@cncdrive: I am thinking the same but more along the lines of something changed that's causing noise coming from the breakout board. I have done my best to verify that everything is grounded. @ger21: I just tried your suggestion and the servo still keeps turning with no stop in sight. When setting up the servos, I was sure to uncheck the "Start at ABS Zero" option checkbox. Initially, I thought it might have something to do with the safety circuit I implemented based on @weerasak's response here: http://forum.cncdrive.com/viewtopic.php?f=4&t=1242&start=20#p10138. In order to use his method to implement safety circuit, I changed from using the ALM out pin#18 to the BKO out pin#19. I reversed this change and disabled the safety circuit and still noticed no change in the behavior.
Here's another video of the X axis doing something funny as well...I am not using the software's backlash settings but the X axis seems to be turning in the opposite direction of the jogging direction once the job is stopped. A detailed video here: .
Paul Davis 5x10' CNC Router UCCNC, ETH300, UB1, DMM Servos
But if you remove the step wire from the breakout board to the drive how Gerry suggested and the motor is still moving then the issue can't be the UCCNC, because the step wire is where the UCCNC is sending the movement command. If that wire is unconnected then the movement is not commanded by the UCCNC.
Problem resolved. We are using 3x DYN4 drives to move our router's X, Y and A axis and 1x DYN2 drive for the Z axis. The culprit was the servo ENA circuit on the DYN2 drive (see drawing below per manufacturer). As soon as I unplugged this circuit, the system stabilized. Next, I will be trying to figure out how to get this to actually work without the circuit causing interference.
Paul Davis 5x10' CNC Router UCCNC, ETH300, UB1, DMM Servos