Quote Originally Posted by BuffaloJohn View Post
which is a multi range gearbox for a lathe. How might your design work on something like this?
It would probably work fairly well. Particularly with the low range for threading. But really modern lathes (except for the giant stuff) should only come with perhaps a 2 or 3 speed gearbox. You can go on eBay/Amazon/whatever and pick up a VFD for a couple hundred bucks. Then you have infinitely variable speeds with gobs of down low torque. I have an older lathe that I just leave it in some intermediate speed and vary the VFD frequency. I'll go 6 months without ever touching the gearbox. If you don't have one you should look into it. If you do a lot of work on a lathe it will change your life. It'll run off of regular single phase power, but you need to have a 3 phase motor installed.