Yup, it's step skipping. Right off the bat I'll tell you that (it seems like) printing faster (80mm/s print and 250 travel) or slower (20mm/s print and 150 travel) doesn't change things very much. It's more or less 0.3mm of skipping, and it's on the X-axis. The motor is warm (35-40C?) and the A4988 stepper driver's heatsink is cool with the fan I have blowing on the electronics. I can't think of anything specific that would be causing these issues, but they seem to occur very infrequently and it hasn't caused a print to fail yet. So far it's only affected the looks of figures I've printed, but I fear that for large prints it could cause things to not fit together. If you've had this kind of issue, what caused it?
Applicable machine information:
Folger Tech FT-5 kit
MKS Gen 1.4 Controller
A4988 Stepper Driver
Single NEMA 17 5.0kg/cm Stepper Motor for x-axis
Linear Rail for movement
