Our system operates on v1.3 and we’ve continually updated out OS [currently 9.1.2]
Since fall of 2018 the system operated smoothly. Fall of 2019 the z axis developed an issue in moving in the positive [up] direction. When given a command to move up, it chatters loudly and actually falls in the negative direction. If assisted by hand [use hand to provide upward lift] it will complete the movement command. Movement in the negative [down] direct functions smoothly and without noise.
In default motor settings the issue occurs. In modified Z settings [max/min speed = 150/50; accelerate = 450;steps = 25; microstep = 1] the issue is the same.
I have used new stepper drivers and swapped the motor - issue was unchanged. I have checked alignment of v-wheels, lead screw bracket, and the coupling.
All other X, Y, and Z [in negative direction] work fine. Clearly the stepper motor is not able to pull the z axis upward.
Is there a way to increase the torque of the stepper motor?
What other options are there to get the power needed from the z axis stepper motor?