Hi all. I have a diy router with twin screw on the x axis. When I move in the negative direction all is fine, but when I move positive the axis stalls. The axis is belt driven by one motor. I have removed the belt and the motor moves both ways perfectly so its not an electrical issue, and I can move the axis by hand along its whole travel easily. I have made sure the screws are both tight and can find no play anywhere. Please help