I have a 10" Sheldon lathe

[Clockman44]

I can't get the lead screw out of the apron. I can slide the apron to the end of the tailstock, but the it won't come off. Seems like the cylindrical worm gear will slip on the lead screw, but won't go over the smooth end of the rear lead screw. My question is how do I get the lead screw out of the worm gear.

 

[Janderso]

Can you support the apron and unbolt and elevate the saddle to expose the apron?
Just thinking how I may go about it.

 

[rjs44032]

Hi Clockman44,

Depends what model Sheldon. On L, XL, S, or M style lathes you remove the apron with the leadscrew (LS).

First remove the carrier on the end of the LS. Then take taper pin out of the LS on the QCGB side. I've heard some LSs are threaded into the QCGB shaft. Mine had just a smaller diameter no threads. If yours has threads Make sure its un-threaded before you continue.

Then close the halfnuts and carefully move the carriage until the LS is free from the QCGB.

IMPORTANT the apron is heavy and you would be wise to block it up so you don't loose control of it during removal.
Then drop the Apron by removing the two (or 4 I don't recall) bolts on top of the carriage. The apron has pins that aid in location that may have some slight-interference fit.

You remove the apron with the LS still in. You will see when you do that the LS is captive within loops in back. It goes through the worm between those loops. Once you have the whole assembly on the bench be careful to catch the worm when you remove the LS from the apron or you may drop it.

The complete instructions are on the SheldonLathe yahoo site. Hope this helps.

Best Regards,
Bob

 

[Clockman44]

Hi Clockman44,

Depends what model Sheldon. On L, XL, S, or M style lathes you remove the apron with the leadscrew (LS).

First remove the carrier on the end of the LS. Then take taper pin out of the LS on the QCGB side. I've heard some LSs are threaded into the QCGB shaft. Mine had just a smaller diameter no threads. If yours has threads Make sure its un-threaded before you continue.

Then close the halfnuts and carefully move the carriage until the LS is free from the QCGB.

IMPORTANT the apron is heavy and you would be wise to block it up so you don't loose control of it during removal.
Then drop the Apron by removing the two (or 4 I don't recall) bolts on top of the carriage. The apron has pins that aid in location that may have some slight-interference fit.

You remove the apron with the LS still in. You will see when you do that the LS is captive within loops in back. It goes through the worm between those loops. Once you have the whole assembly on the bench be careful to catch the worm when you remove the LS from the apron or you may drop it.

The complete instructions are on the SheldonLathe yahoo site. Hope this helps.

Best Regards,
Bob

Thank you for your instructions. Mine does seem to be threaded in at the gearbox. I can slide the apron up and down the lead screw, but it won't come off the tail stock end. Seems the threaded lead screw is bigger at the end that goes thru the lead screw end bearing. The worm gear on back stops when it gets to this place. If I can unscrew the lead screw at the gearbox end, will the lead screw come out and maybe I can go out that end with the apron...Thanks for any help..clockman44

 

[Choiliefan]

Perhaps this link shows a machine similar to your lathe: http://www.vintagemachinery.org/pubs/2133/15051.pdf

It's hard to tell from the pictures but the screw may be keyed to the gearbox and/or have a pinned collar...

If so, you should be able to remove the bearing housing at the tailstock end, pull the leadscrew from the gearbox and withdraw it through the apron to the right.

Pictures of your machine are worth a thousand words.

 

[rjs44032]

Hi Clockman44,

Yes you must remove the end bearing and then free the leadscrew from the gearbox end. There should be a tapered pin in the gearbox shaft or the leadscrew somewhere near the gearbox. Sometimes these blend into the shaft and are difficult to recognize. You must remove it by tapping it out from the small side of the taper. Be careful to determine for sure which side of the pin is the small side.

If it is not threaded, it will come out of the leadscrew by closing the half-nuts and carefully moving the carriage until it is free. If it is threaded into the gearbox shaft, you will need to find a non-marring way to free it, using the non-threaded end of the leadscrew. I have never seen one that was threaded so if you have one please post some pics when you have it out.

Once the leadscrew is free, try to avoid the temptation to pull it out of the apron. That is the only thing holding the worm in and there is a lubrication tube for the worm that could be damaged if you do that. Keep the half-nuts closed until you reach the bench and have a chance to observe what's there before releasing it. I hope this helps.

Below is an image of a typical Sheldon leadscrew notice the pin-hole in the shaft at the gearbox end.



The gearbox below looks like mine. My leadscrew has a bore at the end and the pin goes through the leadscrew and the gearbox shaft end.



Best Regards,
Bob

 

[Clockman44]

Hi Clockman44,

Yes you must remove the end bearing and then free the leadscrew from the gearbox end. There should be a tapered pin in the gearbox shaft or the leadscrew somewhere near the gearbox. Sometimes these blend into the shaft and are difficult to recognize. You must remove it by tapping it out from the small side of the taper. Be careful to determine for sure which side of the pin is the small side.

If it is not threaded, it will come out of the leadscrew by closing the half-nuts and carefully moving the carriage until it is free. If it is threaded into the gearbox shaft, you will need to find a non-marring way to free it, using the non-threaded end of the leadscrew. I have never seen one that was threaded so if you have one please post some pics when you have it out.

Once the leadscrew is free, try to avoid the temptation to pull it out of the apron. That is the only thing holding the worm in and there is a lubrication tube for the worm that could be damaged if you do that. Keep the half-nuts closed until you reach the bench and have a chance to observe what's there before releasing it. I hope this helps.

Below is an image of a typical Sheldon leadscrew notice the pin-hole in the shaft at the gearbox end.

View attachment 302806

The gearbox below looks like mine. My leadscrew has a bore at the end and the pin goes through the leadscrew and the gearbox shaft end.

View attachment 302808

Best Regards,
Bob

Thanks Bob, I knocked the pin out at the gearbox and then took the leadscrew loose and the apron slid right out. I now have a problem on the back where this shaft goes into the gearbox housing. The brass bushing is worn and needs replacing. How do I go about getting this shaft out. I have taken all the set screws out, but not sure to try and tap it out from the opposite end or not. (of course putting the nut back on before I tap it) My lathe looks similar to yours, maybe newer. It has two quick change gears in front. Thanks for all the help....(Tommy)...clockman44

 

[rjs44032]

Hi Tommy,

My gearbox had no issues since purchased. So I've had no reason to disassemble it. I did have to repair broken gears in the apron. That's why I knew how to remove that. My machine is an early EXL (10") from 40s.

Let me know the number stamped on the QCGB for your lathe Model # (might be named Catalog No. Then I will see if I can get a parts manual for you. That will provide a break-down of the QCGB.

Also if you haven't done so, I recommend you join the SheldonLathe yahoo group. It's free and one of the members John Knox was an engineer at Sheldon back in the day.

Best Regards,
Bob

 

[Clockman44]

Bob, I got the lead screw off, only to discover that the needle bearing at the end of the housing is, well the needle bearings are gone. Can you still buy parts for the Sheldon lathe. I took two sockets and a 3/8" threaded rod, two washers and two bolts and ran it through the housing and pushed the old needle bearing housing out. Now I need to replace this. Is the Sheldon lathe Co. still in business or do you know where I may could purchase this needle bearing (part # 81, #A-1189, Torrington Needle bearing) in the parts manual I have. Thanks, (Tommy) Clockman44

 

[Choiliefan]

You should be able to buy a new bearing from any supplier such as Motion Industries. All you need is the diameter of your shaft, length and OD of the bearing.