Originally Posted by
datac
motor drivers often have very small windows of time to accomplish things. one of those important things happens to be DIRECTION timing. a definite, repeatable loss... the kind you have indicated could show that during direction change timing, the driver MISSES one or more step pulses each time direction is changed. you need to find out exactly what timing requirements are for the motor drivers you are using, then make sure your control software reflects those exact settings.
If by chance your X and Y settings are identical, and also correct, I would swap your X and Y motor drivers, then re-test your 50 moves. if the driver has an issue, your step loss should have moved to the other axis because the drive moved.
if you have repeatable and reliable step loss... like .005" in 50 moves and subsequently, .010" in 100 moves, you MUST solve this first before worrying about any hardware issues because your problems will never go away.... only get more confusing. what you really need to base your findings on though is number of DIRECTION CHANGES...... that is the moment that usually creates repeatable lost steps.