Please leave the servo motor disconnected for the moment. If you leave the motors on for a while, do they get hot to the touch? As in, not slightly warm, but hot?
Second: Please try the “preflight” test from the user guide– with USB and power disconnected, turn the motor winches through the full range of the machine, to test to see if the motion is smooth and consistent. If it is not, then there may be a problem that is independent of the motors and control system.
