This short clip shows my lathe making a handwheel to put on the back of a stepper motor. This conversion is UGLY as it was done on a whim from parts I had laying around. The motor mounts are based on the plans on the JFettig Machines website and bolt right on. I didn’t have any proper flex couplings so I homebrewed a couple with a hacksaw. They aren’t pretty but they work pretty well!
The motors are 125oz unipolar driven by a HobbyCNC Pro board left over from a router project. The controller is Mach 2 running on an old Dell laptop and the G-code for this was written by hand.
Despite being kind of a hack job, the results are surprisingly good. There is a ton of backlash in both X and Z which would cause trouble if trying to hit the numbers with any real precision. I’m so happy with the results that I am probably going to go back and make a bearing block for the X screw and am thinking about a ball screw for the Z axis. I’d like to add a spindle encoder so I can do threading and that needs good speed on the Z axis.
The cutting tool used here was a CCGT insert for aluminum running at 5 IPM and a .010″ DOC and ~1000 RPM. The finish pass was .005″ at 1IPM. The video doesn’t show it real well but this setup gave a wonderful near-mirror finish, better than I’ve ever gotten on this lathe.