In this application, I'm applying the same external torque whether the motor is rotating cw or ccw. When the motor is rotating cw the motor is rotating against the external torque and every thing is okay. When the motor is rotating ccw the motor is rotating with the external torque and skipping occurs.
I theorized that the motor is skipping as the coils are sequenced to advance to the next step and the external torque is acting to accelerate the motor right through the intended next step. In an attempt to validate this theory I added a small amount of friction to the applied torque in an attempt to dampen (reduce) the acceleration caused by the external load (no other changes were made). It worked, the system now works properly in both direction.
I'm now wondering if I can correct the original skipping problem by using the acceleration/deceleration functions available in the AccelStepper Libary?
Any thoughts or input you may have would be appreciated.