Fabricating a Forward and Reverse Tumbler for a 1937 South Bend Junior Lathe

[Sigung]

This is my lathe.

This is the broken forward - reverse tumbler

I don't have the missing piece that broke off, it was lost years ago, I inherited it this way. There are none available on eBay that fit my lathe, so I'm thinking of fabricating one.

Being so new to machining that I have only just begun to understand how this lathe works, I'm wondering if it's possible to machine the body of this tumbler out of something like aluminum or a mild steel.

 

[T Bredehoft]

You would be better off finding someone who would make it for you. While some might say it could be made on your lathe, as a neophyte, you would become discouraged long before it began to take shape. Ooops, without it in service your lathe could not make it. I expect there are members here who may have one as a spare, or could make one for you, but they will have to make themselves known to you.
Yes, it could be made from Aluminum or Mild Steel, the latter would last longer, (either would outlast you).

 

[Sigung]

Well, the tumbler is actually in service and it works, but only in the normal forward direction. The broken part is where the reverse gear goes. Obviously having the reverse would be a plus..I don't know how often it's useful in machining, but I'd like for the machine to be fully functional as it was intended. If anybody out there is interested in fabricating it I'd certainly be open to that.

 

[Manual Mac]

Dang dude, about 50 or more yrs ago I lived in Sweet Home.
among other things I was a Chokerman for Tack Logging under the Madill yarder.
I suspect I wouldn’t recognize the town now.

 

[Sigung]

Well, the town is surviving the logging bust beautifully, and it has one of the most affordable new home markets anywhere in Oregon. Getting hot here in the summer, though. We had several days over 100 last summer, and this week, we've had several in the upper 90s.

 

[markba633csi]

Why not just repair? That is what I would do. It would take some careful measuring, grinding and welding (or brazing) but it looks quite doable

 

[Sigung]

Why not just repair? That is what I would do. It would take some careful measuring, grinding and welding (or brazing) but it looks quite doable

As I said in the original post, the broken off part is missing and has been for years. There is nothing to repair it with.

 

[markba633csi]

No problem, you fab a new piece.
The first step would be to make a template (out of cardboard for example) so you can accurately locate the position of the original hole.
Next you would do some grinding at the break to profile the area to accept weld filleting. Then fab a matching piece out of cast iron or mild steel and
stick it on. Or have someone stick it on for you, if you don't have welding skills and equipment. A bit of filing and drilling and you're done.

 

[mattthemuppet2]

That's what I'd do ^. I don't have a welder or OA kit, so I'd drill/ tap/ pin the new piece on. Looks like there's plenty of meat in the casting to do so.

 

[Sigung]

I wouldn't have the faintest idea of how to do waht markba633cis is suggesting. My research indicates that cast iron cannot be welded, so there's that...