I was looking at Terry1956's machine earlier this week. It's a Sieg X1 and appears to have 3mm pitch trapezoidal leadscrews. Drivers are set to 1600 microsteps/rev, and Mach3 was configured with 533.333 steps/per. System set to mm, of course. We didn't actually measure movement at the time. I would double-check that the steps/per figure is still set OK, just in case something has changed there. Certainly not obvious why that gcode shouldn't run just fine, though.