View Full Version : Half nut repair options ???
03-22-2005, 04:12 PM
It has become obvious from the problems I have been having cutting threads that I'm going to have to repair/ replace the half nuts on my 1340 Standard Modern lathe.
I called Leblond(parts distributer)new parts are available at $410.00 plus shipping, tax and whatever fee the brown guys feel like imposing this time:-((
I have thought of Moglice, or boring out the threads and installing some sort of brass nut insert.
Has anyone got a suggestion?
What have you seen that works.
I'm not adverse to spending the coin if there is no other option, but I need to know IF there is any other viable option.
03-22-2005, 05:17 PM
I have seen half-nuts repaired on South Bend Lathes (9 inch/10K's). This was done by boring out the old threads and epoxying in a brass/bronze nut with the proper Acme thread. Then the nut is split and the oil holes re-drilled.
The main problem will be building the jigs needed to hold everything ridgid so you can bore out the old threads.
03-22-2005, 07:44 PM
There was an article on using Moglice in a recent issue of HSM. Sounds like an ideal application.
03-22-2005, 08:01 PM
I have taken the nut halves out,made a fixture to hold both parts in alignment(these were dovetailed)brazed the old nut halves up,rebored the two while clamped in the jig and then ran an acme thread tap to make the threads.Once it was back on the lathe I went to the end of the leadscrew furtherest from the chuck and coated the screw with plain white toothpaste and used the leadscrew to lap the nut to fit.The toothpaste is real mild in it's cutting action and disapates rapidly.
But,given the time and the exspense of the tap,$410 doesn't sound too bad.
You maybe could cheat and use a friends lathe to bore the thread in the built up nut thou.
03-22-2005, 08:10 PM
Do you have a picture of the halfnuts? I've got a set taking up space. I don't know what they go to but they are large. Might be worth a look-see.
03-23-2005, 07:59 PM
Thanks for the thought,but I haven't got that far yet. I fixed some slop in the lead screw attachment, but haven't removed the apron yet.
From what I can see they are the style that slide in a dovetail, not open like a clamshell in the south bend style.
03-23-2005, 08:47 PM
Here's one shot of what I have. If it looks anything close, I'll post a couple more pics. These are brand new. There's some surface rust but will clean up nice. Like I said, I have no idea what they go to. They were in a box of stuff from an auction.
[This message has been edited by CCWKen (edited 03-23-2005).]