Machine-
Torchmate Small Shop Machine
3-axis stepper motor drive
USB Torchmate stepper motor controller
DeWalt 2.xxhp router, 8-24krpm
Software-
Torchmate 3 w/ Flashcut
Windows 7 Pro on Lenovo laptop
Cutting-
Polycarbonate
1/8in two-flute carbide router bit
98IPM
0.020in DOC
Issue-
I'll set up everything to run for an extended period of time with a large amount of cut time (vs rapid moves) and it will go fine for some time, but eventually the Y axis (the axis carrying the largest load) will appear to totally 'spazz out'. I.E. the machine will offset from its normal tool path, go through full-thickness material in a hap-hazard manor, and generally muck everything up. Nothing is repeatable other that it appears to be the Y-axis screwing up. After a screw-up it will continue onto the next cut as if nothing happened, but now with the Y coordinates offset.
Mechanical overload?
Stepper motors slipping?
Stepper motors overheating and slipping?
Any thoughts or suggestions on what to try next?