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 ------------------------------------------------------------------ Lots of good information about the choice and use of various chucks, whether for metal lathes or milling machines or drill presses. This file is a bit of a catchall, for chuck issues that were not necessarily unique to a single brand or type of chuck. If you want to know a great deal more about chuck problems or issues or modifications, you really should read the following files also, even if you have no intention of ever buying those brands: Atlas Backing Plates Atlas Chucks General Sherline Chucks Sherline Taig Adapters Taig Chucks. Lots of good ideas or advice that can be adapted for other brands. 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 - 2016 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. ========================================================================= Date: Thu, 01 Mar 2001 19:08:10 -0500 From: Reginald Barron Subject: Re: runout for 3-jaw chuck and WW collets wjw2000x~xxhotmail.com wrote: > What kind of run out should I expect from the 3-jaw chuck...right out > of the box, so to speak, and the WW collets? I am getting about .003 > for the 3-jaw, and over .001 for a 1/4" WW collet. .003 isn't > unreasonable for a 3-jaw chuck, I know, but I did expect a little > better for a brand new chuck. And as for the WW collets, I really > expected something under .001 > I'm thinking of running a Dremel stone down the length of the jaws > with the chuck spinning to tighten it up a bit. I would not fool around too much with a new three jaw. If you are determined to improve it here is a way that is not as drastic as the Dremel method: Make sure everything is clean and without any particles/ grit etc. including the threads of chuck and lathe plus scrolls, put an accurate piece of drill rod in the chuck and ensure there is no wobble and that it is parallel with the ways. Using a DTI determine which jaw has too much material (and how much). Chuck another piece of drill rod of a different diameter to see if you get the same reading with the same jaws high (or low). Do one more check with a third piece. The idea is to determine how much error may be in the jaws, and how much in the scroll. If you get consistent results continue. Remove the jaws, tape fine emery paper too some clean glass. Put an angle plate on top of the emery. Put a little bluing on the face of the jaw with the excess material. Put the jaw with the excess material face down on the paper, with the side of the jaw against the angle plate (to ensure it is square). Remove a "minimum" of material (check to see if any/how much bluing remains). Reassemble and recheck with the DTI. Remember if you have .003 runout, you may only have to remove a trifle over .001. Also, you might have to remove a bit from two jaws, but I would tackle the worst first. I would practice with a piece of keystock or other scrap first, to get the hang of removing a controlled amount of minimum material. Reg Barron ------- Date: Thu, 01 Mar 2001 23:08:30 -0500 From: ron ginger Subject: Re: runout for 3-jaw chuck and WW collets Caution- drill rod is not round. It looks nice and shinny, but take a piece and do some careful measurements and you will find it often has a 'lobe' shape. A ground drill blank would be much better. ron ------- From: "Martin R Gutzmer" Date: Wed Jun 27, 2001 5:02 pm Subject: Size 0 Morse Chucks and parts I have a Craftsman 109 lathe which I have been told uses Size 0 Morse Chucks and parts. Anybody know a source for these? Thanks, Martin ------- From: S1 Date: Thu Jun 28, 2001 1:20 am Subject: Re: [atlas_craftsman] Size 0 Morse Chucks and parts Sherline, Taig and a place in Canada sell parts that will work with the 109. You can buy chucks with a 1/2 20 THD from Sherline, and various live centers from them also. Taig makes #0 taper stuff because their machines have a #0 also. I don't know the name, but I know theres another place where stuff like this can be obtained for the 109. I'm sure there's somebody in this club who knows the name of the other place. Gabe ------- From: "Nicholas Carter and Felice Luftschein" Date: Thu Jun 28, 2001 1:01 pm Subject: Re: Size 0 Morse Chucks and parts Taig does not make any #0 taper tooling. The Taig uses a ram in their tailstock that has a straight shaft and 3/8"-24 threads for mounting chucks. See our web pages http://www.cartertools.com/nfhome.html ------- From: "Randy Pedersen" Date: Sun Jul 1, 2001 12:35 am Subject: Fixing Stuck Chucks I received this from a member of the South Bend group that I belong to since buying 2 SB 9" lathes to go with my Atlas 6". Below is a copy of the message I posted in the South Bend group. Thanks to Paul Hvidston, he sent me this so that I could scan it and post it for the group. As soon as I get my new shop set up this is my first priority although I haven't had any problems with chucks sticking. On the subject of storing chucks if you are storing them in a drawer especially a metal one you might go the a local tack & saddle shop (I'm lucky my dad owns one) and get a piece of 1/4" saddle leather to line your drawer with. If you put a little leather dressing on it it will stay nice and soft and protect the tooling you lay in the drawer. I have tried the foam drawer liners but the heavy items like chucks and milling attachments just cut through it but not the leather. Also if you keep the leather oiled a little it keeps things from rusting. Thanks Paul for the great article. if anybody has trouble downloading it let me know and I can send it direct. Randy ------- From: Rex the Wrench Date: Thu Jul 12, 2001 1:04 am Subject: Re: Spindle drill chucks [atlas_craftsman] jerdal wrote: > There was a discussion of the Jacobs spindle chuck on the Chaski site, and it got me curious. I had looked at one of the jacobs chucks, and that one had coarse teeth on the jaws, such that it would not grip below 3/16 inch rod, which I can do fine with a 3 jaw. I had thought that the Jacobs chucks had much finer jaws, but the discussion seemed to confirm the 3/16 minimum. I had assumed that the one I saw had maybe had the jaws replaced. Anyone else have one who can tie-break the grip range? I had wanted one of the chucks as a sort of interim collet substitute, but when I saw that grip range issue I decided not to go that way. Also helped decide when I saw that it stuck out a lot farther than I thought it would. Thanks Jerry < My Jacobs spindle chuck (model 59B) has a capacity of 3/16" to 3/4". It is very accurate (less than .0005" TIR), and much handier than collets within its range. Consider the investment you would make in round and hex collets in both standard and metric sizes to equal the capacity of the Jacobs chuck. The Jacobs chuck also allows long stock to extend into the spindle bore, can't do that with collets. There is another model (58B ??) that has a max range of 5/8". I don't recall what the lower limit was. Both sizes show up on Ebay from time to time. Rex the Wrench ------- From: sleykinx~xxa... Date: Thu Jul 12, 2001 1:42 am Subject: Re: Spindle drill chucks [atlas_craftsman] jerdal writes: > I had thought that the Jacobs chucks had much finer jaws, but the discussion seemed to confirm the 3/16 minimum. I had assumed that the one I saw had maybe had the jaws replaced. < The 3/4" chuck is this way. (I have one and it is well worth the $75 I paid for it). The smaller chuck will go down to nearly zero but I found the larger chuck to be handier for me. I have a jewelers lathe and a good set of collets for it that I am going to make fit the Atlas ... if ever an occasion comes up I need to or I just have too much time on my hands :) You can always make a split sleeve that fits the chuck and whatever you need to turn that is too small for the chuck. Mark it to align it with one jaw and bore it that way, then split as appropriate and chuck things up. Even more accurate than the chuck if you do it right. Regards Glenn Neff Medford, OR ------- From: Kimchecabx~xxa... Date: Thu Jul 12, 2001 1:28 am Subject: Re: Spindle drill chucks [atlas_craftsman] When I need to use a bit smaller then 3/16, I use a pin vice. This one handles bits from 1/16 down to #80. Mine is from Exacto and is originally designed for model making. Paul/KImchecab Milton,WA. ------ From: catboat15x~xxa... Date: Thu Jul 12, 2001 11:30 pm Subject: Re: Spindle drill chucks [atlas_craftsman] > I had looked at one of the jacobs chucks, and that one had coarse > teeth on... I have a Jacobs chuck that is threaded to fit the spindle of my 12 inch Atlas. Yes it will not grip below about 3/16 or so, but I use it in place of collets for work of that size, and for smaller stuff such as 1/8 inch rod I just grip a pin vice in the Jacobs and go merrily on my way. (Found a machinist's pin vise did not run concentric with the shaft, but a cheapie from American Science and Surplus runs true when the shank is gripped in the Jacobs.) John Meacham High Desert of California, Palmdale, Littlerock. ------- From: fyunchx~xxa... Date: Mon Jul 16, 2001 2:32 am Subject: Re: Spindle drill chucks [atlas_craftsman] My solution was to take a mini-chuck made for Dremel tools (range--#80 to 1/8") and to machine a new arbor for it out of 1/2" drill rod. I hold the arbor in a 1/2" collet. Runs true within .001, and I made the arbor hollow to pass through long stock up to 1/8" dia. Wendall Gates ------ NOTE TO FILE: Stuck Chuck Conversations The following conversation is the result of an all-too common problem of screw-on chucks becoming jammed on so hard (or corroded in place, or any number of causes) that they are stuck and cannot be easily removed. Despite many persons having favorite methods that worked for them (maybe just once!) each and every method has at least some risk of damaging the chuck or spindle or gears. Consequently a prudent person would try the least abusive methods first as applicable to the local situation. A similar discussion relating to a stuck Jacobs chuck turns up later in this file in April 2002. There is another discussion about stuck chucks in December 2004 that appears here as "Re: HELP!!! Frozen Chuck (I don't mean chuck roast)". Conversations on lathe repair for any brand may contain additional tips. In every case, before proceeding make sure the lathe is unplugged! ------- From: "mannyjrl" Date: Fri Jul 20, 2001 7:51 am Subject: Stuck chuck [atlas_craftsman] A few weeks ago I posted my dilema of a stuck 4-jaw chuck on my Craftsman/Atlas 12x48 spindle. I was careless not to note who suggested that I use nylon strapping around my bullgear to keep the spindle from turning as I leverage the chuck with a long bar to unscrew it from the threaded spindle nose. It worked great with hardly a strain on the bullgear assembly! Special thanks to this gentleman and to forum members who responded to my call for suggestions. mannyjrl ------- From: Jon Elson Date: Fri Jul 20, 2001 1:19 pm Subject: Re: Stuck chuck [atlas_craftsman] mannyjrl wrote: >> Special thanks to this gentleman and to forum members who responded to my call for suggestions. << That was me, at least, possibly others. Glad to know it worked. This still has the hazard of putting a LOT of stress on the set screw that holds the bull gear on the spindle, but apparently it can take it. I normally use the back gear with the direct drive pin still engaged. But, one time, I had just put a new 8" adjustable chuck on for the first time, and didn't realize how much inertia there was in the 8" chuck, and spun it onto the spindle. Having read the horror stories of broken back gear teeth, I knew quickly that It was going to take a different approach, or I'd risk the same damage. I had some stout shoulder strap material from various surplus gear, and made up an impromptu strap wrench, and it worked well for me. I think others have also suggested this method since! Jon ------- From: HUNLEY31... Date: Sun Jul 29, 2001 11:32 am Subject: Question Here is a general type question. Is it OK/safe to use a Jacob's chuck in the "live center" to hold small stock while turning? I do 'hobby' work and have found that some, no make that a lot, of my projects is too small to work with a full size chuck. Also does anyone know how small you can reduce a 1/4 HSS cutter to with success. Thanks, Hank ------- From: "Skip Evans" Date: Sun Jul 29, 2001 11:56 am Subject: Re: [atlas_craftsman] Question I assume you mean the spindle. I see no problem with it. In a lot of respects it is more accurate that a 4 jaw chuck. Skip_evans Alvin, TX http://skipevans.homestead.com ------- From: HUNLEY31... Date: Sun Jul 29, 2001 12:00 pm Subject: Re: [atlas_craftsman] Question Yea, I meant spindle, Brain cramp or dane bramage. Tnx. ------- From: sleykin... Date: Sun Jul 29, 2001 2:13 pm Subject: Re: [atlas_craftsman] Question There are Jacobs spindle chucks available that thread onto the spindle. Seems to be a compromise between collets and a 3 jaw. You can also mount a Jacobs with a straight shaft in your 4 jaw to hold small stuff. That way you can true it up with the 4 jaw once and get good repeatability for small stuff. As to how much you can grind off a 1/4 HSS cutter ...That would depend on the application and your skill at knowing when to stop :) Regards Glenn Neff Medford, OR ------- From: Jon Elson Date: Mon Jul 30, 2001 2:32 pm Subject: Re: Stiff chuck [atlas_craftsman] Nick Hull wrote: > *The first thing that I noticed was that the chuck doesn't close > smoothly and requires considerable torque on the key to move at all. > I removed it from the spindle, but I couldn't get it apart. It is an > Atlas 3 jaw scroll chuck. There are five screws in the back, which I > removed, but I couldn't figure how to separate it. There is one > large screw on the face, which I also removed. I think this screw > might be broken off, as the piece that came out is quite short. > Behind it is something that could be a pin or the rest of a broken > screw, but whatever it is, I couldn't move it easily. > Before I took it apart I would remove the jaws and clean everything, > especially the complete scroll -plate. You can clean it a bit at > a time by turning it. Yes, you push a rag into the groove at the beginning, wad it in with a screwdriver, and then follow the groove as you crank the key until the rag is brought all the way to the other end of the groove. You may have to do this several times if the innards of the chuck are really choked with chips. Make sure the screwdriver does not punch through the rag. Jon ------- From: jtaylor... Date: Mon Jul 30, 2001 11:32 am Subject: Re: Stiff chuck [atlas_craftsman] > Before I took it apart I would remove the jaws and clean everything, > especially the complete scroll -plate. You can clean it a bit at a > time by turning it. Hmmm, tried that. Even without the jaws in it, it doesn't turn easily. Jeff ------- From: fyunch... Date: Tue Jul 31, 2001 2:18 am Subject: Re: Stiff chuck I suggest a liberal application of penetrating oil (or even WD-40) to thin out the old grease. I haven't taken apart an Atlas chuck, but many kinds have a stepped plate in back which fits into the body, retaining the scroll. Look for a fine line around the periphery of the chuck. Separate the two pieces by obliquely tapping with a soft (rawhide, plastic, perhaps lead) hammer. W.C. Gates ------- From: "RON Shaw" Date: Tue Jul 31, 2001 9:49 am Subject: Re: Stiff Chuck >>The first thing that I noticed was that the chuck doesn't close smoothly and requires considerable torque on the key to move at all. I removed it from the spindle, but I couldn't get it apart. It is an Atlas 3 jaw scroll chuck. There are five screws in the back, which I removed, but I couldn't figure how to separate it.<< I had exactly this problem a couple of years ago, and one of the list members (I forget who), suggested a solution that worked perfectly for me. Back the five screws on the backing plate out part way. Tap on the screw heads (tap, not beat) with a small brass hammer or the like. The backing plate will start to separate from the body of the chuck. Back the screws out further as needed and continue tapping until the plate and body separate. The plate/body interface is an extremely close fit, so you have to kind of alternate screws so you don't get the plate cocked and jammed. Worked great for me, hope it does for you. Ron Shaw ------- From: Nick Hull Date: Tue Jul 31, 2001 9:29 am Subject: Re: Stiff chuck >Yes, you push a rag into the groove at the beginning, wad it in with a screwdriver, and then follow the groove as you crank the key until the rag is brought all the way to the other end of the groove. You may have to do this several times if the innards of the chuck are really choked with chips. Make sure the screwdriver does not punch through the rag. < I avoid rags since threads can tear out & jam the works. A toothbrush works great and I filed one end to fit the scroll groove for final cleaning. If the scroll is still stiff I would try flooding the area behind it with Kroil etc and try to flush something out before disassembling the chuck. What got in can be made to come out. ------- From: doogdoog... Date: Tue Jul 31, 2001 4:45 pm Subject: Re: Stiff chuck Aloha, before taking it apart I would put a small center punch mark on the halves so you can assemble it the same way it came apart. I always mark things so it goes back the same way it came off. To me it helps retain the accuracy when reassembled. Mahalo, Howard ------ From: Don Smith Date: Sun Aug 12, 2001 7:49 pm Subject: Proper Chuck Size? [atlas_craftsman] I just picked up a Bison 6 1/4" 3-jaw chuck on eBay, and am wondering if it may be too big for my 10" Atlas. The chuck that came with my lathe measures 4 1/4" and weighs about 7 lbs. The Bison chuck weighs in at 22 lbs. My lathe has the babbit-bearing headstock, which I plan to upgrade to Timkens as soon as I can locate an available headstock. Does anyone know how much faster the babbit bearings will wear because of the extra weight of the chuck? Would I be better off with a smaller chuck? Also, I have a 1/2 hp motor on this lathe...if I decide to use the Bison chuck, should I switch to a 3/4 hp motor? Regards, Don Smith ------- From: Jon Elson Date: Mon Aug 13, 2001 12:38 am Subject: Re: Proper Chuck Size? [atlas_craftsman] > am wondering if it may be too big for my 10" Atlas. I used a Cushman 6" chuck for years with my 10" Atlas. The spindle is the same on the 10 and 12", and I now have an 8" adjustable chuck that is VERY heavy. So, the 22 Lb chuck is no problem, I suspect my Cushman is about the same weight. > My lathe has the babbit-bearing headstock, which I plan to upgrade > to Timkens as soon as I can locate an available headstock. > Does anyone know how much faster the babbit bearings will wear because > of the extra weight of the chuck? It really makes no difference. If you check worn lathe bearings, you will see the wear is such that the spindle moves toward the back, away from the cutting forces. These forces are MUCH larger than the weight of the chuck. > Would I be better off with a smaller chuck? Also, I have a > 1/2 hp motor on this lathe...if I decide to use the > Bison chuck, should I switch to a 3/4 hp motor? No, I think I ran my 10" with a 1/3 Hp motor. The belts slipped way before the motor would stall. You don't need that much HP on the light Atlas lathes. Jon ------- From: "R and J Sport" Date: Mon Aug 13, 2001 11:00 am Subject: Re: [atlas_craftsman] Proper Chuck Size? Don: My 10" came with a Craftsman *" 4 jaw chuck that weighs about 40 pounds and it works fine! The extra weight helps smooth out the chatter. I fitted a new 6" 3-jaw to my lathe and there are no problems. Jim ------- From: "R and J Sport" Date: Mon Aug 13, 2001 11:03 am Subject: Re: [atlas_craftsman] Proper Chuck Size? My 10" came with a humongus 8" chuck and has the babbit bearing headstock. It was used by a local farmer for 10 years that way and I used it for boring barrels for re-line for 4 years and the headstock is as tight as the day it came from the factory. I did heed the factory warning and never ran it over about 1100RPM. Jim ------- Date: Mon, 27 Aug 2001 09:06:52 -0500 From: "Dana Zimmerman" Subject: RE: Jacobs chuck [atlas_craftsman] August 26, 2001 HUNLEY31x~xxaol.com wrote: >> Anybody have any experience changing the shank on a Jacob's chuck? I'm thinking of buying a couple off ebay and may have to go from a MT2 to a MT3 or if the shank is damaged change it. Is this a problem? << If the chuck is mounted to the shank by Jacobs taper, the shank is a Morse taper, and you want to save both, this can be a challenge. If you are lucky, the chuck might have a through hole from the front (jaw) area to the back (shank) area. In this case you can open the jaws, drop the shank through a hole in a support, ideally on an arbor press, and press or drive out the shank. Failing that, you have got to get a grip on the shank stronger than the JT grip, and drive a chuck wedge (steel wedge with a notch in it) between the two. The tricky part is getting a grip on the shank without converting it into scrap. In theory the grip of the Morse taper is stronger, as it has a less steep taper and more contact area, but my experience is that the chuck seems not to know this. Penetrating oil might help, I am not sure. Bad words are not proven to help, but most everyone uses them. Try to resist hammering directly on the chuck, it makes them ugly and useless pretty rapidly. Some with experience will tell you it is easy, just bash it in a drill press quill, chuck an end mill in it and attempt to mill with it. The JT will let go when you least expect it or when it can do the most damage. This is called hiring Murphy's Law as an assistant. I have a #2 JT Jacobs chuck, with no through hole, on a MT1 arbor that I would prefer had a MT2 arbor. I want to save both pieces. I hesitate to apply any heat as the arbor is hard. So far, I have not prevailed. In this case the tang has been ground off the MT end by a prior owner, so a violent grip on the tang is not an option. I too would welcome suggestions. ------- Date: Mon, 27 Aug 2001 11:37:34 EDT From: catboat15x~xxaol.com Subject: Re: Jacobs chuck > Anybody have any experience changing the shank on a Jacob's chuck? I'm > thinking of buying a couple off ebay and may have to go from a MT2 to > a MT3 or if the shank is damaged change it. Is this a problem? Jacobs sells a pair of slotted wedges to remove a chuck from a shank. Look to make sure there is not a bolt inside the jaws that holds the chuck onto the shank. That is open the jaws all the way and peer inside for a bolt or screw head. John Meacham High Desert of California, Palmdale, Littlerock. -------- Date: Mon, 27 Aug 2001 17:15:04 -0400 From: "Dick Blaney" Subject: Re: Jacobs chuck On one 1/2" chuck, I removed the JT/Mt2 arbor by opening the chuck jaws and drilling a 5/16" hole through the back of the chuck body and used a pin punch against the JT end of the arbor. Most Jacobs chuck bodies are not too hard, and drill easily. Since then, I routinely "pre-drill" a chuck body before mounting on an arbor. Dick ------- Date: Mon, 27 Aug 2001 20:51:37 EDT From: CaptonZapx~xxaol.com Subject: Re: Jacobs chuck 8/27/2001, dana.zimmermanx~xxatt.net writes: <> According to my training, you got it half right. A few years ago, I made a SET of wedges to take a chuck off of a drill motor. The trick is to make two of them just alike, and drive them together so that one slides up the ramp of the other, and the outside faces remain parallel with each other, thus exerting equal force on the two shoulders involved. A small angle (5 to 10 deg) increases the force, but lessens the 'stroke', so a spacer, or spacers of differing thicknesses can be made to make the wedges work in a variety of situations. It's nice if they are hardened, but mild steel will work if lubed with moly grease. Take two pieces of 1/2 x 2 inch steel bar three or four inches long, drill a hole about an inch from one end, big enough to clear the shank, (or the radius on the shank , if there is one) between the the chuck and holder. Take a grinder and grind a taper on the 2 inch flat, from one end of each piece back to almost the middle of each hole, keepin it flat as possible. Take the pieces and smooth them up on a disc sander, keeping them as similar as possible. clamp them in a vise, and saw out the metal from the thin end down to the hole on both sides of the hole, so that they will slip between the chuck and holder. Grease them up, and put one on one side, and one on the other, putting the sloped faces together. Take two hammers, and bucking with one, smack the other wedge toward the first. A few smacks should do it. FWIW CZ ------- Date: Mon, 27 Aug 2001 23:01:20 -0500 From: "M K (Skip)Campbell Jr." Subject: Re: Jacobs chuck > Not if you go get a set of wedges for removing them. They are 2 "U" > shaped wedges that go between the shaft and chuck and split it apart. I have the wedges (4 different sizes) and it is my experience that they are effective less than 1 out of 3 or 4 times. If you buy a new chuck and different arbors to use on it, you can make sure you don't put them on too tight to remove. If you buy a chuck that already has an arbor, you may or may not be able to remove it. The "drill a hole and punch out with hydraulic press" method works on most difficult arbors but I have one that won't budge on a 20 ton press even with help from the acetylene torch. Good luck. Skip Campbell Ft. Worth, TEXAS ------- NOTE TO FILE: The following discussion is titled "Lapping" but was kept here in the Chucks General file as it very specifically relates to the possible lapping of chuck parts. If you want to see much more on the topic of lapping, see the Lapping and Reaming file on my site. Yes they are talking about Sherline chucks but the principle is the same for all makes. ------- From: buchnerb... Date: Mon Aug 6, 2001 1:27 pm Subject: Lapping [sherline group] I'm waiting for my new Sherline Lathe and Mill set to be delivered next Monday. I was reading the back posts on the board and ran across one where gentleman said he took his 3 jaw chuck apart and lapped the surfaces to make it work more smoothly. How would you do that? Squirt the compound into the chuck and work the chuck around to grind the parts against each other? As you can tell I am new at some of this. Also are there any recommended things I should do to set up my equipment and make sure it is working correctly? Thanks, Bruce Buchner ------- From: n2562001... Date: Mon Aug 6, 2001 5:16 pm Subject: Re: Lapping [sherline group] Bruce, if your chuck is hard to operate I would contact the factory. I am sure they would prefer you have a workable chuck as opposed to one you have to work on. I would square everything up per the instructions and see what happens. The gibbs seem to be a little tight out of the box so you may have to loosen them for smooth operation. One of the weak areas of any $500.00 lathe seems to be the tail stock alignment. I would check that closely with two center points in all directions and if it's a problem I would consider the chuck centering option. Also if you are new to machining I would suggest you work with brass or 12L14 steel until you get the hang of the machines. That way you will know what type of finish is possible. Some of the cold roll steel can be a bear to deal with if you're not used to it. Jerry Kieffer ------- From: "Marcus & Eva" Date: Mon Aug 6, 2001 10:53 pm Subject: Re: Lapping [sherline group, but applies to any brand] Hi Bruce: I would definitely NOT fill 'er up with lapping compound and grind the bits together. You will likely destroy the chuck in moments. The chuck jaws are fitted at the factory to "tenths". If your chuck is not performing properly, send it back to Sherline. They have one of the best service policies in the business. Cheers Marcus ------- From: "Yasmiin Davis" Date: Tue Aug 7, 2001 8:58 am Subject: RE: Lapping [sherline group] I actually do this on a chuck that isn't moving freely after I am sure I have cleaned every bit of grit and dirt out of is. However, I use a metal polishing compounds that would take a very long time to affect the accuracy of the chuck as the grit is very fine. For instance I use 1 micron suspended in a water based solution. I have this in a number of grits from 10 microns down to .5 microns. Yasmiin ------- From: "Yasmiin Davis" Date: Tue Aug 7, 2001 10:28 am Subject: RE: Lapping [sherline group] I buy mine from a supply house that specializes in abrasives but I believe you can find them in a catalog for a large Jewelers Supply. Here is an abrasives house: http://www.abrasive-tech.com/ or http://shorinternational.com/contents.htm is a large jewelers supply house. Regards, Yasmiin ------- From: "Marcus & Eva" Date: Tue Aug 7, 2001 11:26 am Subject: Re: Lapping [sherline group] Hi Yasmiin: I can see, from your comments, and from comments that you have made in the past, that you are an experienced hand at restoring old machinery, and know what you're doing. I am concerned, though, that someone without your experience, might just grab the first can of Clover compound he sees in an automotive joint and "fill 'er up". You can just imagine the hash when the jaws pick up and he uses a ball-pein hammer to bash them free!!! Cheers Marcus ------- From: "Yasmiin Davis" Date: Tue Aug 7, 2001 2:17 pm Subject: RE: Lapping [sherline group] Well yes a little knowledge is a dangerous thing. I have made, and make, my share of mistakes in a year. It's just that lapping properly done makes many rather stubborn tools to use into reliable tools that are a pleasure to use. Adjustable parallels being one example. One can take a non-Starrett set and make them work beautifully with a little work. The key to this as you point out is patience -- never start with something that will take a lot off something at once. Use the conservative approach and take off just a little bit, try it and then take off a little bit more. I also caution people in the use of diamond compounds as they can imbed them selves in the surface and continue to cut after you think you are done. This is one reason I use aluminum oxide compounds when working with cast iron, etc. And always clean the surface very well after lapping. Preferably disassemble the item so that you can make sure all surface are free of lapping compound before beginning to use the tool. Regards, Yasmiin ------- Date: Mon, 15 Oct 2001 00:04:31 -0400 From: Cathy & George Dunham Subject: Re: Inaccurate chucks [SHERLINE BUT IT IS ALSO GENERAL INFO] Accurate I take it as no runout in this case. All chucks, collets etc. will have some runout. The former to a greater degree than the latter. With proper planning you will find a given series of steps can be devised to create several type parts in one chucking. This results in a part in truth despite the chuck runout. The real problem develops when the part needs to be re-mounted to complete. The following are some methods to maintain truth when re-mounting. 1. Usually a collet will give sufficient truth for most work. 2. A 4 jaw independent chuck can set up to very tight tolerance if you take proper care. 3. A wax chuck if you are doing tiny parts. 4. Turning between centers. (Turn the Headstock center true prior to mounting) 5. Faceplate for wheels/disks etc. (face off prior to mounting) Who made your drills? Really accurate jacobs type chucks are rather expensive but can be found on Ebay, flea markets etc. To check out your Jacobs chuck: 1. Turn a 1/4" piece of brass or mild steel 1 1/2" long such that it is true & 1/8"dia. 2. Part off. 3. Chuck it in the Jacobs chuck. It should not visibly wobble. 4. Use a DTI to check the runout at the jaws and at the end. <.003 is probably OK. You did not state if your machine is new. If so contact Sherline for a replacement drill chuck if you feel the error is unacceptable. I hope this helps. Regards George Dunham NAWCC 0135625, AWI 31252 Clock Repair at Antiques & Uniques 152 Route 171 S. Woodstock, CT 06281 (860) 928-6020 ------- Date: Mon, 15 Oct 2001 13:12:41 -0500 From: "Bad Brad" Subject: Drill chucks and centering a four jaw ind. Drill chucks have the potential for chips to work their way into the area where the jaws rest inside the body of the chuck. If you place drill bits with debris on them into the chucks or don't clear out chips and debris from the chuck, the result will be run-out. If you use compressed air to blow chips out the result will be worse because doing so forces loose chips under the jaw seats. Once under the jaw seat when the jaws are tightend the chip smashes and sticks making it impossible to clean out without disassembly. Fortunately most drill chucks can be carefully pressed apart for cleaning. Some require that the jaws be placed at a certain position or damage to the threads will be the result. Over tightening. If the small lathe chucks are over tightened the result can be run-out. If the part moves when turning a lighter cut may be needed instead of more clamping pressure. I hope this helps determine the cause of your problems. For square stock being centered in a four ind. jaw chuck; on a faced off (The part doesn't need to be centered to face.) end, scribe lines from corner to corner & chuck the part. Bring the tail stock center close to -- but not touching -- the part in the chuck. PLEASE NOTE, this method assumes your tailstock is centered properly and the part you are working with is square too. Move jaws until the point at which the lines crossing stays lined up with the tailstock center point. Tip: Do not over-tighten the jaws while trying to center the part. Bring the tension up slowly as you reach center. An indicator can be used on the corners to double check your work. BB ------- Date: Mon, 29 Oct 2001 15:10:42 -0800 From: "Craig Libuse" Subject: Re: live center chucks? [sherline] Keith Yundt wrote: >>> Is there a way to hold a long and thin shaft by holding it with the headstock chuck and the tailstock end, without using a steady rest or standard live center? Is there such a thing as a live center chuck? I was just recently trying to machine a train axle down but I couldn't get the steady rest close enough to the end I was trying to machine because of the wheels, so I got a lot of chatter. I was thinking that if you could use a standard chuck in the tailstock with a bearing like a live center, that would be very handy, but I wasn't sure if it already existed or if there is a simpler way. Thanks, Keith <<< Dear Keith: You could drill a hole in a piece of bronze to fit your axle and hold it in the tailstock chuck. Lube it well and it should support the free end of the axle while you turn it by holding the other end in a drill chuck at the headstock end. This is similar to the 1/8" armature support we used to make to support the free end of a motor armature while truing it up. Craig Libuse Sherline ------- Date: Mon, 29 Oct 2001 15:32:43 -0800 From: "Yasmiin Davis" Subject: RE: live center chucks? Yes there are such thinks as tailstock live chucks. They are rather expensive but they do exist. I an not too sure of the shape of what you are trying to hold but there are also live centers with a number of different adapters like a bull nose etc. I believe that there is one that might fit your needs. Especially if you were to machine something that was the shape you are trying to hold ( a shaft ) on one end and the other being the shape of the live center adapter. A way of doing this would be to drill a hole the size of the shaft in one end of a short piece of stochk and then trun it around and use a center drill on the other end. This would then slip over the shaft and accept the live center in the other end. Holdind the piece of stock in a collet would improve concentricity between the two ends. Yasmiin ------- Date: Thu, 01 Nov 2001 20:02:40 -0500 From: Reginald Barron Subject: Re: Re: live center chucks? > Now, if you want to do things like machine down wheel or driver flanges > or work on the exposed sides of wheels, that takes another device. If > you want a description of how to make that device, let me know and I > will dig it out, if luck is with me. I think it was in a '50s or '60s > Model Railroader article. If it was in an RMC article, it would take > more time. I don't have them indexed. Tom Bank The article was by the late Carl Traub. It was late 60s or early 70s in MR. There is an online RR mag index. Also MR sells photocopies. Traub took a hunk of brass rod with a diameter a little larger than the wheels, faced it down so it would fit between the wheels, bored a hole the diameter of the axle, cut it in half, drilled and tapped so the two halfs could be bolted together over the axle, then the assembly could be held in a 3 or 4 jaw chuck without removing the wheels. For wheelsets with a gear, a section would need to be bored out larger. Reg Barron ------- Date: Fri, 02 Nov 2001 18:13:10 -0500 From: Tom Bank Subject: Re: live center chucks? > For those interested in checking out the Carl Traub article on building > a Model Railroad locomotive driver or other axle-wheel-gear related > lathe collet, I finally dug it out and scanned it. It is in the > Sherline group files in a folder identified as Traub's Wheel Collet. Reginald, Right you are! Thank you much. When I looked in my database with a "Find" on Author: Traub, it popped right up. "Driver Collet for Lathe Work," Model Railroader, July '72, page 55. If there is interest, I could scan the page(s) involved -- unless someone objects on copyright grounds. Tom ------- Note to File: CENTERING STOCK IN A 4-JAW CHUCK. There is a short and very helpful discussion in Oct/Nov 2003 in the file here called Indicating and Measuring, including an updated procedure by Ron, further to his advice in the next message. ------- Date: Sun, 13 Jan 2002 07:07:02 -0800 From: Ronald Thibault Subject: Re: Hello, new to group. Have 101.27440 [HOW TO CENTRE IN 4-JAW] >Seems to run pretty smoothly and a drill rod chucked in the 4 jaw >runs true near the jaws and at the end, at least as good as I can >center it. Not having a good 3 jaw is going to force me to learn to >center things more quickly! I go from 1/2 a thou to messed up in no time! When you go to chuck the piece in the 4-jaw, do it like this: 1. Roughly position it using the circles cut in the chuck face. 2. Put a piece of toolbit in the holder, with #1 jaw horizontal and facing bit, run it in until it touches workpiece, Zero dial. 3. Back the toolbit off (count revs of dial), rotate until #3 jaw faces toolbit, run in the toolbit, and record difference. 4. Rotate whichever jaw was furthest away to face tool, run dial in to half the distance between measurements. 5. Move jaws so the workpiece just touches tool, tighten lightly, then back off just a touch. This allows the workpiece to slide while you are doing the same to jaws 2 & 4. 6. Repeat above for jaws 2 & 4. 7. Run through the above one more time, as dialing in 2 & 4 may have shifted workpiece alignment in for 1 & 3. 8. Mount a dial indicator on the crossslide, with the zero point to the right (this means that as the piece comes closer to the dial, the measurement goes up, this makes it a bit more intuitive when measuring the error). Reset the dial to zero, after each adjustment, with jaw 1 facing dial. Use the crossslide to bring the needle to zero. 7. Using the dial indicator, measure the misalignment between jaws 1 & 3. Adjust the jaws to zero difference. A. The traditional way is to loosen one jaw and then use the other jaw to shift the piece, then tighten them. This works well, but can lead to over-correcting. B. The best way I have heard to do this is to have a second chuck key, and use both at the same time to rotate both opposing jaws, just like the workpiece was on a mill table! 8. Dial in jaws 1 and 3 then 2 and 4. 9. Measure all four jaw points, to see if zero run out, if not repeat above. Ron Thibault Warrenville, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------- NOTE TO FILE: The following thread "Re: Chucks" is mainly about the Sherline chucks, but there is some very good information within for owners of other brands. Also, many new lathe owners do not know about or appreciate the added versatility of having supplemental aluminum jaws that can be machined to custom fit particular jobs. The Taig brand 3-jaw comes with interchangeable aluminum jaws that can be machined and remachined to fit different jobs. They are not cheap enough to be considered routinely disposible; so the wise machinist will buy several extra sets of these relatively inexpensive blank jaws and customize each to important jobs as required by circumstances. And save them for future jobs. Users of other brands will see the possibility of using supplemental jaws if available for their own brand of chucks. They might also want to make or purchase an adapter to mount Taig or Sherline chucks on their own big lathes. Please think outside your brand, and outside these particular brands. ------- Date: Tue, 29 Jan 2002 21:21:08 -0800 From: "Brad Butler" Subject: Re: Chucks [sherline] Dan Kaschner Tuesday, January 29, 2002 wrote: >>A quick question about chucks. I have a 3 jaw chuck that came with the 4400 lathe package. Are any 'tuning' operations recommended? I am actually very pleased with the performance right out of the box, but I have read on other forums / web sites about users of other brand lathes that needed to 'square' up the jaws by taking off a few thousandths, etc. Would this help any? Is it needed? Is it even recommended? Related to this, are the jaws free machining or hardened? I looked at the chuck blanks on the Sherline web site and they indicated that the blank is free machining, but may be hardened.. Are the chucks and / or the chuck jaws hardened? << All that I would recommend is working in the jaws and backplate spiral with some fine lapping compound. This will really smooth out the operation of the chuck. As far as taking a light cut off of the jaws I would not recommend it. The accuracy of a 3 jaw chuck is not only affected by the quality of the jaws but the accuracy of the spiral cut into the back plate. You could take a light cut off the jaws so that it would be more accurate at a set diameter but it would only be that accurate at that one diameter. If you put a larger part in the chuck then you are using a different part of the backplate spiral and any deviations would cause inaccuracy. Your best bet is to only use the 3 jaw when you only need it centered around .003 to .005, any better requires a independent 4 jaw or a collet. P.S. the inaccuracy of a 3 jaw does not reflect the quality of the Sherline chuck. Ever very expensive 3 jaw chucks will exhibit this same range of accuracy. That is simply the nature of the beast. Brad Butler ------- Date: Tue, 29 Jan 2002 22:30:08 -0500 From: "Marshall Pharoah" Subject: Re: Chucks I concur, except that on a larger lathe a chuck with the Set-Tru or Adjust-Tru would help. I don't know that there would be much of a market for one for the Sherline. Still, the intriguing possibility of turning a false spindle to be gripped in the 4-jaw and mount the 3-jaw would more or less synthesize the capability. For one-off's though, the 4 jaw is the ticket. I have a 5-C collet chuck with the adjust tru feature, and I'd prefer to not mess with it too often. Marshall ------- Date: Wed, 30 Jan 2002 08:49:58 -0800 From: "Craig Libuse" Subject: Re: Chucks Subject: RE: Chucks Unless you are careful, though, you will be improving centering at the expense of alignment. Normally, the sources of axial misalignment -- where you can get the workpiece centred at the chuck but the free end wobbles or vice versa -- are the fit of the chuck to the spindle nose, and of the workpiece in the chuck jaws. Mounting the 3-jaw on a false spindle gripped in the 4-jaw doubles the length of this list. It may be possible to reduce this effect somewhat by ensuring that the backplate of the 3-Jaw rests on the top ends of the jaws of the 4-Jaw. Personally, I wouldn't bother *making* a false spindle, since spare part 40230 (an entire spindle) only costs $40! Although I am a little confused, as the parts list says this is made of aluminum, but I was sure that mine was made of steel... Kevin Martin ------- Date: Wed, 30 Jan 2002 13:46:58 -0800 From: "Craig Libuse" Subject: Re: Chucks >> but I was sure that mine was made of steel... << Kevin, my current parts list shows an "S" in the materials column for P/N 40230 (spindle). We publish a number of listings both in print and on the web. If there is a current one that is out there with incorrect information, please let me know which one it is and I will see that it is changed. The spindle is definitely steel, not aluminum. Craig Libuse Sherline Products ------- Date: Thu, 31 Jan 2002 19:36:10 -0500 From: "Daniel J. Statman" Subject: Re: Chucks Dan, I agree with your intention of buying a separate chuck and ordering it with the soft-jaws from Sherline. I have 3 chucks and about 9 sets of jaws. I would order 3 sets of soft jaws for your extra chuck if you plan to do a lot of specialized holding fixtures. This way you never have to send the chuck back if you need a second or third set of jaws. I have also ordered soft-jaws and not sent the chucks back. If you mic the jaw slot's thickness on the chuck the people at Sherline will try to match your size and send you the jaws. If they're slightly too wide, you can file them down. Since you will be machining the jaws in situ, they will run true even if they do not fit perfectly. I find the soft-jaws to be extremely valuable for my work. Daniel J. Statman, Statman Designs www.statmandesigns.com ------- Date: Fri, 01 Feb 2002 08:50:07 -0800 From: Mark Fraser Subject: Chuck Jaws Like many others (who may remain silent) I allowed a jaw of the spinning chuck to contact the carriage, messing up the "teeth" that engage the scroll. Jaws are made in sets of 3 and matched to the chuck. Jaws are ALSO case-hardened, and "tuned" before shipping the chuck. Ultra secret method passed to me by a Sherline person included closing the jaws on a chunk of v-belt near the BOTTOM of the jaws, then running a dremel mounted to the carriage into the opening with the spindle running, so as to just barely let the 1/8 inch stone (or smaller dia) contact the working jaw surfaces. Cut too much and you'll go thru the case hardening, and you'll have semi-soft jaws. I took their word for the complexity, and had them do the re-jaw. Good value. But when I got a larger lathe with badly bell-mouthed jaws, I used the same technique - great results. Hmmmm. I think the Taig chuck I bought (locally when I was in a hurry) for my Sherline rotary table needs some work, too... mark ------- Date: Fri, 26 Apr 2002 17:35:01 -0500 From: "Fred & Liz Lusen" Subject: Stuck Jacobs Chuck I have a Jacobs 6A chuck on a MT to Jacobs adapter. I cannot remove it by the usual means. Since this has crossed everyone's plate at one time or another I am hoping that someone will have an idea. OTHER THEN BEATING THE #%$$!!?? TO DEATH. Thanks, Fred Lusen ------- Date: Fri, 26 Apr 2002 15:48:05 -0700 From: "Bob May" Subject: Re: Stuck Jacobs Chuck Chill the inside and heat the outside. That tends to work with me rather well. For one, I used to dread putting the front end of a chevy engine back together but then I started heating the cam sprocket and the dampener and they go on by simple pushing now. Once the metal cools, the item is on for good! Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Fri, 26 Apr 2002 23:11:23 EDT From: AtlasTV48x~xxaol.com Subject: Stuck Chuck and the big chill I have a CO2 fire extinguisher that I put a small nozzel on when I really need to get things cold. I've used it for installing bearings, assembling fuel injectors, removing frozen pistons from cylinders, removing warts... Good Luck, Dave ------- Date: Fri, 26 Apr 2002 22:09:04 -0500 From: "Richard Meredith" Subject: Re: Stuck Jacobs Chuck I know the feeling. If you open most Jacobs chucks all the way, there is usually a small hole in the bottom of the chuck that leads to the top of the Jacobs taper spud. If you have a piece of pipe, or even the jaws of a vise that will clear the Morse taper, and bare against the back of the Jacobs chuck; then you usually can take a pin punch and sharply tap the end of the Jacobs taper through the hole in chuck. A couple of good hard hammer hits on the pin punch will usually remove any chuck. Good Luck, Rich Meredith ------- Date: Sat, 27 Apr 2002 08:09:56 -0500 From: "Fred & Liz Lusen" Subject: Re: Stuck Jacobs Chuck Rich: This was the second thing I tried. It did not budge. If I had hit it any harder I would have bent the pin punch. The diameter of the hole is not that big. That is what precipitated the "OTHER THEN BEATING THE #%$$!!?? TO DEATH". Fred ------- Date: Sat, 27 Apr 2002 11:31:07 EDT From: CaptonZapx~xxaol.com Subject: Re: Stuck Jacobs Chuck removal Well, when all else fails, get some removing tapers. MSC may list them in the catalog, or you may have to call the customer service number and get Jacobs number from them. CZ ------- Date: Sat, 27 Apr 2002 16:26:12 -0000 From: "thepistolsmith" Subject: Det. Cord substitute I once had a stuck chuck back that defied every possible attempt to loosen it. Finally, in absolute desperation, I poked the funnel mouth of a small carbon dioxide fire extinguisher into a small funnel that I placed in the spindle mouth. One long zap and the chuck back virtually fell off the spindle threads. Then I greased the spindle bore to prevent rust forming. JGL ------- Date: Sat, 27 Apr 2002 13:26:32 -0700 From: "Bob May" Subject: Re: Stuck Jacobs Chuck Throw it in the freezer for the night and pull it out and warm with the propane torch for a moment. Don't get the stuff too hot and you won't affect the springs. Also, the gas stove is a good place to heat things if you have gas. The temp differental will make things go pretty quick. Note that you do want to keep the shaft cool. Another thing to do while doing this is to knock the chuck sideways gently while pressing it off. The surest way to get a chuck loose is to put it in the drill press and try to do some milling with it. That's guaranteed to loosen any chuck, especially if the work is over $100 in value. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Sat, 27 Apr 2002 18:28:19 -0700 From: "Gregory Bowne" Subject: Re: Stuck Jacobs Chuck I had the same problem with an old Jacobs No. 34 attached to a #2 MT Arbor. What I had done is used the wedges to pull the taper out of the chuck as far as it would go, then I had a portion of the arbor cut off. I used a good sized easy out to remove the remaining taper core easily. After that was out, I had the internal Jacobs taper cleaned up with an appropriate reamer. It appeared that the inside taper had galled when the former owner had put it on the arbor. I also replaced the bearings and the jaws before it went back on my Lathe. I can hold a max of +/- .003" with this chuck. I have also used this chuck on my big mills, and the Bridgeport with the same results. Thanks, Gregory Bowne Atlas 10F Sears Dunlap Modelmakers lathe 109.0703 ------- Date: Sun, 18 Aug 2002 22:12:04 -0600 From: Steve K Subject: Re: Advice Needed For Removing A Stuck Chuck! The proverbial "get a bigger hammer" sometimes works by beating the crap out of the chuck, , but before you do you might try these options. The bottom two methods run the risk of destroying the chuck but hey, it will be off ... 1. SOAK the spindle with solvent for up to a week or so.. use KROIL oil, PB Blaster, even wd-40. Anything you can find in the local hardware store. YOu may want to tie a plastic bag around the chuck/spindle to keep the solvent in place. 2. Place a piece of bar stock in the chuck of around 12" or so such that the bar extends over (past) the back way. Now put a block of wood over the back way (You want to protect the ways..) 3. Position the bar so it will travel (rotate) as far as possible -- 180 degrees or more. Put the bar over the front way, put the lathe motor in reverse and hit the power switch. WHAM, the bar stock will hit the block on the back ways and that may jar the chuck lose. You need to be careful.. as soon as you hit the switch, hit is again to turn it off so the chuck does not unscrew and fly off the spindle. What you are trying to do is "shock" the chuck off. A hard impact does wonders, particularly if you have soaked the spindle before. The motor will provide a bigger shock than you can get with trying to lock the back gears and hitting a bar with a hammer. And you don't have to lock the back gear. Second option: 1. Soak as before. 2. Get a supply of dry ice and a propane torch. 3. Play the torch around the chuck, staying somewhat away from the spindle. You want the chuck fairly hot --not glowing, but too hot to touch. (YOu will heat the spindle a little bit, no matter what you do). 4. Hold the dry ice to the spindle... in fact, get a bunch of large chips and shove them inside the morse taper. The dry ice will shrink the spindle, often enough to loosen the threads between the chuck and spindle. Third option: Try to remove the chuck from its back plate. It is the back plate that is screwed on.. so by removing the chuck, you sometimes can get easier access to the back plate and you can force it off. Replacing a backplate is cheaper than replacing the whole chuck. Fourth Option: Machine the chuck off. Don't laugh.. I have seen this done once. NOTHING could get this one chuck off, so we literally took a carbide bit and just shaved the whole chuck down until there was nothing left. We took the jaws out of course and the chuck body was not hardened. No chuck left in the end, but the spindle was not damaged either. Stuck chucks are indicative of chips in the thread or a backplate not machined properly to the spindle register and shoulder. Even 30 years of dried gunk can be dissolved, so be patient when soaking the spindle/chuck. As the other poster mentioned, you can of course remove the entire spindle assembly and then soak the whole thing is a tub of solvent.... Finally, there are other ways to hold the spindle tight without using hte back gear. Basically, it involves an expanding "plug" that fits into the outboard end of the spindle. As you tighten the nut/bolt, it expands the plug inside the spindle. With the plug tight inside, you can put a BIG wrench on the outboard nut (this locks the spindle) and then whale away on the chuck end as you have been doing. Again, this saves the bull and back gears... Good luck.. ------- Date: Mon, 19 Aug 2002 07:04:42 -0700 From: Jay & Anne Greer Subject: Re: Advice Needed For Removing A Stuck Chuck! Hi Jerry: Looks like you have one hell of a problem!! Here is what worked for us with a frozen piston in the diesel engine on a boat I crewed on years ago. We had ended up in Papaete Tahiti with a seized engine. The beer was great at Quinn's, the local watering spot, but engine service was zip. So, after a few drinks and a bit of thought, we went down to the local brewery, "Hinanno" and got a load of dry ice. After gently heating the block around the frozen piston with a torch, we packed the underside of the slug with the dry ice and drank a another Hinanno. A chunk of wood on the piston head and a few taps with a hammer and that frozen sucker dropped right out! We honed the cylinder and sanded the piston a bit and stuck the engine back together. We made it back to Hawaii and then to California without mishap. Voila, I think that sucker may still be running! Perhaps this same technique might be worth a try with your problem. Of course you will need to have the lathe free of mountings and with much gear as can be removed, like the cross feed and tail stock. I would set it on end so the threads can be filled with the best penetrating oil you can find. After an over night soak, I would heat the chuck very slowly with a propane torch and then fill the hollow spindle shaft with dry ice. A cork on one end might be called for here. With the back gear lever engaged to lock the shaft and also a wood workers wood jawed clamp on the gear train end and a chuck key or matching square or hex rod in the chuck spindle I would gently tap the key with a lead or dead blow hammer to unwind the chuck. This might save you from losing the spindle. If not, Clausing can most likely supply you with a new one. If you choose to try this, I would really be interested in knowing how you come out with it. I wish you good fortune no matter how you choose to approach the solution! Cheers, Jay Greer/Common Sense Boat & Tool Co. Inc. ------- Date: Mon, 19 Aug 2002 16:51:09 -0400 From: meycanadax~xxjuno.com Subject: Re: Advice Needed For Removing A Stuck Chuck! I'm now the proud (and relieved) owner of a newly freed 6" stuck chuck. Both lathe and chuck are doing fine. Thanks to everyone who gave all the great suggestion. I've saved the suggestions and may put them all together to have them in the file section of the group for others who may have this problem in the future. For those interested in my adventure; the chuck and spindle had already been soaked in WD40. The motor is not hooked up yet as I'm stripping the lathe apart and so couldn't be used. The Allen key on a 2' wrench bent and the wooden stick broke. I was going to make an ice bar, in a length of 3/4" copper water pipe, to cool the inside of the spindle while heating the chuck, but I'm good with a brazing torch, so with some very precise heating I thought I might not need the ice. Now for the secret weapon, in a truly Canadian way, I used an old hockey stick to turn the chuck while heating the back of the chuck. Sure enough it worked. I thought about using an axe handle to get a hard enough wood, but you use whatever's handy! Thanks again for everyone's help, Jeff Hammer ------- Date: Mon, 19 Aug 2002 22:36:18 -0000 From: "n5kzw" Subject: Re: Advice Needed For Removing A Stuck Chuck! Jeff, I'm glad that you were able to get the chuck off. One accessory that I made for my 6" Atlas (Craftsman) was a spindle wrench. The spindle on the 6" lathe has a collar at the end of the register that is always visible with the chuck installed. I took two 20" pieces of 2"x1/8" steel and set them edge to edge and used some scrap steel to hinge the pieces at one end (after cutting a radius to let the pieces swing). I then clamped the other end together with a 1/8" spacer between the edges. I then milled a hole a few inches in from the hinged end that was the same diameter as the collar on the spindle, and centered on the joint between the two edges. I also had to drill a hole on the joint line to clear the index pin. The end result is a big nut cracker that can slip behind the chuck to clamp on the spindle collar while I free the chuck with a strap wrench or a hammer. I don't know if the 12" Atlas spindle has the same collar, but I've found it a useful accessory. BTW, I made the wrench after I broke the bull gear trying to release the chuck with the back gear engaged. Regards, Ed Bailen ------- Date: Mon, 19 Aug 2002 15:50:17 -0700 From: Frank Evan Perdicaro Subject: Stuck chuck: late to the party The chuck is already off, but I have an idea or two. This issue comes up so often, it might be worth a place in the archives. The same problem as Lautard mentioned in TMBR happened to me. The chuck was not on tight, and I turned on the power. Wow was it stuck. I got mine off, but not before I thought about making up a chuck wrench. Take a piece of 5/8 or 3/4 aluminum plate about 3 or 4 inches in diameter, and bore a 1/2 hole in the center. Put it in the chuck, and mark where the jaws meet the outer diameter. Take it off, and mill, cut, file, or route large notches so the wrench can grip the jaws of the chuck. Then cut a 1/8" deep 1" wide slot across the face, so as to let a 3' long piece of 1" square stock hang stick out of the chuck. Drill the square stock and tap the wrench for 3 half inch bolts. Bolt it up, and snug the jaws down in the slots. Run a piece of threaded rod through the spindle, and add nuts so the wrench will not fly off the chuck/spindle assembly. Hand tighten. This assembly will hold the chuck, but how to hold the spindle? Do not use the back gears, or the index pin. Both are easy to break. One lister already explained how to do it. Make up a cam-action wrench to grip the spindle behind the chuck. The wrench needs to be thin, and custom formed. I suggest 1/4" leaf spring stock. Cut it to fit around the spindle, and to accept a link in the back. (The wrench has three parts: two identical sides, and a link. Total thickness is 1/4".) Then on the front, braze on a pair of sockets to it can be gripped by a large C clamp. Harden, then temper. Thus to remove a stuck chuck, clamp the spindle, chuck up the wrench, and have at it. A dead-blow hammer might be a help, too. ------- Date: Wed, 25 Sep 2002 15:19:44 +0100 From: Steve Blackmore Subject: Re: Chuck seized On Wed, 25 Sep 2002 12:05:01 -0000, you wrote: >One thing I was surprised with, was after about 6 months of not >having used the lathe, the chuck seized. I had to remove it from the >lathe, remove the retaining clip, place the back of the chuck on a >small block of wood, and then give the wood a few firm strikes with a >hammer to dismantle it. >What had happened was I used auto wheel bearing grease at some stage >as a lube for the internals of the chuck, and the grease had hardened >causing it to seize. >I've fixed the problem now - used a white lithium bicycle grease for >the scroll and air tool oil for where the jaws slide. >Any ideas for the best stuff to use inside the chuck? Not grease - it attracts swarf. Some of the dry film lubricants based on Lithium, Teflon, Graphite, etc. are good. Or just plain old oil, lightly applied of course, otherwise you won't like the vertical stripe down you and the wall when you spin it up ;) Steve Blackmore ------- Date: Wed, 25 Sep 2002 13:18:14 -0400 From: Paul Anderson Subject: Re: Chuck seized > Any ideas for the best stuff to use inside the chuck? I'm not sure I would use grease at all. I'd be concerned about the grease grabbing swarf, and damaging the scroll. I generally prefer to use a 30 weight non-detergent oil, like Shell Telus. ------- Date: Wed, 6 Nov 2002 09:09:59 -0800 From: John Sandhagen Subject: Chuck weight The chuck should be appropriate to the item being turned. Big Item, Big chuck. When I was turning a 6" dia x 36" long round of steel, the last thing on my mind was the weight of the chuck (the blank started out about 300 lbs). As long as the jaws don't hit the bed you should be OK. I am guessing, but think the Polish and Chinese chucks weigh more because it's cheaper to over build than to engineer as Buck and others have done. This applies to 12 x 36 only since I've read about the Dunlop and AA's weak spindle. FWIW John Sandhagen the Boneyard 524 E Bishop Pl. Claremont, CA 91711 1-909-869-3550 1-909-626-2796 ------- Date: Sun, 24 Nov 2002 18:21:59 -0500 From: David Beierl Subject: Re: lathe chuck ? At 05:11 PM 11/24/2002, renaissanceman04002 wrote: >model 99 TM 2075 that did not come with a lathe chuck. Any sugestions >about which type of chuck (3 or 4 jaw)would be best for a beginner. I A four-jaw will chuck anything within reason, can do heavy work without destroying its accuracy, and can center work as close as you're willing to spend the time to do. But you have to spend the time, every time. A three jaw can only chuck round or hex stock, is comparatively delicate if you want to keep the accuracy, has a built-in centering inaccuracy that may be different at different diameters. But all you have to do to chuck up your work is to turn the key. They're both very useful. If you can only afford one, I would make it a four-jaw. David Beierl -- Providence RI USA Atlas 618 6"/3/index.html" lathe ca. 1941 ------- Date: Sun, 24 Nov 2002 20:06:11 -0500 From: Ronald Thibault Subject: Re: lathe chuck ? You really need both a 4 and 3-jaw chuck. If you can only afford one, get a 4-jaw, as they are the most versatile. I have a 6" 3-jaw, a 6" 4-jaw, and an 8" 4-jaw. I'm going to get a 4" 3-jaw in the near future. A 4-jaw will hold just about anything that can be held in a chuck, but getting an item centered can be a pain (you have to adjust each jaw separately) (there are techniques to follow that improve the process). A 3-jaw (most are self centering) is great for round, and hex shaped objects (most common), but not much use for square or odd shaped ones. The big advantage is that within their accuracy (0.003" typ) they are quick, just stick in the object and close the jaws, which close in sync. If however, you need to get that piece centered in better than 0.003", you need the 4-jaw. Bison Chucks are the best accuracy for the price (Polish imports, and generally 0.001" accuracy for the 3-jaws), most of the other discount chucks are Chinese and 0.003". Be careful with a used chuck, especially 3-jaws as you do not know how old they are (and how worn), or how well they were treated. Ron Thibault Warrenville, SC USA http://personal.atl.bellsouth.net/t/h/thib9564/ ------- Date: Thu, 19 Dec 2002 09:09:10 -0500 From: "Tracy Atkinson" Subject: Re: Digest Number 982 - dial indicator [CENTERING 4-JAW] About using the dial indicator two hints: After you have eyed the four-jaw for approximate center, spin the lathe slowly and approach it with a pencil very slowly. This will make a mark on the circumference which will tell you which direction it is running out. Invest in a second Allen wrench - one for the front and one for the back will ease the chore greatly. Tracy Atkinson ------- Date: Tue, 21 Jan 2003 05:51:52 -0600 From: "Randy Pedersen" Subject: Re: Jacobs Headstock Chuck [ATLAS GROUP] Ron: There is no adapter for a headstock chuck. These chucks just screw directly on the spindle. I believe the Jacobs numbers go like this: 59B 1/8" to 3/4" 1 1/2" X 8 tpi spindle 58B 3/16" to 5/8" 1 1/2" X 8 tpi spindle 57B 1/8" to 3/4" 1" X 10 tpi spindle also available in 1" X 8 tpi 56B 3/16" to 5/8" 1" X 10 tpi spindle also available in 1" X 8 tpi The 1" X 8 tpi May have a separate model number if anybody has one let us know, or if my numbers are wrong . Randy ------- Date: Tue, 21 Jan 2003 09:21:34 EST From: Sagebush9x~xxaol.com Subject: Re: Jacobs Headstock Chuck PS- I tried to figure how to bore out a regular Jacobs drill chuck & thread to 1-1/2-8, & there just ain't enough meat in 'em... ------- Date: Tue, 21 Jan 2003 15:06:09 -0500 From: Stan Stocker Subject: Re: Jacobs Headstock Chuck Hi Brian; While a good sample with good jaws may be better than many three jaw chucks, a nice small Bison with a carefully fitted back plate will do nicely. The jacobs also tends to let work slip a bit more easily. Consider how many times have you had a drill catch spin a drill in a jacobs chuck, while the work remains secure in a 3 jaw. Given the rarity of the Jacobs spindle mount chucks, one in good shape usually demands a premium well above the price of a small Bison three jaw on sale. If you can't find one at a good price and have your heart set on using a drill chuck on the headstock, you might consider a good quality (Jacobs ball bearing, maybe an 11N or smaller) or excellent keyless (Albrecht 15J0 or 30J0) on a shank to match your spindle taper. No pass through, but I have used this approach for small stuff I didn't have a collet small enough for with good results. If you want multi-use of a fairly expensive bit of tooling, a high quality small drill chuck on a straight shank can be held in an R8 collet for small hole drilling on the mill or in a three or four jaw chuck on the lathe. Given the small diameters and low cutting force/area most of this work involves, the extra overhand from the spindle usually causes no problems. One of these days I'll find a complete set of WW collets at an affordable price, then I'll make a spindle adapter to handle the really small stuff, or just get a spare Taig headstock or complete basic lathe with a WW spindle. Cheers, Stan ------- Date: Tue, 21 Jan 2003 20:57:58 -0000 From: "renaissanceman04002 acricketx~xxadelphia.net Subject: Repairing Jacobs Headstock Chuck Found the site on disassembling and repairing Jacobs chucks. http://www.grm.net/~shlosser/jacobs.htm Simple explanations and good pictures along with a couple of links for parts. ------- Date: Tue, 25 Mar 2003 23:22:24 EST From: n8as1x~xxaol.com Subject: Re: Backplate for Camlock Chucks 3/25/2003 k13x~xxbellsouth.net writes: > a couple of good 8 inch Cushman chucks. Problem is they are > D-series camlocks. After I started looking more closely at them, I > couldn't see any easy way to attach a threaded backplate. Has anyone > had success with such a job? On the other hand, can anyone see any > reason not to do this? I'm trying to make them fit my Atlas > 12 inch lathe. i have pulled the pins ,bored bushed & threaded a 13 in faceplate for my 2x7 Reed spindle i also have a 4 in chuck for atlas that shows signs of having been a D 3 or 4 BUT!!.....if this cushman is as heavy as my bison 8 in (38 lbs + backplate ), i wud not put it on atlas spindle ( which is why my bison is unmounted .probably going to fit it to 1895 reed 14 in......)the 8 in 4 jaw that was sold with atlas /crftsmn lathe weighed abt 15 lb total( i think, & was a hollowed back)...but it is ur spindle & it may NOT take the bearings out or spring it best wishes docn8as ps if u fit it up , let us know in a year or so! ------- Date: Wed, 26 Mar 2003 12:55:19 -0000 From: "kplus13" Subject: Re: Backplate for Camlock Chucks doc, you're right about the weight. They are heavy. I do remember some posts by Jon Elson that mentioned how heavy his 8 inch chucks were. I would think that the weight of a chuck would be much smaller than the cutting force applied. I've never calculated the force required to remove 25 thou, but I think it would be more than say 50 lbf. Like you said, it's my lathe and my spindle. I think I'll have to look at the problem with a more creative outlook. Thanks, Dave ------- Date: Wed, 26 Mar 2003 10:28:23 EST From: LouD31M066x~xxaol.com Subject: Re: Re: Backplate for Camlock Chucks You could make solid spindle and perhaps rather than a 1 1/2 x 8 make it compatable with cam lock...however that still leaves question of whether bearings will take the load. Experiment seems risky to health of lathe. I would assume Atlas designed to lesser standard than lathe your chuck was intended for. Solution may be swap chuck or lathe. Louis ------- Date: Wed, 26 Mar 2003 15:15:48 -0500 (EST) From: Kirk M Scammon Subject: Re: Re: Backplate for Camlock Chucks If I remember correctly, when I fit up a 4 jaw chuck with a camlock to go on a clausing lathe, There was a taper about 1/2" deep in the back of the chuck that matched a taper on the camlock plate, and several screws that held the camlock plate in the taper on the chuck. If the chuck back has a taper in it you can turn a taper on the threaded backplate and drill the holes to screw it on the chuck. For what its worth, I bought an 8 inch Bison chuck for my 12 inch Atlas, but sent it back in exchange for a 6 inch chuck because of the weight. Kirk 12x36 A/C and MF mill ------- Date: Wed, 26 Mar 2003 20:18:35 -0500 From: Ronald Thibault Subject: Re: Backplate for Camlock Chucks Dave: I made my backplate with a spigot on the chuck side with the same shape as the Camlock nose, and used the stud holes for bolting the chuck to the backplate. Ron Thibault Warrenville, SC USA http://personal.atl.bellsouth.net/t/h/thib9564/ ------- Date: Wed, 26 Mar 2003 17:41:49 -0600 From: Ronald R Brandenburg Subject: Re: Large pieces A soft jaw chuck is one that the part of the jaw that extends out from the chuck bolts on a part that stay in the chuck. 'Generally', soft jaws are meant to be machined to better fit parts and to prevent marring the surface and increase the surface area the jaws grip. You use a 'spider' to turn the ID or OD of the jaws to the same dimension as the OD of the part you want to turn. If you have a mill soft jaws are easy to make. You can make them thicker or thinner than your hardened jaws. They are generally made of mild steel so it's really cheap to have several sets for various depths and diameters. Ron ------ Date: Thu, 27 Mar 2003 00:06:35 -0600 From: Jon Elson Subject: Re: Re: Backplate for Camlock Chucks >> Like you said, it's my lathe and my spindle. I think I'll have to >>look at the problem with a more creative outlook. Thanks, Dave >dave ...my opinions are based on fear & trepidition , not experience nor >calculation ( which is probably beyond my present & likely to stay >capability )......having a father who was a MIT M.E ( even though his >diploma read SB ) was a great cushion ...every thing i designed & built, >from barns to farm machinery , was run thru him , & it was almost always >overly stout ( which is the ususal case when treading in unknown waters) >so the atlas MAY handle a 50 lb chuck.........higher speeds would appear >to present more problemsdue to centrifugal forces ...maybe we can get one >of the ME's on board to give us an authoritative analysis? 50 Lbs is no problem. I put a 50 Lb 8" adjustable chuck on my 12" Atlas. It is a little on the big side, but it works. I made a backplate from a raw casting, and modified it for the minimum overhang. I've used it for several years, and it was a GREAT improvement. It was a new Phase-II, and it was the first new chuck I'd ever owned. Jon ------- Date: Sun, 30 Mar 2003 17:52:06 -0500 From: "David R. Kuechenmeister" Subject: Re: Backplate for Camlock Chucks Thanks for the discussion on this topic. I think I'm going to do something similar to this on my three jaw. The four jaw seems to be very adaptable to a conventional threaded backplate, after I remove the studs. On the other hand, the three jaw has what amounts to a bolt-on backshell that has some holes tapped for the studs and set screws. Actually, I guess I might try drilling the outer portion of the new backplate in the same pattern as the backshell, then bolting them both to the rest of the chuck. I think I could bolt the backplate to the stud holes, as well. That would be pretty secure, plus I'd get to figure out the X-Y coordinates for the bolt pattern. I think Machinery's Handbook has a table for that. If not, there's always trig. I noticed with the Phase II toolpost installed, the maximum swing that I can cut is much less than 12 in. More like 6 in. Does that seem normal to those that use a Quick Change toolpost? Thanks, Dave ------- Date: Sun, 30 Mar 2003 19:11:48 -0600 (CST) From: dswrx~xxwebtv.net Subject: Re: Backplate for Camlock Chucks Swing on a metal lathe and the ability to machine a workpiece diameter does not (way gap lathes, excepted) coincide. You can machine a workpiece close to the swing when it is mounted on a face plate, but you are limited to operations such as facing. The swing over the carriage is always very much less. I have machined a 4" flywheel out of a 4 x 4 inch workpiece blank, but this was stretching the limits of a 6" swing lathe! (over 5.5", diagonal) Outrigged boring bar for turning O.D. Measure the distance from the center line of the lathe and the top surface of your cross slide. Double it and this will indicate about the maximum diameter that you can do general turning on. Leo (pearland, tx) p.s. Oops! Should have said operations when part is bolted to a faceplate, including facing.... and other operations, such as boring, shoulder work, etc. ------- Date: Tue, 01 Apr 2003 13:05:05 -0600 From: Rodent Subject: Re: Re: morse taper [FOR TAILSTOCK DRILL CHUCK] > > >Having bought an Atlas 10F recently and got it up and running with > > >the help of the group, I now find myself in need of some tooling Grizzly and many other places sell Morse taper adapters which fit the various drill chuck mounting tapers or threads. You need to decide what size drill chuck you want to use, find out what mounting options they have, then determine if a taper / adapter is made. The adapters with a taper will probably be more accurate than ones with threads, but it's more difficult to remove the chuck from the adapter. Stick with a decent name-brand heavy-duty chuck, aka Jacobs. Avoid the no-name or OEM-style chucks -- these are typically poor quality and physically larger than a quality unit. I have a very old, borrowed Jacobs chuck that is still more accurate than the crap brand one that came with my mill. ------- NOTE TO FILE: There are prior mentions that a chuck mounted on a Morse taper at the head stock potentially can stick, needing a rap to remove, or can slip under heavy use; also sticks out more than a spindle-mounted chuck giving workpiece more leverage to damage the spindle on a catch. It is not uncommon to mount a smaller chuck somehow when a regular chuck is regarded as too large for the job at hand. ------- Date: Wed, 2 Apr 2003 10:53:29 -0800 From: Frank Evan Perdicaro Subject: Re: Digest Number 1421 Despite what others might state, there certainly are Morse Taper chucks. I have one, a 3MT 4-jaw chuck 4" in diameter, for my 10F. Exactly why the chuck was sold mounted like this I do not know. In practice I use it when dealing with the 8" 4-jaw is too much of a hassle. Sometimes if the work in question permits and requires it, I will mount the 3MT 4 jaw in the 1 1/2" screw-on three jaw and go from there. Currently my 4-jaw 3MT is mounted in my rotary table on my mill. Careful use of the mill as an XY table, combined with a rotary table lets one do sort of eliptical milling. Right now I have a zillion dollars of tooling setup to mill Corian drink coasters. There are also plenty of 3-jaw chucks that have Morse mounting, but typically these have some other mount. One nice trick is to use the 3MT 5/8 Jacobs spindle and chuck from a floor-standing Delta drill press (like the 14 1/2" unit) in the headstock of your Atlas. Rotary MT chucks are available too. Looking in the MSC catalog, you will find them expensive, like $600 each. ------- Date: Wed, 2 Apr 2003 23:20:50 EST From: catboat15x~xxaol.com Subject: Re: Digest Number 1421 [atlas_craftsman group] In a message 4/2/2003, >Could anyone please tell me what size morse taper is used on the 10F? As was said morse taper #3 in the head stock and #2 in the tail stock. If you mean a jacobs chuck to hold drills etc in the tail stock get a #2 morse to jacobs adaptor or a chuck already on a morse #2 arbor. This is useful for holding drills and low torgue tools in the tail stock to drill work on the center. Also I use mine to guide taps (not under power). Also get a #2 to #3 sleeve so you can use the chuck in either end. If you are really lucky you may find a jacobs chuck that mounts on the headstock by the 1-1/2 inch threads. I have one and it is the best thing next to a full set of collets for small work. John in the high desert of California ------- Date: Sat, 05 Apr 2003 19:44:14 -0800 From: "Larry Bailey" Subject: Re: 5c collet chuck problem >From: "karlw144" >Reply-To: atlas_craftsmanx~xxyahoogroups.com >To: atlas_craftsmanx~xxyahoogroups.com >Subject: [atlas_craftsman] 5c collet chuck problem >Date: Sat, 05 Apr 2003 18:30:43 -0000 >When I bought my lathe, along with it I got a 5C collet chuck (I >think it's a Bison, says "made in Poland" and has # 1510-5"-5C)and >appears to be very well made.No collets were included, so I just >bought some. Went to use the chuck and the small "index pin" inside >the chuck that keeps the collet from rotating when it's tightened is >darn near flush with the bore. Needless to say, it doesn't keep the >collet from rotating, just buggers up the threads on the collet.Does >anyone know how I can take this chuck apart so that I can bring the >pin back to where it belongs? Or is there something else I need to do? >thanks, karl Try: http://www.toolmex.com/tmx/ & http://www.brassandtool.com/index.html The first is an importer of Bison tools; the second is a vendor. Good luck, Larry Bailey ------- Date: Sun, 6 Apr 2003 08:54:52 -0500 From: "jerdal" Subject: Re: Tool Post Grinder for the electrically challanged > When I got my 618 reassembled and running, I tried the highest speed belt setting, just to see how fast things went, and when I shut the motor off, the chuck spun right off the spindle, on inertia alone. I would not want to try cutting with the spindle reversed on this machine. The motor appears to be a non-reversible sort; for a reason? < I think the chuck spinning myth/issue/danger has been worked to death, and then reconstituted from powder... In general, the highest speeds are not for use with "large" chucks. A 618 doesn't exactly have a *large* chuck, but it IS somewhat relative. High speeds are for collets and small diameter work, in either direction. I have had a chuck spin off my 1 1/2-8 spindle exactly once. I was threading in reverse and cut too deeply. Yes, the chuck CAN spin off, that IS after all how you remove it. No it will not leap off the spindle and run up your leg on a moment's notice if you ever run in reverse. A properly seated chuck will stay put, and needs a shock or some serious pulling to remove. Simply stopping the machine is insufficient to remove a properly seated chuck. IF your chuck comes off that easy, you have some work to do on your backplate, as it is dirty, has bad threads, or a poorly machined back surface, etc, etc, etc. And, finally, of all operations possible on the lathe, grinding is possibly the LEAST likely to produce enough torque or shock to loosen a chuck. Jerrold ------- Date: Sun, 6 Apr 2003 13:33:46 -0700 From: "Bob May" Subject: Re: Tool Post Grinder for the electrically challanged That's the secret with the chuck spinning off. The threads are nicely lubricated and the chuck is freshly applied to the machine and not seated due to excess oil/grease on the threads and stop. Then the lathe is spun up and stopped without any work being done which would drive the chuck into a good seat. The next thing is a chuck dancing across the floor and you dancing to avoid it nipping at your ankles like a guard chihuahua. Bob May http://nav.to/bobmay NEW! http://bobmay.astronomy.net ------- Date: Tue, 08 Apr 2003 22:56:40 -0000 From: "Damon" Subject: Time for a new chuck Heya folks. I'm getting tired of cussing at my 60 year old 3-jaws and am ready to try and get a new 3-jaw for my 10". Are there any drawbacks to a 6-jaw (aside from price?) Toying with if I need a 6 or just a decent 3. At this point having a backplate that registered on the spindle would be an improvement! Damon (started project 10x62 yesterday!) ------- Date: Tue, 8 Apr 2003 16:23:33 -0700 From: "kimche" Subject: Re: Time for a new chuck Go for the larger chuck, I use an 8" 4jaw on my 10x54. The 5" 3jaw that came with it is ok, you should have no problem with a 6" 3jaw chuck. Paul 10x54QC 7x15jet mill/drill ------- Date: Tue, 8 Apr 2003 23:18:37 -0400 From: "RD Burch" Subject: Re: Time for a new chuck A 6 jaw chuck came with my used 5900 lathe. I was at first skeptical as to why someone would pay extra for one. Well, it grips twice as good as a 3 jaw chuck with less jaw force to mar the part. If you want to use it as a 3 jaw chuck, just remove every other jaw. Bob ------- Date: Tue, 27 May 2003 20:50:57 -0700 From: "David" Subject: Re: Sherline lubricant [WAS ORIGINALLY JUST A LUBRICANT DISCUSSION] I too [and, I suspect, everybody else] has trouble with both the 3- and 4-jaw chucks getting swarf in the spirals. My younger brother [who operates a mill whose smallest 3-jaw chuck weighs 240 lbs.] has the same problem. I've found no difference between using a light oil [I still prefer Singer's sewing machine oil, although some of the Teflon-based gun oils seem to do well] and a grease [Sta-Lube]: they all seem to attract swarf as if the thing were magnetized. So I've adopted a policy as follows: any time I tighten or loosen the jaws of either chuck, I open it [or close it] all the way, until just before the jaws fall out. If there is any hitch in its motion, I disassemble it right then--interrupting the job--and clean and lubricate it thoroughly. [Swarf in the spirals will keep the jaws from engaging snugly.] Although it's a pain in the a**, this policy seems to keep my chucks operating smoothly and snugly. Dave Wood PS: I don't think I want to deprive any piece of steel of lubricant, if for no other reason than preservation of the surface. But to deprive the friction of the spirals and jaw-teeth of healing lubricant? Not advised. ------- Date: Mon, 25 Aug 2003 13:43:24 -0400 From: "JERRY G" Subject: Re: Lathe Problems [sherline] Shorty Leatherwood Monday, August 25 wrote: >>Hello List, I am hoping you all can help me with a little problem I am having. I am sure that it is related to my lack of experience with these tools as well as metal working in general. Ok here is the problem. When using the 3 jaw self centering chuck I can insert a piece of round stock and turn it down to the desired OD. If I decide to remove this from the chuck for any reason and reinsert it the thing wobbles horribly from that point on. It is not just .001 or .002 it is a bunch. Any Ideas what I am doing wrong here. I can use the 4 jaw chuck with a little better success but it is a pain to have to dial it in every time a piece goesinto the chuck. thanks shorty << Shorty, suggestion. Buy a second three jaw chuck. And never take the piece out the chuck until you are finished machining everything. Everything will be concentric. Turn it around for the other end and then dial it in on a four jaw chuck. Regards, Jerry G ------- Date: Mon, 25 Aug 2003 18:03:41 -0000 From: "David Christensen" Subject: Re: Lathe Problems I use collets whenever possible. Dave ------- Date: Mon, 25 Aug 2003 09:54:07 -0400 From: "Statman Designs, LLC" Subject: Re: Lathe Problems You do not mention how long the piece is, or its diameter. If it is small enough to fit through the spindle then you can usually re-chuck a piece with minimal wobble. However, if it is bigger than about 0.4" diameter and longer than 2 inches it will be difficult to re-chuck without extra work. here are some techniques to help you. Find the high spots on the wobbling bar by eye-sight and tap it gently with another piece of bar stock or a mallet (gently is the key). Spin again and repeat. Set-up a dial indicator on the cross slide, and use this to precisely "tap" your bar until it is true. Use a steady rest to support the other end of the bar. Center drill the end of the bar and hold it with a live center in the tailstock. Make sure that the jaws of the chuck have no chips or dirt on them. Play with these suggestions and decide which is worth your time investment. Sometimes you do not need ultra-high precision and sometimes you do. Daniel J. Statman, Statman Designs www.statmandesigns.com dan.statmanx~xxrennlist.com ------- Date: Wed, 27 Aug 2003 01:30:16 -0400 From: "JERRY G" Subject: Re: Re: Lathe Problems Shorty, Do you have a machine shop near you? If you do, I think it would be good if you have them make up a test bar for you. Just a piece 6 " long with centers on both ends , say about .500" or .625" diameter and ground on a cylindrical grinder. It will be a reference test bar for you, and well worth the bread. Regards, Jerry G ------- Date: Wed, 26 Nov 2003 01:51:09 -0000 From: "bamboobill2003" Subject: Jacobs chuck Can anyone tell me if there is a set-up that would allow me to mount a Jacobs chuck to a live center tailstock? I'd like to be able to grasp some small workpieces at both ends while turning. Thanks, Bill ------- Date: Tue, 25 Nov 2003 22:05:01 -0600 From: Bill Aycock Subject: Re: Jacobs chuck There is a piece of equipment made for this type of work- the set-up for turning armatures on small electric motors. In this set-up, there are two jacobs chucks- one in head, that works quite conventionally- and a special in the tailstock. Both are mounted in Morse tapers. The tailstock chuck has bronze jaws that fit the shaft of the motor and act as an adjustable bearing. In operation, the motor shaft is clamped in the headstock chuck and the other end is clamped loosely in the bronze jaws. The rotor is turned by one chuck and centered by the other. Bill Aycock ------- Date: Wed, 26 Nov 2003 09:33:38 -0000 From: "Ernest Lear" Subject: Re: Jacobs chuck Simple thing to make. Make a live centre and there plenty of drawings about, that been published in model engineering magazines in the past. Instead of making a coned point on the revolving bit, make it a threaded end and screw it in the back of a Jacob chuck. Ernest ------- Date: Wed, 26 Nov 2003 17:33:56 -0000 From: "brodwidr" Subject: Re: Jacobs chuck My Harbor Freight catalog which arrived yesterday has an item -- "MT2 Live Center with 7 tool bits" -- item 04694-OCUA for $50 -- which looks like it might do the trick. Essentially it is a chuck nose mounted on a live center which accepts different diameter and different shaped tips. Unfortunately the part number is not listed on their web site so it looks like a retail or phone-only offer. Good luck. ------- Date: Sat, 6 Dec 2003 22:23:48 -0800 From: "Orrin Iseminger" Subject: Re: Re: Chuck wobble One thing that causes me problems on my full size lathes is bits of crud getting lodged on the female threads. I use a clean stainless steel wire brush--the kind that's slightly larger than a toothbrush--to "unthread" the debris out of them. On Sherline chucks, I use a shotgun barrel wire cleaning brush. A twelve gauge brush is just the right size. The ell- shaped end of a scribe is useful in picking out the stubborn bits that remain. ( 20 and .410 gauge cleaning brushes are also handy to have around, as well as rifle and pistol brushes of .44, .30 and .22 caliber. They are usually hardened copper and are not apt to scratch steel parts.) Once a chuck has been screwed on over a bit of swarf, the swarf can become embedded in either the spindle or the chuck and it might not come off easily. I always store lathe chucks so that they rest on their jaws, with the threads on top. This way, bits of swarf cannot fall off the jaws and onto the threads. Orrin ------- Date: Fri, 19 Dec 2003 20:57:22 -0600 From: Jon Elson Subject: Re: Question about a Buck Chuck Ernie Weinberg wrote: > An accurate 3 jaw chuck is by far the most important tool for the lathe. Unfortunately my 6" Buck chuck is about .007" out of concentricity. There are three large allen head set screws around the outside of the chuck (in addition to the normal chuck key hole). Does anyone know what they are for? I hope it is to adjust the concentricity. < Yes, this is an adjustable chuck, and that IS what the screws are for. You should remove the chuck from the backplate, and make a light facing cut on the largest diameter face of the backplate until it cuts all the way around the surface. This provides a perfectly true surface for the chuck to mount on. You put a known round shaft in the chuck, and read its runout with a dial indicator held by the toolpost. Turn the chuck until you see the minimum reading on the indicator, then tighten the screw nearest where the dial indicator is currently reading. This will move the shaft towards the indicator. If the total deviation of the indicator was .007" (actual eccentricity .0035") you would move the chuck .0035" and then recheck. Once you get the hang of this, you can recenter the chuck in about 3 trials. There is some feel to how much to loosen the locking bolts on the front of the chuck. Then, you should try several different sizes of shafts, to see if the chuck centers them all accurately. If not, the chuck has been damaged, and the scroll has some wander in it, or the jaws are sprung. Before you do all this, you probably should disassemble the chuck completely. First, wind the jaws all the way out. #3 will fall out first, be ready to catch it. Remove the chuck, and there should be a plate in the center of the back that can be removed with some screws. Then, you should be able to remove the scroll and pinion. Wipe out the entire inside of the chuck, and lightly oil the jaw slides. Wipe a rag through the slot in the scroll, you may have to do this several times to get all the chips out. Clean and lightly lube the gear teeth on the back of the scroll, the pinion, and lube the scroll. Reinstall the pinion, scroll and plate. Put the chuck back on the backplate, and then wind the scroll until the outermost part of the spiral is ready to engage a jaw at slot 1. Clean and lightly lube the jaws, and insert them so they are grabbed in sequence by the scroll, in the correct slots. This should have two-piece jaws, you should remove the top jaws and clean the mating surfaces and reinstall. You really want to take care of this $300 chuck if it is still in good shape. Jon ------- Date: Sat, 20 Dec 2003 11:16:55 -0500 From: Stan Stocker Subject: Re: Question about a Buck Chuck Greetings, Jon pretty much covered it, here's a few little details. When you adjust an AdjusTru style chuck, you loosen the chuck slightly on the backing plate, zero for the diameter you are working, then retighten the chuck body to the backing plate. It isn't a "floating" mount, just one that has provisions for adjustment by design. The chuck itself isn't any more accurate across the entire range than any other good quality chuck. You may well dial in less than 0.0005 TIR at one diameter, but still have 0.002 TIR at some other diameter. Doesn't mean your chuck is sprung or badly worn, just the nature of tolerances stacking up as with all three jaw chucks. I'd add in an additional step, before taking the facing cut on the back plate. Clean the spindle threads and nose well, then blue the contact area of the chuck. Mount and check. A pip or small high spot will make the chuck cock at the final mounting and also cause the chuck to jam, making removal difficult. Take off high spots with a scraper or small stone. Repeat until you have at least 70 percent contact contact with the spindle face. The final tests will require a very thin application of prussian blue. You can also use cadmium blue oil paint if the real HiSpot style blueing isn't on hand. Take just the finest facing cut on the back plate, using a tool honed with a stone to the point that no light is reflected from the cutting edge. This is a critical surface, so take the time to get the tool perfect. Slightly dull tools, or carbide inserts that have not been lapped to dead sharp don't take super fine cuts very well. Have fun! Stan ------- Date: Fri, 19 Dec 2003 16:21:03 -0000 From: "brodwidr" Subject: replacement chuck jaws I recently bought a used Atlas Craftsman 6" lathe, the old 618 style with the 1" 8TPI spindle (101.07301). The three jaw chuck it came with has the complete set of jaws of the "inside" type, but one of the three jaws is missing from the "outide" set of jaws. Does anyone know where I could get a set of replacement jaws for this chuck, or a shop that could machine a substitute third jaw, since I have two jaws out of the three? I know the jaws need to be fine tuned once installed in order to be really true , however I was thinking that perhaps I could do that myself using my rotary tool with a grinder wheel in the flex shaft, and mount the flex shaft to the tool post. Does this make sense or should just go buy a new chuck? Thanks in advance. ------- Date: Fri, 19 Dec 2003 10:15:53 -0800 From: Jay Greer Subject: Re: replacement chuck jaws Hi, You may find a spare jaw or chuck on eBay. However, fitting the jaw accurately can be a hassle and is more easily done in a shop that is set up for servicing chucks. Considering the cost, you would be better off buying a replacement chuck. Best of luck, Jay Greer In Western Washington ------- Date: Fri, 19 Dec 2003 21:44:35 -0000 From: "carbure2003" Subject: Re: replacement chuck jaws 3 jaws usually come as a matched set. You will probably notice a serial number on the jaws at some place. To be good, all jaws need to be of the same set (same serial number). I encountered a similar problem 2 years ago with a chuck that came with my South Bend 10K that I am currently re-building piece by piece. I visited a 2nd hand metal working machinery dealer. He had a shelve full of 3 jaw sets. I brought my chuck there and found a set of outside jaws that fit my chuck with very minor modifications. (I needed to grind about 0.005 in so it fit the chuck slide. The end result was a chuck that centered within less than 0.002 in runout. Important thing to check: the pitch of the scroll plate. I doubt you would be successful on the phone. You really need to trial the jaws in the chuck. (I had to try many sets before I found one that would fit) One jaw was fitting perfectly... the set was missing one In the States, I would try Sobel Machinery in New Jersey. I have never been there but I heard that he has a lot of stuff in his place. Did you ever think about talking directly to Clausing? Good luck Guy Cadrin ------- Date: Wed, 18 Feb 2004 10:36:49 -0500 From: Stan Stocker Subject: Re: How to true worn jaws? grammermaniac wrote: > My 3 jaw chuck is pretty worn and only grips the workpiece with the > end of jaws closest to the gearbox. The work can just float around > out toward the tip of the jaws which makes for chatter machining Hi Michael, you need to load the jaws before grinding. To grind the insides, you can close the jaws on a large washer and grind all but the area covered by the washer. Once this is done, you can either move the washer forward and grind the 3 small raised areas where the washer was, or simply pull the chucks and grind these three spots slightly lower than the finished jaw faces. A nicer approach is to load the jaws with a four hole ring, using this you can grind the entire jaw face in a single pass. A link showing how to make one is at: To grind the exterior jaw surfaces, you need to load the chuck the opposite way, I use a large hose clamp and open the chuck out against one when trueing up inside gripping jaws. Cheers, Stan ------- Date: Wed, 18 Feb 2004 09:51:55 -0600 From: Jon Elson Subject: Re: How to true worn jaws? Sure, this is a standard procedure. You need some rubber bands, modeling clay or some other thing to pull the jaws outward against the scroll, like it was gripping something, but leave the entire jaws clear. Put a Dremel, air die grinder or some similar spindle on the toolpost, and run it in and out against the jaws, until it cuts the full length of the jaws. This is done with the lathe not turning. Use the carriage feed crank to move the carriage in and out, and advance the crossslide a hair at a time. For final truing, set the lathe for a low backgear speed, and engage the slowest (finest pitch) feed on the main leadscrew, and let it run for 10 - 15 minutes, until the entire length of the jaws have been ground. I've used some 1" dia by 1/2" long grinding wheels on 1/4" shank for this job. When the chuck is turning, the grinding wheel only touches it for a fraction of a second 3 times a rev. So, doing most of the metal removal with the chuck standing still, and concentrating the work on the jaw, rather than air, speeds up the job a LOT. (You shouldn't need to ask how I know this.) The jaws are quite soft, no diamonds necessary. There is no way to do this by hand, at least without two tailstocks and bluing compound, akin to hand scraping. Just use the Dremel and standard grinding wheels, and make one fine finish pass (sparking out) so wheel wear will not be a factor. Protect the ways with rags, aluminum foil or similar things, and shove a rag into the back of the chuck to keep as much grinding grit out of it as possible. After you're done, disassemble the chuck, at least the jaws, and clean the scroll teeth on both parts to get the grit out. You may need to use a rag and screwdriver or Q-tips to clean the jaw slides. Jon ------- Date: Fri, 9 Apr 2004 23:37:20 -0400 From: "Bill Hardin" Subject: RE: Bison vs. other chucks [atlas_craftsman] April 09, 2004 Bill Hardin wrote: >>One man's opinion, or, for the internet, IMHO. I have no experience with the larger Bison chucks, but the small, 1/2-20tpi chuck for the Craftsman 109 series and the 3/4x16 for the same group, are outstanding pieces. The manufacturing and design are excellent, and the accuracy is 0.0004" run out. I have been using and selling these for over a year, and comparing them to the various chucks that come in on purchased equipment. I have seen nothing even approaching the quality. I cannot imagine that the other Bison products would be any less value compared to any competitor. It is strange, to me, that the Bison 3 jaw sells for about $25 more than the used 60 year old Craftsman version, and there are still those who buy the Craftsman. Bill Hardin << April 09, 2004 Richard Valentine [richarddvx~xxcooke.net] wrote: >I made a threaded adapter sleeve on the 109 lathe itself to adapt Sherline chucks. Have been using them now for about 6 years with excellent results and they didn't break the bank. Another excellent chuck that works well is the Unimat chucks by making a new backplate to fit the 109 spindle--ropeyanker < Sherline sells a 1/2" x 20 chuck for the 109 that does not require an adapter sleeve. I tried the chuck, for $105. I found it inferior to the Bison. Neither the Sherline nor the Unimat can match the run out of the Bison. Bison's 3/4" x 16 for the Sherline is an excellent replacement for the Sherline chuck itself. We also have a 3/4" x 16 tpi replacement spindle for the 109 series that offers strength over the original spindle, and accepts current accessories made for the Sherline and others. Still has the #0 MT internal. Bill Hardin http://www.homeshopsupply.com Craftsman 109 Lathe Support ------- Date: Sat, 10 Apr 2004 11:15:27 -0400 From: Stan Stocker Subject: Re: Two more chuck questions... Hi William: The best chinese chucks can be pretty good, but unless you can inspect the very chuck you are getting you may get lucky or get a chuck that's not so great. The Bison chucks are uniformly excellent. If you figure on having the chuck for life, the extra cost is well worth it. A two piece jaw design is very useful, for several reasons. First, you can replace just the jaws if they wear or become damaged. Secondly, you can obtain or make soft jaws or special jaws to accomodate tricky setups. hird, you can turn the jaws around quicker for outside work than you can run out the outside jaws and run in the inside jaws on a chuck with two sets of jaws. The third consideration is minor in most home shops, but the ability to make soft jaws is really nice. Another consideration is that the scoll and jaws remain unchanged as you go from inside to outside or special jaws, so once you dial in the chuck for runout you may see less variation when you change jaws. Cheers, Stan ------- Date: Mon, 06 Sep 2004 21:22:04 -0500 From: Jon Elson Subject: Re: adjust_tru chuck [atlas_craftsman group] susandormans wrote: >I just got a 12 X 24 craftsman after having used a Chinese made 7 x 10 >for the past couple of years. It came with a independent 4-jaw and a >3-jaw scroll chuck. The 3-jaw is an ajust-tru made by Buck. Now based >on the name I'm assuming (hoping) that it is adjustable, since it's >out by about .015 when I chuck on to a piece of drill stock. It has >four set screws near the back that I'm guessing are for making >adjustments, but I can't seem to make any adjustments. There are 12 >screws on the face, six around the outside that look like they attach >the chuck to the back plate and six smaller ones near the through hole >that I thought may need to be loosened to make an adjustment, but no >luck. Any advice? Almost certainly you have to loosen the OUTER screws to adjust the chuck. It moves the whole body of the chuck. The adjusting screws push against a boss in the center of the backplate. The inner screws hold a plate against the back of the chuck body that retains the scroll. Since you'd know this if you have had it apart, you obviously haven't. There are no springs or other gotchas in there to jump out if you take it apart. You should run all the jaws out, and clean the scroll and the jaw guides, then relube it with light oil and put them back in. If the chuck looks well used, you should probably strip it completely to properly clean it. Putting the jaws back in requires one trick. You line up the scroll thread so that the outermost turn is about to enter slot #1, insert jaw #1 to that slot and engage it with the scroll. Repeat in sequence for jaw 2 in slot 2, and jaw 3 in slut 3. You should remove the jaws and clean them every few months of light use to get all the chips out. Grinding chips into the jaw tracks and the scroll will ruin a good chuck, and the Buck is a very good and expensive chuck. A brand-new Buck 8" Adjust-Tru chuck is worth more than your lathe! (If you don't believe me, look it up in the MSC catalog!) Jon ------- Date: Mon, 6 Sep 2004 21:54:23 -0500 From: "jerdal" Subject: Re: adjust_tru chuck Slack the hold-down screws a bit when adjusting. Or put heavy belleville springs on them (solid cone springs). The adjustment is just exactly opposite of a 4 jaw. Screwing in moves the body towards the wrench. Slack the opposite screw before screwing in the near one. You'll like that chuck, if it's any good. I have a 4" buck adjust-tru, and it is great. Jerrold ------- Date: Tue, 07 Sep 2004 03:19:24 -0000 From: "susandormans" Subject: Re: adjust_tru chuck I took the chuck apart and cleaned it. It had some rust between the back plate and the chuck. It cleaned up real nice and was fairly simple to adjust once cleaned. Thanks for the advice. Randy Dormans ------- Date: Mon, 13 Dec 2004 01:15:22 -0000 From: "kplus13" Subject: Problems with Four Jaw Chuck [atlas_craftsman group, but generic] I had a small aluminum plate that I wanted to face on both sides. I had really intended to fly cut it in a mill, but things didn't work out. So I decided the 4-jaw chuck would give me the same results, right? All I wanted was two parallel sides and a measured thickness between them. I put the plate in the 4-jaw and centered it very roughly. Faced it. Took it out and put the faced side against the jaws in the 4-jaw. Faced it again. This time I was measuring the thickness. Turns out one end was about 5 thou thicker than the other end. The piece was about 2in by 6 in and it's the thickness on the narrow ends that differ from one another. The thickness on the 6 in sides is the same, within my tolerances. I WAS careful to seat the plate all the way down on the jaws. I wasn't as careful about making sure the ends weren't swapped when I put the plate back into the 4-jaw. I could very easily have taken the side that was on top when removed after the first facing and put it on the bottom when setting it up for the second facing. Doesn't seem like it should matter, though, does it? Yes, I did tighten the carriage. After the first pass, anyway. It would have been higher in the center in that case. I did two plates and the results were exactly the same for each plate. Five thou higher on one end. This is the 4-jaw that was bought about the same time as the lathe, circa 1940. Is the chuck just worn, am I sloppy, am I expecting too much for an operation that should be done on a mill, anyway? Thanks, Dave ------- Date: Sun, 12 Dec 2004 19:24:20 -0600 From: xlch58x~xxswbell.net Subject: Re: Problems with Four Jaw Chuck Remove the jaws from the chuck and put an indicator on it to see if the face is flat before you do anything else. Charles ------- Date: Sun, 12 Dec 2004 18:10:04 -0800 From: "Bob May" Subject: Re: Problems with Four Jaw Chuck Sounds like your jaws aren't the same height. This isn't a dimension that is really set accurately on many lathe chucks. To check, clamp onto a piece of stock that will allow you to measure the facing distance for the surface that you used and use your DTI to see what the differences are. Also check to make sure that it isn't a slop in that direction that is causing the differences. You may want to turn or grind the front of the chuck jaws to let you get the surfaces parallel on your work. I'll note that if you measure an error on a piece of work, putting it back in with the error on the face you are going to work will allow you to get parallel faces on the work. Bob May http://nav.to/bobmay http://bobmay.astronomy.net ------- Date: Sun, 12 Dec 2004 22:43:07 EST From: jmartin957x~xxaol.com Subject: Re: Problems with Four Jaw Chuck If the jaw tops on the chuck were originally ground in the chuck, it might make a difference when they are placed in different slots. I think I'd set a dial test indicator to indicate on the jaw tops, then swap the high and low jaws and see what happens. If it makes a difference, find the best arrangement and then number the slots and jaws. First, though, I'd try indicating on the chuck face with the jaws removed. John Martin ------- Date: Tue, 14 Dec 2004 19:21:47 -0500 From: Kuechenmeister Subject: Re: Re: Problems with Four Jaw Chuck The chuck did indicate about 6 thou of runout. I took the chuck off the backplate and found out that the backplate indicated about 6 thou of runout. Took a light pass to face the backplate, put it back together and the chuck indicated some runout but it was too small to measure. Thanks again. Dave ------- Date: Wed, 15 Dec 2004 07:09:23 -0500 From: Kuechenmeister Subject: Re: Re: Problems with Four Jaw Chuck On Dec 14, 2004, David Beierl wrote: >And after you took the chuck off and cleaned the mating bits of chuck and >spindle and remounted it things are still good, yes? I imagine you've >already been through that but if not...never hurts to make sure. >David Beierl -- Providence RI USA Atlas 618 6"/3/index.html" lathe ca. 1941 You bet. Except for the fact that the backplate indicated some runout, I was concerned there was crud on the jaws, on the spindle, between the backplate and chuck... I even used a torque wrench to put the chuck back together, so I wouldn't have uneven forces applied to the chuck. Since I was measuring everything, I looked for runout on the spindle, too. Couldn't find any, so I have that little bit of known performance to build on. Dave ------- Note To File: The following FROZEN CHUCK conversation has some new solutions beyond what was discussed in earlier threads in July 2001 and April 2002 above. While they are talking about an Atlas here, the methods are fairly generic. Caution: some methods have caused damage to chuck or spindle or gears when done by other people in other perhaps similar circumstances. Whichever method you choose, if any, it may and can damage your lathe. You should seriously consider getting the advice or assistance of a local machinist. Even then, your lathe might be damaged. Reading a broken record? No, just preparing you for the worst possible outcome. Good luck. ------- Date: Mon, 13 Dec 2004 20:58:41 -0000 From: "Tom" Subject: HELP!!! Frozen Chuck (I don't mean chuck roast) [ATLAS_CRAFTSMAN GROUP] Hello, new guy in shop is having difficulty with 3-jaw chuck. I can't get it to unscrew off of the spindle of my "new" Atlas 618. Is there some trick I am missing here? Thanks for your help, in advance. Tom ------- Date: Mon, 13 Dec 2004 17:04:35 -0800 From: "Glenn" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Tom, pretty common problem. First attempt is a piece of wood jammed between the jaws for a lever and squeeze the belts together like a strap wrench. Next attempt is a longer lever and a real strap wrench on the spindle pulleys. Avoid putting much pre$$ure on the back gears they can be broken easily. Don't try to use the indexing pin to lock it ... same reason. If all that fails ... you may have to get serious and turn something with the tool upside down or on the back side and the lathe running reverse. Slow speed! Not for the faint of heart :) Glenn ------- Date: Tue, 14 Dec 2004 02:09:56 -0000 From: "jjjorg1" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) You might also try placing an expanding mandrel (if you have one - may be able to get one from a machinery supply house like Mcmaster Carr) with wrench in the opposite end of the spindle when trying the wood or strap wrench on the chuck in order to create an opposite torque to loosen the chuck without stressing the geartrain. You might also try putting an old chuck key into the chuck sidehole and rap the key a few times with a hammer in a counterclockwise direction to create a sharp torque which sometimes loosens the chuck but this may also mar the sidehole and certainly damage the chuck key. JJ. ------- Date: Tue, 14 Dec 2004 04:50:58 -0000 From: "russenc" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) I've never done this before but have read somewhere that if you clamp down on an impact extension/socket in your chuck you can use an impact wrench to free the chuck. I would like to see what others think of this idea before trying it I'd hate to see you do unnecessary damage to your lathe. Russ ------- Date: Mon, 13 Dec 2004 21:19:20 -0800 From: "Glenn" Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) This has been tossed about on rec.crafts.metalworking several times and it seems the concensus is that it is potentialy quite harmful. It would be like taking a really aggressive intrupted cut. The bull gear is locked to the pulley with a pin that could be damagaed if you lock the pulleys and the keyway on the bull gear would get hammered if you lock the bull gear. Which reminds me in my last post on the subject I said to put a strap wrench on the pulley and I should have said on the bull gear. I think the key on the bull gear could take more stress than the pin that locks the bull gear to the pulley. The internal expanding mandrel or an internal pipe wrench might be an option as that end of the spindle is not a critical fit. A few scars in there would be preferable to broken gears or pins etc. I still don't like the idea of an impact wrench on those bearings but if it is a last option before you toss the lathe why not? Glenn ------- Date: Tue, 14 Dec 2004 00:08:42 -0600 From: "jerdal" Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) If the other ways don't get it off, possibly it can be disassembled in place (assuming its a 3 jaw chuck!). Some have the screws in front, or they are around the edge in rear, where an angle screwdriver can be brought to bear. With the front half off, the front of the threads is visible, and it becomes easier to get penetrating oil in. As a last resort, turning it off is much easier if the chuck is disassembled. Chucks tend to be made of material which can be turned. One would start on the threaded boss OD, working inwards to smaller diameters. Hopefully it will release before you get to the thread crests. "Tossing" the lathe on account of a stuck chuck is simply not an option. If it is, toss it this way please. I could use a smaller machine, although I'd prefer a Schaublin or Levin, if you have one with a stuck chuck/collet... :-) Jerrold ------- Date: Mon, 13 Dec 2004 22:42:51 -0800 (PST) From: Ken Tjomsland Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Another one usually mentioned is to place a piece of hex stock in the chuck, fit a standard six-sided socket to the hex, then use an air-powered impact wrench on the socket. Make sure no gear teeth are engaged in the system to keep from breaking a tooth! Ken Tjomsland ------- Date: Tue, 14 Dec 2004 23:08:45 -0000 From: "Tom" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Dear Friends, Thanks for all of the suggestions. The story of "Chucky" continues. I don't have an expanding mandrel (good idea!) or some of the other equipment mentioned so . . . here is what I've tried. So far, I've broken a band clamp - cracked the housing and snapped the rubber band in two. No biggy, I didn't like the way this clamp worked anyway. I read in an old machine shop text about cinching a stout piece of hardwood in the chuck jaws and giving it a couple of whacks with a mallet while holding fast the spindle. Didn't work. I unscrewed the two halves and split the chuck, thinking that would get me closer to the spindle so I could squirt some Liquid Wrench into the thread ends. The chuck isn't really frozen, as in rusted, it's more like jammed up against the spindle end so, I don't know if the Liquid Wrench will do anything or even if it will penetrate far enough. BTW, if you've never taken a chuck completely apart, do it. It is a masterpiece of machining art! Anyway, I've decided to leave it for now and come back to it after I've remounted the lathe, countershaft and motor on a bench I don't have yet. Then, if keeping my fingers crossed hasn't loosened the chuck I'll try just running the spindle in reverse. Then maybe try freezing the spindle with an ice pack (read that somewhere on this site) and heating the chuck with a hair dryer ("What kind of cut would you like Chuck?") to get them to free themselves. Then do the reverse thing. Or the whack attack. Finally, if no luck, I'll rig up some sort of tool post on the back way and try to make a chuck freeing cut on a piece of aluminum with the spindle running in reverse. I guess if all of this fails I can remove the spindle and tackle it again, out of harms way. What do you all think? I am taking it easy because this little guy is in very good condition - no chunks missing anywhere and not a flake of rust - and it came with all the change gears and both a steady and follower rest. I would be sick if I damaged it in any way trying to budge this great old chuck. Since the lathe didn't come with a face plate it has probably had this chuck on it forever and a day. Thanks again for all the help. Tom ------- Date: Tue, 14 Dec 2004 18:49:21 EST From: LouD31M066x~xxaol.com Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) If you are tempted to get rammy (as my steptather would say) tote up the price of all the things that could be damaged by doing so. Heat and cold sounds like a good plan. If all else fails remove headstock from lathe bed and try to score a complete replacement unit on ebay. A stuck chuck is no one's idea of fun. Louis ------- Date: Tue, 14 Dec 2004 19:23:38 -0500 From: Charles Gallo Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Please, buy a new headstock for a stuck chuck? Machine the darned chuck off if it comes to that - if you can, just go with a parting tool between the shoulder and chuck - being careful. If the chuck can be removed from the backing plate, it's fairly easy to machine the plate off ------- Date: Tue, 14 Dec 2004 20:10:27 -0500 From: David Beierl Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) At 18:49 12/14/2004, LouD31M066x~xxaol.com wrote: >If you are tempted to get rammy (as my steptather would say) tote up the >price of allthe things that could be damaged by doing so.Heat and cold >sounds like a good plan. I'm right with this part, that stuff's expensive... >If all else fails remove headstock from lathe bed and try to score a >complete replacement unit on ebay. A stuck chuck is no one's idea of fun. But it sure seems an awful lot would have to fail to get to here -- sacrificing the backplate or even the whole chuck seems a clear win over wrecking the headstock. And lathes are peculiarly suited to removing rotating obstructions in way of the toolpost... Of course if a spare headstock let you put the other aside and tackle it at leisure while keeping the machine usable in the meantime, I can see some attraction there. David Beierl -- Providence RI USA Atlas 618 6"/3/index.html" lathe ca. 1941 ------- Date: Tue, 14 Dec 2004 17:18:48 -0800 From: "Glenn" Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Tom, You need a better strap wrench :) Not one of those plastic things with the rubber band for removing jar lids... If you pull the spindle with the chuck attached you should consider something like a barrel vise. A block of wood with a hole drilled lengthwise through it and then cut in two lengthwise to hold it in a vise. It will come off eventually ... my "Toss the lathe" comment was meant as humor as in a ridiculous idea... Good luck Glenn ------- Date: Tue, 14 Dec 2004 22:28:21 EST From: LouD31M066x~xxaol.com Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) If chuck is really stuck there may be some nastyness with spindle too. My after the fact moment of enlightenment is sometimes ebay complete headstock is cheaper than an OEM spindle. Don't ever buy a lathe without taking chuck off is another moment of enlightenment. Learned hard lessons the hard way. Louis ------- Date: Tue, 14 Dec 2004 22:32:25 -0500 (EST) From: x xx Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Well, I think the long way about is the quick way home. And by going the long way about you avoid all the landmines :-) If you don't have an expanding mandrel, make one - it's a piecacake. Pull the handle bars out of a bicycle to see how they are made, then go and do likewise. You'll need, or at least find convenient, this gizmo for tricky threading later on, so take the opportunity to make it now. Make it to take a tommy bar. When you get the lathe attached to your bench, stick the mandrel in the spindle and stick the tommy bar in the mandrel, then block and wedge both sides of the tommy bar so the spindle is prevented from turning either way. This way no stress will be put on the change gears let alone on the backgear which is pretty frail. Then number the jaws and the jaw slots on the chuck and pull the jaws out so you have a smooth, unobtruded outer surface on the chuck. Make a standard "strapwrench", using any old piece of webbing and a bit o' stick, and take it to the chuck. As whazzisname said: " Gimme a fulcrum and a lever and I'll move the Earth" Sam ------- Date: Tue, 14 Dec 2004 22:41:24 -0600 From: "jerdal" Subject: Re: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) > Please, buy a new headstock for a stuck chuck? > Machine the darned chuck off if it comes to that - if you can, just go > with a parting tool between the shoulder and chuck - being careful. > If the chuck can be removed from the backing plate, it's fairly easy > to machine the plate off Da#n straight. If you can't save the chuck, the rest of it can be saved for sure. I'd leave the chuck split for machining, as I mentioned before. Should be quite smooth around there. And, you won't have to go clear to the back, most likely, the register area is unthreaded, and hopefully isn't frozen up. Plus, as you cut away material that was backing up the threads, they should relax and let loose before you are in danger of cutting into the spindle. But, since that is an Atlas 6", the crosslide and carriage is very thin, maybe even thinner and lighter than the "AA" or "109" type. So take very easy light cuts, and avoid any attempt to do the least bit of serious hogging if you do need to cut it off. The more so because you will have to extend the tool rather far out. Here is a place that proper use of the lantern post could be advantageous. If you set it up right, any problems will just knock the tool out of the way. Jerrold ------- Date: Wed, 15 Dec 2004 18:05:23 -0000 From: "misterfxt" Subject: Re: HELP!!! Frozen Chuck air impact Well, on my logan 820 the chuck was stuck too. It hadn't been touched for 10 years. I tried all the gentle approaches. Nothing worked. An old time machinist told me to try the air impact wrench on a socket extension in the chuck trick(after grinding some flats for the chuck jaws to grip). The spindle was freewheeling so no damage. Three whacks from the air impact wrench and off it came. I even ran the tool as slow as it would go. Try it. ------- Date: Wed, 15 Dec 2004 19:31:22 -0000 From: "Tom" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) > "Toss the lathe" comment was meant as humor as in a ridiculous idea... > Good luck Glenn Glen, I knew that couldn't have been a serious suggestion. My goodness, as a last resort, it is in such good shape, I could dismantle the whole lathe and sell the parts. Somehow, canibalizing doesn't seem right, though. Thanks for the input, Tom ------- Date: Wed, 15 Dec 2004 19:54:33 -0000 From: "Tom" Subject: Re: HELP!!! Frozen Chuck (I don't mean chuck roast) Jerrold, yes, I've taken the chuck apart and could easily machine it off - thanks for that idea in your original responce. It (to me, anyway) was one of those ideas that was so obvious it was completely invisible to me. I hope it doesn't come to that though - it's a fine old tool and I respect fine old tools greatly, even if just to hold and look at and appreciate. But this chuck also looks to be completely usable too - even came with the set of "inside" grip jaws, that don't even look used. Tom ------- Date: Wed, 15 Dec 2004 20:01:22 -0000 From: "Tom" Subject: Re: HELP!!! Frozen Chuck air impact Jerome, I might have to see who I know that owns an impact wrench. Good to know that you were able to break it free while spindle was freewheeling. Thanks. Amazing all of the responces and ideas my question has generated. I feel blessed to have stumbled upon this site. Tom ------- Date: Wed, 15 Dec 2004 20:08:23 -0600 From: Rex Burkheimer Subject: Re: HELP!!! Frozen Chuck air impact I vote for the impact wrench. With the tumbler gear in neutral, and the pin pulled in the headstock gear, backgear disengaged, the rotating assembly will still have enough mass to resist the rotation of the air tool. It should come right off. If you can't find a loaner, just go buy a cheapie. HF probably has one for $25. HD probably rents them, or possibly a 110V variant. Rex B Ft Worth ------- Date: Wed, 15 Dec 2004 21:12:45 -0600 From: Jon Elson Subject: Re: Re: HELP!!! Frozen Chuck air impact Tom wrote:>Jerome, >I might have to see who I know that owns an impact wrench. Good to >know that you were able to break it free while spindle was freewheeling. Actually, you probably don't need an impact wrench. Once you have the chuck body off, you have this thin backplate still on the spindle. Leaving the spindle disengaged from any gears, you should be able to put a bolt in the holes in the plate and whack the bolt with a piece of 2x4. This should impart PLENTY of impulse to the plate to loosen the grip. You might want to just give it one or two whacks in each hole, then move the bolt to the next hole, and work around the plate. If this doesn't work, I don't think the impact wrench will do it, either, unless you use a 3/4" tool (which I would not recommend). Jon ------- Date: Wed, 15 Dec 2004 23:03:49 EST From: n8as1x~xxaol.com Subject: Re: Re: HELP!!! Frozen Chuck air impact 12/15/2004, elsonx~xxpico-systems.com writes: > PLENTY of impulse to the plate to loosen the grip. You might want to just give it one or two whacks in each hole, then move the bolt to the next hole, and work around the plate. < or go one further...put 3 scrap bolts in & take the stoutest flat/round bar u can find , abt 12- 18 inches ,place thru the outstanding bolts , THEN , smack the far end w/ a 3 lb hammer !!.....if u lock the back gears ,put a REAL stout piece between the chuck jaws & jump on the end , U WILL take a tooth out on a 1912 reed -prentice 14 in.... trust me on this ... best wishes docn8as ------- Date: Wed, 15 Dec 2004 23:32:08 EST From: catboat15x~xxaol.com Subject: Re: Stuck chuck When I got my 12 inch lathe the three jaw was stuck, frozen, tight whatever anyway I could not get it off. Got some penetrating oil (Not Liquid Wrench, some brand the hardware store owner recommended). Then while I re-organized the shop to make room for the lathe, I just left the lathe on the garage floor with the back gear engaged and the bull gear locked with its pin. Had a wood block in the three jaw that was stuck and everytime I passed the lathe I gave the wood block a medium tap with a hammer. (Not hard, just enough to jar things a bit.) One morning the chuck just spun off with no effort and no damage. Apparently the small "jolt" allows the oil to seep in a bit more each time it is jolted a bit until the penetration is complete or far enough along to allow the chuck to unscrew. Now when I mount a chuck I carefully clean all the threads, spindle etc and mount the chuck with a final 1/4 spin so I hear the happy "Thunk" of the chuck or face plate seating solid on the spindle. Never had a problem with anything seizing again. ------- Date: Thu, 16 Dec 2004 17:08:03 -0000 From: "Tom" Subject: Re: Stuck chuck I like this plan. It goes with my "crossing my fingers" approach. I have been periodically squirting the Liquid Wrench at the end of the spindle threads and spinning it both ways. I'll try the gentle whack method too. I have faith that this rascal is going let go eventually. Thanks for your advise. Tom ------- Date: Fri, 17 Dec 2004 04:15:50 -0000 From: "Tom" Subject: !!! Frozen Chuck Unstuck !!! Gentlemen, start your engines. I freed the rascal! Here's what I finally did. It has been bugging me so I kept farting around with it and finally, without even planning to do it today, I drove the dang spindle out (I had studied Clausing's instructions last night). After I had the spindle, with chuck plate attached, in hand, I reassembled the chuck with jaws and proceeded to wing it. You know how it goes. I am a woodworker and once made a set of hard maple auxiliary jaws to hold various diameters of wood dowels in a vertical position in my woodworking vise. What it amounts to is two flat mated 1" thick, 4"X12" maple boards, clamped and drilled through their 4" width with the center line for the hole being their interface, such that each of the two jaws has one half of the diameter of each vertical hole, so that when you put them together you have a 4" long through hole. [---o---] This would be a plan view. You still with me? I clamped the spindle in these jaws, in the 3/4" hole, along its longest step, that is a little larger than 3/4" diameter, and tightened the works in the jaws of my massive woodworking vise, about as tight as I could w/o using a cheater. Next, I inserted a long maple lever across the face of the chuck, between two of the jaws and cranked on it. The spindle just wanted to turn in the wood jaws. Hmmm? Next I screwed a 3/4"X16 nut w/washer onto the spindle tight up against the bottom of the jaws, and again cranked on my lever. What was that? I think it broke free. Eureka! It spun right off. Why it was so tightly jammed, I haven't a clue. As I had suspected there was no rust whatsoever. Besides greasing the threads and the interface of chuck and spindle I am not sure how to prevent this happening again with this chuck. Any suggestions out there? What with the intimate relationship I am developing with my new lathe, I think I may have acquired a new mistress. Now that I know removing the spindle is easy - much easier than I would have thought - I think I'll go through the whole lathe, cleaning, greasing and oiling. Why isn't it suggested to pack the Timken roller bearings with bearing grease? Seems it would make more sense than oiling them with 10wt or even 20wt oil. Thanks again, to all who took the time to share their solutions. Tom ------- Date: Thu, 16 Dec 2004 23:42:25 EST From: jmartin957x~xxaol.com Subject: Re: !!! Frozen Chuck Unstuck !!! I might try Never-Seize instead of grease, but I'm not sure how much good it would do. Woodturners often put a leather or plastic washer between the register shoulder and the chuck, but this wouldn't be so hot on a metal lathe, as you want more accuracy and want the chuck to index solidly against the shoulder. Interrupted cuts are what really lock the chuck on, so you should avoid them. But you can't avoid them, so no help there. Best I can suggest is to remove the chuck fairly often. John Martin ------- Date: Thu, 16 Dec 2004 21:16:58 -0800 From: "Glenn" Subject: Re: !!! Frozen Chuck Unstuck !!! What works best for me is to give the chuck a sharp twist the last 1/4 turn or so. It "thunks" into place and is tight but removable easily and does not seem to tighten up more from use that way. Also use a thread cleaning pick everytime you put it on. A single chip in the threads can lock it up pretty good. I made my pick from welding rod (gas rod) bent like a hairpin with the ends tweeked straight out and ground to a 60* edge. It holds itself against the inside of the threads and you just unscrew it to clean the threads. A light coat of spindle oil is all I ever use on the threads. Just to keep rust away mostly. You don't want the chuck to unscrew when you stop the lathe from high speed! As to grease in the bearings. It will do bad things in there like hold chips and get hard and block the oil that is needed to lubricate them properly. #10 spindle oil works great. The felt wicks in the oil cups may need to be replaced if they are hard and don't let the oil pass through. It should take about a day for the oil to drain down in the caps. The oil flows through the bearings and carries the small particles that could cause damage on out. I should have said SAE 20 wt non detergent oil. I think it is the same as #10 spindle oil but I am not sure now that I think about it... I bought 1/3 of a yard of 1/4" thick felt at a fabric store that works great in the oil caps and way wipers. You will notice the countershaft (jackshaft) has no wicks. They are sintered bearings and act as a wick. The "oldies but goodies" section of the clausing website has lubrication and assembly charts. http://www.atlas-press.com/servicebulletins.htm YMMV ------- Date: Fri, 17 Dec 2004 18:27:18 EST From: n8as1x~xxaol.com Subject: Re: !!! Frozen Chuck Unstuck !!! In a message dated 12/16/2004, jmartin957x~xxaol.com writes: > Best I can suggest is to remove the chuck fairly often. congrats !!! feels goooood , nicht war ! i have never stuck a chuck in near 50 yrs ...(YET ! ) ..& i think J Martins suggestion is the reason!!. doing 4 jaw work & between centers tool making keeps the spindle shldr freed up ....just register chuck w/ a LIGHT chunk as U it seat it from maybe a 1/16 turn ....never spin it on to register ,manual or power... stuck chucks are usually from as mentioned ,interrupted cuts ,carelessness / wrecks ..or ??? instant forward after running in reverse (3 phase power) FWIW ...powdered rosin , (brownells was a source ) on the blocks was used for barrel block clamping , back when olde tymers used wood for blocks ( as i still do ) made the difference between holding & not best wishes docn8as ------- Date: Sat, 18 Dec 2004 01:35:34 -0000 From: "tj_bassi" Subject: Stuck chuck.....stuck spindle.... The thread on the stuck chuck reminds me of a situation with my first lathe, a 6" Timken Craftsman. The chuck was fine, but the spindle pulley was frozen to the spindle, making use of back gears impossible. It stayed like this for a few years, and yet it was oiled regularly with the rest of the machine. When it came time for a new belt, I poured 3 in 1 oil all over the spindle assembly every night for a week and tapped the spindle with a rawhide mallet, and after a few nights it let go. When the spindle was out for the belt, we found NOTHING...not even a speck of dust, it looked as clean as the day it was made. I didn't lose any sleep over it, but it would have been interesting to find out what was locking the pulley to the spindle. Tj Bassi ------- Date: Sun, 30 Jan 2005 11:31:32 EST From: jmartin957x~xxaol.com Subject: Re: 3-Jaw Chuck Tightening? [atlas618lathe group] 1/30/2005, n5kzwx~xxarrl.net writes: > On the Atlas_Craftsman group, I asked for advice on tightening a > Craftsman 3-jaw chuck on a 618 lathe. There was some discussion, and > some confusion so I thought I'd post a few photos. Unfortunately, > their photo section is having problems, so I'm moving the discussion > over here. The photos are in the Photos section in the 3-Jaw. > Chuck folder http://tinyurl.com/3kpun > The chuck in question is threaded for a 1x8 spindle, and has a > Craftsman part number of 333.22970 (I think -- it's pretty faint). > The question is, how do you tighten this chuck? It has a hole for a > tommy bar on the scroll plate, but there's no other place on the chuck > to grab it against the torque from the tommy bar. > I have been using an adjustable wrench slipped over one of the jaws, > but that doesn't feel right. I've already had to replace the bull > gear after breaking some teeth off, so I don't want to use the back > gear to lock the spindle. I made a wrench to grab the collar behind > the register, but it's a bit of a PITA to use, so it only comes out > when the chuck is jammed too hard on the spindle. Any suggestions? > Ed Bailen Drill a hole in the chuck body to accept a second tommy bar. Even better, drill three - one between each set of jaws - and drill a few more in the scroll as well, so you'll always be able to get at a convenient set of holes. That said, tommy bars aren't really a good way to tighten a metalworking chuck. A geared scroll is much better. If you want to do a little better than the tommy bar, make up a pin wrench to fit in the tommy bar hole. You can make one for the hole you drill in the chuck body as well, but that one may have to have a slot to clear the protruding jaw. I use these all the time on Sherline chucks and on specialty wood lathe chucks, and they work a lot better than the tommy bars. John Martin ------- NOTE TO FILE: There has not been much in discussions lately to fit into "Chucks General". Lots have already been well covered so far in this file. Also see all the other chuck files here arranged under lathe brands. Someone there may have the solution you are looking for. Chuck information can often be adapted from ideas about another brand. And I will keep looking for new stuff to add here. ------- Date: Wed, 25 Jan 2006 13:39:10 -0000 From: "paul_probus" Subject: Re: Using Anti-Seize to prevent STUCK CHUCKs? [atlas_craftsman] Bernie: In my experience, a chuck stuck on a lathe is the result of the chuck tightening itself further onto the spindle. Anti-Seize is great when used to prevent nuts and bolts from seizing on due to corrosion. But corrosion should not be a problem with lathe spindle to chuck connection unless you leave your lathe in a humid area or outside. One of the best methods that I had seen for avoiding stuck chuck syndrome was to use a thin thermoplastic washer. If the chuck tightened itself on due to use and you could not remove it the conventional way, application of a little heat to melt the plastic washer should allow you to get the chuck off. Paul ------- Date: Wed, 25 Jan 2006 12:20:36 EST From: jmartin957x~xxaol.com Subject: Re: Re: Using Anti-Seize to prevent STUCK CHUCKs? The plastic or leather washer is often used with woodturning lathes. With metal lathes, I'm not sure it's as good an idea. The fit of the chuck to the register and against the shoulder is what gives it its accuracy. Having a compressible substance between the surfaces will affect its accuracy. And, unless the washer is machined in place on the spindle, it may not be of even thickness. All of which may be fine in most circumstances, but when you're trying for the utmost accuracy it may be a problem. Finally, if you're cutting threads and want to remove the chuck during the operation to check them (against the spindle, say), you'll have to be very careful to tighten the chuck identically each time to keep the register to the leadscrew exact. Probably not a major problem, though. All of which is to say it's not a bad idea and would probably work most of the time, except when you need the greatest accuracy. The best thing, of course, is not to get the chuck stuck. Which means keeping it oiled and never - ever - threading it on under power. And, similarly, never throwing the lathe into forward when it's in reverse and you see the chuck unthreading. John Martin ------- Date: Wed, 25 Jan 2006 17:13:49 -0800 From: Steven Harris <79ramchargerx~xxwavecable.com> Subject: Re: Using Anti-Seize to prevent STUCK CHUCKs? I am using coloidal graphite in isopropal alcohol on my spindle threads. I have been doing it since the first time I removed the chuck. When I was in the Navy we used it to prevent galling on threads. Since I started using it I have had no problems removing my chuck or faceplate. It dries to a very thin film and is not sticky like other anti-seize compounds. Steve ------- Date: Thu, 26 Jan 2006 02:34:26 -0000 From: "Paul" Subject: Re: Using Anti-Seize to prevent STUCK CHUCKs? Steve, I assume "coloidal" graphite is graphite of a certain range of small size particles. Where do you purchase this? Paul ------- Date: Wed, 25 Jan 2006 18:49:53 -0800 From: Steven Harris <79ramchargerx~xxwavecable.com> Subject: Re: Re: Using Anti-Seize to prevent STUCK CHUCKs? Yes Colloidal is a size range. I have not had to buy any in a very long time. For what I'm using it for the 2 oz bottle is a lifetime supply. Here is the info from the label. MFR PN neolube no 1 Huron Industries, Inc Port Huron, Michigan 48060 I did a search for it on the web. Here are some links. http://www.p-b-l.com/pbl2000/Neolube.html This link has the same stuff I use although I did not get it there. http://www.sisweb.com/sptd/tubeaccs.htm If you get some, whatever you do, do not spill it. A 2 oz bottle will cover over a 100 sq ft. Steve ------- Date: Thu, 26 Jan 2006 08:48:59 +0100 From: "hlees" Subject: Re: Re: Using Anti-Seize to prevent STUCK CHUCKs? Most piano shops use the stuff to dry lube the wood action parts. The bottles are very small. I drop a ball bearing in so that it can be agitated before use. ------- Date: Sat, 28 Jan 2006 02:44:10 -0000 From: "seaies" Subject: Re: Colloidal stuck chuck, etc. For years I have used a paper gasket made from typing paper to keep the chuck from sticking, I learned this trick from the Supper Chef that I worked with in the Navy on a Repair Ship, the Ajax AR8. Ride safe Mike on the rock ------- POPULAR SCIENCE ARTICLE: HOW TO TRUE UP A WORN CHUCK [atlas_craftsman] Posted by: "Bill Senko" bigbears04x~xxhotmail.com senko400 Date: Fri Jan 26, 2007 5:46 pm ((PST)) Hi Guys. I just posted a link to a pdf. file of an article that I had from a December 1962 issue of Popular Science. The one page article shows and explains how to true up a worn three jaw chuck. I haven't tried this procedure so I am not sure if it would work or not. The article does have two pictures and gives an explanation of how it is to be accomplished. Good luck to all who try and fix their worn chuck. Sincerely yours, Bill Senko Link url: http://groups.yahoo.com/group/atlas_craftsman_projects/files/True%20Up% 20A%20Worn%20Chuck%20pdf.%20file/ File Name:True Up A Worn Chuck pdf. file A Popular Mechanics article from December 1962 ------- Re: Chuck Jaw Rework [atlas_craftsman] Posted by: "jerdal" jerdalx~xxbrick.net Date: Tue Jan 30, 2007 6:05 am ((PST)) jerdalx~xxbrick.net wrote: >> See previous posts for the reason there is not only no problem with loading out towards the end of the jaws, but the fact that you HAVE to do that. Of course, you don't need to crank on the chuck key super hard.....But loading at the back of the jaws is useless for grinding, since you need to grind parallel AS THE CHUCK IS , not how you wish it were. << Jon Elson wrote: > Well, it worked FINE for me, when I did it on a well-used Cushman chuck. But, it was a VERY well-made chuck, and the jaws were not at all loose in their slots. If the jaws were loose, then this would be a problem no matter where you loaded them while doing the grinding. If you loaded them at the tips, then it would take too much material off the back end of the jaws, and they would never grip except at the tips. When the jaws or slots are too worn to hold the jaws from rocking in the slots, I think it is time to retire the chuck. < Actually, since the jaws are loaded NORMALLY in such a way as to tip them out the same as when loaded at the jaw ends, grinding should be done in the same condition as use, loaded out away from the chuck face. Contrary to what you have said, grinding with them loaded out at the tip is the ONLY way to avoid having the jaws grip solely at the "heel", which leads to unstable gripping, shifting work and much frustration. Rather than leading to gripping only at the tip, it ensures gripping all along the jaw. I have done several chucks, all that way, and all now grip along the entire jaw. But, naturally you are free to use your tools any way you wish... JT -------- Re: Re. Chucks [atlas_craftsman] Posted by: "catboat15x~xxaol.com" Date: Fri Jun 22, 2007 7:31 am ((PDT)) We have discussed and cussed chucks, but what we are looking at is "work holding". My experience has been modified by my inability to purchase a three jaw chuck for my first Atlas. (I was in school on the G.I. Bill and $$$$ were in short supply.) So my first chuck was a four jaw, and it did not take me long to learn to center work in a four jaw as accurately as I needed for a particular piece of work. (A neat stunt with the four jaw is to have two chuck keys, as you loosen one, take up on the opposite side, it really speeds things up.) Then the next was the Jacobs that threaded onto the spindle. Really handy for small work and if I started with stock a little oversize it was "right on" as you finished the part's OD while in the chuck before parting off. Otherwise I was close enough for "government work" as they say. Next thing (after finishing school and getting a job) was the long desired three jaw scroll chuck. Pretty good when new but not "right on" but in using that thing I found a hint in a magazine. If you have to remove your work piece from the three jaw, pick up a piece of chalk and mark where jaw number 1 was gripping and when returning the work to the chuck locate that mark under jaw 1 again and it will be pretty close. Another scheme I have used is to make up a "false spindle nose" (aluminum is OK) which you should do anyway if you are going to make up a back plate from a casting. Then if I have to remove work from the lathe to put on the drill press table I just unscrew the chuck from the spindle complete with work piece, screw the chuck onto my "false spindle" that is on a plate now and put that over on the drill press, do my work screw the chuck back on the spindle and it ends up just like when I took it off. Then when doing work that is irregular shape and you have one datum plane on the piece you can bolt the work onto a face plate by the use of an angle plate or straps whatever. In other words there are many ways to "skin the cat" and none are wrong if it does what you need at the time and doesn't harm your favorite toy. John Meacham from the high deserts of Calif 12 inch Atlas lathe, mini mill, HF band saw and a rusty file. ------- Big bore Myford 7 on a small-bore budget [MyMyford] Posted by: "drookle" a.troupx~xxemail.com Date: Mon Aug 20, 2007 6:13 am ((PDT)) This idea came to me while I was pondering the temporary "embarrasment of riches" of having two chucks to choose from for the same job. This arises from the fact I'm temporarily luxuriating in the possession of two Seven-Series lathes. I'm just in the process of quitting an ML7 in favour of a Super 7, working out what to sell and what to keep (and doing improvements to key components of the latter while I've got another lathe to do the work with). So I temporarily have two 6" 4 jaw independent Burnerd chucks, which differ only in that one has a backplate while the other (which came with the Super 7) has a threaded body. These are a special build -- I imagine the Myford 7 series was one of the few lathes numerous enough to earn such an indulgence from a chuck manufacturer. On the face of it, it's no contest which chuck to keep, the short-coupled threaded body seems to hold all the aces. The threaded body confers less overhang past the spindle bearings (more rigid, less chatter) and also means that there is more space available in the gap for swinging a long item held crosswise, lying on the face of the chuck, at 45 deg to the cardinal axes of the 4 jaws. (Admittedly, this is not something I tend to do since I acquired a vertical milling machine). However, in this case, it occurred to me that there was one other important consideration. As I often do, I wanted to "hide" as much of the workpiece as possible within the chuck, bearing in mind the pathetic spindle bore of a trad Myford. There is much more hiding space inside the chuck with the backplate than lurks within its short-coupled cousin. And it occurred to me, that all these years I've bemoaned the lack of a large spindle bore, a glorious kludge had eluded me. All I need to do, to simulate spindle bore "up the wazoo", is to make a second chuck holder for the 4 jaw, effectively a s - t - r - e - t - c - h - e - d backplate: a long cylindrical bell housing, with a female spindle thread at one end and a "backplate" flange at the other. If it's quite long, I can support it with a fixed steady BETWEEN the chuck and the spindle nose. Setting the steady up would be a snap, given that the surface it is steadying is already running true. The only snag is that the standard Myford steady limits us to about 50mm diameter: if I follow this line of inquiry up to the hilt, I'd ideally go to a 60 or 65 mm journal OD for a massively rigid "spindle", and make a purpose-built housing, solidly clamped to the bed right behind the new chuck location, probably travelling with the extension spindle, and incorporating a decent-sized roller bearing (radial loads only; thrust still the preserve of the real spindle). Properly done, as well as providing a stiffer spindle, this would overcome some of the springiness inherent in any gap bed. And it would mean the saddle would spend more time up the far end, where most beds don't accumulate much wear, to balance things up a little. In this way, trading length to gain diameter, it would be quite reasonable on our 'toy lathes' to simulate a hollow spindle of into which we could bury a diameter of 40mm (!) to a depth of 200mm, and still have a length of 500mm available outside the chuck. Trading some length for diameter would suit those who, like me, do a lot of work that is shortish and fattish. This is especially the case if, as I often do, you work with aluminium, which doesn't respond well to running a fixed steady on it for any length of time. ------- Re: 4 jaw self-centering chucks [MyMyford] Posted by: "tr0up" tr0upx~xxyahoo.com Date: Sat Nov 10, 2007 9:26 pm ((PST)) "HG" wrote: > Anyone got views on these? Are they accurate? (I can't quite see how they manage the trick with 4 points of contact.) And what happens if the stock isn't precisely square? Or am I missing the point? I get fed up trying to centre square stock in the 4j independent to turn a section of square round -- and even quite small errors show the round part isn't in the centre of the stock. Same with holes of course. I do use the "centre some round stock of the same size first and then just loosen 2 adjacent jaws etc etc" method, but it's not always very accurate, I find. Maybe I should just try harder. Henry < Henry, If you get a good one, and provided you use it only on stock that is precisely round or square (or hexagonal, which not many people realise) they are brilliant. This is not as big a limitation as it sounds, because it's detrimental for the continuing health and accuracy of any self-centering (three, four, six or eight jaw) chuck to use it on work which is not uniform in section from one end of the jaws to the other, which tends to go hand in hand with the above characteristics. Most bright-drawn (steel) or extruded (alu alloy) bar stock material will be fine. SC chucks should NEVER be used on hot rolled (ie "black") steel bar stock, or castings. My view is that they are not nearly as popular as they deserve to be; as well as the obvious advantages when chucking square stock, they are substantially more secure, as each jaw works in direct opposition to another, and the opportunities for the workpiece to escape into a gap between jaws is reduced, because the gaps occupy smaller portions of the circumference. More jaws also works better when gripping thin-walled workpieces. This is a big part of the rationale for 6 and 8 jaw chucks, but even a 4 jaw is substantially less prone to distorting such a workpiece The only significant drawback with increasing numbers of jaws is the workload of reversing the jaws, but if you already have a 3-jaw you can keep the jaws reversed on that and leave the 4 jaw in "male workpiece" mode most of the time. The other (which again is more apparent with 6 and especially 8 jaw chucks) is that the scrolls are more exposed to chips, and so the chucks are harder to keep clean and free running. (Brief foray, OT from strictly Myford territory, follows: I don't have a 4 jaw SC of a suitable size for my Myford; however I do have a 200mm 4 jaw Rohm SC chuck which I purchased with the intention of keeping it for best when doing smallish jobs on my big lathe. A my big lathe is not currently going, I mainly use it quite a lot, lying on its back, on my Arboga vertical mill-drill. For quite a few jobs with a horizontal long axis, it's more versatile than a vice, and self centering to boot. I use rectangular loose pieces of bright MS rectangular in lieu of one or both vice jaws for these jobs. Without touching the chuck's orientation, you can clamp a workpiece along, across or at 45 degrees to the long axis of the bed. And of course it's perfect for round, square or hex bar held with the long axis vertical.) Back to Myfords: A 150mm Pratt Burnerd 4 jaw SC came up recently on the local www auction site and closed at NZ$170 -- which was above the limit I'd set myself, having spent way above my budget on Myford stuff recently, but it was hard to walk away. That's a ridiculously low price for a chuck described as (if memory serves) "like new". ------- Re: 4 jaw self-centering chucks Posted by: "HG" hgx~xxallthemunros.com Date: Sat Nov 10, 2007 11:16 pm ((PST)) Many thanks for such a comprehensive -- and positive-reply. I hadn't really thought beyond the square stock point and certainly didn't realise a 4j sc would work well with hex. Thanks again- I'm off shopping! Henry ------- heavy adjustment Burnerd 3 jaw chuck question [MyMyford] Posted by: "svenalferink" sven.alferinkx~xxwur.nl Date: Wed Nov 14, 2007 5:34 am ((PST)) I've got a ML10 with a Burnerd 3 jaw chuck. This chuck is turning quite heavy when adjusting the jaws in or out. I cleaned and greased (used molygrease) the jaws, cleaned the rotating threads that drive the jaws and checked that the jaws are in the right slots (no's 1,2 and 3). Without the jaws in the chuck the adjustment is easy and the key can be turned with one finger. I compared this chuck with another and it really adjusts heavy. I'm also thinking that because of this heavy turning it does not center the workpiece very accurately. Do any of you have any suggestions about the cause and the solution to this "problem" Sven ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "joegib1946" joegib1946x~xxyahoo.com Date: Thu Nov 22, 2007 10:23 am ((PST)) Sounds like you may have swarf/chips trapped in the scroll. When you remove the jaws the scroll turns freely because it is not trying to drive the jaws though the jammed chips. These can get into the scroll when you chuck larger workpieces that expose the scroll to turnings flying off the toolbit. A quick fix may be to: a. Remove the chuck from the lathe b. Remove the jaws c. On the workbench jam an old tooth brush (or better still, a brass suede brush) into one of the jaw slots at the inner end of the slot d. Turn the chuck key anti-clockwise while keeping the brush firmly in the slot e. This will wind the brush out of the slot and hopefully bring all dirt/chips with it f. Watch for the end of the scroll through the slot under the brush and make sure accumulated debris is swept out of the slot rather than rolled past it g. Do this several times and for the final passes first clean the brush and dip it in white spirit/alcohol to loosen any dirt sticking to the scroll faces. h. Thoroughly clean the jaws, oil and install them and check for ease of movement. i. If movement is still tight/rough, remove the jaws. Looking from the front of the chuck, turn the chuck key and watch the scroll as it turns. Look out for chips embedded in the scroll walls. If you see any, dig them out with the point of a scriber. If this procedure doesn't solve the problem then I'm afraid you'll have to disassemble the chuck and clean all parts thoroughly to restore it to proper operation. This is something you should do at least yearly anyway. Joe ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "svenalferink" sven.alferinkx~xxwur.nl Date: Mon Nov 26, 2007 4:58 am ((PST)) Thanks Joe, for the detailed answer. I already did the cleaning with the toothbrush and that didn't help. So I'll check the scroll for embedded particles as you advised. I already had a look at the chuck to see how I could disassemble it but removing the three bolts did not result in the thing falling apart. How should I proceed in taking the chuck apart? Thanks, Sven ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "Jim Guthrie" jimx~xxsprok01.plus.com Date: Mon Nov 26, 2007 9:04 am ((PST)) Sven. The last time I took my Burnerd 3 jaw apart, I think I remember it needed a bit of gentle persuasion with a soft mallet to get the body apart. The other question that I was wondering was if you have had the chuck from new, or did you get it secondhand with the problem. I was wondering if someone had sourced some jaws from another chuck which might have been a slightly tight fit on the scroll. Jim ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "joegib1946" joegib1946x~xxyahoo.com Date: Wed Nov 28, 2007 5:30 am ((PST)) Hi. Jim Guthrie's correct. The inner backplate unit secured by the 3 screws is a close (but free) fit in the chuck body but the flange forming the back is rather deep and heavy. So it tends to bind against the inner chuck body when you try to pull it out. Suggest you proceed as follows: 1. It is desirable that on re-assembly all parts of the chuck be restored to the same location occupied originally. You'll note that each keyhole unit is numbered. You should first mark the chuck body alongside the keyhole unit entry point to match the number on the unit. Ideally, you should use small number punches. Alternatively, you can make small centre punch dots - 1 dot for keyhole 1, 2 dots for keyhole 2 etc. Or, if you on't like the idea of permanently marking the chuck, make temporary felt-tip pen marks. 2. Wrap a thick elastic band tightly around the chuck circumference in line with the keyhole units (this is to stop them falling out when the inner backplate is released and the chuck is reversed). 3. Unscrew the 3 screws securing the inner backplate. 4. Reverse the chuck and holding it between your hands (face upwards) jiggle and shake it horizontally. The backplate should simply fall out of the chuck body (do this over a soft surface like a folded newspaper). 5. Reverse the chuck and you'll see its internals, similar to a planetary gear arrangement except that the keyhole units are actually bevel gears. Remove the elastic band and push the keyhole units out through their holes in the chuck body. 6. Reverse the chuck body and do the jiggle/shake thing again. The "planetary" gear unit should then fall out of the chuck body (you'see that the other side of this unit is machined with the scroll). And that's disassembly completed. 7. Wash all parts with solvent (I use white spirit), scrubbing out all grime/chips. Check the parts for embedded chips and pick them out with a scriber. Allow to dry, oil all parts and then re-assemble the chuck ensuring that the keyhole units are restored to their original positions. Don't forget to clean the chuck jaws in the same way before inserting them. Hopefully, this will solve your problem. ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "svenalferink" sven.alferinkx~xxwur.nl Date: Thu Nov 29, 2007 1:02 am ((PST)) Thanks again for the very detailed and well written answers, Joe and Jim. As for Jim's suggestion about where I got the chuck: I bought my ML10 secondhand (6 months ago, and its my first lathe) and I got it with the heavy adjustment chuck problem. So I don't know if the previous owners (I know I'm at least the third owner) changed the original jaws. The jaws have a serial number but I did not see a serial number on the chuck, should there be one somewhere? And should it be the same as on the jaws? Thanks a lot for the dissassembly instructions for the chuck, I'll first try to find some posts on how to get the chuck of the spindle. The spindle is right hand threaded I guess? So counter clockwise to unscrew? Sven ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "Jim Guthrie" jimx~xxsprok01.plus.com Date: Thu Nov 29, 2007 2:26 am ((PST)) Sven, Another couple of things I was thinking. Did you get a set of outside jaws with the chuck -- you should get such a set with a new Burnerd three jaw -- and if you did, do they also exhibit the same tight feel. If you think that the tightness might be caused by excess depth of the teeth in the jaws, after cleaning the chuck as Joe lays out, maybe try a paper gasket between the front body casing and the chuck back to see if that frees up the movement. If the teeth are too deep and you are still able to operate them, then a thou or two of relief using a paper gasket might just do the trick and make operation a lot easier. You are also reminding me that it's about time I stripped mine down again. I haven't been able to get much time in the workshop for the past few years, so it's been a bit of a time since it has been cleaned. :-) Jim ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "Jim Guthrie" jimx~xxsprok01.plus.com Date: Thu Nov 29, 2007 6:16 am ((PST)) >The jaws have a serial number but I did not see a serial number on the >chuck, should there be one somewhere? And should it be the same as on >the jaws? Sven, I've just been out in the workshop and checked out my internally threaded Burnerd three jaw. This is the chuck I bought new with my ML10 about 35 years ago. All the six jaws have the same six digit number stamped on them as well as the numbers 1, 2, or 3. There is a design number stamped on the front face of the chuck and another two numbers, one of which might be a serial number and the other looks like a Myford part number -- it's certainly got the word 'Myford' in the number. On the back of the chuck, there is a stamped three digit number which matches the last three digits of the six digit number on the jaws. This three digit number is not stamped as neatly as all the other numbers which might imply that it is done manually at some inspection or finishing process. Maybe others might know the significance of the numbers. Jim ------- Cleaning Burnerd 4 jaw chuck [MyMyford] Posted by: "Lawrence Keating" steamcatx~xxshaw.ca Date: Wed Nov 28, 2007 10:18 am ((PST)) I'm slowing cleaning all the accessories I received with my recently purchased new/old Super 7. One of the chucks that came with the lathe is a Burnerd 4 jaw chuck made for Myford. It is the low profile model that is threaded to mount directly on the spindle (ie. no back plate). It has 4 cast in recesses in the back. It was easy enough to remove the jaws for cleaning but I'd like to know the best way to clean all the crud from the screws as well. Can they be removed? It looks like there's some sort of round posts from the back of the chuck that holds the screws in place. But I can't see how these could be removed. But they had to be installed somehow. Any ideas?? Thanks ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "svenalferink" sven.alferinkx~xxwur.nl Date: Fri Nov 30, 2007 6:02 am ((PST)) Hello Jim, I went to my shop yesterday evening and checked my 3 jaw chuck also, and the numbers are exactly as you described. Both sets of in and outside jaws have the same six digit number and the last three digits of that number are stamped on the chuck. So I needn't worry about someone mixing up the jaws. My outside jaws are moving considerable easier than the inside jaws I am having the problems with. I'll check dimensions on both sets to see if there is a difference in thread height or pitch to try to identify the problem. To describe the problem better: With the outside jaws in the chuck I can turn the key with one finger, with the inside jaws I need to use my whole hand to turn the key. Thanks for helping, I'll keep you posted on my progress. Sven ------- Re: heavy adjustment Burnerd 3 jaw chuck question Posted by: "Frank Chadwick" fr4nk.chadwickx~xxtiscali.co.uk Date: Fri Nov 30, 2007 9:26 am ((PST)) Hi Sven, Hope you don't mind my butting in on this one; the inside jaws may still be very new and unused, hence stiffer. Also you may like to try loading one jaw at a time to see if the trouble can be more precisely located. Just a thought, Frank C. (Sunny Saddleworth UK). ------- Re: Reversing Chuck Jaws [atlas_craftsman] Posted by: "jerdalx~xxsbcglobal.net" Date: Sat Nov 17, 2007 5:54 am ((PST)) > Yes folks, chucks DO wear out - which is we see the threads RE > regrindingchucks all the time. If you can afford it, buy a new one. Yes, chucks DO wear out, and yes, there ARE chucks which are "too far gone". However there ARE "legitimate" reasons for re-grinding the jaws ... i.e. ones not related to a basically worn-out chuck with floppy jaws and a lumpy worn scroll. One reason is if the jaws get damaged, especially if ONE gets damaged, such as by spinning a part in the chuck. Yes, chuck jaws ARE hardened, but some PARTS are hardened also, and such a part can raise burrs on a jaw or cause other such issues. Grinding will restore a good surface if done right. Any chuck which is not "loose" can have jaws re-ground to bring it back to reasonable performance if they are damaged. Often the scroll path is OK but it's center bearing is worn, allowing it to move off-center. If the scroll bearing is shimmed, and the jaws are ground, you may well get, for a trifling price in materials and time, a chuck which performs as well as you can expect ANY 3-jaw chuck to perform. They are not a precision device. Now, not all problems are curable by grinding. If you are re-grinding the jaws because the chuck is holding parts inconsistently off-center, THEN the doom-sayers may be correct to trot out their "book larnin" about it being correct only at one place on the scroll, etc, etc. Of course it would be wise to check for loose scroll bearing, as well as jaw timing and correct positions before condemning it. Naturally, even if it IS "only correct at one point on the scroll", but it holds parts securely and isn't ridiculous anywhere, it may be perfectly usable for you. You should be expecting no better than centering within a few thou for ANY 3 jaw. Attempting to get one accurate to 0.001 is silly. I'd certainly ACCEPT that performance, but not EXPECT it. For grinding, you DO want to start with a chuck in which the jaws are not rattling. Generally, jaws which move any direction except in and out are a sign of a chuck that needs to be demoted to the drill press soon. That problem is not fixable in any realistic way. Chucks make dandy vises for round items even when no good for the lathe. You may want to grind the jaws before using it as a drill press vise, however. The runout won't matter in the least, but it needs to hold tight. JT ------- Re: Reversing Chuck Jaws Posted by: "catboat15x~xxaol.com" Date: Sat Nov 17, 2007 7:07 am ((PST)) On my first lathe, I bought new from Sears (that gives you some idea of how old I am) all I could afford while going to school on the GI bill was a four jaw chuck. A trick to dial in a four jaw quickly is to get two chuck wrenches and use one in front and the other at the rear so when you loosen one, take up with the other. Makes zeroing in with the four jaw much faster and easier. The other thing with a four jaw independent chuck is when close to zeroed, turn the chuck backwards by hand and let the tool drag on the work a bit. When you get a full scratch around the work piece, you are closer than most three jaw chucks will center. Even with a three jaw, if you have to take the work piece out of the chuck for some reason it probably will not be centered when you put it back on the lathe. You can get fairly close if you mark the work piece with a chalk line under the number one jaw before removing it; then when putting it back in the chuck, put the work under the same jaw. I have been playing with this hobby long enough now that I know thousands of ways to do things wrong. John Meacham from the high deserts of Calif 12 inch Atlas lathe, mini mill, HF band saw and a rusty file ------- Getting the best out of your Self Centering Chuck [MyMyford] Posted by: "tr0up" tr0upx~xxyahoo.com tr0up Date: Fri Dec 14, 2007 9:54 pm ((PST)) Even the most dismal cockups sometimes have their redeeming aspects. I've always dreaded the chuck unscrewing - threaded spindle noses are a REALLY bad idea - but in over thirty years it had never happened to me. Now I've done it twice in three months. I can forgive myself for the first instance; I'd newly purchased a very old but rather lovely Super 7, and failed to check the motor rotational direction before turning it on. In my defence, I plead that it was a single phase motor. I'm accustomed to checking rotation for newly installed machine tools, hydraulic power packs etc with three phase motors, where it's theoretically wrong half the time, and in practice it seems to be more often than that... Single phase motors always rotate the way they were initially wired (unless they're already spinning faster than the centrifugal switch setting in the other direction when you turn 'em on !) I caught the chuck before it did too much damage to the bed (whew) and my hand healed up within weeks. You would think this combination of emotional and physical would teach me a lasting lesson, but this last time it was entirely my fault. I'd taken on a paying-type job which involved drilling hundreds of 2.5mm holes 40mm deep in brass rod. It was taking two minutes per hole in the ML7, not good. I was wishing I had the Super 7 running: at 3000 rpm (I'm fitting a DC motor) instead of what I had always imagined to be 650 rpm, things should go much faster, and feed pressure should reduce as well. I thought, why not put our discussion about maximum speeds with T1 whitemetal bearings to the acid test? All the pulleys from my Super7 are interchangeable (mine has the clutch in the step pulley), and the motors are the same speed, so I should be able to have a sneak preview of how the other half have always lived. It was while doing this that it occurred to me to wonder what speed the ML7 actually achieved, so I dug out an ancient rev counter (the mechanical sort, with a rubber `live centre', which literally counts revs). I held this against the nearly closed chuck jaws for a timed period and found I was really only getting about 500 rpm. When I fitted the Super 7 pulleys (including the MUCH larger motor pulley) I repeated the exercise on top speed, but it was more difficult to hold the rubber cone into the jaws, so I swapped hands and waited for the second hand to come around. With swapped hands, I mistakenly turned the switch the wrong way, so reverse rotation ensued. With the massive increase in ratio and starting direct on line instead of via a clutch, my best chuck instantly leapt most of the way off the thread and smacked into the end stop I had set up on the boring table. In grinding to a halt, it garked up the spindle nose most horribly, which I'd managed to keep absolutely pristine for thirty long years. It was a steel body, integral threaded chuck, which are scary on an ML7 with the soft spindle at the best of times, but I'd NEVER got it crooked or stuck, and I always had a moment of delight when I cleaned the spindle nose prior to fitting a chuck and saw that it looked literally as good as new. So you can probably imagine I felt a little sick. I'm almost over it, but it has not been easy. Today I finished repairing the spindle nose, and gingerly refitted the chuck. Initial indications were that the TIR was now about 0.12mm, at least twice what it was. However, I thought I'd check the other keyholes. Novice chuck users may not be aware that even the best SC chucks usually perform differently depending which of the holes you use to tighten them, so the first job with a new chuck is a session with a DTI and various diameters of strictly round bar (you may find that one hole is best for large work and another for small). Mark the holes and always use the optimum one from then on, unless it's really not fussy work. Imagine my surprise and delight when I found that one of the formerly poorly performing holes was now an absolute star, often centering most diameters of work to within 0.01mm ! (Not quite as repeatably, but at least three times as accurately - at best - as before my little episode, and it almost always achieved this figure with only two tries). This may not last, as clearly one or more jaws are now sprung, but I'm making the most of the consolation for now ! So the point of this post is NOT to emulate the first part of my sorry tale (duh !) but the triumphant conclusion. You might just find you can have collet-like accuracy on a SC budget. ------- Preventing Inadvertent Reversals [MyMyford] Posted by: "tr0up" tr0upx~xxyahoo.com tr0up Date: Fri Dec 14, 2007 10:32 pm ((PST)) (as distinct from advertent versals) http://www.frets.com/FRETSPages/Machining/Tooling/SwitchSafety/switchs afety.html This guy's stuff (ideas, energy, machines) is uniformly nice - inspirational, in fact. I already planned to do something along these lines (inspired by the mechanical latches on old race-car gearshift H-gates to lock out reverse) when I set up the drive for the Super 7, but now it seems like a serious priority (see my last post) For anyone wondering why a screwed-nose lathe should be fitted with reverse at all, try running a small button die (in a tailstock holder) the full length of a bar under power and then see how you like winding it off by hand ! Also great for tapping under power. For those who were brought up to believe a tap will break if it's not stopped and reversed several times per rev, this only applies to tapping by hand, and the reason you have to reverse and break the chip is that you've stopped, which you were forced to do by a design fault in the human wrist which prevents unlimited rotation. If you tap under power, and use ground-thread HSS taps, they last much longer than they would if you used them under the same conditions (eg in the lathe) pulling the belts by hand and reversing in the old fashioned way. Getting back to the topic of this post (sorry for the detour): If you screw the cleaned chuck on to a clean, dry spindle nose with a judicious 'wrist snap' at the end, the chuck will normally stay put for the sorts of work instanced above. Do not under any account try running the lathe in reverse for turning, for boring (except for tiny holes where it greatly improves visibility of the tip), or LH threads when it's almost essential) but most particularly, do NOT follow the advice occasionally given (properly directed at "proper" spindle nosed lathes with no provision for a rear toolpost) to part off in reverse with the tool upside down in the ordinary toolpost. Beware when starting in reverse, particularly in high speed modes - if you don't have a clutch, use the countershaft lever as a poor man's substitute to ease the spindle up to speed. To paraphrase Oscar Wilde: "Take my advice, I'm not using it..." I should have the sackcloth and ashes back in the closet in a few more days. ------- Re: checking headstock alignment with a 'virtual faceplate' [MyMyford] Posted by: "tr0up" tr0upx~xxyahoo.com tr0up Date: Tue Jan 1, 2008 1:00 am ((PST)) Earlier this year, Piet Butter wrote: > Had an attempt yesterday trying to measure alignment against the 7" > face plate but that did not work out as the face plate has quite a > bit of a wobble, which can be easily fixed as soon as I have the > headstock square with the ways. I came across this looking for a different matter, but I wish I'd spotted it at the time. Piet doesn't seem to be within reach of a computer at present, but for the sake of anyone who might grapple with this topic: The best way to simulate a dead flat faceplate, dead square to the spindle axis, is to use the 4 jaw chuck and a straightedge and a DTI. As well as being cheap (or free), it gets away from one of the limitations of the (expensive) test bar when you need to check the bedways vs headstock alignment: being round, the test bar is problematic if the top of the bed dips towards the chuck. In this scenario, the probe of the DTI will travel below centre height on the bar, a spurious deflection of the needle will result, and confusion ensue. The basic idea is to grip the straightedge sideways in the chuck (using a crafty dodge described below), clock the face (the narrow face which faces towards the tailstock) at (say) the far end, near the motor, and repeatedly tap it more square in the jaws so that when the chuck is spun half a turn, the other end converges on the same reading on the DTI. Now you effectively have a datum face, square to the spindle axis, and true to the limits of the resolution of your DTI. 'Fabelhaft', to coin an archaic German expression of satisfaction. Clamp a machinist's square to the bed lying flat, pack up one end of the thin blade to keep it level if it's that sort of square (personally I like the simple, rugged one-piece toolmaker's pattern which are made from flat gauge plate) Now run a DTI (on a surface gauge, with the dowels pushed down) across the square to get one face parallel to your datum in the chuck, then tighten the clamps and run the same gauge along the long blade of the square, indicating against whichever shear is not used to guide the carriage (if this is not obvious, Search recent posts for "wide guide" or "narrow guide"). This will tell you if the headstock needs to be swivelled. The correct answer is "no". (There's almost nothing you could do to a Myford, without rendering it unfit for further service, which would require such drastic measures) The other shears can now be clocked up, and a diagram drawn on graph paper exaggerating the x scale by say a factor of 100 or more, depending how much deviation you've measured, to give you a picture of the shape the shears are in. Now that you know if the bed is true, and if so, where, you can also check the front face of the cross slide, with reference either to the 'virtual faceplate' or the square on the bed. Then if you're really keen, take off the cross slide and check the front dovetail on the carriage. Use a piece of ground silver steel or similar under the overhang of the dovetail, then butt up a ground parallel or what have you to make a flat surface for the indicator probe. A ground parallel will also serve as the straightedge in the chuck - ideally it wants to be thicker than a steel rule, but the rule out of a decent combination square will do at a pinch. Aternatively, use a piece of high quality keysteel (sold at most engineering supply houses), preferably at least 12mm square, and definitely one that has been wrapped in a bunch in an oily wrapper rather than kicking around the shelves getting bent. * * * * Some who are new to lathes, and a few who are not, may not have realised that a 4 jaw chuck, because the jaws are ground at 45 degrees so they can almost meet in the middle, can be used to grip any rectangular or square section workpiece whose length is the maximum which can swing in the gap - 250mm, in the case of the 7 series. The trick is to open the jaws quite wide, turn the chuck so the 4 jaws, viewed from the tailstock, look like a X rather than a + , and place the bar horizontally so it lies on (say) jaws 3 & 4, on those 45 degree faces. Then use the chuck like a vice, where jaws 3 & 4 are moved together as though they were a single vice jaw, and ditto with 1 & 2, to centre the workpiece (for this exercise, by eye using the engraved rings against a feature of the jaws is plenty). Leave the final tightening until you've squared the bar across the bed as described above. If you're doing this with a view to machining the bar, you may have to include packers between the jaws and the workpiece, if it is of low sectional height, so that the jaws will be further apart. If you have a 4 jaw SC chuck (wonderful things) this is a really quick dodge. What's more, such a chuck, clamped lying on its back on the table of a drill press or (drill) mill in X rather than + configuration, will self-centre work, and hold it either across or along the bed in the case of the mill, without moving anything. ------- Re: checking headstock alignment with a 'virtual faceplate' Posted by: "Eric Parsonage" ericx~xxeparsonage.com Date: Tue Jan 1, 2008 3:08 am ((PST)) Troup, Thanks so much for this. I was wondering how I would be able to check if the cross slide was setup up correctly; now with this straight edge in the 4 jaw that becomes trivial. Regards Eric ------- Re: chuck jaws [atlas_craftsman] Posted by: "S or J" jstudiox~xxtbaytel.net Date: Wed Jan 23, 2008 10:45 am ((PST)) redragonnetx~xxyahoo.com on Jan 22, 2008 wrote: >I have an Atlas 618 with the 5 inch 3 jaw chuck but it came with only >the inside jaws! Does anyone know where I can buy only the outside >jaws? Thanks, Norm Thomas Camillus,NY Hi Norm: The 618 came with standard chucks of 4" diameter; so the 5" you have was added later. You did not identify the chuck make/model so that may explain the lack of response so far. While 5" chucks may be used with caution, with larger stock the jaws can stick out beyond the chuck and pose the risk of a collision with the bed or whatever. So if you do use a 5" be sure to check for clearance before switching on. Jaws are normally fitted to their individual chucks -- so jaws acquired even from the original manufacturer may be too tight or loose. While you may find a correct set on auction sites, you will not know if they fit properly until you actually receive them. Why not just acquire a new 4-jaw 4 inch chuck with reversible jaws? After a bit of practice centering stock in the 4-jaw, you may prefer its precision over the 3-jaw and make it your standard one (outside of dealing with occasional hex stock). And this new-to-you chuck certainly does not have to be a frequently overpriced used Atlas. Lots of good, brand new imports available. Most folks agree that if you could only afford one chuck, the 4-jaw has the most versatility. But if you want a new 3-jaw as well (with 2 sets of jaws), you can always sell the 5" to help cover the cost. Might be your easiest and perhaps best option. There is a lot of useful informatiom about chucks suitable for the 618 discussed in various subject files on my site including: Atlas Chucks General Atlas Backing Plates for Chucks Chucks General Atlas 618 Gems regards Steve -- in Thunder Bay, Ontario, Canada Machining and Metalworking at Home http://www.janellestudio.com/metal/ ------- Re: chuck jaws Posted by: "scott bryan" sportycaferacerx~xxyahoo.com Date: Wed Jan 23, 2008 11:16 am ((PST)) Hey Norm, I just bought a cheap 3 jaw from Grizzly for around 50 new. Beats a wore out used one for the same price. What I did was mount the 3jaw on a MT arbor that fit the tail stock and use it to generally center the work in my 4 jaw; then just pull it out and put in a live center or whatever I need. Saves a lot of time with a good 4 jaw to be dead on. ------- outside jaws [was chuck jaws] Posted by: "redragonnet" redragonnetx~xxyahoo.com Date: Wed Jan 23, 2008 12:34 pm ((PST)) Thanks for the replys to my chuck jaw problem! My chucks are 4" & not 5" like I claimed! I also have the 4 jaw chuck with what I believe are reversible jaws? The faces of the jaws are flat so it looks like they would work in any direction. Anyways that is the chuck I will use with large diameter stock. Thanks for straightening me out. Norm, Camillus, NY ------- Re: Chuck an old Chuck? [MyMyford] Posted by: "Thomas Staubo" thstaubox~xxonline.no Date: Sat Mar 8, 2008 7:36 am ((PST)) John Stevenson wrote: > Before you go grinding chuck jaws check that there is NO wear where the scroll fit the body. If there is, no amount of grinding will rectify this as it will always be on the move. I spent the best part of 1/2 a day truing up a 10" 3 jaw only to find that it held different diameters better than others. To be honest given the cost of a decent chuck nowadays I don't feel it's worth the time and effort to get a half assed job done. < That's a good advice, John, to check for wear before attempting to rectify any run-out. The other day, I found a very nice tutorial on disassembling a three-jaw chuck, and grinding the chuck jaws. It showed a clever alternative method of holding pressure on the chuck jaws, without using a ring at the rear of the jaws, to hold on to. Using a ring (or disc) to hold on to, is the method I have always seen described before when grinding the jaws, but that's not possible (on my chuck at least) if you want to grind the jaws in one go. Take a look here: http://www.homemetalshopclub.org/news/aug04/aug04.html#truing Thomas ------- setting up 4-jaw chuck [atlas_craftsman] Posted by: "Dave Williams" roninx~xxaristotle.net Date: Wed May 14, 2008 7:07 pm ((PDT)) I need to drill some 5/16" holes through some 5/8" square steel stock to make some new toolholders for another piece of equipment. The holes have to be offset near one corner of the square stock. This sounds like a job for the four-jaw chuck. I can lay out the position of the holes with ink and a scribe, but how the heck do I locate the workpiece in the chuck and keep it from shifting when I tighten the jaws? I figured I could put the center in the tailstock, run it close, and eyeball it by guess and by gosh, but I'm hoping there's a better way! ------- Re: setting up 4-jaw chuck Posted by: "Michael Fagan" woodworker88x~xxgmail.com Date: Wed May 14, 2008 7:24 pm ((PDT)) You need a dial or dial test indicator and some way of mounting it so that it is rigid and on the centerline of the spindle. Then, you'll need to scribe centerlines down the side of the stock so you know when you've got the indicator pointed dead-center on the side of the square. First, you're probably best off centering the stock (equal reading on all four sides). Then, working with one set of jaws at a time, offset the stock by the distance from the centerline to your desired hole location. By all means, use the center punch marks and the tailstock center to make sure you haven't made a mistake in the process. Let me know if you need clarification Michael ------- Re: setting up 4-jaw chuck Posted by: "Dave Williams" roninx~xxaristotle.net Date: Wed May 14, 2008 8:46 pm ((PDT)) Michael Fagan wrote: > You need a dial or dial test indicator and some way of mounting it so > that it is rigid and on the centerline of the spindle. Then, you'll > need to scribe centerlines down the side of the stock so you know when I can do that. 1) Center the workpiece with the indicator. 2) With the vertical jaws just snug, back off the rear jaw, then shift the workpiece back with the front jaw until the indicator reads the correct offset. 3) Tighten back jaw. 4) repeat steps 2 and 3 as needed... 5) turn chuck 90 degrees 6) repeat steps 2 and 3... Jeez, no wonder nobody likes 4-jaw chucks! ------- Re: setting up 4-jaw chuck Posted by: "n8as1x~xxaol.com" n8as1x~xxaol.com Date: Wed May 14, 2008 8:50 pm ((PDT)) center punch where u need to drill the hole....make up abt a 6 in long piece of 3/8 round stock w/ a point on one end & center drilled on the other ...put the point on the part where it is center punched & the center drilled end in the t/stock center ....now set up an indicator near the point & adjust the pairs of jaws till the indicator reads zero TIR ......easiset way for me is to record the total runout, then move the chuck till it reads 1/2 the runout & zero the indicator there.....now line up one pair of jaws w/ the indicator & adjust to zero ...do that w/ thye opther pair ......repeat both & u r there....quicker than i can type it ....under 2 minutes w/ practice.... best wishes docn8as PS ...a spring loaded test bar is an improvement, but a straight one will work fine ...& it can be near any reasonable diameter bar....u cud even chuck a piece of 1/8 in rod ..put a point on it & indicate ...but a 1/4 to 3/8 rod is preferable ...stndrd tool maker accessory that shud be in every machinist box ------- Re: setting up 4-jaw chuck Posted by: "TCHarex~xxaol.com" Date: Wed May 14, 2008 9:52 pm ((PDT)) I agree completely with the wiggler that N8as1 suggested with two improvements that I am sure he is aware of. First, when you cut the point on it, without removing from the chuck, also cut a diameter about a half inch back from the largest diameter of the point. This establishes a surface for your dial test indicator to run on that is exactly concentric with the point that you just created. Second. You don't have to do this to make it work, but if you are happy with your new tool and want to improve it, some suggest that you use a small boring tool and open up the female taper so it can wiggle more easily while you are dialing it in. Second and a half, live centers work fine here, the tail end does not have to be the most wondrously concentric part, only the head end. Regards, Tom ------- Re: setting up 4-jaw chuck Posted by: "Ed Locke" EdLockex~xxMindspring.com Date: Thu May 15, 2008 2:06 pm ((PDT)) I love my 4-jaw, and rarely use a 3. The slight (and when you get used to it - it IS slight) extra time involved to center the workpiece is more than made up for in the accuracy of the center. If you are turning everything relative to the current set-up - the 3-jaw is great. As soon as you have to flip the piece or turn something on a piece with existing features the 3-jaw is just sloppy. The only thing I don't like about the 4-jaw is chucking up hex stock! Ed ------- Re: setting up 4-jaw chuck Posted by: "Michael Fagan" woodworker88x~xxgmail.com Date: Thu May 15, 2008 3:43 pm ((PDT)) I, too, use a wiggler whenever possible, but you should keep in mind that it relies on the accuracy of the centerpunch mark, whereas using the dial indicator to directly measure the offset avoids this issue. If accurately locating the centerpunch is easy (for example, using a height gauge), then by all means, this works quite well. ------- Re: setting up 4-jaw chuck Posted by: "Jim" jimmy163333x~xxyahoo.com Date: Thu May 15, 2008 6:28 pm ((PDT)) I'm also in agreement,but I rigged up a tool that I think is easier to work with. I put a 60 degree point on a short piece of 1/2" square stock and added about 6" of either 3/16" or 1/4" rod to the back of that. You just grab the rod end in a tail stock drill chuck. Centerpunch your part, put the point in your center punched mark, and the indicator rides on the flat of the square that you set perpendicular to the bed. (The point doesn't have to be concentric to the sides or rod, as long as it's not allowed to spin). Center out the punch mark with opposing jaws in both axes of the 4 jaw chuck and give another final check after you think it's good (the indicator reading shouldn't move). And I haven't added it yet, but it really does need to be spring loaded. My point got a little messed up because as you get closer to center the rod tries to move closer to the tail stock. It still worked fantastic, much less frustrating than trying to set the indicator on a round part. Your first try might take pretty long to get the hang of a 4 jaw chuck, but after you get good (with practice) it should only take a few minutes to set it up. Another thing about 4 jaw chucks is that a part can be taken out and put back right on the money, which is almost next to impossible with a three jaw chuck. To spring load mine I'm going to drill a socket in a round bar that the rod will slide smoothly in, put a spring in the hole and pin the rod to a slot to retain it and keep it from spinning. Try the square way, you'll never go back. Jim ------- Re: setting up 4-jaw chuck Posted by: "catboat15x~xxaol.com" Date: Thu May 15, 2008 7:36 pm ((PDT)) Make a "wiggler" first. Just a straight length of drill rod or some other straight rod. Turn one end to a 60 degree point, the other end with a center made with a small center drill. Put the point end of the rod into a center punch mark where you want to center the work, use your tail stock to hold it there under light pressure. Dial in the end close to the work and you have done the work. The best hint I ever got from this list in centering things in the four jaw was "Use two chuck wrenches" One towards you and one in back as you move one jaw move the opposite jaw to match, makes setting up the four jaw a lot easier and faster. ------- Basic machining question [atlas_craftsman] [info applies to many brands] Posted by: "tony_dspglobal" zampini1x~xxcox.net Date: Sun Jun 15, 2008 8:35 am ((PDT)) Hello, I'm currently building the Hamilton Upsur single cylinder gas engine. A basic machining question has come up several times, and I'd like to get some expert opinions on it. Here's the issue: Let's say I have a 1" diameter rod that is 2-3 inches long. The OD is already machined, and I want to true it up in a 4 jaw chuck. So I do this in the usual way, but find out if I indicate near the chuck, it is running true, but if I move the indicator out to the end of the piece, it is a few thou out of true. I assume the chuck jaws are not perfect, which results in this problem. My question is, how do I make the piece run true along its entire length? I tried small shims between a jaw and piece, but this is hit or miss, and very time consuming. Thanks for any tips anyone can offer. I need a better way! Tony ------- Re: Basic machining question Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Sun Jun 15, 2008 8:54 am ((PDT)) The spindle axis of your lathe's headstock may not be parallel to the ways of the saddle. What lathe do you have? On some machines this is adjustable, others not. Your tail stock may be adjustable to allow turning tapers. In this case you can hold the work piece between centers, driving it with a lathe dog, and adjust the tailstock 'til the work indicates true. DC ------- Re: Basic machining question Posted by: "Jerry Kimberlin" kimberlnx~xxcomcast.net Date: Sun Jun 15, 2008 9:07 am ((PDT)) You don't mention the way your chuck is attached to the lathe. If you have a cam lock, then the problem might well be the chuck jaws. If you have a screw on chuck, then chances are you have never scraped in the backplate so it sets perfectly against the spindle locating point. If not, you can easily do that. Frequently with a screw on chuck, chips and other stuff gets in the threads and between the back plate and spindle. These have to be cleaned free of all particles. Well, I don't know if any of this makes sense for your machine and your situation. Maybe you can get back to us later with some more detail about the spindle and chuck. Regards, JerryK ------- Re: Basic machining question Posted by: "Ron Colonna" ron.colonnax~xxverizon.net Date: Sun Jun 15, 2008 9:15 am ((PDT)) Tony: Indicate the piece close to the chuck and set it running true. Move out to the end of the work and indicate there. Bump the high side into truth with a rawhide hammer. A light tap is usually all that is needed. Sounds crude but is necessary especially with older equipment. Ron Colonna ------- Re: Basic machining question Posted by: "tony_dspglobal" zampini1x~xxcox.net Date: Sun Jun 15, 2008 12:07 pm ((PDT)) Hi all, I guess I should have mentioned that I have a Sherline 4400 long bed. And I have already "scraped in" the backplate, which is only a small area on the Sherline. I'm gonna try indicating the chuck body itself and see if it runs true. Stay tuned. Tony ------- Re: Basic machining question Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Sun Jun 15, 2008 2:38 pm ((PDT)) Tony: Neither the Chuck register or the spindle on a Sherline Lathe will require "Scraping In" unless damaged. To do so may actually cause damage. The stock you are mounting in the chuck must also have flat parallel surfaces where it is gripped by the chuck jaws for stable accurate cuts. It must also be gripped by the full length of the Jaw gripping surface to be properly secured and prevent movement. If not additional clamping/ mounting procedures may be required. If these items are in place, most likely the problem is with headstock alignment. Since you have a Sherline lathe the headstock alignment is adjustable as mentioned by DC. The Alignment procedure for what Sherline terms "Maximum Accuracy" is covered on Page 12 of the "Assembly and Instruction Guide". You are certainly on the right track by checking the accuracy of your equipment. It is not practical to correctly fit rings or pistons to a cylinder that is not properly machined. Jerry Kieffer ------- Re: jaws and re-grinding [atlas_craftsman] Posted by: "jerdalx~xxsbcglobal.net" Date: Fri Sep 5, 2008 7:02 pm ((PDT)) > I don't know if you saw Denis' pictures, but the the wrong scroll thread and wrong jaw order things are out. It's still possible they're in the right order but in the wrong slots, but one of his pictures was of the jaws removed and laying next to each other. The gripping faces on them are waaay different; somebody has done a real number on these jaws. I suppose it's possible the backplate was off and somebody ground the jaws erroneously to compensate for it, but when things get this ugly the world becomes a much bigger place. Jim < I didn't see any pictures, didn't look for them. And, if the jaw faces are so obviously messed up, there is no need to look farther. But, that said, the subject of "out" three jaw chucks comes up so often it's worth enumerating the ways the jaws can LOOK "out" and yet really be perfectly fine if put together right. That set of jaws can be re-ground in place to be quite usable. You DO have to preload them, and the best way to do that is to drill a 1/8 hole in each one, insert a pin in each hole, and close the pins on a suitable sized slice of pipe. You can then get a grinder in and grind the jaws to grip evenly while turning the chuck on the spindle.* Do get the jaws in right before grinding.... The drilling can be done with a carbide masonry bit, if you have no other, but a proper carbide spade bit would be better. Cobalt drills don't seem to work on hard steel for me, although others claim good results. Don't waste time with the fancy 4 hole layout in a plate of metal that is often touted. It is 3 times the work, and requires very good accuracy to get results not a bit better than the pin method. The rubber band, spring, and backside of jaw loading methods are mentioned only to be condemned to the outer darkness as totally unworthy, unworkable, and generally both useless and counter-productive. When it has been ground, the chuck will not be any better overall than it was, but the jaws will at least grip precisely in one spot, reasonably well everywhere, and won't be bell-mouthed. Anyone who expects better than 0.003 centering from a 3 jaw badly needs to make friends with a 4 jaw chuck. JT * the idea is due to Rich Carlstedt. ------- Re: jaws and re-grinding Posted by: "n8as1x~xxaol.com" Date: Fri Sep 5, 2008 8:56 pm ((PDT)) jerdalx~xxsbcglobal.net writes: >Anyone who expects better than 0.003 centering from a 3 jaw badly needs >to make friends with a 4 jaw chuck. probably true if using prethrded b/plates as received.... or buying used on ebay may be lots worse ...BUT i have 6 in buck ,( came off an indexer), new 5 in bison, & three new 4 in china 3jaws, that i fitted b/plates to the spindle of the lathes & none were worse than .0015 tir one inch from chuck ..... one china, the buck, & bison were .00125 tir ....surfaces were hardened on the china chucks ,as well as the others, but they have not seen enuf use to know how long they will hold the tolerance...& if ur chuck doesent repeat to satisfaction, grinding jaws is a waste till / if u true, bush & return the scroll pivot & then u can plate the jaws to tighten them in the slots...& on & on... the bison has been in home shop use for abt 4 yrs now & repeats between .00075 & .0015 tir now...for some reason, one larger opening of the chuck hangs around .002 tir ..but my collets are gathering dust ...i just go to the 4 jaw when i need more....or for heavy or dicy setups...... ...problem is keeping the 3 jaw true ....a couple rip outs from the chuck, cause part hung out too far w/out a center in it, & ur accuracy is severely compromised...sometimes, judicious marking /scraping w/ a piece of carbide will bring it back ...SOMETIMES...for rough heavy work, if u want to use a 3 jaw, u better have & use a rough old one ...or u surely will have one SOON ... best wishes docn8as PS if anyone needs (ha), some totally trashed, wore out, butchered, 3 jaws ....i have the evidence of many sorry trades/acquisitions over the last 50 yrs, available ..... from 9 in down to 3 in ...one chuck's jaws on a 100 yr old lathe were so bell mouthed that lathe took a planing cut rather than turning the diameter down ...looked like it had been cut on a shaper....took a while to figure out how that was even possible .... but it was & IS ...... ------- Re: jaws and re-grinding Posted by: "jerdalx~xxsbcglobal.net" Date: Sat Sep 6, 2008 6:30 am ((PDT)) > were worse than .0015 tir one inch from chuck ..... one china, the > buck, & bison were .00125 tir .... You are doing well with that, but it falls well short of "centered". Why does everyone hate 4 jaw chucks and try to force a 3 jaw to substitute for one? There is a reason for a 4 jaw independent chuck, and centering is the main issue. It isn't even hard to do, but "amateurs" seem to always think it is "an advanced technique" that does not apply to an "amateur" or "home shop" worker. I guess that is right up there with avoiding turning tapers, and wanting "plans" for everything. If you are going to do shop work, the plain fact of the mattter is that sooner or later you will have to do something slightly more difficult. So you DO it, and learn. BTW, grinding jaws is the very opposite of a "waste" of time, since the main reason is NOT to make it center perfectly, but to get the bell-mouth wear off the jaws, so it will actually grip a part and not let it flop around. The 3 jaw when NEW won't center perfectly, except by pure chance, and should not be expected to. So obviously there is no reason to try to improve it, unless it is messed up, such as by a part spinning, or bell- mouth wear, etc. You absolutely will NOT get it perfect, but that is no reason to discard the idea as "a waste". In this case, it sounds as if one jaw is worn/ground down, and so evening them up will improve the chuck back to only its "natural" off-center amount. Not one thing wrong with that (so long as you know it still won't be "perfect"). It will help when holding smaller work, for which a slight off-center will be a bigger error vs diameter than with a piece of 3" stock. JT ------- NOTE TO FILE: MOUNT OR DISMOUNT CHUCKS WITHOUT BED DAMAGE These methods will help you mount (attach) a chuck to the headstock, or dismount (detach) it with greatly reduced risk of dropping the chuck and damaging something. The simplest protection for the ways is a wooden board placed across the ways underneath the headstock spindle. This board can be improved by attaching wooden blocks underneath it on either side of the ways so that it cannot accidentally slip off the ways. A better protection is to add blocks of wood to the above design so that the chuck is cradled at the exact height necessary to attach it to the spindle. Now you can concentrate on attaching/detaching the chuck without having to awkwardly lift it at the same time. A cradle will be needed for each diameter of chuck. The cradle can also be used to hold the chuck on a shelf so it does not roll off. This design is very useful when handling heavier chucks. A simpler device, best suited to smaller chucks, is a rod that fits through the headstock spindle and is securely held in the chuck jaws. With care it will prevent dropping the chuck when you are attaching or detaching it. In all cases be careful as you do not want to damage any parts including your own. ------- Re: Myford S7 4" SC 3jaw chuck - runout problem [MyMyford] Posted by: "Paul Bache" paulbachex~xxbtinternet.com Date: Fri Feb 6, 2009 2:49 pm ((PST)) "timperrin97" wrote: > The jaws are in the correct places and the backplate is correctly orientated. I think it is just many years of neglect. I only got the machine over the summer but before that it had had little use at my school and even less maintenance. My original theory was that the jaws were worn, but it doesn't matter if i use the inside or outside jaws, the error is more or less the same. < It's a simple method of holding round bar stock quite accurately in a worn chuck. Hold a piece of round bar in the chuck; bore/drill and ream it out to the required size; before taking it out of the chuck, centre dot where No1 jaw is; then remove it and hacksaw through the length somewhere between the jaws; remove any burrs and replace, making sure the centre dot is in the same location as when it was removed. I've got a collection of them in imperial and metric sizes -- much cheaper than a new chuck, and will give repeatable accuracy to within a couple of thousandths. Regards Paul ------- Re: Myford S7 4" SC 3jaw chuck - runout problem Posted by: "Paul Bache" paulbachex~xxbtinternet.com Date: Fri Feb 6, 2009 2:55 pm ((PST)) "timperrin97" wrote: > That is a cunning plan. I will have a look into that. I presume that the material used is brass? < I've used brass, but no reason not to use steel; might be worth popping into your local library and get a copy of "model locomotive building" by LBSC -- lots of useful tips in it! ------- Re: Myford S7 4" SC 3jaw chuck - runout problem Posted by: "timperrin97" bobwozere12345x~xxaol.com Date: Sat Feb 7, 2009 4:24 am ((PST)) There are some operations that need the work piece to be turned around or be milled after turning and such like. I also don't like turning round bar round again if that makes sense. It is already round so why should I have to make it round? Either way, I prefer the 4 jaw. Less stressful than the infernal 3 jaw. ------- Re: Myford S7 4" SC 3jaw chuck - runout problem Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk Date: Sat Feb 7, 2009 4:27 am ((PST)) Curiously, round bar isn't always round. Regards, Tony ------- Re: Myford S7 4" SC 3jaw chuck - runout problem Posted by: "Paul Bache" paulbachex~xxbtinternet.com Date: Sat Feb 7, 2009 4:31 am ((PST)) I've found the split collet method surprisingly accurate; turned my "Tich" axles that way! I found that it was quicker and easier than using the 4 jaw, but then that may be my inadequate skill with setting the thing! Also I'm using a very much older and lighter ML4 ------- fixing chuck scroll problems [atlas_craftsman] Posted by: "jerdalx~xxsbcglobal.net" Date: Sat Feb 14, 2009 7:48 am ((PST)) The subject of worn scrolls has come up a couple times. I have found that worn scrolls are not always what you think. Tradition- ally, they are supposed to be wear on the actual scroll spiral. And there doubtless IS wear there. But the wear is generally distributed, unless the chuck was used continuously at one diameter, or cranked down by "Bubba" using a cheater bar. Many times, the scroll plate is worn and loose on the cylindrical center that forms its "bearing". After all that gets wear regardless of work diameter. This allows the scroll with the jaws, to move around and refuse to re-center in the same place (it won't "repeat" well. In bad cases, it may allow the jaws to actually shift under cutting loads, causing minor dig-in's etc. It seems hard to believe, due to the jaw angles, but I can only explain some faults that way. In any case, if you find that condition when you disassemble your chuck (which you should do once or twice a year to clear swarf), you can insert shim stock to take up the slop. This will make quite a difference in the operation of your chuck. You can obtain shim stock in thicknesses from 0.001 up. That will take care of slop from a bit over 0.002 up to whatever. I suggest not concerning yourself with slop under 0.002, unless you really want to. It doesn't pay well for the hassle of working with very thin shims. In any case, I have fixed a couple chucks with shim stock, and found a very substantial improvement of operation, of centering, of ability to tighten, and general smoothness. You want a piece of shim that will wrap just about all the way around the bearing area. Be very careful when working it between the bearing and scroll. A fold will give you a hassle in continuing, and may require cutting a new shim. JT ------- Re: A Small Experiment... [taigtools] Posted by: "kd006" kd006x~xxyahoo.com Date: Sun Aug 30, 2009 12:29 pm ((PDT)) Nicholas Carter wrote: > Over on the Taig blog I just posted the results of an experiment I did > on boring the 3 jaw chuck jaws. The results were odd, to say the least. > http://cartertools.blogspot.com/2009/08/1050-3-jaw-chuck-jaw-bo ring-test.html > felicex~xx... is Nicholas Carter and Felice Luftschein. See our > homepage at www.cartertools.com/nfhome.html Nick, I have always wondered how boring a chuck with a washer would not leave a lip of some sort in the back of the jaws causing problems. Your experiment also shows that boring on loose jaws is going to end up with some runout so making a relief for the washer just may compound things. Since the taig jaws are screwed on it would almost be intuitive to center by adjusting the jaws rather than boring. I may have to try that, I have a couple of Taig 3 jaws I have never used so when I get the shop set up I will try that I guess. Right now I use an import steel chuck which after maching the mounting plate face and bolting it to the chuck was slightly under .001 runout guess I just got lucky. Kristin ------- Re: A Small Experiment... Posted by: "deanofid" deanofidx~xxyahoo.com Date: Sun Aug 30, 2009 4:19 pm ((PDT)) Kristin, when you get done boring the chuck jaws there is indeed a lip, or bump, left at the bottom of each jaw. You have to clean it up with a boring bar after removing the washer (before you chuck up your workpiece). Dean ------- Re: A Small Experiment... Posted by: "WILLARD WHEATON" wwheatonjrx~xxverizon.net Date: Sun Aug 30, 2009 5:02 pm ((PDT)) The following link shows a technique for truing 3 Jaw Chucks that is very simple and does not prevent you from truing the entire face of each jaw. It utilizes 3 square pieces of 1/8" thick low carbon steel placed between the jaws. Refer to Dick Kostelnicek's article called "Truing Those Tired Old Chuck Jaws" in the Houston Metal Shop Club's Volume 9, No. 8 August 2004. I made a set for an Atlas 9" lathe 3 Jaw Chuck, by first laying it out in AutoCad. The 3 pieces ended up to be 1" square. The lips of the pieces engage the 60 degree sloping surfaces of the jaws, leaving enough clearance so the grinding stone can engage the faces. I measured the distance between the 60 degree surfaces of each set of jaws, and fitted the pieces so there was very little clearance before tightening. Take a look at his writeup, you may find it to be better than the washer technique. http://homemetalshopclub.org/news/aug04/aug04.html Willard E Wheaton Jr Chalfont, PA ------- Chucks, faceplates, spindle threads - that sort of thing [MyMyford] Posted by: "obald102" obaldx~xxihug.co.nz obald102 Date: Thu Sep 3, 2009 1:44 am ((PDT)) ML7 I have two three jaw chucks, a four jaw and a faceplate. None of them screw onto the headstock spindle completely and they all don't do it to varying degrees. My outside jaw three jaw chuck barely goes on two complete turns. The male thread (on the spindle) looks pristine. All the female threads (on the work holding devices) look OK-ish. Passing the finger over them they are a little rough but there are no obvious dings. I have been through them all with a piece of bent sharpened wire and scraped all the swarf and gunk out of the threads. Doing this all the threads felt gritty and bumpy. After this crude manual scrape/clean there was no appreciable difference as to the ease of fit of the attachments onto the spindle. Any ideas? ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "Frank Chadwick" fr4nk.chadwickx~xxtiscali.co.uk m1ck1es Date: Thu Sep 3, 2009 2:13 am ((PDT)) Hi, I get round this problem by running a 1-1/8 x 12 tap down home-made and s/hand backplates. I think it came from RGS tools. You may also need to relieve the untapped end of the backplate which seats on the plain (shoulder) end of the spindle nose. Frank C. ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "ravensworth2674" ravensworth2674x~xxyahoo.co.uk Date: Thu Sep 3, 2009 8:10 am ((PDT)) We've been here before- and recently!!!!! I got shot down over this. 55 Degree and 60 degree threads are the most likely causes. The 'standard' tap is 60 degrees but the Myford tap is a 'bastard' to Myford. At the end of the day and once the chuck goes on, it is the register which holds the chuck in place. Of course, there could be a worn leadscrew somewhere in the camp. Time for the three wire system or the microscope on the crests????? Oh dear, oh dear! N ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "obald102" obaldx~xxihug.co.nz obald102 Date: Thu Sep 3, 2009 12:24 pm ((PDT)) I'm unsure as to what 'recently' means. I have been a regular reader (and occasional contributor) for about six months and I don't think it has been covered in that time. If you could point me to the previous thread I will happily go there and stop wasting people's time. I doubt the 55/60, imperial/metric thread angle is the root of the problem as two of the backing plates are originals from when the lathe was manufactured and have the machine's serial number (vintage 1951) stamped on them. The number corresponds with that on the lathe's bed. ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "grampys2002" d.wainx~xxxplornet.com grampys2002 Date: Thu Sep 3, 2009 3:23 pm ((PDT)) I had the same problem with the Myford face plate. To check the thread I turned the faceplate around and tried to screw it on the spindle. It would not go so I fastened a piece of round stock to the faceplate and held it in the 4 jaw chuck. I centred it up, set up the correct gear ratio and then with a threading tool mounted I very carefully worked the tool through the thread in the faceplate. I used a handle on the spindle and worked by hand rather than using power. It did not take a lot and I made sure I tried the thread on the spindle quite often. Whatever you do don't machine the plain part which is the locating section. If the part is from Myford that will be the correct size. I assumed the thread was Whitworth and used a tool accordingly. I'm not sure what Norm is mumbling about. David in Canada ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "ravensworth2674" ravensworth2674x~xxyahoo.co.uk Date: Fri Sep 4, 2009 12:50 am ((PDT)) Sorry, but I am not mumbling! I may be sitting up here in an Austrian Alp but there are 2 factors involved. The first is the register which must agree dimensionally between the spindle nose and each chuck, face or catch plate or whatever. At this point, no one knows whether the male and female registers are even concentric let alone be correct. Then we come to the thread which should be Whitworth 12TPI but any old rattling fit (within reason) is OK. Sorry but no one knows from millions of miles away what the so far unmeasured parts are. Somewhat grumpily, this is basic measurement- not done. Regards from me and the CuckooClocks N ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net Date: Fri Sep 4, 2009 1:35 am ((PDT)) Norman. You still haven't explained your comment about the Myford thread "55 Degree and 60 degree threads are the most likely causes. The 'standard' tap is 60 degrees but the Myford tap is a 'bastard' to Myford". What does what the thread angle matter if "any old rattling fit (within reason) is OK." This all sounds very contradictory to me. Regards, Cliff Coggin ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "timperrin97" perrti02x~xxgmail.com timperrin97 Date: Fri Sep 4, 2009 4:28 pm ((PDT)) I used to have problems getting my 4 jaw and faceplate on which I managed to solve by not screwing the chuck onto the spindle but screwing the spindle into the chuck. This might be a totally different problem but it is worth trying. If you simply hold the chuck up to the start of the thread with light pressure applied, then rotate the spindle (by a handle or by feeding the belt through by hand) and the chuck goes on a bit easier. As I say, this may be a totally different problem but I think it is worth a try because it involves no work. ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "mckay3d" mauricex~xxmckay3d.com mckay3d Date: Fri Sep 4, 2009 7:25 pm ((PDT)) I have had no problems with tooling for my S7, but I did have a problem with a face plate for my Schaublin 70. It just would not go on, even after I ran a correct size tap through it. I ended up putting the face plate in the 4 jaw on my Myford and centered it to 0 run out and just skimmed the bore of the face plate about .0005. It hardly made any swarf at all and the face plate went on smoothly. Maurice ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "lioneltedder" lionel.tedderx~xxvirgin.net Date: Sat Sep 5, 2009 3:42 am ((PDT)) Hello, When I purchased a new Prat-Burnerd threaded-body chuck for my, then, new Myford ML10 almost thirty years ago, it came with a note to the effect that the register had been bored slightly undersized to allow for possible wear on individual machines, and that the register should be eased by scraping or rubbing with fine emery cloth until it fitted correctly. The register was only undersize by a very small amount and armed with a sharp scraper, fine emery cloth and engineer's blue I soon had a snug fitting chuck. I was told, at the shop where I bought the chuck, that had I ordered the chuck and the lathe at the same time, this fitting would have been done at the Myford factory. This might be one thing to look at on your chucks. I have a set of taps from RDG for the Myford thread, these work reasonably well for cleaning and sizeing the tread, but I had to spend some time stoning the flutes to remove the large burrs from the cutting edges before they would cut on-size. Better quality, but far more costly, taps can be had from Guy Lautard in Canada, but the RDG taps can be made to work. I don't think that Ravensworth's suggestion regarding 55 or 60 degree threads is the answer. A 60 degree thread, size for size would have a different pitch (just compare BSW and UNC) so a 60 degree threaded tap would not screw into a 55 degree threaded hole without completely messing up the thread. Regards Lonel ------- Re: Chucks, faceplates, spindle threads - that sort of thing Posted by: "lioneltedder" lionel.tedderx~xxvirgin.net lioneltedder Date: Sat Sep 5, 2009 4:21 am ((PDT)) Hello, In my last post I stated that the pitch would be different, size for size, between 60 degree and 55 degree threads. I really meant to say that the depth of thread would differ. I have also noticed that some of the non-Myford backplates, usually made of steel, sold by some of the ME suppliers have quite tight threads, at least the two I have did until I ran my tap through them. I did read on one forum, it might have been this one, that these are supplied with 2.5 mm pitch metric threads, but I cannot confirm this. Lionel ------- Re: 3 Jaw Chuck eccentric [myfordlathes] Posted by: "anthrhodesx~xxaol.com" Date: Tue Feb 2, 2010 10:56 pm ((PST)) In a message dated Mon Feb 1, 2010, Tony Jeffree writes: > I think Mike D's point was that there are no guarantees that the register in the back of the chuck will be "... as perfectly centred as you could possibly want", so if you assume that it is, you may be disappointed. The alternative strategy being to not use the register, or leave some slop in it, so that you can adjust the final position of the chuck relative to the backplate before you tighten the bolts down finally. < If you're interested in determining whether the register in the back of the chuck is concentric with the scroll you might try: In a 4-jaw chuck mount a piece of round stock and true it to what you consider to be an acceptable degree of precision. Check the concentricity close to the 4-jaw and at several intervals along its length; you want to know that it is concentric with the spindle along its entire length or within the tolerance that you find acceptable. Turn your 3-jaw so that the jaws face the 4-jaw and tighten the 3-jaw onto the round stock close to the 4-jaw. Recheck the concentricity of the round stock on the tailstock side of the 3-jaw to determine that it has not changed during the mounting of the 3-jaw or because it's too light to support the weight. Now clock the register on the back of the 3-jaw. Your reading will be in relation to the accuracy of centering of the round stock and the scroll of the 3-jaw. If the movement recorded is within what you consider to be acceptable you could make the fit between the register and the back plate quite snug; if the runout is unacceptable and you want to try to get the chuck to run with greater concentricity, you MUST NOT make a close fit between the register and the back plate -- it will only guarantee that the chuck cannot be made to run with greater truth. When you have completed this test, remove the 3-jaw from the round stock and recheck the concentricity of the round stock. Since part of the test depends on the accuracy of centering of the round stock, you want to know that this has not been altered during these tests. To know about the accuracy of the scroll, you could perform this test on several different sizes of round stock. If the scroll is accurate the tests should all have the same result. Just a thought. Anthony Berkeley, Calif. ------- Cushman Chuck Disassemble? [atlas_craftsman] Posted by: "wheezer" wheezer606x~xxverizon.net Date: Fri Feb 12, 2010 8:27 pm ((PST)) I have a very nice used Cushman 3 jaw chuck for which I would like to take the back plate off. I have removed the screws from the back plate. There is a locating pin that is below the surface of the back plate. There is no apparent way to get the back plate off the chuck body. Ideas anybody.. please. Thanks lance ------- Re: Cushman Chuck Disassemble? Posted by: "jerdalx~xxsbcglobal.net" Date: Fri Feb 12, 2010 9:24 pm ((PST)) If these are screws holding the back and front together, screw them BACK in, but leave them a bit loose, engaged a few turns only. Rap them in turn with a brass hammer, while holding the chuck, and it should pop apart without much fuss. ALL decent 3 jaw chucks come apart. It's just a matter of how. JT ------- Soft Jaws [myfordlathes] Posted by: "Dave" david.milwayx~xxntlworld.com david.milway Date: Sun Jun 27, 2010 10:30 am ((PDT)) When I bought my S7 it came with a 3 jaw chuck which had about 15thou runout making it almot unuseable. It had obviously been "well used" in its previous life. I replaced this chuck with another I bought while visiting Myford's factory, and the original chuck was just left on the side. I thought some soft jaws would make the chuck usefull and had some jobs which could be helped by them. I had previously read an article in the June 2006 MEW on making soft jaws and finally plucked up the courage to try and make some. The jig I made was a little different but did the same job. I actually found that making the jaws was not difficult at all and that most of the worries I had amounted to nothing. The first set of teeth took about 1 1/2 hours to cut and the next and susequent sets took about 1/2 hour each. There are 6 sets in total as you need to make 2 sets of teeth. One of the jobs I needed to do was reduce the width of a 6" diameter ring for the smoke box of my traction engine. This required extenders to the jaws which were added to the ends, with soft jaws this is easily done. The job just fits on the S7 and must be machined with care as the jaws stick out a long way. I have added some photos in Dave's bits. On a test the jaws were shown to have a runout of 1.5thou which is much better than the chuck was originally. This could be better if the jaws were machined close to the operating setting Dave ------- Re: Soft Jaws Posted by: "Ken Strauss" ken.straussx~xxgmail.com kstrauss7 Date: Sun Jun 27, 2010 5:06 pm ((PDT)) Could you upload a photo and/or description of your revised jig? How is it better, easier to use or whatever? ------- Re: Soft Jaws Posted by: "t_staubo" thstaubox~xxonline.no t_staubo Date: Mon Jun 28, 2010 1:20 pm ((PDT)) Very interesting, Dave! I love home-made tools and tooling, but I don't have a mill yet so it's not going to be a project for me yet. Ken Strauss; Dave DID post pictures of both the jig and the finished chuck jaws. Link: http://tinyurl.com/2ee75jf/ Thomas Norway ------- Re: New hobby [atlas_craftsman] Posted by: "David Beierl" dbeierlx~xxattglobal.net Date: Sat Jul 31, 2010 11:53 am ((PDT)) At 07:56 PM 7/29/2010 Thursday, n8as1x~xxaol.com wrote: > may be over much, but spending a year w/ a 4 jaw > before getting a 3 jaw wud be advantageous as well ... I'll second that. My grandfather didn't have a three-jaw with this lathe, nor my father, and nor do I -- although I tossed the worn-out Almond Engineering (Athol MA) chuck in the scrap bin and bought a Bison 5" that's a bit large for the machine but works great.. I lie -- I welded a back onto a 5/8" Jacobs chuck and threaded that; but of course it's only good up to 5/8. And I have a 3/4" one that I think I'll be able to fill in, then bore and thread the taper to get it closer to the headstock as well as more capacity. The Jacobs chucks have a solid bottom but it's soft, and often it's already been drilled through by someone trying to get the taper unstuck; so it's no big deal to open it out to pass stock through. I'd love a "real" three-jaw and likely some day will get one, but that day may be a while off yet as money is tight. You get pretty good at centering in the four-jaw after you do it a few hundred times. When I get enough money for a three-jaw I expect I'll spend it on a Noga flexible magnetic base for my dial gauge. The most irritating part of the job is getting my no-name magnetic base to hold the gauge where I want it. Yours, David Beierl -- Providence RI USA Atlas 618 6"/3/index.html" lathe ca. 1941, shiny-new Taig mill. ------- Re: Is this chuck too heavy for my 10" lathe? [atlas_craftsman] Posted by: "Glenn N" sleykinx~xxcharter.net Date: Mon Feb 21, 2011 6:01 pm ((PST)) "mikestabbs" wrote: >I just bought a 6" 4 jaw chuck and an adapter plate from CDCO and MAN is this thing HEAVY! I have a 10-246 Atlas and the 3 jaw chuck it came with is like half the weight of this new 4 jaw setup. Am I going to damage my lathe if I use this? Should I send it back and buy a smaller chuck? < I have a 7" Kitagawa 3 jaw and an 8" 4 jaw on my 12" lathe. The heavier chucks act like flywheels and smooths things out it seems. You won't have any problems even if it is a plain bearing headstock as the plain bearings can actually carry more load than the timkens. ------- Re: Is this chuck too heavy for my 10" lathe? Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Mon Feb 21, 2011 4:00 pm ((PST)) This might be old hat, but a trick I learned from the guy that sold me my AC lathe was to find a 1' length of broom handle that will fit into the bore of the spindle. When I need to remove the chuck, I slide the rod through the chuck and about 1" into the bore. Tighten the chuck snuggly on the rod. Then spin the chuck off. When the chuck disengages from the spindle, the rod supports it. Of course I also have a piece of wood over the ways as an added precaution. I find it much easier to handle a heavy chuck with that rod secured in the jaws. As I get older, I know I won't be able to lift this chuck. I will then make a small ways mounted crane to move it around. Just finished one for my mill. Rick ------- Re: Is this chuck too heavy for my 10" lathe? Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Mon Feb 21, 2011 6:23 pm ((PST)) I ran an 8.25" Phase-II adjustable chuck on my 12" Craftsman. With the back plate it must weigh 50 Lbs. The 10" and 12" lathes have the same spindle. It certainly didn't do any damage. You do want to set it up so the overhang of the chuck is at a minimum. I cut down the backing plate I got for mine so the chuck could be as close to the spindle as possible. Jon ------- Re: New file chuck handling Posted by: "c_h_a_r_t_n_y" mgibsonx~xxstny.rr.com Date: Tue Feb 22, 2011 6:45 am ((PST)) MY experience for what it is worth: Chuck Cradle link below: Chuck Handling The chuck cradle in the link in "files" is just a quick fix that meets my requirements. Easy to see how to make it more professional but to each their own devices. In my case, it should have 4 wedges to get more length but I am going to do that sometime. Maybe over 30 years ago, my father ran a one man shop and had a large long very old lathe with a 3 jaw. He wanted a 4 jaw to re lengthen drive shafts for race cars. Need 4 for the yoke. I knew my way around Cincinnati as I had been there numerous times in my employment to get shop work done and milling machines rebuilt. So I measured up his spindle threads and we went off to some old surplus machine tool place. They had chucks in piles on the floor, where you picked your chuck, backing plate, and wrench. Pay cash, load it yourself. We found a 4-jaw and checked it out, only to find it had 5 sockets. Seems it had a scroll plate and independent jaws. So it was all steel, very heavy, maybe 250 pounds. I think it was 14" chuck. We found a section of scrap pipe, chucked it and one of us on each end and could carry it to the car. Mission accomplished. Well sort of: Now to get this thing on the lathe. Had to make a quick chuck cradle, then used a rope block and tackle with a rope through the hole to pick up the chuck and put it on the cradle to match it to the backing plate which was turned by trial and error to fit the chuck. The block and tackle was made permanent in the ceiling and he made a shelf behind the lathe to store the other chuck and switch them back and forth with the rope through the chuck center and the block and tackle to lift and swing. Sometimes two or more can share ideas and come up with a winner. My father has been gone over 20 years and now my brother has the shop and lathe. Happy chucking chart ------- Re: Is this chuck too heavy for my 10" lathe? Posted by: "c_h_a_r_t_n_y" mgibsonx~xxstny.rr.com Date: Tue Feb 22, 2011 5:10 am ((PST)) Re to mike Lathes are made to handle the weight. Larger issue is getting it on and off the spindle safely. I put a ultra simple chuck cradle design in files with a link this am. This is for a 4" chuck which I can pick up fine with one hand, but putting in the cradle and presenting it to the spindle, then turning the spindle to the chuck to engage the threads properly aligned, saves damage to the threads. chart ------- Re: Is this chuck too heavy for my 10" lathe? Posted by: "mikestabbs" mike.stabilex~xxverizon.net Date: Tue Feb 22, 2011 6:08 am ((PST)) Chart: Thanks for posting the photos of the cradle. I hadn't even considered getting this chuck on and off of my lathe safely. Mike ------- Re: Is this chuck too heavy for my 10" lathe? Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Tue Feb 22, 2011 5:28 am ((PST)) Chart, I like your nice and simple cradle. I've seen some that are cupped to prevent any rolling but I think they are also used for storage. I seem to recall a few with a scrap of carpet lining the cup. I too stick reminder notes all around my shop. In my case, it is to prevent making a given mistake for the SECOND time :-/ My favorite trick there is to put blank self stick labels on thin rubbery magnets and trim to fit. When I need a semi-permanent label, I write on the label and slap up the magnet. The front of my mill is covered with such little notes. It stays put until I want to replace it. Recently I've been thumbing through old projects books from Village Press. I saw a rather nice way mounted crane in there. I can see that as I get older, the chucks won't be as easy for me to lift and I certainly do not want to hurt myself. Rick ------- NOTE TO FILE: The following is just part of a much larger conversation in the atlas_craftsman group at Yahoo. Most of it dealt with the standard methods of refining/grinding jaws that have been discussed before in this file. The following messages also deal with alternatives, whether just starting with a new chuck or getting one with two piece jaws. ------- Re: Retruing Chuck Jaws Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sun Apr 24, 2011 11:33 am ((PDT)) Original Message----- From: Elton E. (Tony) Clark Sent: Sat, Apr 23, 2011 10:36 am > *I'll be interested in this thread and any solutions I haven't tried on my Atlas 6 and Atlas 12. A buddy bought his toolpost grinder over and we did the deed on the 12 using a ground washer for the centering device . . made it worse. Then we ran the lathe at top speed trying for a centrifigal effect of the jaws .. no luck. I'm thinking maybe one can't really true the jaws in a worn out chuck.* < wear/warp from over-tightening in the scroll, wear in its bore, or its stud, or loose jaws in slots will not allow repeatability ...grinding the jaws WILL allow a part to be held w/out wobble, but achieving a reasonable repeatable runout requires more effort than it's worth for a small chuck.... & FWIW ...my experience in buying used 3jaw chucks w/ 1 1/2X8 thrds has been dismal.....in last few years, i have fitted BLANK backplates to three 4 inch china chucks & one 5 inch bison 3 jaw .....3 chucks repeat 11/4 thou & one china chuck is 11/2 thou out..... collets are gathering dust .... best wishes docn8as ------- Re: Retruing Chuck Jaws Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Sun Apr 24, 2011 11:34 am ((PDT)) JR Hurd wrote: > Remember _*//*_Remember that this will make the jaws "perfectly" true > _*/on that lathe and at that diameter./*_ Regrinding jaws to improve centering may not help at all. Regrinding for the case where the tips of the jaws are worn away so that the work is only held at the back end of the jaws is likely to help a lot. I have done it for that exact reason, and it greatly improved the operation of the chuck. This is a common commercial shop operation, done on an as-needed basis when the jaws have worn. Jon ------- Re: Retruing Chuck Jaws Posted by: "Charlie Gallo" Charliex~xxTheGallos.com Date: Sun Apr 24, 2011 2:21 pm ((PDT)) Haven't MOST commercial shops gone to two piece jaws, partly for this reason (just replace the tops). I know this is the 'big buck' solution, but in my case I didn't have a choice. The 3 jaw that I got with my lathe was a 5" or so, and was missing one set of jaws, so I bought a new chuck, with 2 piece jaws -- what a pleasure (my previous lathe - an Atlas 6" had 1 piece jaws) it is to use the 2 piece jaws, particularly when you need to flip them around, or like next weekend, when I need a 'special' set of jaws (need an extra deep set to clear a protrusion on the 'chuck' side of some parts I need to turn). 73 de KG2V - Charles Gallo Quality Custom Machine-shop work for the radio amateur (sm) ------- Re: Retruing Chuck Jaws Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sun Apr 24, 2011 5:20 pm ((PDT)) > Haven't MOST commercial shops gone to two piece jaws if scroll is damaged, worn or master jaws are a tad loose, soft jaws will NOT be repeatable .......unless chuck scroll happens to be unworn in the needed area...& jaws are tight. but agreed, soft jaws on a decent chuck are really advantageous. docn8as ------- Re: Retruing Chuck Jaws Posted by: "jerdalx~xxsbcglobal.net" jtiers Date: Mon Apr 25, 2011 5:45 am ((PDT)) It is common to see the practice of re-grinding jaws discounted as "worthless" for various reasons, typically that the worn scroll will not allow repeatability at all diameters anyway, etc, etc. Now, it is perfectly true that an actual worn scroll will vary the timing of the jaws, sending the part off-center, and may or may not affect repeatability. One would expect the worn spots to be in the SAME PLACES all the time, so at any particular diameter it will act the same always. However......... 1) obviously for bell-mouth jaws, the knee-jerk "you can grind it but it won't repeat, every diameter will be different, grinding it is worthless" comment does not even apply. 2) Even IF it is a "worn scroll", you have to ask yourself "is it better if fixed, or will it be better if I leave it as bad as it is now?" -- usually it will be somewhat improved if you grind it. 3) The nay-sayers apparently expect a 3 jaw chuck to EVER be accurate... but if you want accuracy, use a 4 jaw, 3 jaw chucks are only convenient, not good. Repeatability is also only a convenience, and if you want true repeatability, buy a new chuck; after you actually USE it it is "worn" and won't be as good. Also see comment about wear not moving around, so if it is true at one diameter it should remain so for a while. 4) The biggest cause of non-repeatability is NOT a worn scroll, but a worn scroll PIVOT...the center bearing that the scroll turns on. Take the chuck apart and insert a thin shim between the scroll ID and the center pivot of the chuck...it must go around virtually the full circumference, which will be 1/2 the thickness of one that goes in on one "side" of the pivot. You may be shocked at how much better the chuck behaves after that. If the whole scroll shifts, you get non-repeatability, AND shifting under load, possible dig-ins, etc. JT ------- Re: Retruing Chuck Jaws Posted by: "Glenn N" sleykinx~xxcharter.net Date: Mon Apr 25, 2011 11:01 am ((PDT)) Add to that list that with the small chucks that came with these lathes, overtightening the jaws will warp the front face out. It is a good idea before you start grinding to remove the jaws and check the face for flatness. Glenn ------- Spin Dry [atlas_craftsman] Posted by: "indianfourrider" indianfourriderx~xxyahoo.com Date: Wed Apr 27, 2011 12:35 pm ((PDT)) After parting off or oiling a chuck, I wipe it down then put a plastic bucket over the chuck and run it for several seconds at 400 rpm or so. This works well for me since wiping the chuck down never seems to get all off the excess! YAKHIKT* A 'regular' utility (2 gallon?) fits over my 8" 3- and 4-jaw chucks and still allows them to spin. I cut the bottom off a bleach bottle for my smaller chucks - built-in handle! Others may have come up with something similar but I haven't seen it posted here. *You All Know How I Know This! ------- Any fix for worn-out key socket in chuck? [atlas_craftsman] Posted by: "sculpturenmotion" ghtkx~xxbellsouth.net Date: Tue Jul 12, 2011 2:16 pm ((PDT)) The chuck that came with my lathe will not tighten fully because the socket that the chuck key turns has become distorted. Instead of being a straight-sided square hole, it is now tapered. The harder one tries to tighten, the more the key is forced out of the hole. Is there an easy fix for this. (Of course, I recognize that the rest of the chuck may be too worn to justify much effort.) ------- Re: Any fix for worn-out key socket in chuck? Posted by: "Doc" n8as1x~xxaol.com Date: Tue Jul 12, 2011 2:52 pm ((PDT)) i have repaired the key socket on a 3 in 3 jaw chuck by drilling out the socket abt .032 oversized of the od across the flats of the desired new size....i then took a lathe bit, squared the end & drove it into the new hole ...in this case since it is a blind hole, i did it in stages, wiggling out between each stage ....the amt of oversize wil depend on the size hole, the object being that only the corners will need broaching, (fairly standard proceedure).......i have broached holes up to .455 this way using lathe bits & just pounded them thru in one proceedure & then drove them out .......touch up w/ a square file may be needed if key is larger than broach by a few thou. (holes in boring bars for square bits etc.) i have not ground any clearance back of the edge of these bits, BUT that wud make it easier .....HEAVY hammer & eye protection, cause both lathe bit & hammer are hardened,(not recommended proceedure, BUT) & i have chipped the broach occasionally; finished socket looks factory. fwiw ...chuck JAWS may be tapered & hold the part differently each time or inadequately ...after they are trued, & this has to be done correctly, if the chuck will 1/2 way repeat the same runout, but if it is too MUCH, the backplate register where it contacts the CHUCK can be relieved abt 10 thou + and then a piece of drill rod may be centered up in the jaws by tapping the chuck till centered, then tightening the backplate to chuck bolts HARD ... if it will NOT reasonably repeat runout, you can take it apart (it is the 3 jaw i am talking abt) & put a 360 deg shim around pin if any looseness between the scroll & the pin it rotates on ..... on more valuable chucks, you can turn the boss true & bush the scroll .... if due to abuse the scroll has SPRUNG in places either use as is, or use on drill press to hold objects ...been there on near all of the above ... now you know more than you wanted to know. best wishes docn8as ------- Re: Any fix for worn-out key socket in chuck? Posted by: "Keith Mc" actix~xxPROVIDE.NET Date: Tue Jul 12, 2011 3:56 pm ((PDT)) Lots of ways to "hack it", if you don't care about mods to the chuck: Here's a FEW silly ideas, just off the top of my head... (... a lot of them depend highly on how much work you wish to put into this...) 1) EDM - If you have access to am EDM rig, you can "resquare" the hole. Use a stock square electrode, or mill a block of graphite to create the square electrode of the desired size. Perform a basic plunge EDM cut on the key core. 2) Rotary Broach - There are "square cutting" rotary broaches available. (This is best to borrow or rent vs buy, as its price may exceed the chuck's worth.) USe one to "requare" the hole (or convert it to a hex hole, or whatever). 3) Mill - Using a SMALL diameter end mill - create a "screwdriver slot" by extending the hole at the midpoints of two opposite faces (or at 45 deg on two opposite corners.) Create a flat blade "screwdriver" to match the slot. 4) Dremel slotting - Taking out the key core, cut a REAL slot across it with the carbide wheel for a giant flat blade screwdriver, then reassemble. Again, grind a big flat screwdriver's edges to match the width of the key core (or fab a new key for the slot out of thick flat stock and add a handle). 5) Machine a new replacement key core for the chuck. Design it to use whatever you wish as a key. 6) CNC Mill out a square pattern. Plunge file or broach the inside rounded corners sharp. Create (or buy) a new chuck key to match the new dimensions. 7) Simpler - Do (6), then mill outwards at 45 deg in an X pattern slightly at each corner, JUST enough to "oversquare" it for a square key. As long as you have a lot of flat on each edge, the key will still work even if it isn't gripping the very corners. Keith Mc. ------- Re: Any fix for worn-out key socket in chuck? Posted by: "David G. LeVine" dlevinex~xxspeakeasy.net Date: Tue Jul 12, 2011 On 07/12/2011, Rexarino wrote: > Build up the chuck key with J-B weld, making a tighter fit? Not such a good idea, but build up the socket that way and it might help... Partially fill the socket, cover the key with release (wax the "L" out of it!), force it in to the bottom, then remove it. JB Weld is really good stuff; there are other metal filled epoxies which MIGHT be better, but none so available. Another cheat, drill out the hole to take an Allen Hollow Lock Screw Nut [for address: paste the following two lines together without a space] http://www.reidsupply.com/GrpResults.aspx?pid=10022617&aitm=MAC-670&ap id=10022617 thread it in, Loctite with Red and use a hex key. The hardened hex will take a LOT of force, and the Loctite is pretty solid after it cures. Another trick is to bore it out for an Allenut [for address: paste the following two lines together without a space] http://www.reidsupply.com/GrpResults.aspx?st=ALLE NUT&pid=0&aitm=HAN-6036&apid=0&bi= (yes the spelling is right), press it in with Loctite Red and use a Hex key. While the square wrench will no longer fit, hex keys are relatively easy to come by and can be cut down to fit. A piece of hex key brazed into a "T" handle will give you a good, solid chuck key. Dave 8{) ------- Re: Any fix for worn-out key socket in chuck? Posted by: "Rex Burkheimer" burkheimerx~xxgmail.com Date: Wed Jul 13, 2011 6:15 am ((PDT)) Take out the part. Bore it out oversize. Turn an old 1/4 or 3/8 drive socket so the OD is a press fit. Press together with loctite. ------- Re: Any fix for worn-out key socket in chuck? Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Wed Jul 13, 2011 8:37 am ((PDT)) Now, THAT'S a plan that will actually work. I might suggest brazing the old socket to the pinion. Jon ------- Re: Any fix for worn-out key socket in chuck? Posted by: "L Leonard" metalmechanicx~xxyahoo.com Date: Wed Jul 13, 2011 8:34 am ((PDT)) Buy a new chuck. It will cost as much or more in money, labor and aggravation to repair the old one. I suggest one with soft jaw capability. Be well, Larry ------- Re: Any fix for worn-out key socket in chuck? Posted by: "RG Sparber" rgsparberx~xxaol.com Date: Wed Jul 13, 2011 11:27 am ((PDT)) Larry, I'm confused by your suggestion. As a hobbyist, if I want to spend a week making this repair and both enjoy the time and learn something, then does it matter even if in the end I toss the chuck? If there is aggravation in the task, I would hope that any sane hobbyist would put the task aside. There is no time clock at the entrance to MY shop ;-)) Rick ------- Re: Any fix for worn-out key socket in chuck? Posted by: "L Leonard" metalmechanicx~xxyahoo.com Date: Thu Jul 14, 2011 5:04 pm ((PDT)) Rick: Having been a mechanic 40+ years, I've fixed my share of old tools. Sometimes I was successful and got that fuzzy warm feeling, but, more often, not. If the key socket is hopelessly worn, chances are the chuck is in worse shape. I suggest using the chuck as an excuse to get a new one with soft jaw capabilities. Accurate and easy to use. I work in an old shop with old, worn out tools and use a lot of body english to get my parts right. When in my shop, I want to produce work with no headaches. This is just my opinion. L ------- Re: Any fix for worn-out key socket in chuck? Posted by: "RG Sparber" rgsparberx~xxaol.com Date: Thu Jul 14, 2011 6:58 pm ((PDT)) Larry: Now I understand where you are coming from. I am a newbie compared to you. Relatively speaking, my tools are also a lot newer than yours. Your insights about the chuck do make sense. If the goal is to bring the chuck back to full working order, then it would be smart to fully understand what is worn out before starting to put time and money into it. But if the goal is to see if a socket can be rebuilt, then that is a different story. When my 3 jaw chuck broke and I figured out it was the pinion gear, I bought a new chuck. However, I still have the broken chuck and may someday try to fix it... Rick ------- Re: Any fix for worn-out key socket in chuck? Posted by: "sculpturenmotion" ghtkx~xxbellsouth.net Date: Wed Jul 13, 2011 9:34 pm ((PDT)) Well, it has been interesting to see the creative range of solutions that have come in! With each one I have thought, "that's a good idea, I'll try that", but in the end, the deciding factor was that I found that I had a 9/32" chuck key which more-or-less matched the over-sized opening to the hole (originally 1/4"). I decided to try broaching with a lathe bit. It was going a little slowly, so I used a pencil-type die grinder with an 1/8" tree-shaped carbide bur to grind out the socket. Every once in a while I cleaned up the sides with the lathe bit (glued into a wooden handle for a previous task . . . so I didn't hit it directly with the hammer). The end result is not pretty, but it works quite well. I spent about an hour and 15 minutes on it. Thanks to everyone for your suggestions. HM ------- [atlas_craftsman] new article available: Making Soft Jaws for a Bison 3 Jaw Lathe Chuc Posted by: "RG Sparber" rgsparberx~xxaol.com Date: Thu Jul 21, 2011 7:36 am ((PDT)) This is another in my series for people new to our hobby. Although the resulting parts are used on my lathe, they are made on my mill. I make 3 jaws which means that it is worth my time to use a fixture that speeds up "production". If you are interested, please see http://rick.sparber.org/csj.pdf I welcome your comments and questions. All of us are smarter than any one of us. Rick ------- Grip Tru Chuck [myfordlathes] Posted by: "colinharwood.rm" balljointx~xxgmail.com Date: Thu Sep 1, 2011 3:01 pm ((PDT)) Hi All: I have just acquired a 3 jaw grip tru chuck, which doesn't have any instructions on how to adjust it. I was wondering if anybody here either has instructions they could copy for me or could tell me how to adjust it. Many thanks Colin ------- Re: Grip Tru Chuck Posted by: "Rich Dean" toolman8x~xxcopper.net Date: Thu Sep 1, 2011 7:12 pm ((PDT)) Colin, I have 2 of these Pratt Burnerd chucks. The "The Mounting and Operating Instructions...." say NOTHING about how to adjust it in 4 languages!! If yours has the backplate installed, remove it and install on the lathe nose. Take a light skim cut over the bolting face to eliminate any runnout or wobble. Don't touch the shoulder. There are 3 socket screws in the back (not back plate). These must be snug, but not tight. The 3 cone runnout screws in the side of the body are used to force the body to one side. As you tighten the screw, the body will come toward the screw as it is pushing on a shoulder in the rear part of the body. You can now appreciate that the back screws must not be fully tight. Also, before adjusting a given screw the other two MUST be slackened off to allow the body to move. If you do not, the chances of breaking a screw are very good. Don't force it. Did I miss anything? Cheers, RichD ------- Re: lathe chuck [Screw-On Chuck stuck on spindle] [atlas_craftsman] Posted by: "Michael Tarver" diesel_guy01x~xxatt.net Date: Tue Oct 18, 2011 6:16 pm ((PDT)) If you have an impact wrench, take a soft short bolt of the largest size that you have a socket for, say a 5/8 or 3/4, grind 3 flats on it to match the 3 jaw chuck (or 4 flats, if a 4 jaw chuck), chuck the bolt up, disengage backgears and other locks (ie let the spindle spin freely), hold some part of the spindle with a rag or strap wrench, and bang away. I have loosened several very stuck chucks like this, and you risk ruining nothing except the bolt. Michael ------- [Changing a chuck thread size to fit a different threaded spindle] Re: FS lathe chucks [atlas_craftsman] Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sun Dec 4, 2011 11:32 am ((PST)) FWIW ...for general info, & whoever may be interested....IF you chuck a large bar in the off size thread chuck, & then chuck the other end of the bar in a 4 jaw, truing up the off size threads & register, then bore out & rethread, or if needed bore out & drive fit a bush, which you then thread as needed ..... & if needed, pin the joint w/ a drlled hole & a fitted driven nail, cut off & filed ( round key ), you will have the required fit ...or if you must, use a roll pin ...a properly fitted hard drive is sufficient alone, but if you need insurance ?????.....do not thread the bush into the chuck ....bad news..... i have done this fix well over a dozen times on chucks & near as many on face/drive plates, odd ball threaded items going cheap on ebay ...... ifty years ago, low on the curve & not knowing any better, i cross threaded 1x8 OVER 1x10 ....still have the 3 jaw & the 6x18 although not in use.....runout was very close to a thou. so i never "did it right" ...but i did need to be careful, when stopping the lathe from high speed. if not "thunked on" at the beginning, it wanted to come a tad loose.... best wishes docn8as ------- Ready To Grind Chuck Jaws, But How? [atlas_craftsman] Posted by: "bigcheif4" patrickonbx~xxgmail.com Date: Fri Apr 20, 2012 12:52 pm ((PDT)) Hello Gang, OK, well I've decided to go ahead and try to grind the jaws on my 5" chuck and see if I can get it back into shape, but I'm not sure how to go about this. I found this article here: "Truing Those Tired Old Chuck Jaws" http://homemetalshopclub.org/news/aug04/aug04.html ... second to last article on the page is about grinding the jaws in a chuck. Only problem is, they do not explain how they're doing it. All I can see is the grinder bit in the photos, but not how it's mounted to the lathe or how to make sure it's absolutely straight/square/true. Someone said there was something here about it, but I cannot find anything on it anywhere. Can someone point me to a "how-to" article on mounting a grinder/motor/ something on my lathe so I can try this? I would really like to try this before I go drop a couple hundred bucks on a new chuck. I would really appreciate any help you might be able to offer. Thanks, Patrick ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "wa5cabx~xxcs.com" Date: Fri Apr 20, 2012 3:28 pm ((PDT)) Patrick, The file on the adjustable chuck jaw grinding jig is in the files section of the Projects list. Folder title True Up A Worn Chuck pdf file. The Projects list, despite the now out of date title, provides additional file and photo storage space for the main Ailas_Craftsman list. Mentioning that you are already a member in good standing of the main list is sufficient to get you approved for membership. Mentioning that you have an Atlas or Atlas/Craftsman lathe is also sufficient. There is also a third list with a similar purpose, atlas_craftsman_pics. I think that membership approval rules are similar. ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Fri Apr 20, 2012 1:08 pm ((PDT)) The bit does not have to be exact. I used two cutoff wheels in a Dremel stacked up. This was just so it did not wear down as fast. I used the slowest feed possible, slowest back gear speed and took off 1-2 thou per pass until I saw the bit hit all 3 jaws along their entire length. I repeated the last pass several times both ways without changing the depth of the cut. I use a piece of angle iron with a hole drilled to match the Dremel mounted in a tool holder. It was a bit sloppy but did not chatter. Picture here: http://shdesigns.org/Craftsman-12x36/grind.jpg Rick has a dremel mount on his web site: http://rick.sparber.org/tad.pdf Harbor freight has an thin air die grinder that is supposed to fit in the boring bar holder of my QCTP. One of these days I'll pick it up. Scott G. Henion Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "Carvel Webb" carvelwx~xxabsamail.co.za Date: Fri Apr 20, 2012 1:15 pm ((PDT)) Hi Patrick, The most common approach is to use a Dremel or similar grinder, and rig up a clamp to clamp it to the top slide - I have seen anything from a fancy machined holder to a couple of pieces of scrap and hose clamps - so whatever comes to hand for you. If the jaws are still a snug fit in their slots, another option to apply the necessary tension to them is to use the outside race of an old ball bearing which is large enough to slip over one of the jaw steps so that there is enough opening of the jaws to get the grinder in . Take very slight cuts with the chuck turning slowly, and be patient :) Good luck, Carvel ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "wa5cabx~xxcs.com" Date: Fri Apr 20, 2012 2:21 pm ((PDT)) Patrick, I don't recall what all you said you got with the lathe. But if you have the milling attachment, the vise on it will fit the spigot on top of the cross slide. And you can use it to hold your Dremel or other small grinder. I made my holder out of oak. First figured out the required dimensions versus material I had on hand. It had to be wide enough above the vise to take the hole for the Dremel. And narrower below so that it would fit into the vise. I cut it out on the table and band saws. Cut a starter hole at the calculated location to put the Dremel on center. Then, because my Dremel has two OD's near the front where I wanted to hold it, I mounted the block in a 4-jaw chuck and bored it to fit. If your grinder isn't stepped like this, you could probably get by with just a hole saw cut. Finally, I split the block vertically through the center of the hole. If I had had a chunk of aluminum large enough, I would probably have used it. But the oak works fine. And getting the grinder parallel to the lathe center line is just a matter of rotating the vise and locking it down at the proper place. I also thought of a way to do it using the compound. But the vise made the clamp simpler (only the one large diameter hole to cut, and no hardware required). The other part that you need is a jig to load up the jaws in the proper direction. One of the sites has a drawing of one that is made of a piece of round plate about the diameter of the chuck. One hole in the center about the same diameter as the hole through the chuck. Three holes around that which intersect the center hole just enough to let the nose of the jaws stick through. Diameter of the three holes just large enough to fit around the jaws to about the second step. When you slip this over the jaws and tighten them, it loads them in the same direction as a workpiece would. I thought that I had the article saved on the local machine but the only one that I can find here right now is of a more complicated one that can be adjusted to work on 3" to 6" chucks. But if you look at the drawing as though it were all one piece, you can see how the one piece version would be made. Or maybe someone on the list saved the URL of the onepiece one. Robert D ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Fri Apr 20, 2012 2:28 pm ((PDT)) You can also (I prefer doing it that way) use a short piece of heavy wall tubing machine it on ID & Od and face one end all in the same set up and take that piece and chuck it on the outside grip of your jaws and indicate it to dead nuts then you can start grinding away. The shims in the jaws they show on that pic is a joke. GP ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Apr 20, 2012 2:43 pm ((PDT)) Guenther ...did you just say that w/ the jaws in tension toward the inside as when gripping the inside of a tube, that you will get as good a result in grinding as when the jaws are in tension to the outside? jaws will be in contact w/ opposite sides of worn scroll & jaw threads ....doing as you say wd seem to be ok for grinding the jaws for holding tubing from inside or parts from a central hole, but not for gripping on the OD.....pressure wud need to applied in the opposite drection for gripping on the OD. best wishes docn8as ------- Re: Ready To Grind Chuck Jaws, But How? Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Fri Apr 20, 2012 2:57 pm ((PDT)) Doc: I have ground several jaws in my lifetime and always had tension to the outside and was always accurate. The way it is shown on the pic you will not know how much tension you have on each jaw, the wear on the ring gear is not always the same to the inside because the chuck is mostly used that way. So what I am trying to say: with outside pressure on the jaws, the ring gear is used very little like that, so it makes it more accurate. GP p.s. I totally forgot. I always disassemble the chuck and check the ring gear, I mean measure the gear grooves. If the grooves are worn a lot I would not waste my time grinding jaws. If possible replace the gear. If you can't find parts it's time to buy a new chuck GP ------- Re: question about 3 jaw chucks and grinding of jaws [atlas_craftsman] Posted by: "jerdalx~xxsbcglobal.net" jtiers Date: Sat May 12, 2012 10:34 pm ((PDT)) "Doc" May 12, 2012 wrote: > FWIW ...my experience .......if you try this w/ worn chucks, after > grinding true the 'bellmouthed jaws", which is mandatory, as i did > for years.... (no money at first & later too cheap to buy new, > going crazy w/ light duty worn crftsmn chucks), & you started w/ six > thou runout, you still have runout all over the place cause it will > not repeat...i finally started buying new or barely used heavier duty > chucks, regaining sanity & fitting them to my lathes....i still > have one or two worn out chucks around if anyone wants to try > their luck ...one of them is a counter weight on a pully arrangement > on my 1960 crftsmn drill press helping to balance the heavy table & > rotary /crosslide vise..so it moves ups easier ....it keeps gaining > weight each year.... > best wishes > doc One serious fault in the advice to grind chuck jaws is the idea that grinding the jaws is "it", all you need to do to bring the chuck "in" to concentricity. Nothing could be further from the truth. If you have a good tight chuck with belled jaws only, it DOES work to grind them, of course. However, there is ANOTHER area of the chuck which wears, and that is the "bearing" between the "scroll" (which moves the jaws) and the center of the chuck body. When this wears, the entire assembly of scroll and jaws can shift somewhat even though the chuck BODY does not. Since chucks are rarely taken apart for cleaning and re-lubrication, wear is common as the dry scroll "grinds" against the dry chuck body when the chuck is tightened. The jaws hold the work, and the scroll holds the jaws against the work, so anything that allows the scroll to shift will put the jaws at some off-center position relative to the chuck body, and potentially cause runout problems. While it usually won't shift once tightened, it WILL shift during tightening, which is one reason why there is often advice to use just one of the pinions for all tightening. Doing so will tend to always shift the scroll in the same direction, minimizing the amount of random movement. However, it is possible to shim the scroll bearing if it is loose, which may work what appears to be a minor miracle as far as making your chuck more consistent and reducing random runout. Disassemble and clean the chuck, then use a feeler gage between scroll and center post of the body to discover the clearance when the (clean) scroll is shifted over as much as possible. The shim thickness you want will be half this, or the nearest standard size less. Cut a piece that is a suitable width and just short of a full "wrap" around the center post of the chuck body. Work it in between the scroll and body when they are assembled, then lube and re-assewmble the chuck. I would be surprised if that didn't make a noticeable difference in runout. The thinnest shim normally available or practical to work with is 0.001", so a clearance of 0.002" is likely the least you can correct. But an inconsistency of that little is not too serious. brass shims work as well as steel. However, if the jaws are too loose, and tilt or tip more than a small amount in their slots, scrap that chuck, or move it to use as a vise on the drill press (very good, BTW, for holding round stuff). Ditto if the scroll bearing surfaces are rough and ridged, because you won't get a shim in easily or maybe at all in that case, and it will get torn up anyway. JT ------- lifting large chucks [myfordlathes] Posted by: "Rodney Gentry" rgent14x~xxhotmail.com Date: Sun Jun 17, 2012 12:47 pm ((PDT)) A bit off topic this one, but does anyone have a good method for lifting large chucks when swapping 4 for 3 jaw and vice versa? I ask because I recently pulled a muscle when doing so, although I'm sure I lifted correctly. Just shouldn't have done it on my own I suppose. I wondered if one of those 4 stem box spanners you use for loosening car wheel nuts, held in a 4 jaw chuck and lifted by two people would work safely. ------- Re: lifting large chucks Posted by: "Bob Hamilton" bobx~xxhamilton-bob.freeserve.co.uk Date: Sun Jun 17, 2012 1:17 pm ((PDT)) My suggestion for doing it alone is to grip a length of bar that will protrude through both sides of the chuck sufficiently to enable easy ????? lifting. Have some wood on the bed to land it on, then slide the chuck and bar so that the bar enters the "Spout", then lift and slide the bar and chuck onto the "Register". A bar (or tube) that is close to the bore of the "spout" will probably give better results than something quite small. I suppose the correct answer is to not lift something that is too heavy and awkward ELFANDSAFETY, but we do these things. Hope the back is better soon. Bob ------- Re: lifting large chucks Posted by: "we'realldoomed" sardinesarniex~xxyahoo.com Date: Sun Jun 17, 2012 1:44 pm ((PDT)) Bob's method is good, it's standard toolroom practice. It works very well. I use a 1.5" diameter steel tube as a lifting bar. ------- Re: lifting large chucks Posted by: "steve auty" turbomanglerx~xxbtinternet.com Date: Sun Jun 17, 2012 3:57 pm ((PDT)) how big is your myford lathe?? because i can lift both my 3 jaw and 4 jaw chuck of my ml7 in my hand easily. steve ------- Re: lifting large chucks Posted by: "steve" turbomanglerx~xxbtinternet.com Date: Mon Jun 18, 2012 9:27 am ((PDT)) Oh didn't realise you where talking about a Colchester. In that case I cannot lift the 13" 3 or 4 jaw chucks, from my Dean Smith and Grace lathe in one hand. I struggle to lift the 4 jaw with 2 hands. Tho I didn't mention those as I thought we were on a "Myford" group talking about Myford subjects? People will be posting pictures of Volkswagon camper vans on here next. Can't we just keep this group related to "Myford"? Steve ------- Re: lifting large chucks Posted by: "Andrew Curl" methuselahx~xxntlworld.com Date: Tue Jun 19, 2012 1:05 pm ((PDT)) Steve, the chuck question may or may not be viewed as appearing on the "wrong" group, but have you heard of a Myford 254? Also, our chap with the camper asked a perfectly pertinent machining question, and I wonder if you would have found such need to ridicule that if he hadn't made reference to the application, either. Some questions and answers are relevant to all lathes, and there's no reason they should be excluded from the group. The place would get a bit boring if the only posts were along the lines of "I just bought an ML7, and have posted the photos in the files section". Yawn. Groups like this flourish if the subjects covered include techniques and set-ups, and not just endless discussions about serial numbers alone. Myford made other lathes besides the seven series, too. Andrew UK ------- Re: lifting large chucks Posted by: "Alistair Campbell" campbell_alistairx~xxyahoo.com Date: Tue Jun 19, 2012 2:44 pm ((PDT)) Very well put Andrew. ------- great travers tool tech help [atlas_craftsman] Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Jul 13, 2012 2:38 pm ((PDT)) Thot i shud post this tremendous customer service ... among other things i ordered a "top industrial quality " 0-1/2 drill chuck $18..chuck arrived in 3 days, well made, finished & hardened, no name ..put a dowel in it & 10 thou runout ......UGHHH !!!....checked the adapter ...near zero runout .....several years ago i ordered the same, only it was named, & the runout was circa 2 thou... in the past i have magic marked the jaws, taken a piece of carbide to the jaws & scraped 5 thou runout down to 0-2 thou on my 1965 crftsmn 15 in. drill press after long use .......tedious & a PIA... a week later i get a call from Travers checking on the new catalog sent ...i said i need to talk to tech help ....told tech the runout was 10 thou ...he said " i don't want you to use that chuck, SCRAP IT" .. transferred me to "returns"....she said i am sending you a new chuck (at no cost)... two days later chuck arrived ..runout was under 2 thou throughout xcept at one setting, it was 2-1/2. hallelujah ! ....better specs than needed for drilling .....outstanding customer support ..& i felt praise shud be given when due .... hassle free !!!!! best wishes doc ------- NOTE TO FILE: Anyone wishing to have a set of soft jaws on a chuck used to be obliged to buy a new (and probably expensive) chuck with this feature. The majority of chucks that regular folks own already have hardened steel jaws. The innovative solution that follows is a simple and inexpensive and temporary add-on to a chuck we likely already own. Neat. And the solution will work for any brand of similar chuck. ------- [in atlas_craftsman but applicable to other chuck brands] Re: does anyone make softjaw master jaws for atlas chucks Posted by: "Steve" skadsmx~xxgmail.com Date: Wed Sep 5, 2012 9:55 am ((PDT)) Make a set of these: http://www.chaski.org/homemachinist/download/file.php?id=10384&mode=view Steve ------- Re: does anyone make softjaw master jaws for atlas chucks Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Wed Sep 5, 2012 1:07 pm ((PDT)) Steve, Thanks! It is a very elegant solution to the problem. I noticed that 2 of the jaws have holes drilled in the corner and one has, I assume, been filed square. I vote for the holes in the corner to insure the corners don't hang up plus it is easier to make. Even if milled out, I would leave the relief in the corners. Rick ------- Re: does anyone make softjaw master jaws for atlas chucks Posted by: "Steve" skadsmx~xxgmail.com Date: Thu Sep 6, 2012 10:33 am ((PDT)) Thanks for the compliment, Rick. Means a lot coming from you. What you can't see in the picture is that the back side is cut out so that more of the jaw fits and makes it more stable. Steve ------- Sloppy chuck [atlas_craftsman] Posted by: "stewart" stewartdl1x~xxcox.net Date: Mon Nov 12, 2012 10:01 pm ((PST)) Greeting, I'm a new member. Years ago I had a clock shop in my garage, as a refuge from my full time job making clock gears, arbors, etc. on a Craftsman lathe, I sold it for years ago when I moved to AZ. but couldn't stand not having a lathe around for tinkering. So I bought a another lathe circa 1939, completely dismantled cleaned and painted it, i.e. pictures above. But I have a problem. I'm restoring an Craftsman 12" lathe and have a problem with the three jaw chuck. It has about a .010 slop in it when chucking up a rod and measuring the wobble with a dial indicator. What I have found out is that it can be fixed by mounting a grinding device on the tool post and running it into the chuck, grinding all three jaws at one time. I have no idea what that device can be. Has any one had this problem and solved it? The main shaft - which the chuck in screwed onto - has a .001 variation. Is anyone familiar with this problem? Regards Stewart ------- Re: Sloppy chuck Posted by: "Scott Henion" shenionx~xxshdesigns.org Date: Mon Nov 12, 2012 11:04 pm ((PST)) On 11/13/2012 1:01 AM, stewart wrote: > i.e. pictures above. The group will strip all attachments (pictures) I did mine using a dremel tool: http://shdesigns.org/Craftsman-12x36/grind.jpg I hear the Harbor Freight air grinder will fit a 3/4" boring bar holder. It works best if the jaws are held outward. I uses some springs made by slotting some steel wedged in the jaws. I had 0ver 0.010 error in mine. After the grind it is 0.003-0.005, about what this old chuck can do. As the scroll is probably a bit worn also, you will always have some error. Scott G. Henion Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 ------- Re: Sloppy chuck Posted by: "Carvel Webb" carvelwx~xxabsamail.co.za Date: Tue Nov 13, 2012 1:46 am ((PST)) Scott has described it nicely, but before you go grinding, just check that the chuck is a clean and snug fit on its backplate, and ditto on the spindle nose. Good luck, Carvel ------- Re: Sloppy chuck Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Tue Nov 13, 2012 5:17 am ((PST)) Stewart: With that much slop in the chuck I would look at the ring gear in the chuck first. If you're lucky and are able to find the maker of the chuck you may be able to buy the gear. The recommendations of other members are ok but keep in mind once you grind the jaws they will only be accurate for the setting you ground them in. If you want to spend the money buy a Buck chuck that is the best out there or you can buy one from Kalamazoo chuck company they used to be buck years ago and sold and restarted under Kalamazoo chuck; the quality is the same but you may save some money. GP ------- Re: Sloppy chuck Posted by: "Jacjie" irene4popsx~xxyahoo.com Date: Tue Nov 13, 2012 5:50 am ((PST)) I used a Dremel with a handpiece. ------- Re: Sloppy chuck Posted by: "jerdalx~xxsbcglobal.net" Date: Tue Nov 13, 2012 5:52 am ((PST)) This old warning comes up ALL the time whenever anyone mentions chuck grinding.... And it isn't strictly true, either. The reason for grinding is NOT for runout... You should expect runout in any 3 jaw chuck. If you have *only* 0.005", that's not so bad. After grinding the chuck won't be much more accurate ANYWHERE than it was... and you should not expect it. 1) Grind jaws to get rid of jaw wear, bell-mouthing, etc. Do not expect to make it more accurately centered, UNLESS you know that one jaw has extra wear vs the others. 2) For an inaccurate chuck, check for wear on the scroll bearing where it rides on the center "post" of the chuck body. If you have more than a very few thou wear there, the chuck will be all sorts of inaccurate, and, worse, may tend to "slip around" in use. For that you can work a shim into the loose bearing to take up the slop; I've done it with chucks before with very good results. 3) the issue of wear on the actual scroll is over-rated. No doubt it occurs, chucks DO wear, but the chances of one particular place being heavily worn compared to the rest of the scroll are low, unless that particular chuck was used for one specific size of part all the time in production. It does happen, but perhaps an Atlas, or nearly any other threaded spindle machine, is one of the less likely machines to be used in intensive production... Maybe 70 years ago. Go ahead and grind if you want to, and don't listen to the ones predicting doom and gloom. It may be that your problem is not plain parallel wear, and grinding will actually fix it. But you DO have to hold the jaws in the same position as when in use. I like drilling a hole in the end of each jaw, putting in a pin, and holding a ring with the pins, to put pressure on the jaws. The "shop tales" suggest rubber bands, etc, but they are nearly worthless for that. JT ------- Re: Sloppy chuck Posted by: "Rick Sparber" rgsparberx~xxaol.com Date: Tue Nov 13, 2012 6:11 am ((PST)) JT: Well put. As long as the error does not change over time, it can be nulled out by machining the part. Just start a little bit oversized and do not remove the part until done. Rick ------- Re: Sloppy chuck Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Tue Nov 13, 2012 6:22 am ((PST)) Chucks that have a set jaw position have run out problems after some use. The answer for the problem is a true adjust chuck but most hobbiests don't want to spend the the money for a adjustable chuck. GP ------- Re: Sloppy chuck Posted by: "James Irwin" jirwin1x~xxaustin.rr.com Date: Tue Nov 13, 2012 7:39 am ((PST)) The FIRST thing to check and adjust is the headstock (spindle) bearings. They must be tight first. Jim Irwin ------- Re: Sloppy chuck Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Tue Nov 13, 2012 9:57 am ((PST)) Before you mess up the chuck, make sure the chuck body is well-centered. Also, make sure the chuck backplate is flat, you can take a fine facing cut on it until it cuts all the way around. When backplates are moved from one lathe to another, they may not mount perfectly true to the spindle axis. It is also possible your spindle is bent, so read off the ID of the spindle taper with a dial indicator. You say "wobble" which means to me a misalignment of the axis, not a runout or parallel eccentricity. If the chuck body is wobbling, regrinding the jaws may not help much. If the body is off-center, then you definitely don't want to regrind them in that situation. If the chuck is a loose fit on the backplate, it may just need to be recentered. Badly worn jaws usually have more wear at the tips, so the part is only held at the back of the chuck, allowing the work to wobble in the jaws. A sure sign of this is parts that have wear patterns on them when removed from the chuck. The part was wobbling in the jaws from the cutting forces, and the jaws dug into the work at the back end. This is the perfect candidate for a re-grind. You use a die grinder, Dremel or similar tool, toolpost grinder if you have one, or whatever you can cobble together to run a grinding wheel on the inside of the chuck. You need to use putty or rubber bands to pull the jaws against the outside of the chuck, just like it was gripping something, but leaving the inner face of the jaws free to grind the whole length. Jon ------- Re: Sloppy chuck Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Tue Nov 13, 2012 4:36 pm ((PST)) John: The ring gear in the cuck controls the jaws. The runout is not always on the same jaw. You may not have any runout if the ring gear is in the proper position. Years ago when we used gray iron a lot the fine dust from the iron was death to ring gears. It was important to keep the chuck clean. Some people use old brake rotors for making parts that material is also bad for the internal parts of a chuck. So keep it clean and a chuck will last. I am talking about shops that use their lathes daily to make money. GP ------- Re: Sloppy chuck Posted by: "jerdalx~xxsbcglobal.net" Date: Tue Nov 13, 2012 4:47 pm ((PST)) IF the actual scroll (the backside of what GP calls the "ring gear") is truly worn in the spiral part, then there will be variation of runout over what the chuck quality would have allowed when it was new. Each diameter the jaws hold will be different. So what? So nothing much, actually. Anyone who expects a scroll chuck to be very accurate really needs to discover 4 jaw chucks, or buy $150 per each collets (cheap collets are about as good as a good scroll chuck). Maybe they need a new lathe too. But it is much cheaper to fix the chuck to where it is no worse than you should expect it to be. Worn jaw faces you grind to get rid of the bad wear that can allow the part to 'flop around" while seemingly held tightly in the jaws. Other corrections can fix intermittent issues with accuracy, and movement of the part, etc which are NOT a problem of worn faces on the jaws. Maybe you can also make the chuck more accurate, but if the jaws are that different, you should make sure they are in the positions they were made for, and are in the correct order. In the wrong order, they will have stupidly huge errors. In the wrong places, but right order, you can have smaller errors. The scroll in the chuck, which is shaped like a flat donut with a gear on one side, and a spiral on the other, turns on the center post of the chuck as a bearing. That bearing wears. When it wears, the chuck allows the jaws to tighten in slightly different locations depending on the forces applied and which key spot was used to tighten, making for unpredictable runout. Sometimes it may shift or even allow the work to loosen. You can take apart the chuck and see. If the scroll is loose on its center bearing, you can shim it, and it will then be much better. Not like new, but better. After that, if the jaws are worn, you can grind them to grip the part all along their length, instead of only at the base. In the links here you can see the insides of a D E Whiton chuck that came with a Rivett 608. You can see how the scroll will fit on the center of the chuck body, and you notice it has only ONE key pinion, so it always is tightened the same way. http://smg.photobucket.com/albums/0803/jstanley/?action=view&cur rent=DHW6.jpg http://smg.photobucket.com/albums/0803/jstanley/?action=view&cur rent=DHW7.jpg Many worn chucks can be corrected to a usable state. But when the slots (ways) in which the jaws SLIDE are loose, then it is time to look for a new chuck, as that is not correctable with a reasonable effort. For grinding... the best way is the pins I suggested, an idea originally from Rich Carlstedt. The pin holes do not need to be drilled very accurately, but will work as well even if the ring is held off-center somewhat. It looks like this when the ring is on the chuck held by the pins: http://smg.photobucket.com/albums/0803/jstanley/?action=view&cur rent=chuckgrind.jpg Someone mentioned the plate method, which you can find on the logan lathe site. That isn't bad, but the plate must be made with holes positioned very accurately. If not, it will push the jaws sideways, and maybe cause the grind to be inaccurate. You can adjust the size of the holes somewhat to minimize the inaccuracy, but ultimately you are holding each jaw by two points, which must be accurately placed to avoid side forces. To each his own poison. JT ------- Re: Sloppy chuck Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Tue Nov 13, 2012 8:22 pm ((PST)) Guenther Paul wrote: > the ring gear in the chuck is the problem. The ring gear/scroll CAN certainly be the problem, but I would not say with certainty is is ALWAYS the problem. It is pretty easy to check the fit of the scroll, and if it is loose, then it should be fixed first. I have heard of people making ring-like shims to properly constrain the scroll, and that it helped them. You can buy brass shim stock in a bunch of sizes, and cut off a strip and roll it up with your hands to the right size. > If you still can find a new ring gear that will fix your run out. > Grinding will only have the fix for the dia. you grind it in. > All other dia. will still have run out. No, actually, if the scroll is sloppy, then you will get non-repeatable centering, it will change every time you tighten the jaws, especially if you use a different pinion each time. > It may be time to buy a chuck. I bought a Phase-II chuck for my 12" Craftsman some time ago when it was on sale, and it was an EXCELLENT unit and I still use it (on my 15" Sheldon). I get repeatable .001" runout (0.0005" eccentricity) at all sizes, even after 10+ years of home shop use. > If you get a new 3 jaw chuck get the adjustable one for a little more. Yes, I agree, my Phase-II is a knockoff of the Buck Adjust-Tru style, and is quite easy to line up. But, it is so darn accurate, I rarely use that feature. I just centered it once, and never have to bother with it again. The adjustable chucks need a different backplate, however, that has the boss for the adjusting screws to bear against. Jon ------- Re: Sloppy chuck Posted by: "Jon Elson" elsonx~xxpico-systems.com Date: Tue Nov 13, 2012 8:24 pm ((PST)) Guenther Paul wrote: > It was important to keep the chuck clean. Yes, in the home shop, you should tear down your chuck every so many months (depends on how much you use it) and clean the inside of the chuck. I wind the jaws out and clean and re-lube at least the scroll teeth and jaw grooves every 6 months or so. It will greatly prolong the accurate life of the chuck. Jon ------- 3 Jaw chuck accuracy Myford/Burnerd [myfordlathes] Posted by: "Jolyon" hell0x~xxyahoo.co.uk Date: Sun Dec 30, 2012 3:11 pm ((PST)) My ML7 came with a virtually unused looking Burnerd 3 jaw chuck with an integral backplate threaded for the ML7 spindle. I took it apart and cleaned it; the scroll looked unmarked and is a very snug fit in the body and the jaws look unworn. The thread in the body is clean and the spindle is true. So, it surprises me to note that the chuck centres to no better than 4 1/2 thou on a 1 inch test bar. The wobble worsens as the dti is moved towards the tailstock. Using the external jaws yields the same results and the chuck is a secure fit on the spindle and screws home to the shoulder. Does this sound OK; or is this chuck not as good as it should be? The chucks on my Colchester (Burnerd 4 inch and Solar 6 inch) centre to 2 to 3 thou. Yours, Jolly ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "alighazizadeh" alighazizadehx~xxaol.com Date: Sun Dec 30, 2012 3:25 pm ((PST)) Hi Jolly, I have a very old Myford ML7. I have the same problem with all the stuff that came with the lathe, the run out is just unacceptable. I eventually took the back plate off the Pratt chuck and remachined it in situ; it now has a 0.003" run out about 3" from the chuck jaws. Not great but acceptable. The Griptru chuck was eventually sorted out with the help from the forum and it runs with 0.0015" run out. Personally I think it is all to do with the spindle but I have no way of proving it. Good luck and regards, A.G ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "Jolyon de Fossard" hell0x~xxyahoo.co.uk Date: Sun Dec 30, 2012 4:43 pm ((PST)) Hi, Thanks for that. Interesting. I'm just working out how I can re-machine the backplate and still have it a snug fit on the chuck body. It all looks so well finished; it's just sch a shame it's this far out!! Jolly ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "alighazizadeh" alighazizadehx~xxaol.com Date: Sun Dec 30, 2012 5:29 pm ((PST)) Hi Jolly. If you decide to re machine the back plate please make sure that you have enough material so the spindle nose does not stick out of the back plate. I have two back plates, one is quite thick about 1/2" thick and the other one just under 3/8" so be careful; there are also some blank ones available from eBay for about £20.00. I assume that these could be custom turned on your lathe to your requirement provided that they are a good fit on the spindle. Of the two that I have, only one fits the spindle properly. Regards, A.G ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "David Everett" deverett2003x~xxyahoo.co.uk Date: Sun Dec 30, 2012 8:39 pm ((PST)) Before you go machining the backplate, have you tried assembling the chuck body to the backplate in the three possible combinations? You might be pleasantly surprised that in one position, the runout will be acceptable to you. Dave The Emerald Isle ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net Date: Mon Dec 31, 2012 4:40 am ((PST)) Your chuck seems fairly good to me, probably better than was ever intended. It is a mistake to think 3-jaw chucks will ever give perfect centering so don't worry about it. If you require perfectly concentric fixing use a 4-jaw, a collet, or work between centres. Cliff Coggin Kent, UK ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "Robert Mitchell" rmm200x~xxyahoo.com Date: Mon Dec 31, 2012 10:00 am ((PST)) I would go with the previous poster; rotate the backplate through all three possible mounting positions, and check runout at each. And make sure the backplate and chuck mounting parts are scrupulously clean and burr free. Sounds like your mounting is tilted. When disassembling anything with symmetric mounting holes - mark each piece so you reassemble it in the same spot. Robert Mitchell ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "Jolyon" hell0x~xxyahoo.co.uk Date: Mon Dec 31, 2012 11:28 am ((PST)) Hi all, Yes, done that and the runout went up to 16 thou so it'll be put back to where it was. Everything's clean and flat and burr free. Never mind... the lathe was a gift so I'm not complaining (too much) ! Happy New Year to you all ! Jolly ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "Kevin" tadpolex~xxbtinternet.com Date: Mon Dec 31, 2012 1:51 pm ((PST)) alighazizadeh wrote: > The Griptru chuck was eventually sorted out with the help from > the forum and it runs with 0.0015" run out. Personally I think it > is all to do with the spindle but I have no way of proving it. Hi Ali. The real advantage of the GripTru, and I suppose its reason for existence, is that you can bring it to more or less perfection when gripping one particular diameter. So imagine having to do an operation on the end of a number of pieces of bar, all cut from the same length. You'd chuck the first piece then adjust the chuck so that the workpiece was rotating concentrically. Having done the operation you'd then remove the item and chuck the second, which would be held concentric also, to fairly close limits. For the next job, working on material of another diameter you'd have to check and probably adjust again. When talking of "run out" it might be helpful to try to determine whether variations seen with the DTI are due to the test piece being eccentric to the spindle axis but parallel to it for its full length, or not parallel to the axis, or indeed a combination of both. Kevin, NW England, UK ------- Re: 3 Jaw chuck accuracy Myford/Burnerd Posted by: "alighazizadeh" alighazizadehx~xxaol.com Date: Mon Dec 31, 2012 5:50 pm ((PST)) Hi Kevin, Happy new year. As I only use the machine for hobby, model engine making, I am unlikely to want to machine like a production line. I would probably zero in on a diameter somewhere between the required dimensions and then carry on. I do understand what you are telling me though. Regards, A.G ------- Elliptical chuck [shopbuilttools] Posted by: "Rod" granthamsx~xxwiktel.com rodney_grantham Date: Tue Jan 29, 2013 5:59 pm ((PST)) After several inquiries about my prototype elliptical chuck, http://www.youtube.com/watch?v=xAoM-CRZBNY I put together a pdf of the components and dimensions, e-mail me to granthams at wiktel dot com if you're interested and the 5 page pdf is yours. There is a likelyhood of building an elliptical lathe is in my future. Making the thing in metal requires making patterns for castings and a fair amount of machining, and a few tweeks this thing needs. So, a fair amount of thought and planning has to be done before building it out of metal. I would welcome any comments or suggestions before jumping into this project again. Rod ------- Re: Elliptical chuck Posted by: "mason" masonx~xxcoolaccess.net Date: Tue Jan 29, 2013 6:38 pm ((PST)) why/what do you use one for. i saw your video but fail to see a use for the result. mason ------- Re: Elliptical chuck Posted by: "Rod" granthamsx~xxwiktel.com Date: Tue Jan 29, 2013 8:18 pm ((PST)) One of my hobbies is making jewelry and faceting stones. Many of these stones and even a large amount of finished stones do not fit in the available bezels and prong settings. A tapered oval mandrel set of varying ratios is my solution to the problem. How the tapered mandrel works is a short segment of tubing is formed over the mandrel to get the proper proportions and size to fit the stone. If you have ever gone through the hassle of fabricating a mount with all the cutting, sawing, soldering and filing to get the damn thing to work, you would feel my pain. My prototype is the result of many years of trial, error and downright failure. I have a cnc vinyl cutter and it will make ovals of any size or shape, but when trying to get this idea into a lathe, it just don't work. At first blush, folks have suggested a cnc machining center. Even the lathes with multi-axis tool changers can make the goofiest bolt you can imagine, but no joy with a tapered oval mandrel. It seems to be something about the varying surface speed of turning an oval that makes for a poor finish. Anyone who has actually seen a tapered oval mandrel about 8 - 12 inches long made, please speak up. This long comment is in no way meant to put anyone down or cause an arguement. Like I said earlier, my elliptical chuck is only a prototype, and I plan to make a dedicated elliptical lathe out of metal once I feel confident it's a final version. It just annoys the hell out of me when after spending a lot of time on a project and explaining to folks how I got there, there is always some yoyo that has a GREAT suggestion. So here's your chance. I would very much appreciate any comments, suggestions or other words of wisdom about things this group may add to my chuck before starting a new build. Rod ------- Re: Elliptical chuck Posted by: "Bruce Bellows" bbellowsx~xxrogers.com Date: Wed Jan 30, 2013 4:20 am ((PST)) Hi Rod I happen to have a reprint copy of the "Handbook of Turning" circa 1846. In it is a short section on elliptic turning and the assembly looks very similar to your set up. I will try and scan the section and send it to you however I will not be able to get to it until after this coming weekend. Bruce ------- [Myford Collet Chuck Plans] Re: Uploading files [myfordlathes] Posted by: "Martin" dumptongeex~xxhotmail.com dumptongee Date: Fri Feb 1, 2013 11:57 am ((PST)) On 01/02/2013 19:37, Haydut1200 wrote: > Martin, > There's no room for anymore files. Yahoo, in their unfathomable wisdom, > allow 100mb for all files, and 100gb for photos, and seem determined not > to change it. Oh dear Curly, what a state of affairs. For anyone wishing to download my enhanced PDF version of The Myford Collet Chuck .zip(Exploded view), here is a link to my Drop Box https://www.dropbox.com/s/7ewj8bkzy67tdul/Myford%20Collet%20Attachment.pdf Cheers Curly Martin C ------- Re: 3/4 Jaw Chuck Key Source? [atlas_craftsman] Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Tue Feb 26, 2013 1:39 pm ((PST)) > Is there an easy source to find a replacement 3 or 4 jaw chuck key > for a Craftsman/Atlas 12" lathe? Skipp / pretty simple to make them ...even w/out a mill/shaper ...simply file up the square / hex from a suitable piece of rod ...tap in & out as you file to mark where you need to file ..drill a hole thru the other end & insert a cross bar ....you can hold the cross bar in place by upsetting burrs w/ a punch on either side of the main bar........if you have not learned to file, now is a good time .. you will never regret acquiring the skill ...a good part of my metal working enjoyment comes from making my own tooling .....but lately the temptation to use the cheap china tooling is interfering w/ my pleasure ....still make a lot of special taps, c/bores /cutters /whatever but spending 2 + hours to make a $10 item makes me feel a tad foolish ...fortunately, time no longer means money ! if you have welding capbilities, it gets easier .....for some sizes, you can use a discarded socket welded to a t bar & of course w/ mill shaper abilities, you do not need the filing skill... chuck key will hold up longer using drill rod or 1045 / 4140 stress proof ...but i have made a a 1/2 dozen or so from plain old 1018 mild scrap steel, milled /filed the flats long so i cut cut off the buggered & worn end but but have not needed to do so. best wishes doc ------- New Atlas 618 tailstock chuck and arbor [atlas_craftsman] Posted by: "abigalesdad" abigalesdadx~xxcomcast.net Date: Sat Mar 23, 2013 11:43 am ((PDT)) I'm planning to purchase a new MT1 tailstock chuck for my Atlas 618 and I'm looking for recommendations, sources, any words of wisdom. Thanks! ------- Re: New Atlas 618 tailstock chuck and arbor Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sat Mar 23, 2013 9:28 pm ((PDT)) FWIW ..a few years ago ordered t a 1/2 in chuck from Travers tools .. circa $20....china, all working parts hardened, well finished, less than three thou runout...needed an xtra last year, ...ordered again....nice looking chuck, again well hardened but TEN THOU runout...called tech service ...asked what the runout supposed to be ...told him it was ten thou...he said, i dont want you to use that, throw it away, sending another ....new chuck arrived . runout under three thou...unlike some others, cannot get better service than that...!!!! have read recent posts that jacobs quality not what it used to be ...if you go American, a lightly used older jacobs #34 or even more expensive ball bearing 14N wud be a good choice...jacobs 33C taper preferred. (ebay) pick up a morse taper #1-#2 so you can use it in your headstock, if you do not already have one. i am sure others have recommendations. best wishes doc ------- Re: New Atlas 618 tailstock chuck and arbor Posted by: "Glenn N" sleykinx~xxcharter.net Date: Sun Mar 24, 2013 9:09 am ((PDT)) The only thing I could add to Doc's advice is, you don't want a keyless chuck. I have also had very good luck with the cheap chucks, I did have to adjust the ring gear on one to make the key fit right, but that is common even with a Jacobs chuck. Glenn ------- Re: New Atlas 618 tailstock chuck and arbor Posted by: "Carvel Webb" carvelwx~xxabsamail.co.za Date: Sun Mar 24, 2013 10:23 am ((PDT)) The Emco Compact 5 also has an MT1 tailstock , so if you do a search on that you will find some good sources , Regards, Carvel ------- Re: New Atlas 618 tailstock chuck and arbor Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Sun Mar 24, 2013 10:55 am ((PDT)) You can buy a repair kit for Jacobs chucks. It will replace all the guts of a chuck. The number is in the front of the chuck where the key holes are. The arbor is irrelevant. ------- Re: New Atlas 618 tailstock chuck and arbor Posted by: jerdalx~xxsbcglobal.net Date: Sun Mar 24, 2013 3:22 pm ((PDT)) You can indeed, but the thing will cost you more than three used chucks, one of which will probably be plenty good enough to use. I've had a ball bearing unit torn down for years... kit was like 50 or 60 bucks, and I have other chucks the same size, so it's never been a priority. JT ------- Buying a 4 jaw chuck [myfordlathes] Posted by: "davetherave_11" davetherave11x~xxgooglemail.com Date: Tue Mar 26, 2013 3:18 pm ((PDT)) Good evening ladies & gents, I have an independant 4 jaw that has a rather alarming amount of runout. Depending on how things pan out, I may have to replace it. My dilemma is this: I cannot justify spending a large amount on a brand new chuck. Is buying a second hand chuck (made by a reputable manufacturer) from that well known auction site a safe option? Or would it be safer to buy a brand new chuck from one of the lower-end suppliers? Thanks ------- Re: Buying a 4 jaw chuck Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Tue Mar 26, 2013 4:17 pm ((PDT)) Dave, The things to look for in a four-jaw are as follows: 1. Loose fit between jaws and body. The main indication of a worn chuck is jaws which can be rocked in their slots. If they rock, they will not hold straight, and you will get runout. The usual cause is wear or over- tightening of partially-chucked rod, which also causes the condition called bell-mouthed jaws whereby the jaws do not close properly at near the outside. Again this causes big TIR. Loose jaws is a very common problem especially with a cheap chuck with unhardened jaws. I have Portass, Adept, and Perris chucks which fit this bill, all got by auction. 2. True-running of face of chuck body. The guide slots, in which the jaws run, are parallel to this surface. Ergo if this surface is off, the whole thing is wonky. Causes are: monster dig-in, cheap manufacture, and bad backplate fitting job. True running of the sides means little if this other condition is met. Unlike a three-jaw, a four-jaw can be somewhat eccentric as long as the jaws are good enough to let you centre the work without wobble. It is possible to make chuck jaws. There are many articles in vintage Model Engineers on this. However it is not easy and it was usually done out of desperation, during or right after one of the great wars. Ye takes yer chances with auctions. No testing is possible. If inspection or reliable source is out of the question, I would go for a reputable manufacturer and fit a genuine Myford backplate. A low-end chuck from RDG (not RDG-Myford) would seem alright. If it is rotten to begin with they will take it back if you squawk. Beware of non-Myford repro backplates which tend to have horrid threads which only approximate BSW, and the registers are usually quite bad. A dodgy fit will probably not affect accuracy if the body runs true, but you don't want to harm the precious Myford spindle nose. Myford have been selling the Czech-made Bison chuck for perhaps 10 years now. At first they also sold the splendid, classic, Myford-style low- profile Pratt-Burnerd item. The Bison are quite decent and the P-B remains the best, but probably around 500 quid nowadays. There are actually quite a few of both around, used, and a good deal is possible if you can inspect or you have some assurance. Andrew ------- Re: Buying a 4 jaw chuck Posted by: "Robert Mitchell" rmm200x~xxyahoo.com Date: Tue Mar 26, 2013 7:13 pm ((PDT)) Unhardened independent jaws are kind of intended to be machined for a specific job. Bell mouth in those can certainly be fixed by boring. Clamp on a washer or something at the back of the jaws and indicate it as close as possible before boring. Something similar can be done with a grinder on hardened jaws. If the jaw rocks in its slot -- get new jaws... Always try to find an old PB chuck in good condition, versus anything new. Robert Mitchell ------- Re: Buying a 4 jaw chuck Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net Date: Wed Mar 27, 2013 1:16 am ((PDT)) I believe this is one of those cases where if you buy cheap you get junk. Low cost always means low quality, though sadly the corollary of high cost equals high quality is not necessarily valid. Cliff Coggin Kent UK ------- Re: Buying a 4 jaw chuck Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Wed Mar 27, 2013 2:27 am ((PDT)) Agree with Robert. I would add that soft jaws ought to be for special purposes but, on low end chucks, can be just for economy. You can regrind jaws with a square and a grinder if worn at gripping faces, and if unhardened skim them true in the lathe, but you are buggered if they rock. The RDG cheap chucks are really not very good but they are cheap and might do for awhile. A used Pratt-Burnerd is indeed usually a good option, but remember that condition is key, and ability to test or get assurance. aw ------- NOTE TO FILE: The following tip provided by Doc is applicable for any number of situations, so I have repeated the wording to make it easier for search engines to find the variants that folks are looking for. In this instance the tip was placed in both the Chucks General and Threading files here. Increasing thread depth for a dog plate. Increasing thread depth for a back plate. Increasing thread depth for a face plate. Increasing thread depth for a chuck. Picking up a thread on a lathe. ------- increasing thrd depth on a dog plate [atlas_craftsman] Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Sun Mar 31, 2013 6:19 pm ((PDT)) FWIW .....fitting an ebay dog plate to a lathe in the garage, 28 feet from the basement shop & up a flight of stairs. d/plate was correct thrd (10TPI), but thrd was shallow & wud not start. i ground an ID spring caliper tip to 60 deg + so it wud not bottom out & used the 4 jaw backplate as a guage ...inserted the spring caliper between thrds & adjusted for right feel ...check against the d/plate & it was TIGHT (too lazy to cut a dummy spindle & didn't want to walk up stairs 1/2 dozen times checking the fit (81 yr old knees), so thought to use the spring caliper for gaging fit ...i have a factory OD spring thread caliper & it has been VERY useful, abt as good as the thrd mic. set up the lathe for 10TPI & internal thrdng.......engaged the thrd dial & the 1/2 nuts & adjusted carriage to an inch or two from the thrds, a bit beyond contact, & then fed carriage in to abt 1-2 thrds & shut the lathe off....VERY IMPORTANT TO GET THE SLACK OUT THIS WAY or you end up xthrdng ...NOW use the xslide & compound to center your bit in the hollow of the thrds using your eyes & TACTILE sense to center it up ...this is the only difficult part ....next set your xlide / compound dials to ZERO ...this is how to pick up a thrd after losing it all due to movement, jam up, wreck, whatever .... well worth knowing. two 5 thou cuts & two 3 thou cuts ...later i gaged w/ the spng caliper & it felt the same between thrds as on the chuck b/plate ..i unscrewed the face plate w/ the still attached d/plate & climbed out to garage to check fit ...went on smooth w/ no shake till near the register ....i backed off two turns & it went smooth for a few turns, did the same a couple more times & the fit was way better than it needed to be for a dog plate ..good enuf for a 3 jaw....( to my surprise, i expected to have to take a couple of cleanup cuts of a thou or so)..... & by backing off a couple turns & then screwing on some more, i was most likely working out some rough cutting. hope this may be of value to some. best wishes doc ------- Re: increasing thrd depth on a dog plate Posted by: "L. Garlinghouse" lhghousex~xxsuddenlink.net Date: Mon Apr 1, 2013 11:08 am ((PDT)) Just a quick comment on this general thread about threads . . . I was making something to screw on the spindle. Knowing I was going to have the problems already discussed, my first step was to make a plug- gage so I could test the threads without doing all the things we have been discussing. For the "master" I used the dog-plate aka face plate as the female thread gage. I managed to get a really nice fit. So I cut the threads on my project and stopped when I had a nice tight fit on my plug gage and was gloating about all sorts of things. Then I tried what I had just finished on the spindle and it was very sloppy. So what went wrong? On my plug gage I had left the crests of the threads too sharp. They had interfered with the flatter root of the thread on the face-plate giving me a false "snug fit." If you have ever seen a real plug type thread gage you will note that the crests of the threads are flat. The thing you are really gaging is the pitch diameter. So when making your thread gage, don't worry about making the crests of the thread flat -- just as long as you don't get down to the pitch diameter. The OD of your plug gage is not important as long as it is small enough. Too big, like maybe according to the max on the spec, and you may get a false positve. L8r, L.H. in Arkansas ------- Re: increasing thrd depth on a dog plate Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Mon Apr 1, 2013 12:09 pm ((PDT)) over many years i have fitted over a dozen back, dog & face plates w/out a spindle dummy ...slow & repetitive trials ....why ? ..mostly afraid of what happened to you .....finally on the barnes 4 1/2 i made a spindle copy, & things went well ...this last thrd deepening, i got lazy & wanted to see what i could do w/ a spring caliper ..i filed the points to 60deg plus a tad to make sure they did not bottom out ...& i wud read somewhere near the middle of the thread. I still am queasy abt using a spindle copy for a 3 jaw, since i want a no shake fit & a register as close to 1/2 thou over as i can get. maybe if i use wires & mic over them, i can make an ACCURATE copy?? i once saw a post in which 3 sizes were cut on the same bar .. no go, go, & way too much. tnx for your experience doc [In a later message this same day Doc wrote: i have mentioned this before, however to me it looks like atlas & other older spindles were cut w/ a V thread & therefore current taps like my 1-1/2 x 8 are useless for fitting to the spindles, since they are made to a different standard.] ------- Chucking [myfordlathes] Posted by: "ianjones2003" ianandjoellex~xxgmail.com Date: Sun Apr 14, 2013 8:18 am ((PDT)) Hello All I'm currently making a part from Aluminium alloy. It is max 1 1/2" dia and only 2" long and most work can be done by holding it in the chuck once, doing the work and eventually parting off. However I need to then reverse the item in the chuck and turn some features on the end (which was parted off). How can I prevent damage to the OD by gripping in the chuck? I've been here before and find it hard to grip sufficiently to prevent movement while not too hard, damaging the alloy. Not a problem with steel or even brass. I'm sure this is a problem which has a simple answer. Hope so! My solution (not tried yet) is to wrap the alloy in some shim steel to grip in the chuck. Would this work? Regards Ian ------- Re: Chucking Posted by: "David Littlewood" davidx~xxdlittlewood.co.uk Date: Sun Apr 14, 2013 8:45 am ((PDT)) Ian, I am assuming you have a Myford lathe (probably 7 series) and don't have access to a larger machine. If so, then I can imagine two choices, with a third if you do have such access. First, acquire a set of soft jaws for your chuck; chuck a piece of scrap somewhat smaller than your workpiece so it's set back from the face, and turn a recess in it at least several mm deep and of the exact diameter of your piece. Remove the piece of scrap and chuck your piece (using the same key hole). This should hold your piece with minimum or zero marking as the recess of the jaws will be an exact match for the diameter of your piece. If you can use a 4-jaw s/c chuck to do this, so much the better. Second, make yourself a sleeve with a wall thickness of 1-2 mm and diameter to match the spigot on your workpiece, put a slit along its length, and chuck your piece held inside this. If you make the wall thickness too great you may have to put some grooves around the wall part-way through to make it flexible enough. You may need to hold in a 4-jaw independent to get perfect concentricity. This is, you will notice, a form of your idea, and you may actually find it feasible to make the "tube" by rolling some sheet - but it will need a decent wall thickness to avoid marking. Third option - find a friend with a bigger lathe and a Burnerd Multisize collet chuck or similar. Check on some scrap to make sure this won't mark the alloy. David Littlewood ------- Re: Chucking Posted by: "Malcolm Tulloch" malc395x~xxbtinternet.com Date: Sun Apr 14, 2013 8:46 am ((PDT)) Hello Ian, Cut an old Coke can up into strips, fold them in half so that each jaw has a double layer between it & the job. Make sure you clock it in before taking a cut. All the best, Malc. ------- Re: Chucking Posted by: "Bob Hamilton" bobx~xxhamilton-bob.freeserve.co.uk Date: Sun Apr 14, 2013 9:46 am ((PDT)) Is it possible to part off at a length that would allow a centre drill to be used. This would mean that less force would be required to grip the job in the chuck as the centre would give a lot more support and confidence. Finally machining the little bit in the middle away very carefully should cause no problems. Of course using some other soft material under the jaws will also help. Something else to consider is that unless the chuck is totally unworn, the jaws are likely to not be parallel. Any material used between the jaws and the job would probably be best located towards the outer end of the jaws, particularly if you will be able to get the job pressed back against the face of the chuck with the centre. Bob ------- Re: Chucking Posted by: "Ken Strauss" ken.straussx~xxgmail.com Date: Sun Apr 14, 2013 11:08 am ((PDT)) As you mention, a single layer of beer can is sometimes insufficient to prevent marring. I acquired some copper flashing (roof stuff) from the local scrappie and cut it into strips perhaps ½-inch wide and an inch long. Although a little more expensive I find these much more convenient than cans. A length of copper water pipe that is slit lengthwise makes a nice sleeve. Scrap pieces of copper pipe up to a few inches in diameter are readily available from plumbers. Cyanoacrylate glue (Crazy glue) works great for items that are relatively short. I attach the items to a faceplate or chuck a short piece of stock, face it and then glue the item to the end. Heat causes the glue to release so avoid heavy cuts. ------- Re: Chucking Posted by: "Nick Brady" nickbrady920x~xxyahoo.co.uk Date: Sun Apr 14, 2013 3:36 pm ((PDT)) Buy/make a set of nylon jaws, these cost me 12.00 inc p&p off fleabay. ------- Re: Chucking Posted by: "Ian and Joelle" ianandjoellex~xxgmail.com Date: Mon Apr 15, 2013 12:11 am ((PDT)) Hello All. Thanks for the ideas. I'd never heard of nylon jaws before and will follow that up longer term. I have "collected" several sets of feeler gauges over the years so I think one of them will be sacrificed to provide some shims for the current job. Regards Ian ------- Re: Chucking Posted by: "Robert Mitchell" rmm200x~xxyahoo.com Date: Mon Apr 15, 2013 6:58 am ((PDT)) Feeler gauge stock is about the last thing I would use for shim stock on jaws. They are high carbon steel with a spring temper. Aluminum can stock is extremely uniform in thickness, and is soft enough to form to the jaws. If you don't like that - buy some brass shim stock. Use your feeler gauges for spacers. Robert Mitchell ------- Re: Face Plate ? [myfordlathes] Posted by: "furkaoberalp" a.websterx~xxsympatico.ca Date: Fri Aug 23, 2013 1:19 pm ((PDT)) "clankennedy2004" wrote: > Hi, Just a quick question to the group to check to see if whether a > 4Kg faceplate may be too heavy for a ML7's spindle bearings ? The 'light' Myford type four-jaw weighs 6 kg and the big faceplate 5 kg according to my bathroom scale. This surprised me since my first reaction was that a 4 kg faceplate is very much indeed a flywheel. I would not worry about a 4 kg faceplate unless you load it up with something heavy and spin it too fast. Andrew W ------- Re: Face Plate ? Posted by: "Alan Moore" a.j.moorex~xxbtinternet.com Date: Fri Aug 23, 2013 3:26 pm ((PDT)) I would think the main danger with a large faceplate is unbalanced loads. It is important with odd-shaped workpieces to bolt on counterweights to balance the load, otherwise you can shake the bearings to bits quite quickly. Regards, Alan ------- ML7 Faceplate ? [myfordlathes] Posted by: clankennedy2004x~xxyahoo.co.uk Date: Sun Sep 8, 2013 4:18 am ((PDT)) Hey guys, Well I got myself a 9" Faceplate off E-Bay. It seems allright if heavier than I thought it would be. I cleaned her up a bit and tried her on the Spindle and she fits fine. Runs true, by eye, anyway so I think she'll do. My query though is how do I tell if it's original Myford or not? I think they have a number in the parts list but I forget what it is at the moment, but the actual faceplate has 1917 indented into the casting on the backside under the paint. I can see no other markings. Any clue what this is? Perhaps a earlier 9" faceplate for ML4 or Drummond? I think the ML7's 9" faceplate serial number was 1347 but I'm not sure. ------- Re: ML7 Faceplate ? Posted by: "David Everett" deverett2003x~xxyahoo.co.uk Date: Sun Sep 8, 2013 4:51 am ((PDT)) 1917 under paint. Could there be any mistake? 1,3,4,7 are very similar shaped numbers. Just a thought. Dave The Emerald Isle ------- Re: ML7 Faceplate ? Posted by: iankirkup984x~xxgmail.com Date: Sun Sep 8, 2013 1:29 pm ((PDT)) According to my very old sellotaped together accessory list the Myford 9" faceplate is part 1437. Ian ------- Re: ML7 Faceplate ? Posted by: "Pete W." enwodex~xxyahoo.co.uk Date: Sun Sep 8, 2013 6:16 pm ((PDT)) Hi there, You need to distinguish between the various manufacturing stages and realise that each stage needs to have its own identity. For instance, the face-plate will have one identity as an un-machined casting and, associated with that there will be a pattern for which the foundry will designate its own identity. Thus, the number cast into your face-plate may be the pattern number. For parts produced in quantity the foundry might well have several patterns, each with its own identity number. Then, there will be a drawing of the face-plate in its finished state, after the casting has been machined. This will have the identity number quoted in the catalogue. Manufacturing drawing systems vary widely from the cottage industry to the large concern employing a range of sub-contractors so what I have written above is far from definitive -- I offer it merely to point out that part identification, manufacturing stage by manufacturing stage, is a wider process than is usually seen by the end customer. Best regards, Pete W. (aka 'Enwode') ------- Making a faceplate [atlas_craftsman] Posted by: "David Weaver" abigalesdadx~xxcomcast.net Date: Thu Oct 10, 2013 8:27 pm ((PDT)) I am going to make a faceplate for my Atlas 6" since I don't have one. It's my intention to use an aluminum disk I have that is currently about 6" in diameter and about an inch thick. I'm going to have to take at least a 1/2" off the radius just to get it on the lathe. It also has a 5/8" threaded hole in the center that will need to be enlarged and threaded to fit my 10 tpi spindle. This will be a major project for me since I've not made anything on this relatively recent acquisition and have not done any threading. I'm looking for any suggestions, helpful hints on the sequence of making this thing, and maybe some suggestions on size because an inch thick might be a little too much. Thanks! Dave ------- Re: Making a faceplate Posted by: cliveadams23x~xxaol.com Date: Fri Oct 11, 2013 12:04 am ((PDT)) The first thing you need to consider is how you're going to hold it on the lathe. From your description it seems like it's a plain disk with no bosses? If there's a boss you could obviously grip it in a chuck to bore out the threaded hole, otherwise you would need to use reverse jaws to grip the outside of the disk. You *could* remove the extra 1/2" radius with a saw and file but of course aluminium is a pain for clogging files. I use the old trick of chalking the file to alleviate clogging but it's only a partial solution. Other than that, a woodworking router with a trammel bar centred in the threaded hole -- but the piece would need to be secured to something solid and you'd need to take a lot of shallow cuts. Once you've got it to size, and the centre hole re-threaded, your best bet is to place it on the spindle and do all the work there since it will be naturally centred and run true. I actually made a start on a faceplate for my 10F a few weeks ago, but from a different direction. I made a wooden pattern on the lathe and sand cast the faceplate -- came out looking OK. I made mine with a boss so I could grip it, and got as far as skimming the rough off the outside edge, facing the front and partially boring the hole for the spindle before I decided to start over. I had considered making sand cores to form slots but for my purpose I can just drill and tap holes for the catch pin and when there's no more room for holes I'll just re-melt and re-pour it because I still have the wooden pattern. Next time I'm going to cast a steel boss into the centre so I can remove the faceplate from the spindle more easily since I can imagine that the torque would stretch the aluminium threads and lock the faceplate to the spindle. The one I already made won't be wasted since I can use it as a sanding disk platen for a bench grinder I'm converting to a linisher. Hope you get a workable solution to your problem. Clive ------- Re: Making a faceplate Posted by: "Guenther Paul" paulguenterx~xxatt.net Date: Fri Oct 11, 2013 5:03 am ((PDT)) I would not recommend aluminum for the face plate. I think you will have problems with the thread on your spindle in a short time. Stay with steel or gray iron. GP ------- Work holding in a chuck [myfordlathes] Posted by: qthurtlex~xxgmail.com busybeingrelaxed Date: Sun Jan 5, 2014 11:42 pm ((PST)) As a beginner I have recently had three different problems holding work in a three-jaw chuck on my ML10. Unfortunately, I don't have (and can't afford) a proper collet-based work-holding system, which I think would answer the problems. 1) Protecting soft materials in a chuck. When turning down aluminium bar (eg 25mm diameter), I normally wrap a thin aluminium (beer can) strip around the bar a few times (with the same number of layers under each chuck jaw). Sometimes, I try paper in the hope that it will avoid slipping. The problem is that, if I dog-up the chuck very tightly, I might still mark the work, and it might still slip. I make an effort not to apply too much cutting force, but once I overstep the cutting force, the damage is done. What techniques do people use to minimise this problem? 2) Gripping mild steel tightly enough Recently, when holding a turned 20mm diameter MS bar in the chuck and using a die to put an M12 thread on a prepared end (11.8mm diameter with chamfered lead-in), I found that the work roatated in the chuck (marking the prepared finish) despite being gripped in the vice as tightly as I could. The problem was the large force needed to form the thread (die held in a tailstock holder, chuck rotated by hand using the chuck-key [yuk!], only small 'bites' taken before backing-off to break the chips). Any thoughts on gripping work as tightly as possible? 3) Holding a threaded rod in a chuck I use my 'wrapping aluminium strip' method (see above) for holding threaded rod (eg M10 or M8) in the chuck when I want to turn it down. Obviously, the steel tends to cut through the aluminium and damage to the thread can occur. I suspect that a better method would be to get some suitable copper tube as a sleeve and slide the threaded rod inside, before gripping it. Am I missing any other tricks for gripping threads? Many thanks in advance for any light you can shine on this topic. Best wishes Q ------- Re: Work holding in a chuck Posted by: ejandptrx~xxbtinternet.com philandjorobbo Date: Mon Jan 6, 2014 1:18 am ((PST)) Q, To protect work such as yours I have always used a strip of emery paper, ordinary medium grade, wrapped round the work, inside out –- back to the work. Align the join in the emery between the chuck jaws. Same goes for threaded rod. If you want to make sure of it, tap a bit of round bar to screw the threaded rod into and hold that in the chuck. You can use a locknut so it doesn’t get screwed in too tightly. I would find M12 a bit big to cut like this, but put a good taper on the end of the work so it starts easily and will then draw itself along. Plenty of thread-cutting lubricant and frequent stop and reverse to clear the chip. Really you need a mandrel driving handle to get more, smoother and controllable force. Using the chuck key is a bit jerky, and as you say yuk! And of course, make sure you have a good quality die, preferably HSS. You also mention “despite being gripped in the vice as tightly as I could” in which case some soft jaws for the vice. You can also get soft jaws for the chuck,but this is not an economy measure! Phil ------- Re: Work holding in a chuck Posted by: "NORMAN HEDGE" Norman.Hedgex~xxbtinternet.com Date: Mon Jan 6, 2014 2:33 am ((PST)) Hi. I too think M12 is a "big ask" with a die in the lathe. Why not try screw cutting the bulk of the thread and then just finish off with the die? Norman ------- Re: Work holding in a chuck Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk Date: Mon Jan 6, 2014 2:55 am ((PST)) Of course, one way to ensure that you don't have problems gripping bar stock is to start off with hex bar instead of round bar :) Regards, Tony ------- Re: Work holding in a chuck Posted by: "mark Dean" markdean61x~xxmsn.com Date: Mon Jan 6, 2014 3:00 am ((PST)) Hi Q, I would tackle all three problems in a similar way. Take a short length of bar, clean up the outside and then chuck the cleaned up part in the three jaw chuck. Then bore it to the size of collet you need, (or bore and tap it to size). Centre punch it next to jaw no. 1, to re-align after removal. Oops, not quite finished yet. Remove the bar, hacksaw through to the bore, between jaws. This should hold like a collet; for the threaded version, a bolt can be used as a stop, to save the part from turning. Hope this helps, all the best, Mark ------- Re: Work holding in a chuck Posted by: "Andrew Curl" methuselahx~xxntlworld.com Date: Mon Jan 6, 2014 3:36 am ((PST)) Although not initially cheap, investing in a coventry diehead (and some rocol RTD) will leave a smile on your face every single time you want to thread up to 9/16". Many of my dies came from Michael Watson. I can't remember where the head itself came from, suffice to say that I haven't seen another on a MT2 shank before or since! For holding studding, lock a couple of nuts together and grip by them. By all means use thin card to protect the work, but not emery cloth! Andrew ------- Re: Work holding in a chuck Posted by: peterroachx~xxbtinternet.com Date: Tue Jan 7, 2014 11:45 am ((PST)) As a prelude to any other changes of method, check that the chuck jaws are in good condition and concentric, Grind them at the size that you most commonly use. If the work is held concentric with the full length of all jaws holding the work piece, less likely to slip. 1/ Try using brass strip rather than aluminium. Being harder will not deform when the jaws are tightened to the same as soft Aluminium, but will still protect the work piece. 2/ Suggest you put 80% of the thread on with the lathe to screw cut and only use the die for the clean up/finish. On a lathe as small as a Myford would prefer to screw cut, rather than use die on M8 and upwards. 3/ I use a piece of hexagon bar with a tapped hole to mount the all thread or bolt. Use a nut to lock the work in position in the hexagon bar and you have a rigid non damaging holder. You could use a deviation of this last method, for the other two and either machine flats to a sacrificial extension to the job or dog as additional anti rotation. Alternatively cut the threads first, mount on the thread and the final cuts will remove any jaw slip damage. ------- Re: Atlas historian [atlas_craftsman] Posted by: wa5cabx~xxcs.com wa5cab Date: Mon Jan 6, 2014 5:05 pm ((PST)) In a message dated 1/4/14, wa5cabx~xxcs.com writes: >> All 3-jaw chucks should have two sets of jaws. One set is for >> chucking on parts whose diameter is up to about 1/2 of the chuck >> diameter. Above that, you should change jaws. In a message dated 01/06/2014, jmartin957x~xxaol.com writes: > Is this really what you meant to say? I realize that most of us often > use the longest step of the inside jaws for outside gripping of small > diameters, but the two sets of jaws that a 3-jaw chuck should have are > properly inside jaws and outside jaws, not large diameter and small > diameter jaws. John I know that almost everyone calls them that, although there seems to be some disagreement as to which set is called Inside and which set is called Outside. But calling them Inside and Outside is misleading because you can use either set for either function. The choice should be decided by the workpiece and safety, not by whether you are chucking on the ID or the OD of the workpiece. I think that you are calling the Inside jaws the ones with only one step that can clamp on the outside. But I've seen catalogs and ads that were written the other way. For workpiece diameters up to about 1/2 the chuck diameter, these are the safer and better jaws to use for Outside gripping. You have or can have more surface area engaged and you don't have the longer jaw whizzing around by your left hand. For larger diameter outside gripping, you should switch jaws and use the longest step on the other set. Anyway, what I was trying to explain was that regardless of what you or someone else call the jaws, you should use the ones that are the safest for both the machine and the operator. I would agree that it makes more sense to call the set of jaws with three outside steps and one inside the Outside jaws. But probably 90% of the time you should be using the Inside jaws for outside gripping. It's the remaining 10% that results in beds getting chewed up. And there is really no excuse for it. Robert & Susan Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: Chuck Jaws [atlas_craftsman] Posted by: wa5cabx~xxcs.com Date: Thu Jan 23, 2014 4:06 pm ((PST)) > I have a 5 inch 4 jaw Chuck, and a 4 inch 3 jaw spiral. Problem is I > only have one set of jaws for each Chuck. Can the other set of outside > hold jaws be had, or am I just hosed? Kevin, 4-jaw chucks normally have reversable jaws and only come with one set. This is of course if each jaw has its own drive screw (they are rare but there have been scroll-driven 4-jaw chucks made). They are about as rare as scroll-driven 4-jaws but there have been scroll-driven 3-jaw chucks made with reversible jaws. The way that you can tell whether jaws are reversible or not is that the thread teeth on the back of the common not-reversable 3-jaw chuck jaws are cut on an easily visible arc. If you try to load one into the chuck backwards, the threads will jam. Reversible jaws will have teeth each of which is oval. Reversible 4-jaw chuck jaws will have straight teeth cut at an angle equal to the thread lead across the width of the jaw. Odds are about 99:1 that the jaws in your 4-jaw are reversible and those in your 3-jaw aren't. You can sometimes find another set of jaws that will physically fit the chuck but if you just use them as-is the runout will likely be excessive. You will need to fit them to the chuck by the same process that you would use if the original jaws were worn or bell mouthed. Robert Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: Chuck Jaws Posted by: "Kevin Gibson" k3030aix~xxyahoo.com Date: Thu Jan 23, 2014 5:37 pm ((PST)) Robert, You nailed it, looks like the 4 jaw is reversable and the 3 jaw isn't. As long as the 4 jaw is reversable, I won't worry about the 3 jaw. Thank you. ------- Re: Chuck Jaws Posted by: jmartin957x~xxaol.com Date: Fri Jan 24, 2014 2:23 pm ((PST)) > Due to the scroll teeth on the back of the 3-jaw chuck's > jaws, they generally are NOT reversible. Old chucks > had 2 sets of jaws, inside and outside. Jon That's what I always thought too, until Robert set me straight. They should be referred to as small jaws and large jaws. Those that I - and I presume you - have always called the inside jaws should really be called the small jaws. Never too old to learn, I guess. John ------- Re: Chuck Jaws Posted by: "Charles" xlch58x~xxswbell.net Date: Fri Jan 24, 2014 2:34 pm ((PST)) Buck and Bison didn't get the memo obviously ..... http://www.buckchuckusa.com/products/manual-chucks-atsc-3-jaw.html http://www.bison-bial.com/lathe-chucks/3204-80-1 They clearly state that their solid jaw chucks "SHIPS COMPLETE WITH: Inside and outside gripping solid jaws" Charles ------- Re: Chuck Jaws Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Fri Jan 24, 2014 3:19 pm ((PST)) robert's terms make more sense to me ...always had to stop & think what inside/outside MEANT ...both types hold the bar on the OUTSIDE ...& if you think it means where the jaw grabs the part, that doesn't help since the inside jaws sometimes are used to grab the bored part on the outside of the jaws. but, again, if bOTH sets of jaws are near the same size, then w/ robert's terms, one must think that we talk of small or large parts to be chucked ....MY HEAD HURTS .... ....so i bought my bison 5 in w/ reversible top jaws. best wishes doc ------- Re: Chuck Jaws Posted by: jerdalx~xxsbcglobal.net jtiers Date: Fri Jan 24, 2014 4:34 pm ((PST)) To be fair, and I believe this was mentioned.... The jaws that are "tallest" towards the center (we could call them the "convex conical" jaws) are good for both small stuff held by the OD, and any size from the diameter of the highest (innermost) step onward, when held on the inside, as pipe could be. It helps if the pipe is no larger than the chuck, if you hold with the outermost jaw section. The next step provides its own "stop". If you have solid material of large diameter, your only choice is to hold BY the outside of the part, WITH the "outside" jaws, i.e. the "concave conical jaws". But you could have the option of holding large pipe that is not any bigger than the chuck with the same jaws on the inside of the pipe. That works just exactly the same way as using the other set in the same way, other than the length of jaw in contact. Virtually any "usage referential" name is meaningless. Size related names are meaningless. One may as well call them "A" and "B" jaws. Or one can simply observe that most refer to them as "inside" and "outside" or at least as "jaws" and "outside jaws", and go with the flow. I shall do that in lieu of any more cogent reasons for a change. The "convex" and "concave" are descriptive, but not likely to catch on. I reckon we were all a tad bored, or we would realize we don't give a rip. JT ------- Re: Chuck Jaws Posted by: "Charles" xlch58x~xxswbell.net Date: Fri Jan 24, 2014 5:40 pm ((PST)) Inside jaws are stepped and ground so that each step face can grip the inside of a pipe. There is of course one face that has to be oriented in the opposite direction so it is ground with its face to grip on the outside. So an inside jaw typically has three inside faces and one outside. The reverse of all of this is true for an outside jaw. Picking up a random tool catalog from turn of the last century and they offered chucks with only inside or outside jaws as well as both and they are called that, so the terminology has been used by the manufacturers of chucks continuously for well over a hundred years. From a functional standpoint though, Robert's nomenclature makes sense. Charles ------- Re: Chuck Jaws Posted by: wa5cabx~xxcs.com Date: Fri Jan 24, 2014 8:45 pm ((PST)) Yes, I knew that they had always been called that. But it's like left hand and right hand turning cutters. On any given day, I would have about a 50:50 chance of telling someone which was which. :-) Robert Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: Chuck Jaws Posted by: "Carvel Webb" carvelwx~xxabsamail.co.za Date: Fri Jan 24, 2014 11:10 pm ((PST)) Interesting thread. To be honest this is the first time in 50 years that I have heard the jaws of a universal chuck described as anything other than 'inside' and 'outside'. A quick search amongst the files turns up the following - Atlas catalogue (1945) - "complete with two sets of jaws (inside and outside)" Myford catalogue (1964) - " complete with inside and outside jaws" Emco brochure (1974) - " complete with 2 x 3 jaws " (no mention of inside or outside) Our instructor at school put it this way (50 years ago and somehow stuck) - " Lathe universal chucks come with two sets of jaws - inside and outside. he choice of jaws is informed by the nature of the work piece you are clamping. To remember which is which think of clamping a pipe - the inside jaws clamp 'inside' i.e. in the bore tightening outwards, and the outside jaws on the 'outside' clamping inwards. But generally use the inside jaws for bar stock because the contact surface of the jaw is longer." I must have been interested, because that picture and description has stayed with me since. Keep well, Carvel ------- square stock in a 3 jaw chuck? [sherline] Posted by: "DAVID DAZER" ddazerx~xxsbcglobal.net Date: Fri Feb 14, 2014 3:25 pm ((PST)) I need to drill the center of 1/4" square stock. Is there a way to cheat and use a 3 jaw chuck? I am making some parts and only need to do this 4 times. On a related note, would this be a good time to buy a 4 jaw, self centering chuck? I don't mind buying one if it will make this job easy. I figure if I need it now, I will need it another time. Dave ------- Re: square stock in a 3 jaw chuck? Posted by: procterx~xxihug.co.nz kwstse Date: Fri Feb 14, 2014 3:45 pm ((PST)) Hi, you could make a collet out of, say 3/4" diameter aluminium. Drill a 1/4" hole in the middle. File it square. Cut from outside to one corner. Put it loosely in 3 jaw chuck and slide the 1/4" brass through it and tighten. Greg.Procter, Hukerenui, New Zealand. ------- Re: square stock in a 3 jaw chuck? Posted by: procterx~xxihug.co.nz kwstse Date: Fri Feb 14, 2014 4:17 pm ((PST)) Hi Joel, I thought of the across the corners diameter hole a little after I pressed "send" and just before my wife called me for lunch. :-) Of course the corners of the square brass will cut small 'V' s into the aluminium collet each time. Either reposition the brass each time and toss away the collet after half a dozen uses or live with a slight inaccuracy. Greg.Procter, Hukerenui, New Zealand. ------- Re: square stock in a 3 jaw chuck? Posted by: "joel taylor" flyer_55x~xxpacbell.net Date: Fri Feb 14, 2014 4:08 pm ((PST)) Actually along the same lines as Greg mentioned, take the 1/4 square and measure across the corners with decent calipers. This should give you a number around .334 or so. Drill a 11/32 hole in your alumn collet. (I would prefer 1/2" as it would compress a bit better). Once you have the hole drilled, use a hacksaw and cut a slit lengthwise. The slit doesn't need to be perfect, just give the collet a chance to compress a bit and clamp the 1/4 square. Chuck this up with your 1/4" square in the middle hole and tighten up your chuck. You will have the brass as centered as any scroll chuck could get. The disclamer is that I did this on a 5" keyed three jaw chuck on my 8/14 lathe. I might have gotten better leverage at clamping this than you can get with the bars on a Sherline chuck. If this is the case, than the only choice is a square collet as mentioned below. 'g luck. Joel ------- Re: square stock in a 3 jaw chuck? Posted by: "Thayer Syme" thayerx~xxgryffinaero.com tcsyme Date: Fri Feb 14, 2014 4:52 pm ((PST)) Dave. This sounds like a perfect excuse to buy more tooling in my book. I would, however, get the independent 4 jaw instead. Independent jaws give you better holding power than a scroll, and the option to work off center if you desire. Centering isn't so bad once you get a little used to it. A dial indicator and a pair of chuck wrenches should have you within a thou or two in almost no time. Thayer ------- Re: square stock in a 3 jaw chuck? Posted by: "Ken Condal" kencondalx~xxyahoo.com Date: Fri Feb 14, 2014 6:21 pm ((PST)) First off, for this and many other projects, a 4 jaw independent chuck is your best investment. As others have said, once you learn how to use it (YouTube has a ton of stuff on that) you can dial in a part exactly. Any self-centering chuck will have an error, although usually small. It depends on what you're making as to whether that small error will matter. Just this week I completed a part which required mounting square stock on the lathe. I'd never done it before but I watched this video and then made the part without any problems. This guy talks a lot (too much) but hang in there and you'll learn a lot. http://www.youtube.com/watch?v=aA0suYN72SE Ken ------- Re: square stock in a 3 jaw chuck? Posted by: "JERRY G" chieftoolmakerx~xxearthlink.net Date: Fri Feb 14, 2014 7:00 pm ((PST)) Hi Dave, try this. Do you have a QCTP? Put your part(s) in the QCTP holder. Use the 3 jaw (with edge finder) to locate the square stock's height. Edge in Cross slide movement. Once center is located relative to the lathe spindle, center drill, drill, etc. Jerry G (Glickstein) Anytime is a good time to buy a 4 jaw universal chuck. Get the 3.1" ------- Re: square stock in a 3 jaw chuck? Posted by: procterx~xxihug.co.nz kwstse Date: Fri Feb 14, 2014 7:38 pm ((PST)) Sherline also do a four jaw scroll chuck. It would be useful if you're going to machine a lot of square stock to round :-) but otherwise fairly useless. Most people will find the independent four jaw much more useful and versatile. Greg.Procter, Hukerenui, New Zealand. ------- Re: square stock in a 3 jaw chuck? Posted by: alanhyx~xxlive.com alanhaisley Date: Sat Feb 15, 2014 7:55 am ((PST)) If the 3 jaws came to a knife edge you could use .0193" of packing between one jaw and the part. Unfortunately the jaw edges have thickness and so some GREATER amount of packing would be needed. You could discover this by trial and error and for four parts might be the way to go. Clean up the end of the square and mark diagonals on it as accurately as you can. Put it in the chuck with .0193" of packing and by eye decide how much more packing you need to add to get centered. While you could use the tailstock center as a visual aid, you might do better with the smallest drill that you have as a guide. If when you make the diagonal marks you scribe them over black ink, you might be able to see the center crossing while running the lathe at low speed. If so, when you have the right amount of packing it will stop being a circle and will be a dot. Good luck. Alan ------- Re: square stock in a 3 jaw chuck? Posted by: jlkiefferx~xxcharter.net n2562001 Date: Sat Feb 15, 2014 8:06 am ((PST)) In sherlinex~xxyahoogroups.com, Greg Procter wrote: > Sherline also do a four jaw scroll chuck. It would be useful if you're going to machine a lot of square stock to round :-) but otherwise fairly useless. Most people will find the independent four jaw much more useful and versatile. < Greg, I would have to respectfully disagree. If the Sherline self centering four jaw chuck is used as your primary chuck, it is more accurate and holds stock more securely than a Sherline three jaw. It has the limitation of not holding hex stock the same as the three jaw will not hold square stock. The combination of both chucks for general machining greatly increases one's efficiency in regard to capabilities and skill development. Jerry Kieffer ------- Re: square stock in a 3 jaw chuck? Posted by: procterx~xxihug.co.nz kwstse Date: Sat Feb 15, 2014 12:10 pm ((PST)) Hi Jerry. If everybody agreed on everything we would all be sitting in front of Fox News being entertained and noone would want a lathe. :-) The four jaw scroll chuck is next on my list after: 3 jaw small, 4 jaw independent, 3 jaw large, ER collets, milling cutter holders ... Of course preference comes from the particular usages of the owner. Greg.Procter, Hukerenui, New Zealand ------- Installing/removing heavy chucks [atlas_craftsman] Posted by: kbx~xxmuziker.org kbjorling Date: Fri Nov 21, 2014 5:08 pm ((PST)) Prefatory disclaimer: I apologize in advance if I'm wasting everyone's time with something everyone already knows. A recent message on an unrelated subject mentioned the awkward, potentially knuckle-bruising, ways-dinging operation of trying to man-handle a heavy chuck onto or off of a lathe spindle. I know the experience. It was already bad enough with the relatively small 4-jaw I had on my 618. When I prepared the remove the 7-1/4 inch chuck that was already on my 10F when I acquired it, I said (to myself, silently, yet loud and clear) "uh-uhhh". (I think that's Yiddish for "no way, Jose"). My solution is so simple I can't imagine that nobody else does it -- but I've seen several references to bruised knuckles and none to this practice, so here's what I did, and have continued to do ever since: 1. Take a wooden dowel, ideally of the largest diameter that will fit the thru-hole of the spindle, and at least a foot long, preferably long enough to run a little over the entire length of the spindle+chuck. (A cylinder or tube of other material may work just as well, but I like wood.) 2. Open the chuck jaws enough to allow the dowel to pass thru and insert the dowel so that at least a few inches protrude from the front of the chuck, with at least 8" or so inside the spindle. (Again, best if it runs the whole length.) 3. Unscrew the chuck, allowing it to tip off, onto the dowel. Now you can lift the chuck away with both hands. If you're worried about scuffing the threads, tighten the chuck jaws around the dowell, and support the weight of the chuck by lifting the protruding bit of dowel with one hand while turning the spindle backward until the threads disengage, then let the weight of the chuck settle onto the dowel. The same steps, working backward, make it easier and a lot safer to install the chuck, at least up to the point where the threads engage. I keep my trusty dowel nearby, on a loop of string hanging from a hook. I use it and a rawhide mallet, also always nearby, to drive stuck collets and/or adapters from the spindle nose, tapping on the dowel from the rear, of course. This is why I recommend having the dowel a little longer than the spindle. Kurt B. ------- Re: Installing/removing heavy chucks Posted by: "Lance Eggleston" gbofx~xxverizon.net crashbone256 Date: Fri Nov 21, 2014 5:47 pm ((PST)) I use a piece of 1/2" pipe, so I can bring up the TS center to hold the right end, spindle bore holds the left end, spin the chuck onto the pipe, place some 2x4 pcs on the ways, push the TS away and lower the chuck to the ways. Use the pipe to move the chuck to the shelves, roll it into its slot. Since I have a 16" lathe also, I built a crank lifter with a J-hook to replace the pipe, lifter replaces my muscles I just swing it 90* and lower it. Lance ------- Re: Installing/removing heavy chucks Posted by: "Glenn N" glennsneffx~xxgmail.com sleykin Date: Fri Nov 21, 2014 11:19 pm ((PST)) I do it that way except I use a 3/4" aluminum rod (what I had) and put a 2X6 block under the chuck on the ways and it only drops about 1/4" so you can lever it off and then pick it up using the rod as a handle. The block of wood really helps going back on. Glenn ------- Re: Installing/removing heavy chucks Posted by: wa5cabx~xxcs.com wa5cab Date: Sat Nov 22, 2014 9:12 am ((PST)) I use a 4x4 post, length = width of ways and top cut away in an arc so that it will just slide under the chuck when the chuck is on the spindle. Unscrew the chuck until it runs off the threads and is sitting on the block. Reverse to install. Robert Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: Installing/removing heavy chucks Posted by: paulguenterx~xxatt.net paulguenterx~xxatt.net Date: Sat Nov 22, 2014 10:43 am ((PST)) It is funny to me there is no chuck that could be that heavy where one would have a problem to lift it, that is used on any model Atlas/ Craftsman lathe. GP ------- Re: Installing/removing heavy chucks Posted by: "James Rice" james.ricex~xxgmail.com jlrice54 Date: Sat Nov 22, 2014 11:35 am ((PST)) Not really but I do use a 4x4 cradle to protect the ways if I use a 6" chuck. Asian 6" chucks plus the cast iro back plates will make a pretty good dent in the ways if dropped. Lifting it isn't an issue. But I'm only 60. Eventually, if I live long enough, the weight of that 6" might become more than I want to wrestle with. My Dad lost a lot of arm strength the closer to 90 years of age he approached and as his health continued to fail. James ------- Re: Installing/removing heavy chucks Posted by: "Lance Eggleston" gbofx~xxverizon.net crashbone256 Date: Sat Nov 22, 2014 10:54 am ((PST)) That really depends on the individual's medical condition. There are many people who cant lift over 10 lbs. Lance ------- Re: Installing/removing heavy chucks Posted by: paulguenterx~xxatt.net paulguenterx~xxatt.net Date: Sat Nov 22, 2014 1:00 pm ((PST)) I have a 16" south bend and lifted the chuck to start it on the spindle. GP ------- Re: Installing/removing heavy chucks Posted by: "Glenn N" glennsneffx~xxgmail.com sleykin Date: Sat Nov 22, 2014 1:39 pm ((PST)) I guess you haven't "aged" enough yet Gunner ;) I find recently that stuff I put on the shelf with one hand 10 years ago takes everything I have to move it off now. Stay Young! :) Glenn ------- Re: Installing/removing heavy chucks Posted by: "James Rice" james.ricex~xxgmail.com jlrice54 Date: Sat Nov 22, 2014 2:32 pm ((PST)) I have too but I figured why strain muscles and smash fingers. You know, Work Smarter,Not Harder. Besides I plan to be enjoying this hobby until they plant my butt, so I might as well get set up for the day when I won't feel like wrestling a150# chuck onto the lathe. [?] James ------- Re: Installing/removing heavy chucks Posted by: paulguenterx~xxatt.net paulguenterx~xxatt.net Date: Sat Nov 22, 2014 4:04 pm ((PST)) I am chuckling at the reponses i get. I agree it would be much better and easyer to lift the chuck of my south bend with the help of a hoist. I am planning to have one as soon as i decide where the lathe will set forever or as long as i own it. But now atlas lathe chucks don't weigh much so eat your Wheaties guys. GP ------- 6inch Chuck Problem [myfordlathes] Posted by: chcx~xxjacom.co.uk egkk2709 Date: Fri Jan 16, 2015 7:26 am ((PST)) I have a 6" independent 4 jaw Bernard chuck (model 34) that I wish to overhaul/clean. However the jaw screws are held in place by 'yokes' that are approached from the rear where they seem to be peened into place. How do I get it apart? regards Christopher C ------- Re: 6inch Chuck Problem Posted by: "P ROBINSON" ejandptrx~xxbtinternet.com philandjorobbo Date: Fri Jan 16, 2015 11:16 am ((PST)) Christopher, The "yokes" are not peened into place, just a bloody tight fit. (A "drive fit") Remove the jaws (just unwind until they come off - put them back in the same place) and use a thin drift/drifts (or make a u-shaped tool) and drive this down the side of the screws in the unthreaded neck part in the middle to bear on the inside of the yoke. If you are lucky the "yokes" will come out of the back of the chuck. Often plentiful applications of lubricant, and some heat, are required. Sometimes they are immovably stuck, but if you just want to clean it then flush it out well after the jaw removal and use some light (spray) grease on reassembly. Phil (by dictation!) ------- Re: 6inch Chuck Problem Posted by: chcx~xxjacom.co.uk egkk2709 Date: Fri Jan 16, 2015 2:38 pm ((PST)) Hello Phil. Many thanks - you have described the problem/solution exactly. I didnt want to start hitting it too hard if I was on the wrong track. The chuck has had virtually no use and most of it is in very good condition. Sadly it was left in a bucket of water so rust must be removed and a general clean up is needed Again many thanks Christopher ------- Re: 6inch Chuck Problem Posted by: "P ROBINSON" ejandptrx~xxbtinternet.com philandjorobbo Date: Fri Jan 16, 2015 2:49 pm ((PST)) Christopher, "left in a bucket of water"? didn't have a kitten tied to it did it? Seriously, if you can't dismantle it then you could try rust removal by electrolysis. You still need to scrub around with toothbrushes etc afterwards, but better than leaving it rusty. Phil ------- Re: 6inch Chuck Problem Posted by: "Paul Kennedy" clankennedy2004x~xxyahoo.co.uk Date: Fri Jan 16, 2015 10:55 pm ((PST)) I have a similar chuck and it came apart in the same manner. However I discovered that one of the drive pins that retain the screw that operates the jaw was damaged. I think it was a home made effort and the two small retaining 'lugs' which fit the recessed part of the screw holding the screw in the chuck body were somewhat worn and out of shape although still functional. I'm not willing to use the chuck in this condition. My questions are: where would I get a replacement retaining pin and if I have to make it, what material should I use as I'm assuming that it's hardened/tempered in some fashion; and finally how would I harden the pin with limited equipment! I have gas and a blow torch but I'm not sure it's going to be sufficient. Also I would possibly need a supplier of the carbon compound which is used in the hardening process. Your help is of course appreciated. Thanks Guys ------- Re: 6inch Chuck Problem Posted by: "David Everett" deverett2003x~xxyahoo.co.uk deverett2003 Date: Sat Jan 17, 2015 2:37 am ((PST)) Use silver steel for any hard bits. This is easily hardened by heating with your gas torch until red heat. Dunk immediately in water. Make sure it goes into the water vertically to avoid any distortion. Once cool, remove from the water, clean down with scotchbrite or similar and then warm gently until you see the colours turn to indigo (deep blue). The best way for doing this is to get a small tin of brass or bronze filings, lay the pin on them and heat from underneath. As soon as you see the colours darkening from pale straw remove the heat. The SS should continue to darken and when the correct colour has been reached again dunk in the water. I've heard that some people put a drop of 3-in-1 type oil on the water surface before the dunking. Dave The Emerald Isle ------- Re: 6inch Chuck Problem Posted by: "David Littlewood" davidx~xxdlittlewood.co.uk dmlittlewood Date: Sat Jan 17, 2015 3:01 pm ((PST)) Two points worth adding here. First, to harden properly the steel should be held at red heat for a couple of minutes (the time required depends on material thickness, you should research this). Of course, for many purposes a hardening that doesn't go all the way through, or doesn't reach maximum level, may be fine. Second, don't make it too tight a fit, as hardening the steel makes it expand by a very small amount; probably only a thou or less at these sizes, but more than enough to turn a close fit into a won't fit (DAMHIKT). Tempering reduces it slightly, but not all the way back to starting size. David ------- Re: 6inch Chuck Problem Posted by: enwodex~xxyahoo.co.uk enwode Date: Sat Jan 17, 2015 3:05 am ((PST)) Hi there, Christopher and Phil, As an alternative to electrolysis, may I suggest that you consider citric acid? It's available via eBay in crystalline form and is quite cheap. For your chuck, I'd suggest half filling a plastic bucket with warm water and stirring in the citric acid crystals until they stop dissolving. Degrease the chuck and then immerse it in the citric acid and go and do something else for a while. Inspect regularly. Turn occasionally. Allow sufficient time for the process to get into the interstices. When the gentle bubbling ceases and signs of rust are gone, remove the chuck, rinse in clean water and then in methylated spirits or IPA to dispel the water and lightly oil to protect the fresh surface. Once you're satisfied that you don't need it anymore, the used citric acid solution may be safely (and legally) disposed-of down the domestic drain (one of its other uses is as a food additive so it's safe to do that.) Don't be tempted to use phosphoric acid preparations (e.g. Jenolite) for this purpose, because they don't remove the rust -- they chemically modify it, leaving the product in place, complete with dimensional build-up. (Jenolite works fine for its intended purposes but this isn't one of them!) The citric acid approach is slower than electrolysis in actually removing the rust but is much quicker and simpler in getting prepared and set up, so probably quicker overall. (That's once your citric acid has been ordered and delivered.) And you don't need an electrical PSU or battery charger. I hope this helps. Best regards, Pete W. (aka 'Enwode') ------- NOTE TO FILE: Now that electrolysis and citric acid have been mentioned in this thread, anyone facing a rust removal situation would do well to read the text file here named Rust Removal, where these and other methods are discussed in far greater detail and there are many useful tips. Similarly the topic of hardening steel is well covered in the text file here named Heat Treating. ------- Re: 6inch Chuck Problem Posted by: "Alan Moore" a.j.moorex~xxbtinternet.com Date: Sat Jan 17, 2015 6:08 am ((PST)) Paul, If your chuck is a Pratt Burnerd one then you can still get replacement screws and retaining forks from the 600 Group. www.600uk.com Be warned, though, they are not cheap. Regards, Alan ------- Re: Chuck removal [atlas618lathe] Posted by: "Lynn Chidester" clynnchidesterx~xxgmail.com Date: Thu Jan 22, 2015 2:32 pm ((PST)) On Thu, Jan 22, 2015, egpacex~xxhotmail.com wrote: > My advice would be to repeatedly soak the seam where chuck meets the spindle with kroil penetrating oil. Give it a few days to work and it will probably unscrew with just a light tap. Kroil is amazing! You can get it on Amazon, not cheap though. Google it and see all the raves about it. < Another thing I've used as a penetrant lube (like Kroil) replacement is to apply some silicone spray lube (look for the aerosol 12oz can at the local auto parts store) to the joint between the chuck and lathe spindle. Then apply a shot of NON-FLAMMABLE aerosol brake cleaner to the same joint (from the same source). My experience is that the NON-FLAMMABLE brake cleaner (which contains perchloroethylene) penetrates the crevases, and carries with it the silicone lube, hence lubricating & freeing up the joint. If the chuck was loose and was spun on TIGHTLY under power, then sometimes the only solution is to machine off the chuck back plate. The Machinist Bedside Reader books have several episodes/stories of such cases, and the efforts required to solve such. ------- Re: Chuck removal Posted by: anakedmachinistx~xxyahoo.com anakedmachinist Date: Thu Jan 22, 2015 6:38 pm ((PST)) Yes! I removed the chuck! I engaged the back gears like Kyle said and used some channel locks and it spun right off. Thanks for all the input guys. It's been really helpful. This is my first lathe so any other advice in setting it up would be very helpful. I have nearly all the tooling one can possibly get for this specific machine, so I want to get the most out of it as possible. Thanks again for sharing the knowledge! Jeff ------- Re: Chuck removal Posted by: wa5cabx~xxcs.com wa5cab Date: Thu Jan 22, 2015 11:28 pm ((PST)) Never use the indexing pin for this. You will ruin several holes and then shear off the pin. The method given in the MOLO (and what I've used for 30+ years) is to engage back gear without pulling out the pin locking the bull gear to the spindle pulley. If the chuck is just on normally, before I engage back gear, I rotate the chuck by hand until the socket is at TDC. Then lock back gear, put the T-handle wrench in the socket, and give it a smart tug. If two or three tugs doesn't do it (and it always has for me), put a piece of 2X4 in the chuck jaws and tighten the jaws down on it. Give the end of the 21X4 a sharp rap with a shop hammer. If two or three of those don't do it, put on more Kroil and wait another day. Robert Downs - Houston wa5cab dot com (Web Store) MVPA 9480 ------- Re: 4g. Re: Chuck removal Posted by: "John Bump" johnbumpx~xxgmail.com smellsofbikes Date: Thu Jan 22, 2015 9:05 pm ((PST)) My automotive friends swear by a mix of 50/50 acetone and automatic transmission fluid as being even better than pbblaster, kroil, or knock-er-loose. My friend Ed posted this about battling a severely stuck chuck: http://softsolder.com/2009/07/01/lathe-chuck-unstuck/ ------- Re: Chuck removal Posted by: burkheimerx~xxverizon.net ar1911 Date: Fri Jan 23, 2015 7:02 am ((PST)) My direct message bounced, so 'm late to the party. You have solved your problem, but just in case someone else has this issue: Definitely don't use the indexing holes. In fact, on the Atlas, you need to be careful with the backgears as well, it's all Zamak. Best advice I ever got on this: engage the back gears to lock the spindle Clamp a piece of pipe, angle iron etc across the chuck jaws so it hangs over the front of the lathe. (Release back gear to adjust spindle orientation as needed.) Hang a bucket on the pipe. Fill the bucket with scrap iron etc. Load it up. Spray penetrant of your choice on the joint. Go in the house and watch the news with your wife. Most of the time that bucket will be on the floor next morning. If not, leave the bucket there. Apply heat, let it cool some, then apply more penetrant. Check again the next morning. This applies a great deal of torque while not shocking the back gears, or pulling the lathe over on you. Rex B - DFW ------- 3 jaw chuck lubrication [myfordlathes] Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net cliffcoggin Date: Mon Mar 23, 2015 6:38 am ((PDT)) Gents. I am in a quandary about whether to oil the 3 jaw chuck from my ML7 which I have stripped for cleaning. On the one hand oil will allow moving parts to slide over each; but on the other hand swarf will cling and possibly increase abrasion. What opinions and experiences do you folk have? I turn mainly brass and mild steel, plus occasionally silver steel and aluminium. Cliff Coggin Kent England Je suis Charlie ------- Re: 3 jaw chuck lubrication Posted by: "Alan Moore" a.j.moorex~xxbtinternet.com Date: Mon Mar 23, 2015 6:54 am ((PDT)) Oil will also fly off the chuck when it is spinning and make a mess of your glasses. My sixpen'orth is to take the jaws out, oil them sparingly, then wipe off all the oil I can get at. The traces that remain in the crevises will be enough to lubricate the scroll. The main thing is to avoid corrosion - if you can do that with humidity control in the workshop you need very little lubrication. Regards, Alan ------- Re: 3 jaw chuck lubrication Posted by: "wiktoria jablonska" wiktoria_jablonskax~xxyahoo.co.uk Date: Mon Mar 23, 2015 7:57 am ((PDT)) I faced a similar quandry a while back. Called Bison chuck - who recommended Molykote D321 - it's dry (so doesn't attract swarf) and is a great lubricator. It is however twice the price of processed uranium.....but well worth it. Great for slideways, feedscrews, etc. Hugs Anna ------- Re: 3 jaw chuck lubrication Posted by: harry.wilkesx~xxsky.com Date: Mon Mar 23, 2015 8:41 am ((PDT)) Hi Cliff. I watched a youtube mrpete222 -- if I remember correctly he stripped a chuck and lightly lubricated when he put it back together so when I did mine about six weeks back, I lightly greased mine. So far it has not caused me any problems. Cheers H ------- Re: 3 jaw chuck lubrication Posted by: "David Everett" dernhx~xxyahoo.co.uk deverett2003 Date: Mon Mar 23, 2015 8:54 am ((PDT)) I have a Burnerd Grip-Tru chuck. The cavity was filled from new with a graphite type grease. If it's good enough for PB, it's good enough for me. Dave The Emerald Isle ------- Re: 3 jaw chuck lubrication Posted by: "Bob Hamilton" bobx~xxhamilton-bob.freeserve.co.uk ukdiverbob Date: Mon Mar 23, 2015 10:08 am ((PDT)) Molykote D321 That sounds very like a high temperature spray on lubricant that was used on the “Lancing Plate” of filter assemblies on plastics extruders I worked with. It is indeed a dry lubricant that should not attract fine dust type materials and it certainly would not “fling off”. My preference is to remove the chuck regularly and, with the jaws also removed, soak it in a good degreaser. Then give it a good blow out, (I can hear the cries of OH NO from here). A light oiling, followed by a spin for a few minutes to get rid of the bulk of the residue, (with a simple guard in place) seems to work for me. Bob ------- Re: 3 jaw chuck lubrication Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net cliffcoggin Date: Mon Mar 23, 2015 11:34 am ((PDT)) Thanks for your views everyone. I intend to try a dry lubricant in the hope of having, if not the best of both worlds, at least a good compromise between lubrication and non-sticky parts, so have ordered some powdered graphite rather than Anna's Molykote, (which I assume is molybdenum disulphide,) as it costs no more than mere gold. Cliff ------- Re: 3 jaw chuck lubrication Posted by: "Kevin" tadpolex~xxbtinternet.com klokenz Date: Thu Mar 26, 2015 3:07 pm ((PDT)) Won't it be rather messy Cliff, unless you have an oil film to hold it in place (which would defeat the object of using graphite)? Or does sufficient of the graphite stick by itself to clean metal, I wonder? I know that powdered graphite is sometimes recommended for use in locks, so it's got some "form", as it were. I hope you'll let us know how it turns out after you've had a chance to assess it. Browsing back through old copies of ME the question of whether to lubricate chucks, and if so with what, seems to be one of those questions that has been around forever! Kevin, England ------- Re: 3 jaw chuck lubrication Posted by: "Cliff Coggin" clifford.cogginx~xxvirgin.net cliffcoggin Date: Wed Apr 1, 2015 8:07 am ((PDT)) Kevin, and anyone else interested, I lubricated the chuck today with powdered graphite and so far it is as free as I could wish for. I can spin the chuck key with one finger. It is a little messy to apply, but no more so than oil, and unlike oil it washes off the skin with just soap. It remains to be seen how durable it is. I found during dismantling that the inner diameter of the scroll had galled on the central boss of the chuck body, and was the major source of friction. I needed to polish both surfaces with fine abrasive to restore them to the point where the scroll would drop into place again. (I had to knock the scroll out with a hammer and brass punch.) I also cleaned the parts in an ultrasonic tank as it is the easiest way to remove grit from all the nooks and crannies, revealing to my surprise no visible wear except at the aforementioned scroll/boss. I plan to treat my other chucks the same way in the near future. Cliff Coggin Kent England ------- [atlas_craftsman] Subject: RE: (Re)Grinding Chuck's Jaws From: ian bassett ianbassettnzx~xxhotmail.com Sent: Friday, March 27, 2015 9:11 PM An Australian gentleman on you-tube demonstrated jaw grinding with a pencil grinder set up on his lathe. Channel name is xynudu if anyone is interested in watching. Regards Ian Bassett ------- Re: (Re)Grinding Chuck's Jaws Posted by: "David Hair" thehairsx~xxoptilink.us dhlh1984 Date: Sat Mar 28, 2015 4:04 am ((PDT)) This is the best youtube I've seen on grinding the jaws of a chuck. MACHINE SHOP TIPS #147 Grinding the Jaws on a 3-Jaw Chuck tubalcain https://www.youtube.com/watch?v=-yWsjeY6nJU ------- Re: (Re)Grinding Chuck's Jaws Posted by: "James Irwin" jirwin1x~xxaustin.rr.com jimirwin2001 Date: Sat Mar 28, 2015 5:03 am ((PDT)) Chips inside will cause errors that grinding will not fix. So one should clean the chuck before and after grinding to get best results. I suggest for consideration that lapping the chuck tooth to scroll mating surfaces ONLY might also be a very good thing to do, too. And do this before grinding the jaws. Also: The design and proper function of a scroll chuck is to perfectly center any diameter work anywhere in its range. Any errors from this ideal are results of errors in manufacturing or wear or the presence of swarf, etc. or any combination of these. Jim Irwin ------- Re: (Re)Grinding Chuck's Jaws Posted by: jerdalx~xxsbcglobal.net jtiers Date: Sat Mar 28, 2015 5:41 am ((PDT)) Cleaning first is a very good idea. The best reason for it is that it may mean you don't need to grind anything, because the problem was caused by something other than what you may have thought. Yes, perfect centering is the ideal. You'll probably never find a perfectly centered chuck, but you may find chucks that are good enough to use as if they are perfect (until they wear). Jerry ------- Re: (Re)Grinding Chuck's Jaws Posted by: "Glenn N" glennsneffx~xxgmail.com sleykin Date: Sat Mar 28, 2015 10:06 am ((PDT)) Also, before you grind to cure bell mouth, check to be sure hairy hamfist hasn't over torqued the chuck while trying to hold something barely in the jaws. I have seen this tweak the chuck body enough to allow the jaws to cant creating the bell mouth. I beat the chuck body back flat and eliminated most of the bell mouth. This was one of the 6" chucks that came with the lathes new. Not a real fine chuck to begin with, but a nice size for smaller things. ------- Grinding Chuck Jaws Posted by: lhghousex~xxsuddenlink.net garlinghouseles Date: Sun Mar 29, 2015 8:46 am ((PDT)) Swatting a few flies away I boldly offer the following to the moribund horse: Attempting to grind a concave profile to the jaw is not desireable IMHO. Let's assume that you pull off a perfectly profiled concave gripping surface on your chuck jaws and that your resulting curve perfectly matches a 2" diameter. Sooo if you chuck up a perfect 2" diameter you will in theory have a large area of contact at each jaw. But ... if you chuck up a larger diameter (even a small amount larger) you will only contact the workpiece at the sharp edges of the curved profile of the concave gripping area of your chuck jaw (and this will probably deflect them and damage the surface of your workpiece). AND ... if you chuck up a smaller diameter you will only contact along the line of tangency along the center line of the jaw. The same as if you had a Vee groove running parallel to the Z-Z or spindle axis in the center of each jaw. Should you chuck up a piece of hex stock you will have the same situation as an infinitely large diameter (assuming you are chucking on the flats). Not good. So the best you can do that will give you a consistency in holding is to grind the jaws flat and perpendicular to their radial axis. Oww!! Owww!! Them flies are starting to bite!! L8r, LH ------- Re: Grinding Chuck Jaws Posted by: jmartin957x~xxaol.com jmartin957 Date: Sun Mar 29, 2015 11:17 am ((PDT)) I'm afraid I have to disagree. Grinding a concave profile on your chuck jaws is not the goal, but it is the result of what is probably the best method of truing the jaws. I'd rather have the jaws true but slightly concave, than have them flat but out of true (whether radially or bellmouthed). I think that you're worrying too much about a bit of concavity, although it depends somewhat on the width of those jaws at their tips. The only workpiece that jaws with perfectly flat ends will grip with full contact is a hex. Flat jaws will grip any size round only at the very middle of their gripping surfaces. The concave jaws will grip small rounds at the very middle of the concavity but, as the pressure deforms each surface, the contact area will actually be slightly greater than for flat jaws. When they grip large rounds, you are correct in that they will contact only at the edges. But there is a solution for this small problem. After I grind chuck jaws, I rub them on a flat hard oilstone (you could use abrasive paper on a flat plate) to break the corners and flatten them slightly. You don't want to stone so long that you remove all the concavity, as you'll then lose the accuracy you just gained. But just long enough to leave, say, half of the grinding concavity. Check them with a loupe as you go. If you leave a uniform concavity in the middle, you'll have taken the edges down evenly. I think that the method of holding the chuck still and feeding in and out with the cross slide is, at best, awkward. It requires you to feed the cross slide in and out with one hand while moving the carriage with the other. It is a lot easier to rock the chuck back and forth with your left hand while moving the carriage handwheel with your right. No need to have the chuck turning under power -- you're spending too much time grinding air that way. John ------- Re: Grinding Chuck Jaws Posted by: "Steve Metsch" stevemetschx~xxcox.net Date: Sun Mar 29, 2015 11:09 am ((PDT)) The flat jaws only touch on a line tangent to the workpiece. What's so great about that? Stevemetsch in SB CA ------- Re: Grinding Chuck Jaws Posted by: jerdalx~xxsbcglobal.net jtiers Date: Sun Mar 29, 2015 9:22 am ((PDT)) Well, having ground several chucks, I have never found any problems with the concave grind, other than the chance of leaving bite marks on the work, which is a risk even with perfectly flat jaws. I suppose in some "pathological case" of extreme grinds there might be a problem, but it is not worth lossing any sleep over. If the jaws are that bad, you may want to consider a new chuck. Or new jaws, if you can get them. Now, if you really want to avoid it, you have a slight modification to the process. Simply mount your grinder on a milling attachment (or similar) at suitable height, lock the spindle with each jaw in succession at top or bottom, and traverse the crosslide to grind the surface flat. Do not re-adjust in between, for best results. However, as I mentioned, I have never run into an issue with the slight concavity of the as-ground jaws, and I doubt you would either. Of course, you are free to let that theoretical possibility stop you, if you wish, but you are almost certainly over-thinking the matter. Jerry ------- Re: Grinding Chuck Jaws Posted by: "Scott Henion" shenionx~xxshdesigns.org shdesigns2003 Date: Sun Mar 29, 2015 11:15 am ((PDT)) On 3/29/2015 12:22 PM, jerdalx~xxsbcglobal.net [atlas_craftsman] wrote: > However, as I mentioned, I have never run into an issue with the slight > concavity of the as-ground jaws, and I doubt you would either. Same here. The only issue is it leaves more marks on larger stock. If that is a problem, I use collets anyway or aluminum shims (aluminum HVAC tape works well for light work..) Scott G. Henion, Stone Mountain, GA Craftsman 12x36 lathe: http://shdesigns.org/Craftsman12x36 Welding pages and homemade welder: http://shdesigns.org/Welding ------- Re: Grinding Chuck Jaws Posted by: "Ron Mattson" mattsonrjx~xxatt.net mattsonrjx~xxatt.net Date: Tue Mar 31, 2015 4:12 am ((PDT)) I may be beating the dead horse here, but..... Couldn't the jaws, taken out of the chuck, be trued on the surface grinder. The jaws could be mounted threads down on cylindrical stubs (acting like thread measuring wires) on a flat, with a milling vise clamping the jaws together. The vise could be put on the magnetic chuck & the jaw faces ground flat. No matter how you do it, you're limited to the precision of the scroll gear in the chuck, but at least this way the jaws are all the same. Might the factory have done something similar? Regards, Ron ------- Re: Grinding Chuck Jaws Posted by: jerdalx~xxsbcglobal.net jtiers Date: Tue Mar 31, 2015 5:22 am ((PDT)) No dead horse at all.... There may be just a few folks who think 5 posts on any subject is too much ;-) The rest of us are OK. For CENTERING, the key issue here is the exact relation of the face of each jaw (front and back!) to the teeth that touch the scroll. And that in turn depends on the exact form of the scroll. If the scroll is worn, then only in-place grinding can compensate for that error. Each jaw has the teeth offset from the last jaw as much as the scroll face "moves" in 1/3 of a turn. It's a bit of a complex relation, and something of a wonder that any chuck is even reasonably centered after some use. While we are not particularly interested in improving the centering when grinding, we'd surely not want to make it worse. If the back of the jaws is un-worn, as is common, you could likely get at least pretty close by lining them up and surface grinding... we certainly do not all have an surface grinder, though... That would work quite well with a typical 4 jaw "independent" chuck, where the exact size and relation is not as important. The makers might have a fixture that held the teeth at the proper offset as the faces were ground. Or they might grind the faces to overall dimension, and then cut the teeth to the proper dimensions and location. Either would work. I might add that in many cases, it is wear on the center bearing of the scroll, and NOT the scroll form itself being worn, that causes a centering issue. Jaw grinding cannot improve that, and may make it worse, if ground when the scroll is at a maximum off-center position. You may make huge improvements by inserting a thin shim around the center bearing to re-center and tighten-up the scroll. The scroll center bearing gets wear no matter what size the work is, but any particular place on the scroll gets maximum wear only if the work size puts jaw teeth on that spot so they rub when tightened. The scroll center bearing may also be a contributor to the old advice about always using the same pinion to tighten a chuck, once you find which centers best. The pinions both rotate it and also force it off- center, if it can move radially, which it always can, at least a little. Jerry ------- Re: Grinding Chuck Jaws Posted by: shawneliason79x~xxyahoo.com shawneliason79 Date: Tue Mar 31, 2015 5:28 am ((PDT)) Ok, first, sorry about the dead horse reference I started. But I used that method (grinding on a surface grinder) with my old cushman 3 jaw. And as you said it comes down to the scroll... but, also the channels And individual indexing of each jaw to the scroll. So even though I ground them flat and was really happy with the outcome I was back to square one due to the fact that I was then running at over 25 thousands out! So back to the other method I went. Initially I ground the chuck jaws with them loaded from the inside surface but still ended up with a bell mouth. So then I reverted to loading them from the outside and fixturing a grinder with a larger diameter wheel and was able to get down to just around three thousands run out over several different diameters. So I think collectively that's the right way to do this,.. just clean the chuck up really well, true the back plate to the individual Lathe if this has not been done already and load the jaws from the outside. Then grind with a fixed rigid grinder with the largest possible wheel that can be used. Making very light spark passes starting from the inside and using the power feed out. I've only done two chucks but this has proved to be the most accurate way! ------- Re: Grinding Chuck Jaws Posted by: jmartin957x~xxaol.com jmartin957 Date: Tue Mar 31, 2015 8:10 am ((PDT)) That is probably the worst possible way to true up the jaws, unless your chuck is absolutely tight and without any play in the jaws. In which case it is likely brand new and should not need any truing. As many have already stated here, the primary reason for grinding the chuck jaws to true is to correct bell-mouthing. While this can come from uneven wear on the jaw faces, or from a sprung chuck body due to excessive tightening or a severe crash, these are the less likely causes. Generally, it's from wear in the grooves in the chuck body or the jaws. If that is the case, loading the jaws from the outside will reverse that bell- mouthing -- which is good. But, when you grind them in that position and then remove the outside loading ring and use the jaws to hold your work, the bell-mouthing of your chuck will have doubled. Your method intentionally grinds the tips of the jaws more than the inner ends, which is the opposite of what you want. Your success with this method indicates to me that your chucks either were sprung or had uneven wear on their gripping surfaces. Did you check for any bell-mouthing afterward, under load? It worked for you, and that's great. But for most users here, working with old and worn equipment, it will only exacerbate their problems. What it comes down to is that there is no one single best, one size fits all, method. One must first determine exactly what is wrong with his chuck, and decide from there how to correct it. The method that Jerry and others here have suggested is likely best for most people here. John ------- Re: Grinding Chuck Jaws Posted by: "James Irwin" jirwin1x~xxaustin.rr.com jimirwin2001 Date: Tue Mar 31, 2015 8:21 am ((PDT)) What we¹re trying to accomplish is to remove errors from the ideal. If one will carefully analyze all possible errors, realizing that the ideal is uniformly applied clamping force along the line of each jaw, under clamping force, against a true cylinder (work-piece), then one has a chance to find all possible errors and strive to correct them. Grinding the jaws (properly) for a specific work-piece diameter is (the?) one way to attain the idealresult. Other possibilities like the one just proposed depend on ideally machined parts in an idealized set-up, with no wear in the chuck body, and ignores the contribution of scroll errors. No-one has mentioned that chucks with multiple tightening wrench sockets allow some small degree of tuning of the as-chucked work-piece centering. Or the use of set-true chucks. Or the possibility of modifying a typical chuck to set-true configuration. THINK There are always multiple approaches to solving an issue. Throwing up our hands and repeating the lie that 3-jaw universal chucks are inherently inaccurate can only have one possible result: You prove yourself "right". Jim I ------- Re: Grinding Chuck Jaws Posted by: shawneliason79x~xxyahoo.com shawneliason79 Date: Tue Mar 31, 2015 8:48 am ((PDT)) True... each chuck and person is case by case. But I will add that the ring I used was fairly large and perfectly concentric made from a piece of pipe I turned down to work. And I pinned the jaws as close to the face of the chuck as possible which resulted in the second or middle step of the jaws. I didn't load them from the outside, I must have given the wrong impression... I always loaded them inward. I first tried placing a machine bushing on the step on the Backside of the jaws, down inside the throat of the chuck... with unsatisfactory results, so then reverted to loading from the Exposed side. But both times I was loading the jaws in the normal inward fashion... so possibly this held them at a near perfect load on my chucks. And yes I checked them for bell at the outer edge and removed the chuck and checked the inner. And yes, I agree, loading them outward makes no sense to me. You need them loaded as if they are normally used. Sorry for the miscommunication. I basically worked it like Mr Pete but I have non reverse jaws. ------- Re: Grinding Chuck Jaws Posted by: "James Irwin" jirwin1x~xxaustin.rr.com jimirwin2001 Date: Tue Mar 31, 2015 10:24 am ((PDT)) Actually it maters not a wit if the ring is perfect. Any old piece of pipe will do fine. Beauty of using three points! The basis of any stable mechanical structure in the triangle. Using three points establishes the triangle and evenly loads each jaw. Jim I ------- Re: Grinding Chuck Jaws Posted by: "Gregg Eshelman" g_alan_ex~xxYAHOO.COM g_alan_e Date: Tue Mar 31, 2015 10:23 pm ((PDT)) On 3/31/2015, shawneliason79x~xxyahoo.com [atlas_craftsman] wrote: > True.. it is a myth that 3 jaws are inherently inaccurate to a degree.. > and we all know what money buys! Bucks are nice but soooo pricey. Maybe > I'll make one! My 600 dollar bison holds 3 tenths of a thou on precision > rod of any diameter but it's brand new.. and I consider myself lucky. > But my willingness to buy those for all of my lathes is very low > considering what I use them for... so I make what I have worthwhile. . > Which an old scroll chuck is a crapshoot at best.. but it's fun to try.. If you can grind the jaws so that when clamped down they are true and hold the work without allowing the work to wiggle, wibble or wobble, it doesn't matter how worn out it is or how much runout it has as long as you are doing the whole job in a single chucking and don't have to match concentricity to any other part of the workpiece. As long as the spindle runs true, whatever is cut will also be true to the spindle center. Some people use an old "beater" chuck for such jobs and save the nice new or well cared for chucks for the jobs where stock size is minimal for the job or where matching concentricity to existing features is important or where removing and re-chucking will be done. ------- NOTE TO FILE: Of course these latter messages were only part of the discussion; this is one of those topics that often go on and on... ------- New owner help with 4 jaw chuck fitting [myfordlathes] Posted by: lindon.doddx~xxyahoo.com lindon.dodd Date: Fri Jun 26, 2015 10:27 am ((PDT)) Hello, I picked up a an ML7 a couple of months ago and I'm slowly working through setting it up (this is my first lathe). I've run into a problem getting a Pratt & Burnerd 6" 4 jaw to fit on the spindle it's the slim type with the Myford thread in the body of the chuck. It will spin on freely about half way drown but then jams with about 1/8th of an inch to go. The spindle measures 1.2492 at the nose and there seems to be a bit of taper as I run a dial indicator along the shaft towards the register of about 0.09mm so about 3 thou. I have a socket that is almost a perfect fit into the bore of the chuck and that measures 1.2495 - 1.250. I also have a back plate for a 3 jaw which screws on nicely (well used) if I also put the socket in that it fits as tightly as it does in the 4 jaw but only goes in half way before binding so if anything the back plate is tighter than the 4 jaw chuck. Could the problem be the thread on the 4 jaw? It does look like it hasn't been used much. Thanks, Lindon ------- Re: New owner help with 4 jaw chuck fitting Posted by: "Grant Jones Professional Engineer" grantwjonesx~xxshaw.ca Date: Fri Jun 26, 2015 10:35 am ((PDT)) I recently bought a Myford back plate from a UK vendor to mount on a new plain back chuck. The back plate went on my spindle about as far as it sounds like yours is. If you check this site, there has been some discussion about variations in spindles and threads etc. I ended up chucking up the back plate in my other lathe and cutting the thread deeper until I got a good fit. Remember, it is the register boss that is really important, not how tight the thread is. Grant Jones The Cannuck ------- Re: New owner help with 4 jaw chuck fitting Posted by: "Ken Strauss" ken.straussx~xxgmail.com kstrauss7 Date: Fri Jun 26, 2015 10:45 am ((PDT)) Another common problem is a small sliver of swarf in the chuck threads. Also, verify that the register socket in the chuck is deep enough to fully receive the boss on your spindle and that the female threads are cut far enough through chuck. I've seen both issues on direct mount chucks such as yours. ------- Re: New owner help with 4 jaw chuck fitting Posted by: "Barry Forrest" 2barryforrestx~xxtiscali.co.uk tobarryforrest Date: Fri Jun 26, 2015 10:49 am ((PDT)) For what it’s worth I’d go with Grant Jones on this one. I had a new backplate that I machined to fit a new chuck. Initially it screwed “most” of the way down (just under 1/8” short of the register) but not hard up. I assumed after I had fitted and removed a few times it would be OK but it wasn’t, so eventually I ran a 1 1/8 x 12 tap through the backplate thread, it was a bit tight screwing it in and I couldn’t really see any metal to speak of cut by the tap, more like a scraping of “dust”. Perhaps the top of the threads in the backplate? However, it now fits perfectly, not loose but solidly onto the register as good as the “original” Myford chucks. Barry ------- Re: New owner help with 4 jaw chuck fitting Posted by: lindon.doddx~xxyahoo.com lindon.dodd Date: Fri Jun 26, 2015 11:06 am ((PDT)) Looking from the front there are still threads showing at the point it gets tight and measuring the depth of the chuck it's deep enough to reach the register on the spindle. As I don't have access to another lathe, I think I'll have to try finding a suitable tap to see if that makes a difference it's 1-1/8 12 tpi BSW isn't it?. As there is only slight clearance between the spindle and the inner bore of the chuck would I be ok taking a bit off that in case it's binding off the spindle as I screw it in? ------- Re: New owner help with 4 jaw chuck fitting Posted by: burgoynedanielx~xxyahoo.ca burgoynedaniel Date: Sat Jun 27, 2015 6:25 am ((PDT)) Hi, How come you are getting readings of 1.25" for the threads of a spindle that is known to be 1.125"? Putting that aside, before anything else, I would make sure there isn't any chip squished and ingrained into the chuck threads by "scraping" the bottom of each thread with a sharp pointed tool. Daniel ------- Re: New owner help with 4 jaw chuck fitting Posted by: lindon.doddx~xxyahoo.com lindon.dodd Date: Sat Jun 27, 2015 12:37 pm ((PDT)) Hi Daniel, yes the threads in both the chuck and the spindle nose are completely cleaned out no debris in the threads the measurements are taken on the spindle shaft and the inside bore of the chuck body and not across the threads. ------- Re: How to dispose of an old chuck [myfordlathes] Posted by: "Kevin" tadpolex~xxbtinternet.com klokenz Date: Sat Sep 19, 2015 5:25 am ((PDT)) On 18/09/2015, red-rosex~xxgreenview.fslife.co.uk [myfordlathes] wrote: You did ask... ; ) There is, of course, the ever helpful reply ....... This is clearly a rather old chuck which has had heavy use. It was made in the days when metallurgy was not so advanced as it now is, and is probably not as strong as modern chucks, so that whether it is a steel or cast iron body it will be unsafe to use at the speeds present day model engineers routinely employ. As a result of possible earlier abuse it may already have incipient cracks which can only be detected by expensive ultrasonic testing or by catastrophic failure in service. Since it was manufactured before the dangers of asbestos and lead were properly appreciated it is likely that these materials have been incorporated, and would present a clear danger should the chuck ever need to be dismantled, for example for cleaning. The outer surfaces, which will come into contact with the skin when the device is handled, are likely to be contaminated with tarry residues from tobacco smoking and radioactive fallout particles from atom bomb testing of former times. If it has become at all magnetised (which is quite likely) then the rotating magnetic field produced when it is used on a lathe will steadily depolarise the synaptic neurons in the operator's brain cell leading to the well known symptoms of an inability to mentally convert between metric and imperial measure, and a craving for lukewarm tea. This chuck is clearly a dangerous item and should not be used. Its disposal will involve considerable expense for you as it will have to be treated as hazardous waste. Fortunately I am in a position to arrange its proper disposition for you, if you would arrange to send it to me (your expense, well packed, insured and by first class registered carrier). Please contact my secretary off-list for the address details. Oh, and don't forget to send the chuck key also, it's probably picked up some e.coli bugs after being handled by grubby fingers over all those years. Thanks, here to help. Kevin, England ------- Re: How to dispose of an old chuck Posted by: "John Kiely" john_kielyx~xxyahoo.com john_kiely Date: Mon Sep 21, 2015 9:14 am ((PDT)) I would be interested in how you get on with grinding the jaws. However a word of warning, when I used a tool post grinder on my jaws I ended up with the most lovely bell shaped jaws ever. Obviously I was doing something wrong! Start by taking the jaws out of the chuck and grinding them to a common depth first, then and only then try using the a tool post grinder and only remove the smallest amount you can manage to even them up. I need a bit more practice doing this as I now have some seriously square jaws to add to my current collection. If you go too far (I think I have) you can always grind the jaws square and bolt on some replaceable ones which you can also use the toolpost grinder on! If you think that the group here are being a little too smart for their own good, you can be quite sure they have all had the same trouble as you and the ironic answers are only a reflection of their experiences! Good luck John Kiely (IRL) ------- Re: How to dispose of an old chuck Posted by: "David Everett" dernhx~xxyahoo.co.uk deverett2003 Date: Mon Sep 21, 2015 3:42 pm ((PDT)) John: When grinding chuck jaws, there needs to be pressure on the scroll in the same way as when the jaws are closed on to a job. You probably already know that, of course. The link shows a suitable jig that can be used. http://lathe.com/tips/chuck-jaw.htm Dave The Emerald Isle ------- Re: How to dispose of an old chuck Posted by: "Cliff Coggin" cliffordx~xxcliffcoggin.plus.com cliffcoggin Date: Tue Sep 22, 2015 1:11 am ((PDT)) Here's another way way of doing the same thing thing, i.e. putting outward load on the jaws to take up the backlash before grinding. https://www.youtube.com/watch?v=-yWsjeY6nJU&index=46&list=PL6HIFl ed82YXCXpWVcoMvHxr7_qQsXkzR Cliff Coggin Kent England ------- Re: How to dispose of an old chuck Posted by: "John Kiely" john_kielyx~xxyahoo.com john_kiely Date: Tue Sep 22, 2015 3:48 pm ((PDT)) Outward pressure was put on the jaws! My lathe is over 100 years old, the chuck is as old. I made a very bad mistake of starting from the front and working in. The jaws were so badly worn that too much material had to be ground away and as I proceeded from front to back, by the time I got to the end of the first pass most of the material on the grind tool was worn away! It started at a relatively large diameter at the beginning and was quite a bit smaller as I got to the end. For this reason I would not use a grinding disk but a grinding cylinder instead. Now this is just my opinion, I was probably doing it all wrong despite watching the Youtube videos! You live and learn! : ) John Kiely (IRL) ------- Re: How to dispose of an old chuck Posted by: "David Everett" dernhx~xxyahoo.co.uk deverett2003 Date: Tue Sep 22, 2015 4:40 pm ((PDT)) Good point that, John. Of course, when you think about it most wear is at the front, so it makes sense to start at the back and work out. Dave The Emerald Isle ------- Re: Chucks, runout, repair, replacment questions... [atlas_craftsman] Posted by: "Richard Marchi" rfmarchix~xxaol.com marchirichard Date: Mon Nov 23, 2015 3:37 pm ((PST)) Hi Bill in Boulder: I don't disagree that a good 3-jaw can do .0015, or even better. My point is that with careful technique you can turn good tolerances in a not so good chuck. The prior commentator reflected my my view that obsessing about runout on a three jaw is misplaced concern, unless it is bell mouthed so bad that it can't hold a piece safely or has so much runout that you are wasting stock trying to get it trued up. My main 3-jaw is a Chinese 6" and I have never even measured its runout. It turns to within tenths when used properly. Of course, I'd rather have less runout than more... Richard Marchi Washington, DC ------- Re: Chucks, runout, repair, replacment questions... Posted by: "Doc" n8as1x~xxaol.com docn8as Date: Mon Nov 23, 2015 4:21 pm ((PST)) hi Richard. your post reminded me of my antique1895 Reed 14 inch lathe... .when I took the first light cuts on a 1 inch short bar, using the 3-jaw that was on the spindle, instead of turning it down, I was PLANING it ...I was getting longitudinal flats ...I shut it off & just stared, wondering what I had just hauled home .....turns out the jaws were SO bell mouthed that as I took a cut, the bar was shoved away, & as the spindle rotated & brought the bar back into contact w/ the bit it took another cut & again shoved the bar away, repeated cuts ending up planing ...I ground the jaws ...the planning stopped but I could chuck up between 5 and 20 thou repeat .... I could hold a bar near what I thought was true & close the jaws on it & have abt 5 thou tir w/ 2-3 tries .....have thought many times about opening it up & bushing the scroll, just to see if i could get any repeatability. FWIW ....starting w/ a blank backplate, I fit a bison 5 inch 3-jaw to my craftsman commercial ...it is still holding 1-1/4 thou TIR 5 yrs later (lite use) ...I also fitted three china 4 inch 3-jaw chucks to various lathes ...two had TIR of 1-1/4 thou & one had 1-1/2 thou .... they have not been used enough to see if they are still holding .... I fitted the b/plate to the registers w/ 1/2 to 3/4 thou clearance .... Jerry says that is not important, but I am not abt to open up the b/plates to prove/disprove it !! best wishes doc ------- making a chuck back plate [sherline] Posted by: yahoogroupsx~xxselect-gis-services.com Date: Wed Feb 17, 2016 7:21 am ((PST)) Would there be any real difference/advantage when making a chuck backplate to single point the 3/4"-16 thread instead of simply using a tap? It seems to me that because the backplate finishing is completed "in place" the end result would be the same but I may be I missing something. I've created an anonymous poll but would welcome detailed explanations. Thanks! james ------- Re: making a chuck back plate Posted by: "ED MAISEY" holmes_ca_2000x~xxyahoo.com holmes_ca_2000 Date: Wed Feb 17, 2016 7:49 am ((PST)) James, here's what I do if I have to make anything that attaches to the threaded spindle, I have a Taig, I choose my material size, drill and tap the hole with a really accurate 3/4 - 16 ground tap with centres at each end, it usually is a very nice tight fit on the tap I then place a locking nut faced on the lathe true, its a keeper for the toolbox, and machine one face of tapped material or boss between centres of the ground tap, then screw onto the spindle with faced surface against back register and complete the final machining process, works for me, of course the Taig doesn't have a screwcutting system, obviously single point is the norm, but you gotta do what you gotta do. Edmund Alberta ------- Re: making a chuck back plate Posted by: yahoogroupsx~xxselect-gis-services.com Date: Wed Feb 17, 2016 10:51 am ((PST)) Hi Edmund, If I understand your description correctly, you are first machining the backplate between centers while it is still mounted on the (accurately ground between centers) tap. I'm less clear about the why the locknut has to be faced if everything is between centers. ------- Re: making a chuck back plate Posted by: "Tom & Judy Bank" trbank1x~xxverizon.net eimcr28 Date: Thu Feb 18, 2016 7:09 am ((PST)) James, I had to make an adapter for a small woodworking chuck to fit it on my Sherline lathe. The external thread was 1"-8 thread, IIRC, and the inner thread, of course, was 3/4"-16. Even in brass I found that using taps and dies of those sizes was too much for me to get accurate threads when starting from a tap drilled hole or a turned to dimension exterior. I therefore single-pointed the internal thread down to within several thousandths after facing and boring, and then finished up with the tap for an accurate sized thread. Then I reversed the piece on the nose of the lathe spindle and did the external thread in similar fashion. You ask if there is an advantage to single pointing a 3/4"-16 thread? It's the ease of making many little cuts instead of locking the piece in a plumber's vice and brute forcing the thread. OK, so you are working on a plate: disregard the plumber's vice. For your specific job, I'd make the plate, attach it to the chuck, clamp the jaws on a trued round piece with a MT-1 taper in the spindle, true up the front of the chuck, face the back, single point to within a few thousandths, and run the tap in to finish the job. Regards, Tom Bank ------- Re: making a chuck back plate Posted by: yahoogroupsx~xxselect-gis-services.com Date: Thu Feb 18, 2016 8:04 pm ((PST)) Thanks Tom. I've never cut an internal thread on my Sherline but have cut 3/4"-16 external threads on it many times. But those external threads were almost always cut in Delrin. The thought of trying it using cast iron or steel is a bit intimidating...even taking multiple minuscule cuts. Regarding "clamp the jaws on a trued round piece with a MT-1 taper in the spindle...": is this one piece; that is an MT-1 taper with a "nose" that gets trued in place? In other words, is that the taper version of the threaded arbor blanks like those available at Little Machine Shop? james ------- Re: making a chuck back plate Posted by: "Tom & Judy Bank" trbank1x~xxverizon.net eimcr28 Date: Fri Feb 19, 2016 1:26 pm ((PST)) To get the 3/4"-16 thread and the flat on the contact surface of your backplate true, put a MT-1 taper on a short length of machinable steel or brass rod either 1/2" or 3/4" diameter and put a 1/4"-20 threaded hole in the end for a drawbolt, put this in your lathe's taper and snug it up. Then skim the surface to true it up. When you next put the chuck reversed on this shaft, almost against the front edge of the spindle's nose and then tighten the jaws, you should have the chuck centered in relationship to the rotation of the lathe spindle. If you then take a surface cut across the contact surface of the backplate and drill, bore, and single point tap the required 3/4"-16 internal thread (finishing up the last couple thousandths with a tap, you should have as close to perfection no the centering of the chuck as you are likely to get. Of course a lot depends on the lathe headstock being aligned as true as possible when you tighten the chuck jaws on the shaft, which is checked by testing the diameter of the shaft close to the spindle and at its outer end. A tip for making infinitesimal changes when truing the headstock is to place a square on the lathe ways and bring it up against the lower front edge of the headstock. The front face of the headstock may not be precisely true. If so, find out how much it is out of alignment by testing the gap (if one exists) either at the front or rear corner by using leaves of a thickness gauge. Then, depending on which way you need to adjust the (loosened) headstock, insert or change the thickness gauge leaves between the square and the one corner of the headstock to add or subtract thousandths of an inch at a time until the skim cut on the shaft gives you a consistent diameter. I hope I explained this clearly. I think it's a much easier way to true up the headstock than tapping same back and forth with a small mallet. Regards, Tom Bank ------- Re: making a chuck back plate Posted by: yahoogroupsx~xxselect-gis-services.com Date: Fri Feb 19, 2016 2:31 pm ((PST)) Got it! I thought I had the correct interpretation of the set up...and now I know I did. Here's my method for aligning the headstock. 1) make a tapped (2x) metal plate affixed to the backside of the headstock and centered on the headstock pivot. The goal is to have a set of screws (I use 10-32 socket head screws bearing on a brass strip) that can "nudge" the headstock around the pivot point. 2) mount a 5/8" x 3" ground shaft in a taper-mount ER-25 collet 3) mount an indicator on the cross-slide (I use one with 0.01mm divisions) 4) pre-load and zero the indicator at one end of the shaft 5) move the cross-slide a fixed distance (I use 30mm) toward the other end of the shaft and note the indicator reading 6) calculate the headstock angle from the tangent ("rise/run") and note the direction the headstock would need to pivot to reach "zero" 7) loosen the headstock screw 8) "nudge" the appropriate screw to pivot the headstock (I start with a quarter turn) 9) repeat steps 5) and 6) to calculate the angle change effected by the "nudge". You now know angle change per (in my case) quarter turn of "nudger" 10) calculate the "nudge" required to remove the residual headstock angle using the appropriate screw. I usually use two wrenches simultaneously as when adjusting a 4-jaw chuck 11) repeat starting at 8) until satisfied 12) tighten headstock screw 13) re-measure and tweak as needed It's all much easier and faster than it sounds. Once I calculate the "change per unit nudge" the rest can be done in <10 minutes. I have gotten my headstock to <0.01mm over the 30mm travel distance. james ------- Re: making a chuck back plate Posted by: "Tom & Judy Bank" trbank1x~xxverizon.net eimcr28 Date: Sat Feb 20, 2016 1:37 pm ((PST)) James, As has been said many times, whatever works for you will do. Actually, I have a pair of more-or-less "L" shaped aluminum pieces that I mounted at the front corners of my lathe headstock to do as (I think) you are doing. Then I upgraded to the long lathe and found those parts were too short to make the headstock adjustments with the higher long bed. After which I came up with using a square, which has the advantage of also being able to add in a wedge of a known/required angle to set Morse, W-W, Jacobs, and other tapers for turning collets and other accessories. I made my own set of Morse Taper #0 and #1 wedges; the W-W wedge, IIRC, is a standard 20º. I haven't gotten around to making anything with a Jacobs taper yet, but I do foresee the need since I found a reasonably priced Jacobs 0 chuck at Cabin Fever this year. Regards, Tom Bank ------- Re: making a chuck back plate Posted by: yahoogroupsx~xxselect-gis-services.com Date: Sat Feb 20, 2016 6:04 pm ((PST)) Tom, It sure sounds like the two brackets at the corners would use the same "nudging" principle! I've only rarely tried cutting tapers and nothing so critical as for a mount. Your standard wedges must be a real time saver. Best, james ------- Re: making a chuck back plate – better explanation Posted by: "Tom & Judy Bank" trbank1x~xxverizon.net eimcr28 Date: Fri Feb 19, 2016 1:59 pm ((PST)) James, A better way of stating my "Tip for making infinitesimal changes when truing the headstock" is to loosen the headstock setscrew and remove the key under the headstock, then put a 3" or 4" engineer's square on the lathe ways and run it up against the front of the headstock before tightening the setscrew again. Do a skim cut on the shaft which is locked in the spindle's taper. If the diameter is consistent, good. Proceed to put the chuck on the shaft (reversed) and make your internally tapped hole. But if the spindle diameter is not consistent, adjust it by thousandths using thickness gauge leaves pressed between either the front or back corner of the headstock and that square on the lathe ways, followed, of course, with additional skim cut tests. I hope this is a better explanation. Regards, Tom Bank ------- ------------------------------------------------------------------ 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 ------------------------------------------------------------------