I have had a Sherline CNC lathe with a 24" bed (approx 16" of Z) for a few years. It also has a 13" cross slide (also known as a Sherline mill table). My plan is for gang tooling at some point, mostly just for fun. That being said the Sherline is quite a capable and convenient machine for the jobs it is capable of. Anyway like other Sherline owners, I want to modify and or attempt to improve on the original product.
(1) Stock Sherline couplers gave me a problem or 2 over the years.
Either they were frozen to the stepper shaft upon disassembly and required forces that destroyed the coupler.
The taper of the leadscrew and the coupler didnt have enough contact area and therefore slipped (regardless of technique employed to insure their fit, more on that later possibly).
The shaft of the coupler or lead screw would physically break, both have occurred. Of course at different times.
Upon disassembly of the CNC stepper mount (stock Sherline stuff) I notice the inner bearing stands proud. The bore accomodates the bearings ID but not its flange. Since I am improving things, this will be first. My intent is to bore the mount to allow the bearing flange to seat flush. This in turn will allow me more room for the next iteration of coupler.
Before
Attachment 250778
After
Attachment 250780