16” Lead screw play

[ironwrx]

Hi, I recently acquired a 16” SB lathe, which has about 1/4” end play in the lead screw. A friend has a 14-1/2” slightly newer machine and he has a ball thrust bearing where the lead screw goes into the gearbox. Mine has no bearing there, and has the play. What can be done about this?



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[SLK001]

You're missing a part somewhere, maybe a washer with shims, or even thrust bearings. Need model of your lathe.

 

[pontiac428]

That's unacceptable. Lead screw play should be several thousandths, not several hundred. Usually, play is adjusted with a nut at the far right bearing support. Modern lathes have thrust bearings, older lathes may have bronze washers. Same result.

 

[benmychree]

There may be a loose nut inside the change box Get a mirror and flashlight and have a look from underneath.

 

[ironwrx]

You're missing a part somewhere, maybe a washer with shims, or even thrust bearings. Need model of your lathe.

Hi. Thanks for your input. Model 8117C
Serial #1973HKR8 I’m guessing there used to be a bronze thrust washer there. Maybe I can get a thrust bearing?


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[ironwrx]

That's unacceptable. Lead screw play should be several thousandths, not several hundred. Usually, play is adjusted with a nut at the far right bearing support. Modern lathes have thrust bearings, older lathes may have bronze washers. Same result.

On this lathe, there is no nut at the far right lead screw bearing support. It just has a plain end on the lead screw.


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[SLK001]

On this lathe, there is no nut at the far right lead screw bearing support. It just has a plain end on the lead screw.

It's on the part of the lead screw that is inside the gearbox. You might have to unmount your gearbox and LS and check that everything is tight. If it is, machine a brass or bronze washer to put in the gap on the outside, so it will be available for oiling. You have the single tumbler GB, so there might not be enough room on the inside. If there is, a thrust bearing might be able to fit.

You also might want to get the Ilion book A Guide to Renovating the South Bend Lathe Models 10L - 13" - 14 ½" - 16". It will be a valuable resource when working on your lathe.

 

[ironwrx]

It's on the part of the lead screw that is inside the gearbox. You might have to unmount your gearbox and LS and check that everything is tight. If it is, machine a brass or bronze washer to put in the gap on the outside, so it will be available for oiling. You have the single tumbler GB, so there might not be enough room on the inside. If there is, a thrust bearing might be able to fit.

You also might want to get the Ilion book A Guide to Renovating the South Bend Lathe Models 10L - 13" - 14 ½" - 16". It will be a valuable resource when working on your lathe.

I do have the book you mentioned. Thx.


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[MrWhoopee]

This is on my Heavy 10, the collar next to the gearbox has a ball bearing inside.