Lead Nuts for an Old Mill

[firbikrhd1]

I have an old Index Model 40 mill that had very worn lead nuts. Although the manufacturer still supports the machine the price for new nuts was beyond what I was willing to pay. Besides, I needed a new project to work on. I purchased generic led nuts of the proper thread from a supplier for far less than the manufacturer wanted and made these mounts for them. I can easily purchase new ones in another 60 years or so to replace these when they wear out.

 

[firbikrhd1]

Thanks for the compliment Dalee. I was surprised and fortunate that my screw wasn't worn badly. With regard to your worn screw, you could have put it between centers and recut the original thread a little wider which would have at least made the worn screw uniform throughout it's length, then made a custom lead nut to fit the screw. Since you had to make the nut from cored bronze stock anyway the only extra work would have been recutting the screw threads.
Another option may have been to buy some Acme screw stock and graft it to your original screw. Then your new nut would have fit perfectly without "fudging".


Jim B, maybe it's the picture, that bottom screw almost looks like a square thread, the top like Acme, the top one must be the original.

I wonder if you could have coated the inside of your original nut with a release agent and poured it full of a casting material, taken it out of the nut after it hardened and use it as a gauge to grind a tool for cutting a thread on the new screw. It looks like you did a good job on the new screw anyway, and the .008" backlash is proof.