Question for you. How do you know when a stepper motor is bad? I have been having a horrible time with my Y axis losing its zero reference while cutting a project. I spent quite a bit of time trying to isolate the problem and thought I had it narrowed down to Mach3 and/or my computer. I replaced my computer, reinstalled Mach3, and spent several days tweaking the motor tuning to what the Mach3 tech support staff told me to do and I am still having the problem.
I have also noticed that when I am moving the Y axis from front to back it freezes on me in several locations when moving it at 100ipm. However, it runs fine from back to front at that same speed. I have never had a problem with this in the past. I have also taken the machine apart and checked that there was no mechanical binding the entire range of the Y axis in both directions.
Slow down the Z axis to 50IPM (or 20 or 10). Slow down the acceleration. Run some tests. If OK at slower speeds – start bumping up the speed. Is your power supply doing it’s job?
If you think the problem is a stepper motor I will be happy to buy some replacement units from you.
I’m happy to sell you one, but I’m not convinced it’s the motor.