Just got the robot running. Running AR2 software. Able to jog all motors forward and back. Went to Auto Calibrate and this didn't look right. So decided to Calibrate each axis independently. J3, J5, J6 work correctly. J1,J2,J4 do not. They go forward then back a little, if I try to calibrate again it moves forward then back a little. Eventually I need to manually rest the position it moves forward more than back. Not sure what to check first?