What is the best way to turn a ball screw in the mini lathe? I have to turn one down for my Fignoggle CNC conversion I am doing for my mini mill, and it is chipping and dulling my carbide tips pretty quickly :-[
What is normally done is the ends are annealed (softened) then machined then heat treated. If that's not an option try a negative insert with a tough grade of carbide like a Kennametal KC850 & run @ 50 sfm dry. If your finish changes from shiny to dull your part is case hardened & you broke thru the case.
Rigidity is the key - spindle, holder, ways, feed screw, etc. Good luck.
The other option is if you have ( or have access to ) a tool post grinder you can grind the ends to size. I imagine this would be a lot easier on the mini-lathe, but would most likely take longer than regular turning.
Depending how hard the ballscrew is it may be the only option if carbide isnt cutting it.
Haven't been able to check this site after I first posted, but this is how I ended up completing it. I don't know if it was right or wrong - and I hope i didn't warp anything - but first I ground the threads off with my bench grinder, then took a propane torch and heated it until it turned red, then plunged it into a bucket of cement mix (it was sitting in a bucket from where the bag broke) and let it cool for an hour. Chucked it back into the lathe and it turned very easily!