Rebuilding Half Nuts

[benmychree]

Rather than depend on epoxy to retain the inserts, I machine flanges on both ends of the insert that are large enough to allow use of rol pins parallel with the axis of the inserts to retain them, I also make a plug gage the same dimensions as the lead screw to fit the new threads and also to set up the old half nuts on center to bore them out. Brass is a poor material for half nuts, better would be bronze or best, cast iron, which I have used on several half nuts that I have rebuilt.

 

[ltlvt]

Ive got a 9" South Bend Lathe with worn out half nuts that id like to fix before I sell. Has anybody done that themselves before? Any pointers for fixturing?

Note: I've got a really nice south bend 9 lathe and a south bend shaper at my disposal for fixing them.

I rebuilt the half nuts on my Model 100 Clausing but only because you can no longer buy replacement parts for it. I am pretty sure Southbend sells replacement parts for your lathe. I would recommend buying new ones if the lead screw is still good. If it is worn a new nut will only fix part of the problem. I would be checking the lead screw at the end nearest the head stock with an acme thread gage. The gage will tell you what condition the lead screw is in.

 

[Jimsehr]

Search this site for Evanut Has HUGE info about half nuts.

 

[RaisedByWolves]

Yep! Thats them! The actual machining isn't really that big of a deal but how do you hold something like that!

Start with a solid block big enough to get two halves out of and square it.

Drill and thread the nut halves as one unit.

Add in other features necessary for proper operation, then cut in half.

Now remove whatever else is in the way of proper operation and you're done.


ETA: Beat by RJSakowski

 

[ltlvt]

Start with a solid block big enough to get two halves out of and square it.

Drill and thread the nut halves as one unit.

Add in other features necessary for proper operation, then cut in half.

Now remove whatever else is in the way of proper operation and you're done.


ETA: Beat by RJSakowski

Zackly