7x CNC lathe first real part

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.
Video Rating: 5 / 5

sansbury95 says:

November 29, 2011 at 5:41 pm

Oh, and CNCFusion has a kit now, and it costs as much as the lathe. I’m sure it’s well-made and the price is understandable, but you’re probably looking at $1700 all in by the time you’re done (lathe, cnc kit, motors, drivers) and for that kind of money I’d rather buy a good larger manual lathe with quick-change gearbox, power cross feed, big iron rigidity, etc. CNC’ing a 10×22 would probably not cost a ton more and you’d get a LOT more machine.

November 29, 2011 at 6:37 pm

@rushymoto Nope, stock leadscrews. Decided I’d try that first and add fancy ones if needed, so far, not needed. Unless you need to do accurate curves you can compensate backlash pretty well as lathe cuts are mostly in one direction with no reverses like you have on a milling machine.