Hi guys,
this week we had an accident with our MH50/DX100. As a result, an U axis encoder was torn off its place. Actually, a mechanical damage to the encoder turned to be not so hard, the most serious problem was a destructed plastic coupling between the motor and the encoder shafts, so we managed to repair it using the epoxy glue. Naturally, the position of the encoder shaft w.r.t. to motor was lost, as well as ABSO data. Nevertheless, after setting the encoder in its place, I created a new home position, and after some tuning of the ABSO data for the U axis in the "Home Position" screen the robot ran again just normally. After some hours of production I inspected the repaired encoder and it seemed to produce an unusual sound (maybe that was just a wrong impression).
Today we decided to see if there is something wrong with the encoder or the coupling, so we took it off. I thought that the recovery after such an inspection would be not harder than after the accident, so I set the robot in the standard home position (L axis vertical, U axis horizontal), hoping that it would be sufficient to re-create home position after the encoder position change and possible ABSO data loss, as long as robot did not move. The repaired coupling looked nice, but after setting the encoder in its place, the problems started.
After the initial accident, all the axes moved only when I pressed jog buttons. Now when I turn servo on, the U axis starts moving by itself, and after some tenths of second stops abruptly (the brake turns on), and I get an alarm 4327 "Wrong motor rotation". At first, each time this happened, the U axis moved downward, i.e. in its "-" direction. At some moment I put a wooden support under the axis, so now when it reach this support, the next time I turn the servo on it moves upward. And the next time - downward again.
Have you any ideas?
Best regards,
Michael