After converting a unimat lathe to cnc for my buddy, I decided that my own 7x12 mini lathe needs to be converted too. I had this short thk kr26 linear stage that I got for about $40 on eBay. To small for anything else but perfect for the lathe cross slide X axis. The carriage Z axis is a 10mm diameter THK ground ballscrew purchased from eBay for $115. Stepper motors are 300oz-in nema 23 that was given to me. Stepper drivers are Gecko210 also purchased used from eBay for cheap. Power supply is a diy 36 volt output from a transformer salvaged from a old broken desk lamp.
Backlash on both axis is minimal due to the high grade THK ground ballscrews. Rapid speed is set at 100ipm. I had tested it at 200ipm but thought that was ridiculously fast for such a small lathe.
Mach3 Turn running on a old P4 desktop using parallel port step/direction output.
In the video roughing pass is at 5ipm and the finished pass is 1ipm.
http://youtu.be/zuGZxvZJS_wFirst time threading
http://youtu.be/2HpvWgHT8To