Quote
bobc
There is an issue with homing, which doesn't always seem to work, and I get lots of position shifting during printing, even at low speed/accel. I couldn't find a combination of settings that worked. I suspect it may be something to do with step doubling, because there doesn't seem to be any motor stalls, the print head just goes to the wrong place.
Your Repetier symptoms are very similar to what I started getting on my delta after bundling my wiring together creating cross-talk from my extruder motor wiring into the endstops. The extruder would crash into the bed slowly, homing was unreliable and prints ended up tilted and with random level shifts. This was confirmed by disabling end stop checking during moves which fixed all the above.
you can quickly test this by disabling the function in configuration.h
#define ALWAYS_CHECK_ENDSTOPS false
I will probably go back and use shielded motor cables but as end stops should only be needed for homing I have left end stop checking off with no problems at all.