Y axis motors work fine for while than one seems to freeze up throwing the x axis out of whack.Dont think it is a mechanical issue secured motor couplings very thoroughly. I also soldered motor wires to shielded cable wires that came with the kit..Attached a video of it occuring.
Adjust Max Rate down a little in Grbl settings. Motor stalls because its going too fast. As steppers pick up speed, torque drops off (self braking Back EMF)
Did you mean the values on lines $110 , 111,112 120 121 122 or the jogging speed and if you change the maximum speed rates will that change the acceleration rates as well
would be $111 Y Max rate, mm/min for the Y axis gnea/grbl Leave acceleration as is, it stalls when its already up to speed from what I can see in the video. You would have changed acceleration if it stalled while still in the acceleration phase earlier in the move, but doesn't look to be the case here.
9000 is belt speed More like 6000-7000 for a leadscrew based machine with tension, or 5000-6000 without tension
Ok Peter ran some gcode of a square with four holes for a test cut ,square came out perfect but when it went to do hole pattern started doing that squealing shift again, have slowed the maximum on the x and y to 6000 but it is still happening. Could be happening on the accelleration mode this time as it moves from hole to hole.