Ancient lathe chuck adjustment

I Have an old South Bend Heavy 12 and I have a 3 jaw and a 4 jaw and only use my 4 jaw, when absolutely needed. I am looking for a Buck Chuck 3 jaw, if anyone has one around, to fit the Heavy 12?

I have a south bend light 10 the 3 jaw I got with the lathe was terrible I bought a china 3 jaw with a backing plate I was impressed with it. A lot of places sale backing plates

DDoug said: Even if you need someone to stop by and thread that 4 jaw backplate for you, it will be worth it. Working on repairing parts more often than not will be much easier with a 4 jaw. Dialing one in is easy skill to learn. Number the jaws 1-4 to keep track as you turn the chuck by hand and watch the indicator. Click to expand... Are there traveling machinists like traveling nurses? Just call and they'll show up at the shop? I was thinking of taking the backplate to a local machine shop but haven't called any yet. I'd really like to figure out how to cut threads with this lathe but it might be better to start with something less critical.

mekanik said: I bought a Bison chuck for a small lathe I owned. After 25 years The chuck needed some truing. I rigged up a Dremel grinder on the tool post and lightly ground the gripping faces of the jaws. The bent aluminium rods hold the jaws tight against the scroll plate. I made several very light passes with the grinder. I'm very happy with the result. A good cleaning afterwards to get all the abrasive grit off the machined surfaces. Click to expand... An ingenious setup!

mekanik said: I would like to see more pictures of your lathe. What gears are not staying engaged. I see a Zerk/Grease fitting on the headstock bearing. There is an oilier you can get to lube the bearings they should not be greased. Originally your lathe probably had little glass oil dropper on both headstock bearings. 32 wt hydraulic oil is what I use on my lathe and mill. I am guessing the spindle thread is 2 1/4" x 8. If so you should be able to buy an adaptor and machine it to fit your 4 jaw chuck. Here is some history on your lathe: Worcester Lathes Founded by the former president of Whitcomb-Blaisdell Machine Tool Co. around 1910, the Worcester Lathe Company was based, along with many other machine-tool makers, in the state of Massachusetts . A range of regular engine-type machines was made, in both www.lathes.co.uk Click to expand... I will get some more pictures at some point, but in the mean time the link you sent has better pictures than I would take anyway. That is a very helpful article. This picture shows the lever that engages the gear on the end of the main spindle to the change gears on the lead screw gearbox. For some reason, there does not seem to be any mechanism that locks the lever in position. When running in reverse, the gears want to stay engaged, but in forward they will ratchet under load. This lathe had the grease fittings before I got it. I just assumed it was an upgrade that a previous owner had done. How bad is it that it's been using grease for so long? The spindle thread is 1-5/8"-8, which is very uncommon based on the searching I have done.

The shop I work at has a lathe and radial arm drill that both have Zerk/grease fittings. There is a oil gun to lubricate them. I doubt there will be a problem using grease. The spindle bearings are adjustable for clearance and should be lubed with oil. I have no idea the procedure to adjust the spindle bearings on your lathe. There are set screws on the bearing cap in the picture most likely to adjust the clearance, they are probably babbit bearings. The machinists that knew how are probably long gone.

Can you post pictures of the lever and the gears on the end of the lathe with the cover removed? There is probably some kind of detent that keeps the gears engaged. The spring may have given up after 100 plus years.

mekanik said: Can you post pictures of the lever and the gears on the end of the lathe with the cover removed? There is probably some kind of detent that keeps the gears engaged. The spring may have given up after 100 plus years. Click to expand... Good point. I will take the cover off and take some pictures (hopefully) soon.

If the 1 5/8-8 is scarce (read $$$), try for an 1 1/2-8 and once you have the gear issue sorted, rethread it.

Tony Wells said: If the 1 5/8-8 is scarce (read $$$), try for an 1 1/2-8 and once you have the gear issue sorted, rethread it. Click to expand... I think it's worse than scarce, I wasn't able to find a semi finished backplate with 1-5/8-8 at all. So I did buy a 1-1/2-8 backplate and it's been sitting on the bench next to the 4 jaw chuck for a year while I've been ignoring the problem... Time to finally get it figured out one way or another!

If you get really desperate, get a 2H Heavy Hex Nut and weld it on a burned out circle and finish machine it as needed. Or if you can provide an over wires measurement of the spindle, it could be threaded nicely for you elsewhere.

I have a couple old lathes and other machines. I dont like those ZERK. I may have missed something but how did you come up with one jaw being 5 thousands off? I was lucky starting off and worked in a shop that had lathes and got to use them some and learn. The first lathes i owned were not that great but i built a lot of stuff that didnt have to be of high precision. Good luck keep learning.

It's probably been off since long before I got it. Old Doug said: I have a couple old lathes and other machines. I dont like those ZERK. I may have missed something but how did you come up with one jaw being 5 thousands off? I was lucky starting off and worked in a shop that had lathes and got to use them some and learn. The first lathes i owned were not that great but i built a lot of stuff that didnt have to be of high precision. Good luck keep learning. Click to expand...

materthegreater said: It's probably been off since long before I got it. Click to expand... I meet how did you set it up to test it ?

Old Doug said: I meet how did you set it up to test it ? Click to expand... I used a dial indicator to measure each jaw. I tried it with the jaws in a few different locations and it was always the same jaw off by the same amount.

materthegreater said: Are there traveling machinists like traveling nurses? Just call and they'll show up at the shop? I was thinking of taking the backplate to a local machine shop but haven't called any yet. I'd really like to figure out how to cut threads with this lathe but it might be better to start with something less critical. Click to expand... Find a retired machinist to come over and instruct.

I made a discovery while cleaning the chuck. This little screw can be loosened and will slide to the other position which seems to disengage something and allow the jaws to move independently perhaps?

Not sure how that chuck works but I would want to find out why 2 jaws have about the same amount or thread sticking thru and one is way different

Scroll chucks the jaws have to go in in proper order is there any numbers on jaws??

pittsburgh cat man said: Not sure how that chuck works but I would want to find out why 2 jaws have about the same amount or thread sticking thru and one is way different Click to expand... Because I fooled around with it after loosening the screw on the back.