was in disbelief that it wud ever go on the flywheel....heated to dull red & checked ...nope ..... more heat ... at abt a red it slipped on & as it cooled, SUNK DOWN INTO A GROOVE .... cant remember the diameter, but i multiplied it by 3.1416 & coefficient of expanion & 1000 degrees, & yeah !....it sure as h-- opened up. expansion can be a friend .....mentioned before but worth repeating if it still may be of value to someone. the brdgprt M head that was diverted to me from the scrap yard (literally) had the head pinned w/ a BLIND hardened taper oin ....trouble was it was pinned out of tram head was not vertical ....after some frustration i decided to heat the pin up to anneal it & drill it out .....heated it to red & after it cooled, as i started to drill, it just spun right out .... when heated it can only expand longitudinally since it is enclosed by cast iron on the OD ..but when it cools ALL surfaces contract ....same thing w/ a frozen rear axle bearing part in the hub ....i used my torch since it was away from home, otherwise, i wud have just run a bead of weld all the way around & it wud have fallen out after cooling as it did using the torch. best wishes doc ------- Re: Chuck back plates Posted by: wa5cabx~xxcs.com Date: Sat Feb 1, 2014 8:14 pm ((PST)) Lance, It gets larger (although I didn't have the spindle threads in mind when I made my comment). If you have something with a hole in it that you need to press a shaft or rod into, you heat the something and cool the shaft. For example, the left Timken spindle bearing on an Atlas lathe is always tight. To install the bearing without a press, you warm the bearing to 150-200 F. Robert & Susan Downs - Houston ------- Re: Chuck back plates Posted by: "Wayne" harpanet1x~xxcomcast.net Date: Sun Feb 2, 2014 7:31 am ((PST)) At the mention of using cast iron free weights for a source for turning I would suggest good American castings. I was just turning a project using a Chinese 5lb weight last night and it was not pleasant. I used a boring bar to enlarge the center hole to 1 1/2" and that went fine. Easy cutting and a nice finish. When I tried facing it to get a nice surface all kinds of things showed up. There were sections of the usual dull grey of the cast iron and various sections of bright mirror finish like steel and some pure white spots that looked like plastic. Also a few holes. The pile of swarf looked like the layers in an archeology dig instead of the usual grey powder. I had layers of grey, white, and what looked like multi color glitter. I hope this isn’t where they get rid of industrial waste. HWF ------- NOTE TO FILE: There is a conversation about making inside 1" x 10 threads for chucks or backplates that appeared in the atlas_craftsman group. See the message titled "tap for the 1 x 10 tpi [atlas_craftsman]" Date: Mon Apr 21, 2014 in the file here "Threading (Lathe and Otherwise)". ------------------------------------------------------------------ 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 ------------------------------------------------------------------