Sebastian Lathe

[CJ5Dave]

Got this 16 x 36 Sebastian lathe from a friend. His father bought it to use in retirement and never set it up. It is 3 phase and I have the converter sitting in the floor ready. Lathe has been in an old shop for 25 years or so. Good bit of surface rust on ways. The cross slide screw is bent. Maybe I can straighten it enough. The dovetail in the cross slide is about 1/2 inch too wide. Seems to be missing a spacer dovetail from the slide. Also 2 of the 3 chuck tightening screws are missing the worm gear. Wondering whether to use oil and steel wool on ways or derusto and scotchbrite. Good winter project if I can get it in the shop. Took it to the Coop scale and it weighs 2200 lbs. Also need to change the gearbox oil. Without a manual I am thinking 30 wt non detergent motor oil if I can still find it.

 

[benmychree]

The missing cross slide piece is likely a tapered gib. Personally, I would gp at the rusty ways with a carbide scraper, it looks awful, but it may be OK with surprisingly little work.

 

[CJ5Dave]

Crossfeed slide with missing gib. Looks like the toolpost slide is the identical part. I would think some other brand might have a similar gib.

 

[CJ5Dave]

It runs. Goes through the 8 speeds fine. Gearbox oddly is filled with 90 wt oil. I was expecting 20 or 30 wt.
Serial number appears to be made around 1942.

 

[Harry Knutz]

The gearbox most likely has water in it. I would check everything inside the gearbox before you get too carried away.

 

[benmychree]

It would be good to empty the gearbox and flush it out with solvent, and use a more appropriate oil, 90 weight would likely cause the bearings to overheat., I'd think somelike a medium weight turbine or hydraulic oil.

 

[Harry Knutz]

Anything above the oil level will be rusted and or pitted, That machine looks like it was outside for a very long time.

 

[CJ5Dave]

Really the gearbox is great on the inside. Never set outside . The lathe has been in an unheated shop for 25 years. Here is a better cleaned up photo. The ways are cleaning up pretty good. New issue is the crossfeed nut is usable but worn. It is left hand acme 3/4 8 tpi. Not sold in stores. Anybody know another brand that uses this crossfeed nut pattern?

 

[benmychree]

Likely you will have to make one, how much backlash is there?

 

[CJ5Dave]

I will know when I get the gib made, which is at the machine shop now.