Lathe - Cross-Feed



Adding auto crossfeed? (Fri Aug 3, 2001) Crossfeed Nut (Jun 2, 2003)
Powered Cross Feed (Fri Sep 21, 2001) Crossfeed nut replacement instructions (Jun 26, 2003)
Next Project Cross Feed Screw (Fri Sep 21, 2001) Cross feed - compound rest slop (Jul 7, 2003)
New crossfeed dial (Oct 1, 2001) Crossfeed slop (Jul 24, 2003)
10K cross feed bushing (Oct 15, 2001) Cross feed and slide compound brass nuts (Sep 13, 2003)
Replacing cross-feed screw / Heavy 10 (Oct 31, 2001) Successful crossfeed rehab (Nov 21, 2003)
Cross-feed screw replacement (Jan 17, 2002) Inquiry for Crossfeed Screws (Apr 12, 2004)
Cross Feed Nut (Jan 22, 2002) 9" crossfeed nut (Jun 9, 2004)
Crossfeed screw (Jan 23, 2002) "Play" in crossfeed screw (Nov 22, 2004)
Heavy 10 crossfeed acme leadscrew dia (Apr 27, 2002) Cross Feed play (Nov 30, 2004)
Cross feed disengagement (Dec 22, 2002) Price of Crossfeed screw? (Dec 23, 2004)
Replacement cross feed nut (Jan 26, 2003) Crossfeed slop measurement? (Dec 24, 2004)
Crossfeed nut question (Jan 30, 2003) Slop In Crossfeed and How To Correct It (Jan 1, 2005)
Crossfeed nut-success (Feb 6, 2003) Cross feed nut (Jan 5, 2005)
Cross feed parts diagram (Apr 1, 2003) Cross Feed Screw Nut (Jan 8, 2005)
Cross Feed Screw (Apr 24, 2003) SB9 Power Cross Feed (Jan 10, 2005)
Model A power cross feed? (May 4, 2003) Worn crossfeed screw (Jan 16, 2005)
Too much play (May 31, 2003) Slop in crossfeed screw (Mar 6, 2005)
Adding auto crossfeed?
I have a 9" model "C" without the auto cross feed option. If I buy a new apron which has this feature are there any other modifications I need make other that install the new apron? (1256)
Yes you will need the saddle and cross feed lead screw as well. JWE (1257)
Actually, you would only need the screw, as the saddle casting is the same. But that is the easy part. There is a keyed worm gear in the apron that runs in a keyway the length of the leadscrew that provides power for the cross feed. The model C does not have this keyway in the leadscrew. The two options here are get a leadscew off a model B (model A screws would be too short due to the QC box), or cut a key in your current screw. Actually there is a third option, find a QC box and leadscrew and convert to a model A. As you may have guessed, that is what I am in the midst of. I have wrangled all the parts but the crossfeed screw (hmm... isn't that where we started?), and after seeing what they are bringing on EBay I have decided to make my own. Now I'm just waiting for access to my dads shaper to cut the "gear" on the screw. Frank (1260)
Powered Cross Feed
I've got a 9" model 'C'. It's a SB clone (Australian Hercus). Looks the same as SB, apart from the drive. The Hercus comes in the same configurations as the SB. The Hercus 'C' doesn't have a Q/C gearbox or powered cross feed. The Hercus 'B' has the powered cross feed but not the Q/C G/B. And of course the 'A' has all the above. I can live without the Q/C gearbox (I've got a full set of gears). But I miss the powered cross feed (mainly for smooth, end facing). My question is can the cross feed be powered independently? I've had limited success with cordless drill and a jury-rigged ball-crank attachment. The trick is to keep the speed low enough and constant enough, to give a good finish. Ideally a small DC geared motor fixed the compound rest should give the results I want! Has anybody done this? Is there an aftermarket solution to this? Or another way of tackling the problem? Remember I'm in Australia! There is not the same volume of machinery here. So, 2nd hand parts are few and far between, especially 'A's and 'B's. Bill (1578)
I think you have identified the best solution for this problem. The 1967 Hardinge HLV-H I'm restoring uses a low speed DC motor for precisely that purpose, both to eliminate gear tooth vibration that occurs when you feed off of the high speed spindle drive, and to allow infinite adjustment of feed rates "on the fly" without changing the spindle speed or other gearing. I can't address the fabrication difficulty since I don't have your particular lathe, but the Hardinge uses a slow speed gear train in the apron to get torque up to the crossfeed screw, which has a gear as a part of its assembly. That doesn't sound very practical for your lathe. Perhaps a drive off the rear of the crossfeed screw? The Hardinge drive motor travels along with the carriage, so that part of the concept is well proven. Mike (1580)
I saw the other post on the Hardinge lathe. Its a good setup, I don't know about the feasibility of adaptation. Another solution might be one of the single axis CNC retro fits. I think I saw a single axis setup for $100. Tom (1581)
Some months ago I opened a discussion about adding power feed to my model 'C' crossfeed. I've been experimenting with different ways of going about it and have settled on an inexpensive and simple method that really works. I toyed with the idea of feeding power to the back of the crossfeed screw with a bracket mounted motor thru some form of clutch. This turned out to be more trouble than it's worth. In the mean time I picked up a couple motors from a local surplus dealer that I thought would give about the required RPM (0-30 RPM). One was a small 240V AC about 50mm (2") round. It probably would have done the job. It had plenty of torque, but I balked at having a AC lead around the moving parts of the lathe. The second motor I picked up was a geared 24V DC motor. It looks like a windscreen wiper motor and is probably off a truck, being 24V! The surplus dealer stated that the motor would run down to 3V. I tested it with a car battery and it spun at about 20 RPM on 12V. The motor body fits comfortably in the palm of your hand and that's when I got the idea of using it handheld on the crossfeed ball crank. I wiped up a plastic prototype adaptor as a POC (Proof Of Concept) and was pleased with the result. I then took some proper measurements and made a measured drawing in CorelDraw 7. I then made the final adaptor in Al. I remembered an old model train controller buried in one of my junk boxes. I dug it out, attached the motor and tested it out. I can run the crossfeed at between 2 and 20 RPM. I can now get a very smooth, even surface when facing, that I could not achieve before! I have uploaded some pics of the adaptor and a measured drawing along with the CorelDraw file to the files DB at: http://groups.yahoo.com/group/southbendlathe/files/Hercus%20%28Clone%29/Crossfeed%20Drive  Bill (2519)
Maybe this would not work on a Southbend, but I added power crossfeed to my old six inch Atlas. As the computer mavins say, it was a Kludge, but it worked. I drilled and tapped the tail stock end of the lead screw. Secured a flanged drum about an inch or so in diameter there. Took the handle off the crossfeed and replaced it with a similar drum (Added a scale to one side of the drum). Put a pulley (small boat block) on the workbench. To use this power crossfeed you wrap a cord around the cross feed drum, through the pulley then to the drum on lead screw. Sure did not look like a machine shop setup but worked well when facing large jobs. Would have worked better if I could find that "frictionless pulley" and "inextensionable infinitely flexible string" so beloved by my first year physics instructor. John (2521)
Bill, Nicely done. That's just the kind of adapter I was thinking of using with a cordless drill-driver for use as a power compound feed. It's hard to crank consistently when making short tapers using the compound. Your use of a wiper motor is ideal since it uses worm gear reduction and provides a much slower speed and good torque. The only down-side of this type of solution is having to hold the motor during the operation. Could a flex-shaft be used in this kind of application or is the torque too high? Maybe make a clip-on adapter containing a worm-gear reduction right at the ball-crank handle and power it remotely via a flex-shaft. Maybe even a hybrid of yours and John Meacham's ideas and take the power right from the lathe itself. Just thinking out loud. Thanks for the pictures in the file area. Paul R. (2527)
Paul, I tried a flex-drive of sorts on the rear of the crossfeed screw. I tried various types of plastic tubing until I found one stiff enough not to twist too much and give a jerking motion when the kinetic energy overcame the friction. The one I found worked great at almost 90o . It was a high pressure hose with an I.D. of 10mm. I gave up on the idea, though, because it was to difficult to disengage when I wanted to use the crossfeed normally. A clutch system is needed to make something like that work. Besides, holding the wiper motor is no worse than trying to rotate the ball-crank smoothly and requires less concentration on the ball-crank and allows more on the job itself. Bill (2534)
Next Project Cross Feed Screw
Changing out the lead screw in my old South Bend 10" heavy made such a great improvement that I'm going to tackle the cross feed screw next. Got it apart last night 51 years of goo and gummed up oil but "Kroil" did it again ,dissolved everything in less that 2 hours. My lathe came fitted with the Telescoping taper attachment. Several balls in the thrust bearings are missing and the Acme feed screw is badly worn ( looks like a vee thread in the middle ). The nut is no better. I'm going to attempt to sleeve the nut and replace the lead screw with a piece of Acme 7/16"-10 single start threaded rod as South Bend wants a small fortune for replacement parts. Anyone ever try sleeving a cross feed nut ? Alas, anyone have a source of Acme left hand threaded rod and matching bronze nut? Steve (1586)
Try McMaster-Carr, Enco, J L as well as some other suppliers. I replaced the feed screws and nuts in a couple of our old mills at work this way. The other option is buy a tap at about $35 from one of them and turn the screw on your lathe. JWE(1587)
New crossfeed dial
I have completed the new crossfeed dial and bushing I mentioned earlier and have posted pics in the photos section for your comments, questions, and what have you. Briefly, new part were desired because of a previous owners accident and less than acceptable repair. The new pieces are made of 416 stainless, (I had it on hand) and the outside diameter is increased to 2.000", 1/4" larger than the original. This provides more space between the divisions making them easier to read. I also made them much finer than the original. Besides the new dial and bushing, a new sleeve was turned for the dial to ride on, and a new, longer brass "shoe" was needed for locking the dial due to the larger OD. You will notice that I decided to machine a hex on the bushing for tightening purposes instead of the original spanner hole. No particular reason for this, I guess it's just a personalization detail. Please disregard the cardboard backing in the photos, I'm not trying to hide anything, I just needed to force the camera to focus on the intended subject better. So what do you think? Raymond (1666)
Ray, nice job! I went up and looked at the photos. You did a good job on the photos too. I would love to read the details of machining the divisions and the numbers on the dial. Are those numbers stamped with a punch? Chris (1667)
Very nice, Raymond! Did you CNC the dial? It looks way too good to be done manually (esp.the numbers). How easy is it to read the dial? Do you need to fill the grooves with black enamel? All I can say is "I want one". Any thoughts on making 'em for the group? Paul R. (1678)
Chris, Paul, and others: (esp.the numbers). Whadda ya mean, "way too good"?! Is that some kind of crack?! ;) I must admit, I did CNC the numbers and the divisions. (Notice that there are lines of three different lengths!) I used a Yuasa 5C CNC indexer that interfaced with a Matsuura RA-I machining center at work. I made a special engraving tool from a 60 degree Ford uni-flute spotting drill, a plug fixture to hold the part in the collet, wrote the programs for both the mill and the indexer, set it up and ran it off. That is all I did CNC. Everything else was performed at home on this lathe and my Bridgeport. I clamped down tight on the crossfeed gib and used the compound set at 90 degrees while I had all this stuff apart. The radius on the face of the dial was made simply by setting the tool and tool post appropriately and swinging/advancing the compound with the carriage locked. Very easy. I can actually "split" the divisions and go a half a thou without having to squint. I hadn't thought about it too much. It would probably make the dial even easier to read, but the lines themselves are only about .004 deep. My personal experience with doing this to similar items have not been very successful. group? Gee, I dunno. Frankly, I'm flattered you ask. I'd be more than happy to answer any more specific questions anyone may have, but I'd have to put some thought into providing parts and/or machining services to others, in the group or otherwise. I never really considered it before. Hmm... maybe! Raymond (1686)
For anyone interested, I am working on AutoCAD drawings of the crossfeed dial and bushing I made (see message #1666), and will post them in some universal format such as .jpg in the files section when they are complete. Raymond (1751)
Ray I can't wait! This has moved to project #2 in a list of several billion, besides I have to replace the crossfeed screw and nut soon so I might as well do a proper job of it!! Pete (1755)
Excellent idea. If possible I'd like to have a copy of the DWG file in AutoCAD R12 or R13 format (that way it's editable which might be useful). As far as saving it as a pic file of some sort, let me suggest GIF in preference to JPG. GIFs are substantially smaller in byte count for line drawings (save in 16 color format) and are at least semi-editable whereas any editing of JPGs quickly runs into problems with loss of quality. Anthony (1759)
I'm interested in this remark. Why not just 2 colors? (1760)
That's funny! Chris (1762)
Actually, that would be better *unless* he's differentiating elements with different colors. For differentiation, 16 should be ample, for simple black and white 2 color is superior. Anthony (1767)
Raymond, if you could post the .dwg's too it would be greatly appreciated. Frank (1775)
10K cross feed bushing
I have added a new folder to the file section containing drawings for the new bushing and graduated dial I made for my 10K. Unfortunately for some, the drawings are AutoCAD R12 and many of you may not be able to view them. For this I am sorry. I am working on converting them to a more universal format (.jpeg, .gif, .bmp) that doesn't take up a huge amount of space, and I will post another message when I get it figured out. Raymond (1862)
Raymond: Thanks very much for taking the time to post the drawings!! This is something that I have been considering for a while and it is sure easier now that I have some clear direction. I don't have AutoCAD but I was able to open the drawings with turbocad 2D, which I downloaded from the net free from this site. http://www.turbocad.com/ (usual disclaimer) What is the Part # of the thrust bearing? I will have to buy one as my machine has small dials. Pete (1864)
Thanks for the files Raymond, I prefer the .dwg files because I use ACAD all the time. For those without ACAD try Volo View Express, it's Autodesks free viewer, www.autodesk.com  It kinda sorta works about part of the time. Frank (1868)
I am working on converting them to a universal format (.jpeg, .gif, .bmp) that doesn't take up a huge amount of space, and I will post another message when I get it figured out. Folks: With a lot of help from Anthony, I was able to get the drawings converted to .gif and I have uploaded them to the folder. I hope there are no problems viewing them. Raymond (1881)
Thanks for your interest in my little project. Unfortunately, I don't know the part number for the thrust bearings I bought. I just called a local bearing house (Eastern Bearing in Manchester, NH) and over the phone described what I need to replace including id, od, and thickness, and they were able to match it up. The South Bend part number from my 10K parts manual is AS841R1. I would suggest going the local route, factory parts can be rather expensive. Raymond (1882)
Replacing cross-feed screw / Heavy 10
I purchased a "newer" cross-feed screw assembly on Ebay. It includes the dial, handle, brass nut, etc. Is there a trick to removing the old one? Any tips? George (2038)
If you are pull'in and putt'in as an assembly, just remove the rear cover, the little and big screws that secure the nut, and the little oil screw just ahead of the dial bushing. I use a strap wrench on the dial bushing because it is soft as cheese to a spanner wrench. R/h thread. Joe (2041)
Cross-feed screw replacement
And with any of these lengths of threaded rod, can we assume that we can easily machine the end as needed? They aren't hardened too much are they? Am I remembering right. Didn't you (JWE) machine a replacement cross-feed nut for your 9" SBL? I'm reminded of an MW article ("Tyro's First Lathe", Feb/Mar 2000) that describes the replacement of the 7/16-10/LH cross-feed screw with a shop-made 1/2-10/LH ACME lead-screw and re-tapping the original feed nut to 1/2-10. Is this a good way to go? Are the proper left-handed taps readily available? The best thing about machining your own nut is to add a backlash adjustment to it. Your thoughts? Paul R. (2776)
That was the 7/16-20LH cross feed screw for the 9x20 you are thinking of. My SB still has the factory screw and nut and I have not even looked at them in years as there is only half a turn slack in it and for that not worth adjusting it. JWE (2787)
Cross Feed Nut
I don't think all the cross feed nuts are 3/8 - 10 ACME, my Heavy 10 was I believe 7/16 - 10. B.G. (2870)
My 9A is .430-something [very worn] OD by 10 TPI. (2879)
Crossfeed screw
With regards to the crossfeed screw replacement issue, I have a couple of questions and comments. 1) The screw on my 9" Southbend appears to be 7/16"x10 LH. I bought some 3/8" acme screw from McMaster and it is clearly too small. 2) There has been a lot of talk of leaving machining the mounting boss to the end user. How? When I machined a block of brass to hold the ballnuts I retrofitted into my 13" SB, I setup the acme screw in a 5C collet block on the mill, put the old nut on that, and found it with an indicator. Then I switched collets and put in a piece of rod I'd threaded to match the mounting threads on the outside of the ballnut (same thread as used for mounting off the shelf acme nuts), screwed my nut carrier onto that, and tried to mill the boss before the setscrew keeping it from rotating failed. (I saw a post here about someone else who had done essentially the same thing) It came out loose, and so while I don't have any backlash in that screw and nut, I have about .002" inches of play between the nut carrier boss and the topslide casting. I'm getting severely tempted to put roll pins through the topslide into 2 corners. 3) What about just using off the shelf acme nuts mounted in a carrier as above? Or are they not available in left hand thread? 4) What about casting nuts in place from babbit or low melt alloy? 5) What about moglice? Okay, I must admit I'm dragging my feet on this as I have a small can sitting in my shop unused. I'll make the following offer - if there is someone local to the Boston area who wants to help me figure out how to actually get that project accomplished they are welcome to bring their saddle/topslide assembly over and do theirs too as I can't mix up a small enough batch to do only one nut. I'm pretty sure it would be desirable to cast it in place, unless one wants to go through the boss machining hassle in number (2) above. It is my desire to buy new screw stock and machine the end on it for mine, both in case the moglice proves impossible to remove, and because I want to use a trantorque bushing on the handwheel end instead of the SB pin key to make swapping the handwheel for a timing belt pulley easier. Chris (2908)
I have used Loctite Form-A-Thread for everything except head bolts on old Harleys with good results. Has anyone tried it in an application like a feedscrew? I wonder how well it resists abrasion? (2911)
Heavy 10 crossfeed acme leadscrew dia
I just removed the crossfeed and took out the brass nut to see if something could be done about the backlash... but it appears to be 0.4" major dia and 0.333" minor dia * 10 TPI acme. Q#1 Maybe its really a .375" dia * 10 TPI acme? Does anyone know for sure? Q#2 Is the 10K and 9A/B/C also the same? Q#3 I was quoted US$68 from Southbend for a new nut. Are there any other sources? (I'm just measuring the nut, I can't really get at the acme leadscrew itself to measure it without taking it out). Doug (4123)
7 / 16 x 10 ACME on my machines. A '59 and '72. Best to go nut AND screw. You can make them. Shape the nut with a mill. Cut the internal thread with a single-point cutter in your 4-jaw. This way you can control the fit to get it tight. The taps I have found are too sloppy. (4124)
The screw is 7/16 10 acme left hand a real odd ball I never found a tap or die for such critter when trying to do work on this size . You can get 1/2 10 in whatever you need but SB did a odd size here. If all parts are wore out you could probably go 1/2 but for just a nut I would say either make a tap and restore your nut for a project or bite the bullet and buy one. I think there are pics of someone posting restoring one and a really nice job but didn't see how they did the threads . Jim (4126)
Cross feed disengagement
Can anyone tell me how to disengage the cross feed screw so I can use a taper attachment on my SB9C? Any help is greatly appreciated. I don't have a taper attachment yet, but do have some plans for one. I was told the taper attachment is easier to use instead of setting over of the tailstock to do tapers. Bill C. (8189)
There is a special 2 piece version of the crossfeed nut that is used with the taper attachment. It uses a bolt to hold the 2 pieces together. When that bolt is removed it frees the cross slide to use the taper attachment. Check out http://groups.yahoo.com/group/mwhints/files/Boring.pdf  which I think is pretty neat and easier than making a taper attachment. (8190)
Bill You might call Dick in Detroit; he probably has one of these 2 piece nuts. Lew (8191)
Steve. Thanks for the link. This is a much better design than the plans I have. This will be a good project to gain some experience. Bill C. (8193)
Steve Checked out the boring head; I LIKE IT! Looks like it might even be simpler to use than the taper attachment. Lew (8194)
Lew and Bill The boring head idea is a good option to use for small tapers. Clint (8195)
Lew, Clint and Steve. I found a set of plans for an Offset tailstock center that would serve the same purpose. Looks really easy to build. Consist of 6 pieces including a #2MT center that has been threaded on the large end. If anyone is interested in these plans, email me off list and I'll send copies to whoever wants them. It basically like setting over the tailstock. Except you set the offset center instead and the tailstock stays centered. Bill (8198)
Bill I would like to look at them. have you looked at the off setting a boring head in the tailstock method yet? Clint(8199)
Clint. I downloaded another set of plans for a homemade boring head. I will send you both of these files via your email. A boring head would be nice but they're kind of expensive. About 80 bucks for a cheap one. I probably have enough scrap to build the offset center though. I can make the #2MT from an old motor cycle transmission gear spindle. Of course the spindle will have to be annealed before I can machine it. This will also be a good chance for me to try some screw threads. Don't know if I'm really ready for that!! Be looking in your email for the plans. Bill (8200)
Is this something you could post in the files section, Bill? Fred (8201)
Bill OK, I have the plans using a boring head, I was just wondering if you had them. But I am very interested in you using the motorcycle parts. Clint (8204)
Replacement cross feed nut
I'm looking to find how much it will cost for a NEW replacement cross feed nut for a 10" Southbend lathe. Also, is the manufacturer the only point of purchase. (8926)
I bought a new nut for my heavy 10 - cost $65. You have to buy S.B. parts from LeBlond L.T.D. Don't know of any other source. (8927)
Wasn't there a list member making these? Lurch (8928)
No, there are several "private brands" Try Plaza (8931)
Plaza Machinery sells them. When I bought mine they were $35. He also sells thread stock to sleeve into your present cross slide lead screw. He also rebuilds them. I think the price for a rebuild was $65. There is a difference in the nuts depending if you have a taper attachment or not. At least on the 9/10K. I can't say on the Heavy 10 (10L). I don't have the number for Plaza handy at the moment. Tom (8945)
Crossfeed nut question
Could someone please explain the actual physical difference between the x-feed nut for the 9"C [non-taper attachment] and the nut for the 9"A B [taper-attachment models? Can the C-type be modified to be identical, or at least suitable? In the event drawings are needed to explain it, I can read DXF or DWG, as well as Mastercam. Johnny (9003)
The Non-taper is a cylinder with the thread perpendicular to the cylinder. It fits into a round hole. The taper attachment one is sort of an extruded triangle length wise, with a rounded top. The flat base fits into a shallow recess. Really very different and would be best to just make or buy one. I do notice that you are referring to "C's" as non-taper and A B's as taper. This makes me wonder if you are wanting power cross feed. Many A's and B's don't have taper attachments. Maybe some C's had it. Now if your thinking about power cross feed, that has nothing to do with the nut itself. That has to do with the cross slide leads screw. These are different and again might be a bit of work along with work to the lead screw and an A/B apron. Tom(9004)
Tom, can you be a bit more specific? I bought an aftermarket taper attachment for mine, and although mine has the non-taper crossfeed setup, all I do is unwind the feedscrew until the nut disengages, then unscrew the bushing from the carriage and remove the entire feedscrew assembly...is the 'triangle-with-rounded-top' design supposed to allow disconnection without physical removal? (9008)
Brian, The Taper type nut is a solid piece. It is not a disconnect type. I haven't looked at the design intent as to why there are two different types of nuts. I would think the taper nut is such so it won't twist with any side forces from the taper attachment. SB taper attachments use a different cross slide. It has the long slot that the taper attachment connect to cast into it in one piece. This is for the 9/10K only. The heavier lathes have it bolted on. If I was to use the non taper type nut and cross slide and its nut does twist in operation with the taper attachment, I would think of putting in a keyway to keep it aligned. Still, I would check into this a bit more, If I were you. Tom(9009)
Yep...this aftermarket taper attachment comes with an extension that bolts to the stock cross-slide...but if I have to remove the leadscrew assembly to cut tapers, how then could that affect the nut? (9010)
Brian, I don't know the design intent or operation procedure for your aftermarket taper attachment. I don't understand why you are removing the leadscrew. If so then how do you adjust for different cuts of diameter? If I couldn't adjust the depth of cut, I would say this is a poor design. I'd stick with offsetting the tailstock, then. The two operations that a taper attachment is necessary for is large pipe threads (generally pipe threads over 1 inch) and precision ID tapers. I have operated taper attachments on a few commercial lathes. These, you didn't disconnect the cross slide lead screw. You did make sure the taper attachment's bed clamp was loose if you weren't cutting a taper. I hope this helps. Did you get instructions with this piece? Do you have photos of it? I think the home built taper attachments that there are plans for operate much the same as the commercial units. Tom (9012)
On my heavy 10 original taper attachment the cross slide screw is disengaged and the cuts of diameter are adjusted using the compound. (9013)
I have both types of nuts for my SB9a. I converted my machine to taper attachment last summer. The standard nut and the taper nut are essentially the same except that the standard nut has a round stub that fits into the cross slide casting. The taper nut has basically the same dimensions for the cross slide screw, but is flat on the top with a 5/16x24 thread to secure it to the cross slide. I actually modified a standard nut to use on my taper attachment. I will post a couple of pictures tomorrow. Pete (9016)
Lurch writes: Yep...this aftermarket taper attachment comes with an extension that bolts to the stock cross-slide...but if I have to remove the leadscrew assembly to cut tapers, how then could that affect the nut? Looking at the parts list it appears that the non-taper nut is designed to be better supported where it attaches to the non-taper cross slide. On the taper cross slide and nut they've been reengineered so that the nut can be released from the cross slide by merely unscrewing a bolt attaching it. This means the cross slide can be driven by the taper attachment while the nut is still on the cross feed screw, without being attached to the slide the nut won't interfere wit the taper attachment functions. It's a question of which factors were of greater consideration in each case. With no need to release the cross slide from the feed screw and nut the better support was of greater value on the non-taper version. On the taper version, easy release from the feed screw and nut was considered to be the greater value. I'm attaching a copy of the parts list illustrating the differences. Anthony (9029)
Thomas.G.Brandl writes: I don't know the design intent or operation procedure for your aftermarket taper attachment. I don't understand why you are removing the leadscrew. If so then how do you adjust for different cuts of diameter? --- The 9" and 10K lathes use a non-telescoping feed screw. If you were to leave the feed screw connected there would be a conflict between the feed screw thrust bearings and the pull of the taper attachment when the taper clamping lever was engaged. In order to prevent this conflict the cross slide must be released from the feed screw and/or feed nut. When using the taper attachment all cross feed functions are served by the compound slide which is set at 90 deg. to the axis of the centers. On a taper attachment with a telescoping feed screw, which is the standard on SB 10L and larger lathes and appears to be what you are familiar with, the cross feed screw is made in two parts which can telescope axially but are keyed so that all rotational movements of one part are transmitted to the other part. The part nearest to the operator has support bearings in the front of the carriage and includes the crank and micrometer dial. The part away from the operator passes through the feed nut, then has thrust bearings at the taper attachment bracket which is attached to the back of the carriage. When you turn the crank to operate the cross feed the front part rotates the rear part which feeds in the nut and drives the cross slide via the thrust bearings at the taper attachment bracket. Because when the taper attachment is in use there is no relative motion between the rear thrust bearings and the feed nut (they are both feeding at the same rate) the nut does *not* have to be released from the cross slide. Hope this helps in understanding the differences between the telescoping and non-telescoping versions of taper attachments. Anthony (9030)
Crossfeed nut-success
Just a comment. I purchased a 13" about 6 months ago. It appeared to be in good shape. I have enjoyed working with it. I did notice that when using the milling attachments, it would overfeed and jump at times, breaking carbide bits. The measured slack in the crossfeed was about 30 thousands, but that didn't bother me since I had looked at some cheap new lathes with more than that. (I measured this with pressure in both directions.) As an experiment, I reversed the crossfeed nut and about half the slack disappeared. I don't know why that would happen but it did. However, I still had problems due to slop. A closer look at the system showed that the slop was the same over the entire travel of the cross slide. Measurements of the screw diameter showed it to not be worn as far as diameter is concerned. This, coupled with the fact that the screw is hardened steel and the nut is bronze lead me to the conclusion that all I needed was a new nut. After looking at the price of taps and thinking about the problems of making one, I decided to bite the bullet and buy one from LeBlond. With the new nut, measured slop was 10 thousands. Performance has improved to the point it's like having a new lathe. Most of the work I do is on guns which requires some pretty close work, and the difference is amazing. I guess the moral of this is that if you need close tolerances, the cost is worth it, and might not cost as much as a lot of people fear. I see a lot of mention of astronomical "screw and nut replacement costs". I suspect this isn't necessary in the majority of the cases. (9110)
How much were those nuts if you don't mind me asking? Alex (9111)
Cost was $74. It arrived in two days after calling. (9126)
Cross feed parts diagram
Does anyone have a diagram of the parts which make up the crossfeed assembly for a 10" SB? If so, can you post it. (10052)
10K or 10L? Anthony (10053)
http://metalworking.com/DropBox/_2001_retired_files/standardmodernarmy11.pdf Is an army manual for a 10" south bend lathe. There is a diagram there. There is also a manual for a 9"/10K with lots of exploded drawings. (10055)
Umm, no. First of all, the proper url is: http://metalworking.com/dropbox/_2001_retired_files/standardmodernarmy11.pdf  And if that is broken across lines, you can use: http://tinyurl.com/8nv7 Second of all, as indicated by the filename, that is *NOT* for a South Bend Lathe. It is for a Standard Modern Lathe, quite different from a South Bend (and not even made in the same country :-)) Finally, anyone interested should know this document is a about 1 Mb in size, so users with a dialup connection may want to take a coffee break while downloading. There *IS* a manual at the same site for the South Bend 9" Lathe (Model CL 670Z), it is at: http://metalworking.com/dropbox/_2001_retired_files/sbarmylathe.pdf  Or http://tinyurl.com/8nw0  Again, be forewarned, the file size is about 1.2 Mb. -- Scott Logan (10058)
Cross Feed Screw
Please can someone explain how the "cross feed screw " by which I take it you meant the feed for moving the cross slide can work in compress on one model and in expansion on another, surely it must work in both modes as the cross slide is moved back and forth? The implication is that cutting usually takes place on the front of the work piece and that cutting is when the feed screw is most heavily loaded and when precision is required. A feed screw fitted without a taper attachment has its thrust bearings at the front of the lathe. When cutting there is a compression load between the work piece and the thrust bearings which tends to make the feed screw flex out of a straight line. The same applies to a non-telescopic feed screw. A telescopic feed screw, as used on many taper attachments, has thrust bearings at the front for the ball crank and another set of thrust bearings on the taper attachment for the back section of the feed screw. The back section is what adjusts the position of the cross slide and the cutting tool, so when the cutting tool is being engaged with the front of the work piece the screw is pulling from the rear instead of pushing from the front. In this pull, or tension mode, the feed screw is being held in straight alignment, that's the nature of mechanical tension, so it should give greater precision in controlling the position of the cutting tool. Does this answer your question? Anthony (10427)
J.W. Early writes: Anthony did I get it right this time?? Yes. You'll notice I just sent in another response. The person asking the question wasn't making a distinction between when the screw was under load and when it was just moving the unloaded slide, I tried to clarify the difference and why one was significant and the other not. Now because of the fact that the threaded portion of the feed screw is retained at the rear in the taper slide instead of the front in the carriage it now operates in tension as against the normal lathes compression load factor. This is only one of several design features of South Bend lathes that while almost invisible to the average user give them a special flavor for those who see and understand the advantages these unique features give these machines. In fact many lathes with taper attachments use a telescopic feed screw but the smaller ones, the ones most hobbyists have experience with, are less likely to have high end features such as this. Anthony (10429)
Model A power cross feed?
How does the power cross feed work? (I have the manual coming next week) (Please read the below only with the understanding that you did not know the names of all the parts at one time as well) So here is the break down. Hand wheel, next to it and smaller, little flower knob, next to it and up is the lever with three "indexed" positions, then the right is the lever that goes up and down about 60-90 degree sweep. If I guess right, the indexed lever is for off cross and longitudinal power movement, and the lever on the right is for engage/disengage. None of them power feeds anything. (10781)
The left most hand wheel is the manual longitudinal feed. The "little flower knob" drives a clutch and is use to engage (clockwise)/disengage (CCW) the power feed. The lever with three "indexed" positions selects between: UP (power longitudinal feed), middle no feed (allow use of the half nut lever) and down (power cross feed). The level at the right only engages the half nuts, typically used for threading. The half nut level can only be used if the power feed selection lever is in the middle position. Tom (10782)
I was pretty close. So if I engage the "flower knob" and nothing moves, even when the indexed knob is in the up position (or down), what does that mean? Is this the stuck clutch I read about here? Also, aside from the obvious, what's a half nut? Steve (10783)
Handle on far right down: "Flower" knob is the friction clutch...turn right to engage, left to release. Left lever (To right of flower knob clutch): All the way up uses the clutch to longitude feed. All the way down uses the clutch to crossfeed. Center position allows right hand lever to engage halfnuts to feedscrew for threading by raising right hand lever. All Feeds are reversed by the reversing tumbler at left side of head. Don't feel bad: I dunno what to call the clutch knob, either. "The fluted thing that looks like a faucet"? ( 10784)
My opinion for what's it is worth: I would suggest getting a copy of the "How to Run a Lathe" book or consult with an experienced operator in person. Lathes, especially older ones are not that user friendly and its really not a safe tool to just learn by doing with no references or instruction. (10785)
Already have the book on the way. As far as consulting with an experienced operator, I am attempting, but it is not as easy as it sounds. This is my means of doing so, and BTW, I do value your opinion. Steve (10790)
Steve, you may see if you have a local vo-tech school that has a machine shop - Being in a similar situation to yours, I took a night course in the fall and liked it so well that I took another in the spring. Now I just bought a Bridgeport mill to go with my Heavy 10 - looks like I caught a bug. John (10796)
Steve, there are two separate power feed systems in the model A, one for the power longitudinal and cross feeds, and one for cutting threads. Both are driven by the lead screw, the long horizontal screw that runs along the front of the lathe, under the bed, and that goes through the front of the apron (the bit with all the controls we have been discussing). I'm not sure how much of this you know already, but here is a description for beginners (a couple of years ago I knew next to nothing, too). To get a power feed, the lead screw must be turning. Look at the left hand end of the lathe. There is a gear train all the way from the spindle at the top, through the reversing gears, then an adjustable gear train (which you can use to cut metric threads if you have the right adaptor gears, and which owners of B and C models use to get the different power feed speeds), eventually down to the lead screw at the bottom. And on the A, the lead screw goes through the gearbox, on which you need to engage a suitable gear. It might be stating the obvious, but is the lead screw turning when you are trying to get power feeds? Now to how the lead screw provides the power feeds. As I said, there are two separate systems. The power for power longitudinal and cross feeds comes from the keyway in the lead screw. It turns a key, which is captive inside a geared sliding collar arrangement, which turns and acts through the clutch knob and 3-way lever to turn the power feeds. The power longitudinal feed acts by turning a pinion, which acts on the rack on the underside of the bed. The feed for thread cutting is through the half nuts. Imagine a wide, strong nut on the lead screw. The nut is attached to the apron, so when the lead screw turns, the nut moves the apron along at a controlled speed with respect to the rotation of the spindle. Now, to allow this nut to be disengaged, it is cut in half lengthways, so it can be unclamped from the lead screw. Hence the term, "half nuts". The right hand lever on the apron clamps and unclamps the half nuts. Notice that the two feeds use the lead screw in two completely different ways. The thread cutting feed relies on the thread of the lead screw, while the power longitudinal and cross feed uses only the keyway, and relies on the rack for longitudinal movement. Some larger lathes use two separate shafts for these two purposes, but the A combines them on the one shaft. "How to run a lathe" is a useful book, but does not tell you everything. It is not the encyclopedia its name implies. Look for other books or training manuals, keep asking questions on this list, look for knowledgeable people around your area, maybe even do a short course. Whatever works for you. Roger (10798)
So after that bit of info, I went and looked at the lead screw. No it isn't moving, so I opened the sidecase to look at the gears. There are no gears engaged with it. (Photo on http://www.turningwood.com/southbend.htm ) Are there gears missing or something? The gear that drives the leadscrew doesn't touch the gear driven from the headstock. Does it just need to be adjusted? I can turn the leadscrew gear and it will turn the leadscrew. Maybe something is jammed in the tumblers? Also, on the tumblers (dual tumbler gearbox), should I be able to just move the tumbler from position to position? It is pretty tough and the left one won't seem to find another position. Steve (10841)
Steve from what I can tell, you can adjust the gearing to all mate up/e should be the forward/reversing gears then the e20th stud gear to drive the 80 tooth, then on the leadscrew a 56 tooth Just turn/adjust the banjo to position with moving the 80 tooth, once you get the gearing connection, before firing it up, loosen the clutch and make sure the power cross feed lever is in neutral, and the half nuts are not engage, then put power thru to make sure all the gears on the headstock are running smoothly and not to tight, then commence to engaging the apron gears, etc. Clint (10844)
Steve I forgot, as far as moving the gear handles on the gear box, try turning the leadscrew some while moving and engaging the levers, this helps a little to lining up the gears to slide into position, these can be stubborn at times, what ever you do, do not over force it, please do not use a hammer. Clint (10845)
Steve, As Clint mentioned, you need to move the large 80 tooth "idler" gear so that it engages the inner 56 tooth gear on the input for the gearbox (the outer gear on the gearbox is not used). But you also need to make sure that the 80 tooth idler gear also engages the 20 tooth "stud" gear just above it. In order to do this, you will need to adjust the position of the 80 tooth idler gear. The 80 tooth idler gear is held in position by a nut-stud-bushing assembly which clamps the gear to the bracket (called the "banjo"). This is the nut in the center of the 80 tooth idler gear. In order to get the gears to "mesh" properly, you will probably have to adjust the banjo bracket also. There is a "pinch" bolt located between the 56 tooth gear and the circular shield of the gearbox (usually an Allen socket head cap screw but older machines used a square head bolt) that holds the banjo bracket rigidly in place. What I would recommend is to clean the gears first. This will allow you to get the proper meshing (engagement) of the gears without a false measurement due to debris when you go back together. Also, South Bend Lathe recommends using oil instead of grease on the gears. Loosen the banjo bracket pinch bolt and rotate the bracket with the 80 tooth idler gear down and out of engagement with the 20 tooth stud gear. When the gears are clean, loosen the nut in the center of the 80 tooth idler gear and slide it along the banjo bracket until it engages the 56 tooth gear on the gearbox. In order to get the proper mesh of the gears, place a piece of cigarette paper between the two gears when meshing. This will give the gears the proper "backlash" (clearance). Then tighten the nut on the 80 tooth idler gear and then roll the gears to remove the cigarette paper. Next, swing the banjo bracket and 80 tooth idler gear up to engage the 20 tooth stud gear. Again, use a piece of cigarette paper to set the proper backlash. Tighten the pinch bolt on the banjo bracket and roll out the cigarette paper. Now you're set! I also noticed that the "reversing" gears are set in neutral. These are the two gears just above the 20 tooth stud gear. They are engaged by rocking the "tumbler" up or down (center is neutral) Up is forward, and down is reverse. Okay, now you are set. Webb (10858)
There are drawings of the gear train in the how to run a lathe book. There are also scans of it in the files section and at the faq site. you might want to look at the pic as you read webb's write-up. dennis (10859)
BTW, here's an old low-res picture I made to show the proper setup of the gear-train. Note the 40T stud gear is simply being stored on top of the 56T input to the QC gearbox. Swap it with the 20T stud gear to cut the coarse threads as indicated on the gearbox plate. Paul R. (10861)
What then would be a good basic gear set-up for general finish work on a model C? Something I can leave on there most of the time please. I have no gear set, but would like to begin buying, and want to start with the most useful first. I'll confess that the math of these things leave me cold. Len (10862)
I should also have said that I have a running set on there now, of course, but have never counted the teeth, and only the 80 is stamped! Len (10863)
I setup the gears as you all told me, and got the power feed going. Sort of. It would bind in some spots, so what the hey, I yanked it apart and rebuild it. It had POUNDS of crap in it. A lot of plastic and some metal shavings. A gallon of parts wash later and she looks wonderful. Stripped the paint and wire brushed it for that modern sorta shiny cast iron look. Thanks to everyone here and posts, I was able to rebuild it with little problems. Does need new half nuts though (I even know what they are now). I understand someone on the forum rebuilds them, can you pass along the name for me? Steve (10889)
Too much play
I have a Southbend Model a Workshop Lath with a 4'bed and cast iron legs. The serial number is 103656 and it has L.O.R. stamped under the number. I believe it was manufactured before 1941, maybe 1940. My lathe has .026" of play in the cross feed and .045" of play in the compound. By play, I mean that you can move them that much with out turning the screws. I am not sure if the play is caused by ware or if it is somehow out of adjustment. I believe that I would have to destroy something to take apart the crossfeed and compound screws because someone had burred over the spanner holes in the nuts that hold the handles on the screws. Does anyone have any advice on how I can take up some of the play? Gary (11623)
I would like to add that my SB 9"model A has a #3 Morse Taper in the head stock. Other information I have read said that it should have a #2 MT. Does anyone here have a 9" with a #3MT ? (11633)
The standard IS 3MT headstock, 2MT tailstock for a 9". Paul R. (11635)
Sure! My '39 has MT3 headstock, MT2 tailstock. The 13's had a weird taper, but every 9 incher I ever heard of has MT3 in the spindle. Stan (11645)
Crossfeed Nut
I read in someone's post that you have the AS65NK1 crossfeed nut for a 9" or 10K lathe without a taper attachment for sale for $67.00. How do I go about ordering one. Can I call you and give you a credit card number or do I need to send a check? Please give me the proper address and phone#. Gary (11684)
Gary- Please contact me at 888-532-5663 X216 or email at rmarvin@leblondusa.com Rose (11690)
Rose: On my last Email to you I meant Crossfeed Nut not Carriage Nut. Sorry! I have another question. What purpose does the the set screw (20)and the pin (18) that comes as a subassembly with the Crossfeed Nut (19) part # AS65NK1 serve? Gary(11721)
Gary, I'm not Rose, but the setscrew has a 60 degree taper on the end that bears on a tapered pin forcing it against the side of the compound slide mounting hole to keep it in place. Run on sentences are one way to avoid punctuation difficulties. Glen (11724)
Glen: Thanks for responding. However, I have mine tightened but the crossfeed nut stills comes out of the hole if I take the cross slide off. What would be the need to attach the crossfeed nut to the cross slide when the hole in the cross slide traps the cross feed nut anyway? Gary (11729)
Has anyone ever tried to repair a worn-out crossfeed nut of a Sb 9"? If so how did you do it and how did it work. I found a used Acme 5/8- 8 tap today for $.99 with the thought of maybe making a new crossfeed nut. As luck would have it my modal A 9" uses a smaller screw. Gary (11730)
Gary- the threads are 7/16-10 left hand acme. long story...search the archives. Does the cross pin move freely in the hole or is gunged up? try cleaning it. check the 60deg point setscrew too, make sure its a FULL point. You need to trap the nut as there is no outboard bearing on the screw. It will waller everything out. dennis (11731)
Dennis, Would you explain please? The nut is supposed to be free to turn? What 60 degree set screw? We are talking about the cross slide and not the compound, right? Please forgive all the questions but this is exactly what I am trying to fix right now and this is all new information to me. Jim (11732)
Dennis: Thanks. I had not realized they were LH threads. I read the article in the files about the shop teacher who rebuilt some cross slides for his school and did not recall him saying anything about LH threads. The LH treads just killed any of my thoughts about making a new crossfeed nut. I guess I will just buy a new $67.00 one from Rose. I am still interested to find out if anyone has successfully repaired their crossfeed nut. How about telling your long story. I am guessing it goes something like mine would have if you had not pointed out they were LH threads. Gary (11733)
Being bronze, the nut can be planished tighter onto the thread by tapping with a hammer (with a lot of care). Continuing free movement needs checking all the time during the process. I know this sounds like (and IS) a bit of animalism, but as a short term measure it works. I did this on an old lathe some years ago, and the "repair" worked successfully until I scrapped the thing because it was knocked over when shuffling a cart into the workshop and cracked the bed. Len (11735)
I made a new crossfeed screw and nut right on the lathe, but it has been about 10 ago. I didn't know they could be purchased at the time. As I remember, I made the Acme screw first, getting it as close as possible to an Acme thread gauge, then forged an internal threading bar out of 1/4" music wire, heat treated it and ground it to the thread gauge. Then it was simply a matter of threading the nut until the screw I made was a snug but free turning fit. At that point I cut the old crossfeed screw off right ahead of the power crossfeed gear, took what was left of the old screw to another lathe and drilled it out to accept a stub tang on my new screw. Epoxied and pinned in the new screw section, and I was in business. I know this is vague, but it can be done, using the old parts for a guide. This repair has been working well since. Obviously if the parts are available, it depends on which is more valuable, your time or money. (11736)
How were you able to turn a left hand thread? Or, did you use a right hand one. If you used a right hand one how long did it take to get use to turning the hand wheel backwards. Gary (11737)
Jim, The crossfeed nut is shaped like a T. The cross bar part of the T is threaded 7/16 x 10 Acme. The other part of the T is drilled and tapped for a setscrew along the axis of the part. It is also cross drilled for a pin. The set screw and the pin have a taper on the ends. As you drive in the setscrew, it forces out the pin (at 90 degrees to the screw) which impinges on the inside of the cross slide hole. As a last step when assembling the whole thing, you tighten down the set screw. HTH Dennis Pantazis and I have both made replacement cross feed nuts. Dennis had some kind of CNC milling set up that fabricated beautiful looking nuts. For my homemade nuts, I single pointed the Acme threads on my lathe and continually trial fitted the screw until I got a tight fit. I had one of Dennis's nuts on my lathe while I was machining a MLA milling attachment. I used a big carbide cutter in a 4 jaw as a fly cutter. I think the interrupted cut on a big cast iron piece ruined the threads, at least I got a lot of back lash after that. I sent one of my home made nuts to Crazy Bert who was happy with it at first, but after a "milling in the lathe" incident, he had a lot of back lash, too. Maybe the best solution is to buy replacement nuts and screw from Rose. Glen (11741)
Glen, I guess I'll buy one from Rose too. Seems like a vital, although seemingly simple, part to cheap out on. Jim (11750)
Jim, The nut alone may not solve the problem. If there is a lot of wear on the screw, the nut won't fix it. There is a description in the files area (I think) on how to fix it with a piece of LH 1/2 x 10 Acme rod and a machineable nut from MSC. I bought some to try someday. Glen (11751)
That was the case with mine. I had posted about the fix last month. Let me see if I can find the story...... Here it is: My Model A was built in 1952, so was old when I got it. Since I got the lathe, I have manufactured about 2,000 parts that are 8" diameter, and faced on 3 sides(!). One power feed pass to clean the casting and make a datum surface, then the part is flipped on the vacuum chuck, and faced. The first face is then refaced to assure plane/parallel to In the course of this product manufacture, the power crossfeed has therefore cycled more than 6,000 times at a slightly more than 4" excursion. On E-Bay I got a screw and nut from a Model C. Upon removing my crossfeed screw and comparing them I could only stare dumbfounded. The very thread profile in the worn region did not resemble an Acme screw, but rather something with a very thin (-.008) form! So knowing the Model C had no power crossfeed I reasoned that the wear could not be as bad, and it certainly is not. So I intend to use the Model C screw to run the lathe so I can part off the gear section from the Model A screw, and then bore the gear to .441 and press and pin (Or silver solder it) the to correct portion of the Model C shaft. Sounds like fun. I'll let you all know how it works out. I may photograph the process and put it on my site. The Model A screw assembly is a total loss, anyway, as there is radial slop in the crank bearings! Otherwise, I would be trying to rustle up a 12 tooth 20 pitch pinion. (Later that night) Damn I am good. 45 minutes, being careful, and it works great! One thing, though. I confess to sweating bullets when I checked the bottom of the gear teeth, that is the ID of the pitch circle. I only had .018 wall after boring the .441. Whew. Drink Time. With my Foredom and a slitting wheel, I put longitudinal grooves on the mounting surface to insure silver solder flow, 6 equispaced .010 deep, approx. I heatsunk the screw to prevent annealing. So this fix was a piece of cake. Without power crossfeed it appears the Model C screw was nearly new. it had a MUCH easier life than the one in my 1952 Model A. (Or a lazier owner. haha.) Got a nut also. It amazed me how much the Model A assembly rattled around when shaken...the original was really, really beaten up. I wonder if the PO was machining ceramics on it or something. (11752)
I didn't read back far enough on your posts to see which model lathe you have, but I think they all have the feed reverse lever coming out of the gear guard, far left on the headstock. Center position is neutral, the lathe runs without the feedscrew turning. Down is normal, carriage moves towards the headstock, and the up position moves the carriage away from the headstock. You can do a left hand thread just by putting that lever in the top position. If you turn a leadscrew, you'll probably need a follow rest, the screw is long and springy. I'm remembering more about this now, I did it mainly because I had never had a lathe that would cut threads before, and so I thought turning the screw and nut would be a good exercise and a chance to make something useful. (11755)
I can assure you the crossfeed nut Glen made for me was a beauty a real piece off workmanship which I ruined when I was trying to mill with the lathe still mad at my self on that. Bert (11767)
I just received the new crossfeed nut I ordered from Rosie. To install it I had to tap it into the cross feed casting with an Alu. hammer. The old one was a slip fit. Anyway it took all the play out of the crossfeed. I put a dial indicator on it and the .0001 needle did not move when I applied pressure to the crossfeed. The backlash has been reduced to .002", I believe that is better than the original specs. The handwheel turns a little tight, may be too tight to use the power crossfeed? However, I think it will loosen up as it is used a little. I was a little worried that there was too much wear on the crossfeed screw because of the postings about people needing to replace their screws. My screw looks polished where the nut travels but there are machining marks on it beyond where the nut travels. I believe that the screw is not likely to wear out unless someone uses a tool post grinder a lot and the grit becomes imbedded in the nut. Anyway, my lathe is now the precision instrument it was meant to be and I am happy! To think I put up with the play in the crossfeed for the last 24 years. Gary (11823)
Crossfeed nut replacement instructions
Can anyone point me to a prior post or file that will lead me step by step through the disassembly process for getting to my crossfeed nut? It's a 1955 10" Model A. Gene (12291)
Run the cross slide all the way back until the feed screw comes out of the nut. Push the cross slide off of the dovetail, you may need to loosen the gibs to do it. Loosen the screw in the cross slide nut boss. You can see it from the top of the cross slide. Wiggle the nut a little to force the retaining pin back into the boss and pull it out from the bottom. Glen (12375)
Cross feed - compound rest slop
The cross feed on my SBL9B has about 1/2 turn of backlash. When the back lash is taken out, then it's OK but really annoying. It seems the cross-feed handle just needs drifting further onto the shaft. I cannot work out how to get the CF assembly apart even from the parts diagram. The handle will not budge for a start. Next one is the compound rest, when the two grub screws are slackened to allow the rest to be swiveled the whole thing can be rocked back forth! That can't be right. I've just got the lathe am struggling a bit to diagnose the problems. I bought it from a guy who after striking the deal, dismantled it to get it home, it's never been the same since. It was a good price the overall condition tells me that it's OK, just put together incorrectly. Any ideas or maybe an online Haynes for SBL's? Incidentally, does anyone know of a UK spares agent? I know Boxford bits are mostly interchangeable, just in case my problem is a bit more than a missing shim. Jon (12545)
You need to unscrew the whole bushing assembly from the casting as a first step. There is (usually) a hole drilled into the bushing on the bottom side for a spanner wrench. I used the tommy bar from my Sherline chuck on one of my lathes. The bushine is right hand threads. If all else fails, try padding the bushing with leather and clamping it in a vice. This worked on my other lathe. The next hurdle is the nut that holds the crank handle on the screw. This is (usually) a slotted nut. A big screwdriver with a bite taken out of the middle will work. There is a picture of a neat tool to do this job in the files section. I used a piece of drill rod with shoulders milled off to make a screw driver blade and then took a pass with an end mill through the center to span the end of the lead screw. I cross drilled to accept my Sherline tommy bar and the hardened the tool. This will all be clearer if you look at the tool in the files section. The handle pulls off. There is a pin that keeps the handle from spinning on the screw. Don't lose it. Chuck the leadscrew in your lathe. Turn your compound 90 degrees to the lathe axis. Lock the cross slide by tightening down one or more gib screws. Face off the surface of the lead screw that the crank handle seats on. Try fitting it all together. Measure the endplay. Face off. Repeat. If you overshoot you can face off the screw on the surface that runs on the inside of the bushing to increase clearance. Somewhere I have a page from a SB publication that shows how to install a new cross feed screw. It shows this whole process. It might be in the army manual. I will be posting a procedure on how to install ball thrust bearings on your leadscrew as soon as I get the pictures ready to load. Snip slackened back Snip Take the whole compound off by unscrewing the two "grub" screws all the way and jiggling the assembly until it lifts off. There must be some swarf under it or maybe one of the pins that holds the compound in place is upside down. to Snip Have a look in the FAQ's that Dennis Pantazis is editing. Search on FAQ to find the link on the list or I'm sure someone will jump in and provide it, since I cant remember what it is at the moment. Glen (12549)
I forgot to mention the oil screw in the top of the cross slide. If it is screwed in too far it could act as a locking screw. Take it out first to be safe. Glen (12550)
Jon Don't know of any spares agent I'm afraid but its no problem getting stuff sent over the pond. Just contact Rose at LeBlond, pay by credit card and UPS will deliver within a week. Only problem is import duty, UPS wont give you the parcel until you pay the duty by credit or switch card. Having paid the duty you always find that UK customs have overcharged you and there is no way of getting it back! Usually only a or two but annoying. The top slide will rock a little when both screws are well loosened off. Makes it possible to get the thing out without disassembling the cross slide. If it rocks the moment you crack the screws check that the proper wedge ended clamp shoes are in place and the right way up. I have seen a lathe with one shoe inverted and one missing with a home bodged long grubscrew substituted for the proper assembly. Well wobbly! Boxford parts interchange well but there are a few quirks to look out for, mostly in the apron cross slide region. Clive (12552)
The rock in the compound rest was down to the retaining pins being back to front, taper towards grub screw. Just the CF play now. Jon (12595)
Crossfeed slop
I'm putting my 10K back together with a new nut and I still had a lot of slop due to the entire screw moving in out. I removed the crank and snugged up the micrometer dial and placed a washer between the crank and the dial. That seems to fix it, but is it an OK fix? Also, what kind of lube should I put on the compound and crossfeed screws while I have them uncovered? Gene (12923)
On my Boxford I use a shim between the tool slide handle and the dial. This reduces the crossfeed slop to 0.004". I have used this method for the last 20 years. Martin (12945)
Cross feed and slide compound brass nuts
I have and old sb nice machine were can I get those brass nuts. tony (13936)
Nuts can be purchased at LeBlond Lathe Co. but probably quite pricey. They would not be that hard to make if one has access to correct Acme taps, a lathe and perhaps a milling machine. Use existing nuts as sample for correct shape. Could probably buy Acme Tandem Taps in sizes up to 3/4" in either left or right hand thread for 60-100 $ ( www.MSCDIRECT.com) which is probably much less than price of nuts from LeBlond. Also from what little info I have, a lot of SouthBend Nuts are not available unless as part of a screw and nut assembly. Last one I priced from Rose at Leblond was in $500 Range for regular screw and nut and $2500 for Hardened screw and nut for 13" SB. Ron (13938)
Sounds like a business opportunity for someone with a South Bend lathe. (13940)
I will be making these items for my own lathe first at work ( traded my crossfeed screw and nut assembly for taper attachment screw and nut assembly which was quite worn on thread. Ordered a piece of acme threaded rod from MSC which I will cut and turn down to fit in hole made in original remaining piece after thread has been cut off and then either pin or tig weld ) Will also make nuts at work and then when I have my machine back together will think about just that idea. Have follower so long thread will not be a problem and have a miller so nuts will not be a problem. With a sketch or sample any one with a working lathe could make these items. Biggest problem would be different acme taps required for different sized lathe cross and compound nuts. Also with repair as I am making for my own machine I am stuck with whatever backlash comes from commercial tapped hole and commercial Acme threaded Rod. Could work with it however and then make a new screw to suit commercially threaded hole with minimum backlash and then replace again. Ron (13941)
Here is how we do it: Make a short piece of Acme-threaded rod 10-thou undersized. Cast nut in place on rod. Make or acquire tap appx. .003 under-sized. Nut is tapped in one, easy pass. Finish-machine nut on mill. Nut will be very snug on new feedscrew. No play. Joe (13942)
IMHO it is easier to tap a piece of brass with commercial tap and then make screw to suit. This is how we do most things like this at work when both pieces are required except on large threads where price of tap becomes cost prohibitive. Ron (13943)
You can get precision acme threaded rod and nuts from McMaster-Carr but it is more expensive. Get it in alloy steel or B7 which is 4140 steel. For your application the added cost would be well worth it. To make the nuts consider aluminum bronze. Its very rugged stuff and will probably outlast the original ones. JP (13946)
That is the threaded rod I ordered but from MSC. Have material in aluminum bronze for nuts also. Just need to sneak a little time at work to complete. (13947)
Has anyone ever tried to split the nut and put a take-up screw in it? Frank (13954)
Seems like we discussed this a while ago and concluded that it was not really reasable. If you recall, I threadmilled a bunch of nuts on some CNC setups (no I don't have any more, I have no plans to make any more). There is not a lot of room in there to make the nut adjustable. there is room for a 5/8" dowel pin in the chase for the nut. to access the nut to adjust would involve disassembly of the saddle. (13956)
Frank What you want is a two piece nut with the adjustable part fitted to the fixed part with a differential thread. This where say the screw thread is 10tpi and you would use a mounting thread of 16tpi to give a controllable adjustment. This was in one of the Geometer hints that was posted earlier and I think I have seen something else also, will need to look around for it. JWE(13957)
On the subject of two piece nut for SB, just today at work I had to reassemble an 18" VDF crosslide assembly that does feature a two piece nut or as we call it a backlash eliminator nut. It would be quite simple to retrofit this style to a SB. Here is how that one worked. Nuts are as a regular nut would be except they have a tapered edge facing back to back on each nut. Front nut or nut nearest to compound is held with its key or spigot and with a regular Allen head cap screw. Rear nut which features no key or spigot is also held in by regular Allen head screw and hole in crossfeed casting is slotted to allow this nut to be adjusted before tightening. Nuts are assembled on screw with tapers facing each other and then a tapered wedge is inserted at that point. When Crosslide assembly is set onto machine then front nut is tightened tight first and then threaded grub screw is adjusted down on tapered wedge which in turn pushes rear nut away from front nut. Using a dial indicator on cross slide it is now a simple matter of adjusting down on wedge with grub screw until we have minimal backlash but screw still turns freely. You could in practice force wedge down and push nut so far away screw would not turn. When all is set then just tighten up Allen head capscrew on rear nut and job is finished. A final check might be in order in case rear nut twists a bit after tightening and starts to bind screw. P.S. One thing I forgot to mention is that the surface that second nut pulls up to on bottom of cross feed assembly would have to be machined so nut sat flat and was on centerline Any comments on whether this could work on a SB? Ron (13966)
Successful crossfeed rehab
Tonight I finished my first real project - a new crossfeed for my model A. The existing screw allowed me to move the crossfeed forward and back probably 1/4", the screw and nut were so incredibly worn. So my fix: 1. buy 1/2-10 LH precision acme screw from McMaster 2. buy machinable 1/2-10 LH nut, again McMaster 3. Machine nut down to fit in existing slot, with a flat on top of it so center of new nut ends up in the same plane as the center of the old nut (if that makes sense) 4. Machine brass 'plug' that matches what is on the flat of the existing nut - i.e. duplicate the plug that gets the 5/16-24 setscrew that drives the pin against the hole, fixing the nut in place. 5. Silver solder nut and 'plug' together to make complete new nut 6. Drill and ream acme screw to receive 5/16 dowel pin, press fit 7. Press in dowel pin 8. Cut existing acme screw off near the pinion gear. 9. Face pinion gear using compound, with crossfeed gib locked in place 10. Drill and ream pinion to receive 5/16 dowel pin, press fit 11. Press acme screw, containing dowel pin, into pinion gear hole. Voila, I have a new crossfeed screw with less than 2 thousandths backlash! I'm a happy camper. I spent quite some time thinking about what I'd use to press the parts together, when I finally realized I could just use the tailstock ram. Duh, yes I'm a beginner. Of course this took me several nights, but I was just happy it all went smoothly. When I cut that existing screw in half I knew I wasn't going back. John (15129)
Job well done! used the old noggin didn't you? I am so surprised at the creativeness of folks when they have limited resources at their disposal, that is one of the reason I get all bent out of shape when someone asks of ideas of how to do a project with the tools they have at hand and the comments received back is well you need to get a $2,000 machine or tool, and never answers the question on how to do! Good work, look forward to hearing of other great creative works from you. Clint(15131)
John, Thanks for the play by play. I've been going crazy trying to find 7/16-10 LH ACMR threaded rod (OK, I know I asked for help finding 7/16- 12, was a bad night and got my numbers jumbled) never thought to move up to 1/2". BK (15132)
BK, You can always make one. Get a length of 1/2" 12L14 steel, grind a acme threading tool, center the ends of the bar, put between centers, and thread. You have a good sample near the ends of the old one for comparison. It won't hurt to try it. RichD (15136)
Try a company called Nook, I get acme stuff from them. (15138)
It was really pretty easy moving up to the 1/2" screw. Granted it took me quite a while to get the nut machined down to the correct size and shape, though. The nut I used was part 1343K34 from McMaster. Bronze, 27 bucks. The screw I just used the 1018 steel one that was about $21. I figure in my limited usage alloy steel would be overkill. If you decide to go this route, let me know and I'll gladly send you a length of screw and a 5/16 dowel pin to save you a couple of bucks. John (15142)
Don't know if any of you have tried but on the H 10 nut you can buy a 1/2 10 L H Acme tap and clean out the 7/16 nut and save yourself some work on the nut project and you can buy precision ground rod L H 10 acme from several places. I would make sure to use a spare worn out nut if possible. The first time I did it I was sure I would ruin the world but did not. Make sure if you are running a smaller lathe the od of the nut will work. Grumpy (15143)
Inquiry for Crossfeed Screws
I have an idea for a new product, and would like to run it by you folks. I hope this will not be a violation of the group's rules, and if it is, I will apologize. We go to a number of Model Engineering Shows, including the upcoming NAMES Expo. At each of these shows, we display some of the products we manufacture for Logan Lathes. One such product is various Crossfeed Screws. At each show, we get a number of visitors who stop by, and say something to the effect of "Gee, that screw looks awfully close to the one I need for my (South Bend, Atlas, Clausing etc.)" Unfortunately, our screws do not work as made for these other machines, although the Acme thread is the same, at least for the South Bend 9" and 10" (7/16-10 LH Acme). My thought was to make some "blanks" from 7/16" Ground Polished 1215, with the Acme thread already cut, long enough to handle any of the needs, and the other end long enough for the user to finish as needed. I'm not sure yet what price this might command or require, but I'd like input on how long each end should be. My first thought was an overall length of about 20", with about 10"-12" of thread. If anyone has any suggestions or advise, please let me know. In appreciation, once we get this ready (assuming we do), I'll offer free shipping within the US for anyone on this group who would like one. Scott Logan (18368)
Wonderful idea! Please proceed! Consider the compound later. Joe (18370)
Scott The idea is great and would be even better with a more suitable material for the shaft such as high tensile 4130 and a bronze nut blank to be finish machined by the buyer along with it. For me as a machinist it is hard to get a smooth surface finish even with grinding on low carbon steels while 4000 series pre heat treated stock machines to a decent finish that would only require polishing to make a longer lasting feed screw that would not eat up the nut in a short time. JWE (18372)
Scott Great Idea, I'd buy one today! Rick (18375)
At this time I remake cross feed screws and nuts for Southbend lathes 9" and 10". With or with out taper att. Any interest? Bruce (18376)
Scott I like the idea. I have been entertaining the idea of cutting new crossfeed and compound rest screws for my Hardinge T10 lathe but do not have the confidence I can do a good enough job. Depending on the price, I might go for it. I will measure the length of both of my screws and let you know. My compound rest screw is smaller than 7/16 though. Ron (18377)
I might be interested in a cross slide screw for a 9C? Price? Rick (18381)
Count me in. I have been looking for 7/16-10 material without success. I was looking at the possibility of changing to ball screws but the only 10 pitch that fits is 5/16 which seems to thin. Jim B. (18382)
Yes Jim B. (18383)
Great idea. You might also consider including "generic" nuts as well. Keith (18385)
I like your idea. Before you start, we need to establish a screw that would fit every lathe with a 7/16" ACME thread. I guess, the minimum length would be for the heavy 10. At least 2 in should be 5/16" dia in order to mount on the remainder of the old part. A cross feed nut should come with the package. The way I see it is a piece of round bronze stock 5/8" - 3/4" dia that could then be modified by the buyer to suit his needs. If you ship to Canada with USPS, I would take one. Guy (18387)
Scott, Your timing is impeccable! I've been trying to locate acme rod for the crossfeed screws on a pair of 10L's that I'm going through. I just did a quickie measurement of the old screws and it looks like 7.062" for the threaded portion and if the unthreaded stub was about 3" long that would give plenty of length to be fitted into the existing part. The smallest diameter on the stub measures .295" on the screws I have. I looked at the Miller Machine site but came to the conclusion that I could spend a fair bit of time grinding toolbits and practicing cutting LH acme threads for the price of two of those screws. I might even learn something to boot! Anyway, I'm interested. Chris (18409)
Scott The crossfeed screw on my Hardinge T-10 is 14.7" long and the acme threaded portion is ~6.4" long. It has a gear just past the screw threads so I would probably have to cut this out of the original, bore out the center and silver solder it to the new shaft. Ron (18410)
9" crossfeed nut
The crossfeed on my well used 9" has a LOT of lash. I assume that the nut is simply worn out. I COULD I suppose just make a new one, but that means buying a tap that I'll probably only use once .. and a bunch of hassle. What are these worth ? You see, there IS one for sale on eBay right now (a new one), that will go for about fifty bucks (once "handling" is factored in). But that seems a bit high to me. Alan (19560)
Question answered. Nut went for $66.00, with another $20.00 for shipping. For that price, I WILL buy a tap, and maybe even make a couple ! Alan ( 19563)
Alan- Let me know when you find that tap. I have the same problem. John (19564)
Guys, Enco has a left hand ACME 5/8 x 8 tap for +/-$35 each. JJ (19566)
The nut is 7/16 -10 LH ACME. Jim B. (19567)
The part number on that HSS tap is 505-6804 cost $37.65 does not include shipping. JJ (19568)
If you decide to start making them for a "reasonable" price with "reasonable" shipping I would be interested. (19569)
I stand corrected. Shame on me. Here I though I had found the cridder. JJ (19570)
Check with Miller Fabrication on the links. I think they sell the nut only for about $35. They did some work for me on gear repairs and the work was good for a very fair price. Paul (19571)
Yes, and if someone gets a tap for the heavy ten, I'd like to put in an order with them, too. 9" crossfeed nut Alan-(19572)
I have seen things like this many times. Go ahead and get the tap. Make a few trials to get it just right. Then turn off about ten or so before the newly acquired skill disappears. Then sell the tap and the extras to pay for the original project. (19573)
JJ - I was confused, so I went out to my lathe and checked. eeengineer is correct: the crossfeed nut is 7/16 x 10tpi left hand acme. For fun, I checked the compound rest nut as well. It looks like 3/8 x 10 tpi left hand acme. I looked on Enco's website, but could not find either of these taps. Perhaps they could be special ordered. Anyone else have any ideas? John (19578)
I did a quick search. These guys claim 24 hour turnaround. No idea if they sell to individuals or their prices. But the point is there are people out there that do this. http://www.newsontool.com/ (19580)
Sure, we have the taps for both of these. Cost a couple of hundred dollars, and they are not for sale. Yes, they are custom made, and should be ordered in sets of two or three taps. BTW, check again, the compound nut should be a right hand thread. The Logan 9", 10", 11" and 12" Lathes use the same thread sizes as the SB. And you wonder why the replacement nuts cost what they do. We've had a couple of customers purchase our CF nuts to replace the SB CF Nuts, but they need to be modified, as the height and shape are different. There is a diagram in our catalog that gives the general shape, and the catalog can be downloaded from: http://lathe.com/info-req.html  Scott Logan (19581)
I researched this a couple of years ago and was told by two tap companies that 3/8-10 and 7/16-10 could be made, but it would require two taps for each size rather than the two stage taps for normal sizes. The reason given is that the web of the tap would be to weak to take the torque and so separate roughing and finishing taps would be needed. Prices quoted at that time were around $40 per tap for less than 10 each and about $20 for quantities of 40 each or better. JWE (19582)
Alan A couple of other options you can try rather than buying a tap. 1. thread the nut on the lathe 2. make your own taps 3. repair the existing nut with Moglice ( www.moglice.com ) Somewhere I've read how someone repaired theirs with Moglice. Moglice is a relatively thin epoxy with powdered moly in it. From what I have read it pours almost like water. As I recall, you screw the nut on to a unworn part of the screw, dam the ends with putty and inject Moglice with a syringe. The screw needs to be coated with release before hand. I don't the price of Moglice but understand that it is not cheap. Final solution, we should merge our lathes. My crossfeed nut is nice and tight but the compound nut is worn out. Someday I'll have to do something about it, in the meantime I can live with it. John (19585)
I have both the 7/16 x 10 LH ACME and the 3/8 x 10 RH ACME taps. I bought them from: Tracy Tools Ltd. 2 Mayors Avenue Dartmouth Devon UK Website www.tracytools.com These are advertised as "for renewing feed screw nuts". The one nut I threaded seemed a bit tight on the screw. Probably it could be lapped in, though. The taps are not tandem. They are finishing taps only. I could really use a roughing tap to start the threads. Single pointing to start and finishing with the tap would work, I guess. Price was 18.00 pounds each plus VAT and shipping. Their catalog says they have other sizes in stock. Glen (19591)
They're still available, and they're still 18.00 GBP. That's about 33 USD or 45 CDN each, plus shipping, duty and any local taxes. John (19597)
The crossfeed on my Heavy 10 was *shot*. The nut and crossfeed screw itself had *chunks* of metal missing. I believe it was 7/16" -10. What I did was order a bronze "precision machinable acme round nut" from McMaster Carr. 7/16"-10 not available, so I went with 1/2"-10. Also ordered up a three foot length of "precision acme lead screw black finish alloy 4140 steel." The nut was not available in 7/16", only 1/2" from this source. There was enough room inside the Heavy 10 castings to fit 1/2" screw and nut with no problem. I *assume* this will fit inside the 9" castings. Basically what I did was turn the nut in a 4-jaw chuck to leave a boss the same dimensions as the original nut. Then tapped to original thread size (3/8"-16 ?) for the original retaining screw (the one with the little oil plug through it.) Just get the distance from the centerline of the screw to the nut's registering face the same as original. I did have to freehand mill the bottom and sides of the nut (as viewed in the installed position) to clear the casting in the carriage. This could be done with a die grinder or file and patience. The original lead screw was turned down in the threaded section to a convenient size to an arbitrary length and parted off. The new leadscrew was bored to a tight fit and installed with loctite. Total was $22 for leadscrew and $27 for machinable nut. Add in an hour of machine work and it's much cheaper a tap, plus the lead screw will be brand new. All in all it was very easy- my first machining on my new (1943) Heavy 10 and first turning since night course four years ago. Backlash on crossfeed is now not measurable. The only critical part is to get the old and new lead screws co-axial. Mine has a slight visible wobble, which give a very slight tight spot on the end. John (19675)
John, This is just what I was looking to hear. Since the 7/16 is not really available but the 1/2 is. You just performed what I was going to go about. The difference is that I have a 9" and I just purchased a spare saddle with compound that has a worn out cross feed nut. Thanks for going where no man has gone before... I don't mind standing on the shoulders of giants to achieve greatness. JJ (19677)
John I did the same procedure about two years ago to my 13 inch ( late 1960's model), which was perfect except for the crossfeed nut. I bought the precision nut and screw from McMaster-Carr.5/8-8 left hand for a 13 inch if memory serves me. Anyway I use this lathe a lot, still no backlash and on a 12 inch test bar runout is only .0006.(excellent). I chase threads quite often and this inexpensive fix really does the job. Mitch (19681)
"Play" in crossfeed screw
While re-assembling my P W 12 X 30, I noticed that the crossfeed screw has a bit of longitudinal "slop" or play, allowing the slide to move slightly (along the direction of the screw) while wiggling it by hand. The crossfeed screw is threaded into a brass block which in turn fastens to the crossfeed slide. There doesn't appear to be any slop between this block and the slide, so the problem appears to be wear in the brass block. Is there a way to take the play out of this setup, or is a new brass block the only solution? If a new block is necessary, then I would appear to be "hosed", because I am a long way from being able to make one myself. Wade (22191)
Wade, how much slack you got. I mean you are going to chase some slack. My old machine is about .015. I have ran some older machines with as much as .075 to.100 slack in them. If I don't have to chase some slack I couldn't run a lathe. Never ran one that was brand new so wouldn't know how that would feel. As far as being hosed take the nut out and blueprint it, put it back in and chase a little slack and make a new one. Duane (22192)
The brass nut is made to wear first because it is cheaper to replace than the leadscrew. You should be able to find someone to make one for you or you can buy an acme tap and make one up yourself. Another option is to buy a brass acme nut and make an adapter so the total unit matches the 'brass block'. Or, you can live with the backlash. JP (22193)
Wade, How do you know unless you try!?!? Get a couple of pieces of aluminum and try. You may surprise yourself. If nothing else, you'll learn a lot. Don't hesitate to ask questions. Mario (22196)
Absolutely. One of the first things I did 20 years ago with a clapped out 9C, when I knew one or two things less than now, was make a new top slide nut out of aluminum with a handground boring bar. The thread profile match was iffy, the threads themselves were embarrassing, but the whole thing worked better than it did before and I learned a lot. Still got that nut. Ed (22197)
I'd estimate the slack to be about .050 or .060, so I'll probably want to do something about it. You have all offered some really great suggestions, and I want to thank you for that. I am considering all of these options, including possibly making a new nut (scary for me at this point), or modifying this one in some way with set screws, etc., to take up some of the slack. The feed screw thread is 5/8"-8TPI-LH, with a 5/8"-18TPI-RH hole in the top face for the cross slide attachment bolt. This hole has a 1/8" oil hole at its bottom. Wade (22238)
I had some slop in my crossfeed screw when I took it apart and cleaned it up. I was able to take some of it out by playing around with placing arbor washers just behind the handle on the crossfeed screw. Arbor washers come in various thicknesses much like shim stock and I had a package of assorted thickness from McMaster-Carr. I was able to eliminate a lot of backlash. I know this is not a permanent solution, but as the washers wear, I can always add more. Mark (22239)
Wade, A crude fix would be, go to McMaster and get 99044A523 brass acme coupling nut, left hand thread for $29. Drill and tap a mounting hole in the side and shim it in place. Or braze a piece of flat stock to the side and drill and tap the whole assembly. This nut is 2 inches long and is class 2G, sloppy but better than what you presently have. JP (22241)
Cross Feed play
I have a 10K and have too much play in the cross feed. I can push and pull the compound back and forth after setting the desired depth . I can't tighten the gibs too much when cutting threads therefore I would like to know how to tighten the crossfeed assembly. I have a new crossfeed nut installed so it isn't that. There seems to be a gap between the crossfeed "bushing" (as labeled in the SB HTRAL book) and the Cross-Feed Graduated collar. My question is: How do I remove this collar/Bushing assembly to tighten to reduce play if indeed that solves the problem or is there something else I need to do to remove the excessive play. Wayne (22398)
There was a jpg of SB instructions on how to do this. Without looking at the parts diagram, this is what I recall. You need to take the crossfeed screw assembly completely out. Take the nut off the end of the handle and pull the handle off. Watch for the key! The graduated dial should slip off. There should be a short brass plunger under the screw that holds the dial in place. I don't recall if you have to take the bushing out or not. you'll need a pin spanner wrench or something similar to screw it out if you do. On the handle end of the crossfeed screw there is a shoulder that the handle butts up against. According to the SB document you turn that shoulder back an appropriate amount. You measured how much slack you had before disassembly didn't you? You'll need a lathe to turn the shoulder back. You could use yours if you tighten up the gibs to hold everything tight and use the compound screw to feed in the tool. If you lock the carriage and set the compound at 90 degrees you can even use it to measure how much you are taking off. That's what I recall of SB's instruction but I think there is an easier and less risky way. Measure how much slack you you need to take up and put a washer type shim on the inside of the bushing. That should take up the slack. Note that the nut that holds the handle on MUST be tightened until the handle buts up against the shoulder on the feedscrew, it is not used to adjust for slack. All that said, lots of people, including myself just put up with the slack. Once the tool is contacting the work all the slack is taken up anyway. It is a little disconcerting though with interrupted cuts to see the compound moving back and forth. John (22400)
Just because you have a new cross-feed nut doesn't mean your cross-feed screw is like new. Unless the threads are good a new nut isn't worth much. (22402)
Wayne, You can remove the nut (with a 'forked' screwdriver), remove the graduated collar and shim behind it to take out the excess movement there. You say you replaced the crossfeed nut, but how much wear is there in the crossfeed screw? If you hold the crossfeed handle in against the graduated collar and then grab the tool post and shove it in and out, if there is any movement, and the nut is firmly attached to the saddle, that is an indication that there is clearance between the threads of the crossfeed nut and screw. Mario (22403)
Mario et al, I removed the cross feed screw added a .007 washer/shim between the graduated collar and bushing which reduced any noticeable play. I did the same with the compound and improved it also. Wayne (22423)
Price of Crossfeed screw?
I am dealing with a guy on a tailstock, compound, and base for a SBL 16"He says that the crossfeed screw is in pretty good shape, and mine is badly worn. He wants me to make him an offer on the screw, and the dial, and the handle. (Mine has the wrong one on it) I was wondering how much it is worth? (23339)
I paid 400 for one NOS from a guy for a heavy 10 about 3 years ago I understand they are over 800 from LeBlond but that's just what I have heard but I know they are UP there. A good used one should be worth at least 150 I would think but your the buyer so if he is parting out a machine why not offer him fifty bucks in reality probably a good deal for you and him. Grumpy
I'm not going to venture a guess on that one, but you might want to contact Plaza Machinery, (they're online - somewhere). I just bought a new crossfeed screw and nut for a heavy 10 with a taper attachment. Very good quality, about $200 for the two.(23346)
I priced the assembly from Rose and LeBlond. The compound cross feed assembly which is the screw, nut, feed handle and a larger graduated collar ran just under $600.00 for a 9A with the taper attachment. There are several sizes of cross feed screws so be sure your getting the right one. (23347)
Last time I priced a Crossfeed Screw and Nut for a 13" from Rose when she was still at South Bend I believe Regular Screw, Jam Nuts On End and Crossfeed Nut With Retaining Bolt $1400. Hardened Screw, Jam Nuts On End and Crossfeed Nut With Retaining Bolt $1775. $200 would be a steal. Ended up buying Acme Rod and pinning to old screw and making nut at work with their $200 Acme Tap. Cost $20. Results 12/20/04 (23348)
Ed, Your parts and check arrived this afternoon. I have to finish up a grinding job for Precitech. I hope to get to your job right after New Years. I may get started before ,depends on what my wife has in store for me . The honey doos. Their prices are scary. Aren't they? They want more for their parts than you pay for a whole machine. Bruce (23353)
Darn, that must mean the nuts cost $1,575. Seriously, check with Plaza. I didn't see any cross feed screws listed for non-taper or for the compound, but the one for the taper attachment was excellent quality. Greg (23355)
Has anybody tried this outfit? http://www.millermachineandfabrication.com/products.htm  Looks very reasonable. Roy(23390)
They did some gear repairs for me (replacing broken teeth) and the work was excellent. It was also cheaper than I expected. Paul (23397)
Got a few of those honey doo's myself. :) was going to mention that you were taking care of my backlash problem for me but didn't know if you wanted the advertising or not. Sure looks like there is a market for you skills. Ed (23413)
Crossfeed slop measurement?
I have been reading about .003 and so on measurements of play in cross feeds. My 16" has about 3/4 of a turn of play. How are you guys getting the measurements? I am NOT a machinist. I just bought the old lathe a couple of years ago, and I'm kinda like the dog that caught the car? Any help would be appreciated. I also would like any help on books or manuals on how to use a lathe. I own a copy of How to run a lathe, and it is good. I would like MORE! maybe a video? (23370)
Mount dial indicator on saddle with it touching the Crosslide base. Move crosslide in just slightly (you are taking out any backlash ). Zero indicator and Crossfeed Dial. Move Crossfeed in opposite direction until Dial Indicator just starts to move (+ .001 ) Check and see how much your crossfeed dial has moved. Subtract the .001 movement of dial indicator from this figure and you now have the exact amount of backlash in the Crossfeed Screw. Ron (23371)
You can stick a feeler gage between the cross feed knob and the stem sticking out from the cross slide. With the handle turned out towards you. Bob (23374)
I purchased a video that has some interesting old clips on it about running a lathe. It's on a VCR and I'm set up to transfer VCR to DVD so if your interested in a copy and are willing to pay for the media/shipping let me know and I'll make some copies.(23395)
I got my manual in, and I got brave; I took it apart. I found out it wasn't my screw or nut that was worn. It is my bearings on the shaft pinned to the screw. Either it has the wrong handle on it or the wrong nut holding on the handle. I can't tighten up the handle enough to take care of it. I put the nut on the screw and it fits VERY well. I know with the handle on I can move it in and out about 1/8th of an inch. Any suggestions. Also when I took off the dial and handle the bearing had a thin piece of metal wrapped around it, like a shim?? the bearings both of them in and out have "nice 605" stamped on them? Is that even the right ones? The nut for the crossfeed is made of cast iron. I thought they were made of bronze? I forgot to tell you it is a 16" SBL I think it is a 1944 model.157044 is on the tailstock. (23621)
Slop In Crossfeed and How To Correct It
Trucks 1956: I have SB directions on how to fit replacement screws. Details how you machine screw shoulders so handle fits correctly. I realize you are not changing screw but procedure is the same if handle does not fit properly on any screw be it old or new. I can scan and send to you. Contact me off group if you would like me to send you this. Ron (23625)
Ron, I would love to see a copy of those instructions from SB and also whatever else you might have in your stash of SB information. The taper attachment fitting instructions that you sent were very informative. Some of the that stuff didn't even cross my mind when I put on my used taper attachment. In retrospect it was sheer luck that the thing works! Roy (23627)
Ron, I have a 10L that had some slop in the crossfeed. I took it apart and put a slim washer behind the castellated nut on the end of the taper attachment. It helped, but did not fix it. I took it apart again, and put a thin washer at the end of the shoulder just before it goes into the taper attachment. That snugged it up so that I had to back off the castellated nut to allow the screw to turn. Now have the same problem with the compound, but can't figure out how to get the handle off. Both screws look pretty decent, with the shoulders of the Acme thread square. Also, I noticed with the gib on the cross slide loosened up that the screw appears to be slightly bent. I can see the cross slide wandering back and forth. I tightened up the gib and cannot see any weaving now by eye, but will put a dial indicator on it this morning. Is that a problem? Brian (23641)
Cross feed nut
Does anybody know the size of the acme cross fee nut on the heavy 10 Southbend. Is there any place that it can be purchased or does it have to be made special. Vinnie (23750)
7 / 16 10 LH If my memory serves me right. Grumpy (23755)
Cross Feed screws and nuts can be purchased from Miller Machine and Fabrication. They are listed in the links section, I think. (23757)
Cross Feed Screw Nut
I have a 9in A with a taper att. the cross feed nut threads are worn almost to points. I have a piece of aluminum bronze and bearing bronze. What would be the better metal to make the nut from? And I was looking in the FAQ for the removable of a direct reading collar, but could not find it, could someone direct me to the right area to look. John (23845)
We use the Aluminum Bronze for nuts at work. Very tough (wears little ) but also very difficult to machine. Ron (23848)
SB9 Power Cross Feed
What is the power crossfeed useful for? I can't figure out a useful purpose. (23881)
Facing off the end of a shaft or truing up a faceplate among many others. Roy (23882)
Power feed helps to generate a nice smooth cut because of a constant speed, much better than you can do manually. JP(23883)
Use the lathe for awhile and see if you can find any need. Once you grow tired of facing by hand the use becomes apparent. I did a couple dozen tubes. 3/4 ID 1-1/4 OD, 5/8 long from solid Alum. I cut 2" parts from solid on the saw, faced, center drilled and then moved to the drill press for punching the large hole. while I was drilling, I was sawing. Once I had a few drilled, I could do a bore, saw and drill. The bore and saw on feeds and me on the drill press. Made the job go faster. Dave (23884)
It is useful to make a clean, square "facing" cut on the workpiece, especially of a large diameter. I was facing off a 5 1/2" cast iron faceplate yesterday and it takes almost ten minutes of careful hand-cranking to make that work well. With a power crossfeed (which I have coming!!) I could have watched the machine do it!! (sort of) Bernie(23885)
You will find that a much faster and smoother job of parting off can be done under power, plus the tool doesn't suffer as much. Jim (23886)
One thing for sure, it keeps the burns down on your hands from the hot chips. My lead screw was down for a week or so and i had parts to make so I had to hand feed everything. Ended up with a glove on my left hand due to hot chips. Boy you sure don't know what you have until you have to do without. I face a lot of 4" aluminum bar stock, it would be a pain in the butt without the power feed. Bob (23887)
Worn crossfeed screw
Maybe someone can explain a simple concept to me: the crossfeed screw threads on my 1936 9" lathe are about 1/3 worn away and I'm considering turning a new one; I understand this is considered a "precision" screw and I'm wondering how much more precise it would be than one that is turned on a ordinary lathe (like I'm thinking of doing). Rick (24026)
"Precision" is a term usually used when talking machine screws and nuts that signifies either the process used to make them, which usually involves grinding of the thread on the screw, or is sometimes used to signify the fit or backlash between the screw and nut which is sometimes no more than tenths of a thousand of an inch. Ron (24027)
Screw dimensions are categorized by class, 2A, 3A etc. Look in the Machinery Handbook or go to www.engineersedge.com  for a full explanation of screw class. JP (24028)
Slop in crossfeed screw
Any recommendations for curing slop in cross-feed adjustment screw, currently 1/2 turn of handle on my 13" SB? (25788)
Check the threads in the holding nut the lost comes from there a you can screw in the top flat screw on the cross feed it will help a little but 2 to 4 thousand of an inch if so. I have 25 thousands of an inch and to sove it I will have to make an other part the thread is 10-3/8 acme left hand check to make sure to me it is one solution or to buy the nut that grabs the cross feed. Robert (25791)
You are talking about a non-problem. It had a lot of slop in it when it was brand new. To provide a screw with no backlash is possible, but requires more than just a screw. Some of the old Cincinnati Milling machines provided that in the table of some of their milling machines so you could climb cut easily, but if it became out of adjustment at all, it was worse than not having it, and making the adjustment required removing the table. With any lathe, milling machine, or jig bore, anything with a screw that holds your position you must be aware of the direction you are working and in a short time it will be habit. When you are turning the OD of the part, you always go to a right hand reading and it will be accurate. The other factors for accuracy are whether your tool is on center and if you are using a center in the tailstock, is the tailstock on center. When you bore a part you want a left hand reading and when you want to move away from the cut after a pass, you can easily tell by the feel how far you need to go to the right to move away from the cut. Bring your tool back out, and move the slide back to the left to the last cut you made so you know where you were when you decide what your next cut will be. The best addition you can make to your lathe is a long reach dial indicator, a 2 inch is fine. The indicator can be bought inexpensively and by making a nice mount to read the travel of the infeed on the infeed slide, it will be much easier to go back to your location and can work more accurately. It really takes the work out of the whole process. Some of the expensive lathes had this feature built in. One was the American Lathe, as well as some of the LeBlonds and Monarchs, all "high end" lathes. You don't need to "gold plate" your lathe to make some nice improvements on it. A collet set is nice, depending upon the work you are doing. Bill (25795)
Bill Thanks for expressing this so clearly. I and others have tried for years but most new comers seem to get offended when we tell them it is a normal and natural thing to have backlash in feed screws on manual machines. JWE (25796)
Bill Could you tell me the thread size and pitch on the cross feed Please . Ex. 3/8 10 acme LH. Robert (25797)
As Bill has already pointed out, all screws (except ballscrews) have slop or backlash, there are methods using a second nut to minimize it, not eliminate it. However, there are still things you should check, is the screw holding the acme nut tight? My cross slide nut needed 1 1/2 turns to snug it up and the compound didn't have a retaining screw at all... Are the nuts holding the dials firm? Have you adjusted the gibs? Bernard R (25806)
Have you checked the fit of the cross feed screw shaft to the collar in the saddle? Often, in-and-out play of the shaft in the collar and dial are mistaken for slop in the fit between the nut and the screw. The thrust surfaces between the shaft, the collar and the dial wear and in some cases, the whole shaft will have to make half a turn or more to move enough to take-up the slack before the cross slide will start to move (when changing from cranking in to out on the cross feed). Webb (25810)

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