I’m using a MP6500 with a 400-step motor and 8 microsteps, and am having a slight accuracy issue. The first movement after a direction reversal doesn’t quite stay in registration - it appears that the move is about 3 microsteps short. Looking at it in slow motion (e.g. 1 microstep/sec), it seems that the driver is providing the impulses OK, as I can hear the clicks from the motor. But the first 6 or so microsteps are smaller than the normal size, resulting of course in a slightly smaller overall movement. And this movement loss is quite consistent (both ways), and only occurs immediately following a reversal - same direction moves are OK.
So it doesn’t seem to be a driver issue. I have also tried to eliminate the possibility of friction or slack in the drive setup, by manually tweaking the load prior to the reverse move. Might it be a characteristic of the motor?
I wondered whether this phenomenon had been noticed by anyone else, and if there are any ideas on how to identify and resolve it.
I can make a correction by adding (e.g.) 3 microsteps whenever the motor is reversed but that is sub-optimal for a couple of reasons, and this is addressing the symptom and I would like to know the cause.
Any thoughts would be welcome.