I had this problem, but the solution to me was to simply supply power from the supply and not just and the computer. Also check that your coplings and gears and tight on the shaft.by piesafety - Reprappers
So, i have my endstops working and such, but the problems is that when the axsis is homed, the head continues to move even though its triggered, and the oddest part is that after moving for 2 seconds, it then completes the homing procedure. And solutions would be appreciatedby piesafety - Reprappers