I'm using RAMPS 1.4 with ultimachine's sprinter firmware for mechanical endstops and when I attempt to print with pronterface, my X axis goes home to its endstop, touches it, moves a few milimeters away, then back towards the endstop and keeps going. I can hear the motor straining when it does this so I usually switch off the power within a few seconds.
My endstops work perfectly when I manually move any axis in pronterface, does anyone have any idea what might be wrong? Any help is appreciated!