Im new to robotics so probably wrong but i thought with the closed loop servo feedback you could turn off motor possition hold and use the arm itself as a teach pendant? Ive just seen it possible on other small arms.
I have never seen that much backlash in the Nema 11 gearbox for J4. When you say gear and belt are good I assume you mean the sprocket is not slipping on the gearbox shaft and set screw is tight?
I have ordered a new stepper because it seems like there might be a bad winding. Moving J4 in 1 degree increments has problems. Sometimes the stepper moves and sometimes it doesn't. Will let you know if that cures the problem.
