Prototrak MX2 Axis Fault

[ps15]

Greetings.
Let me begin by saying I've already investigated this topic on the forums and looking at the brushes on my troubled motor was the first thing I did.

Full Story: Y-Axis started giving me obstruction fault randomly. Eventually it would not move at all, giving me a fault code every time. Here's what I've done so far.
I removed and cleaned 3 out of 4 brushes on the motor. I couldn't get to the fourth one because the encoder housing was blocking it and I didn't know how to proceed. One brush was tight in its hole and much dirtier than the others with a minor chip in the corner. I cleaned them and blew loose carbon from inside the motor with compressed air only.
This part is a bit weird. I swapped the X and Y cables at the ports outside of the drive cabinet. Jogging Y should now move the X and jogging the X shouldn't move, so I thought. This resulted in the X axis moving a little bit and faulting and the Y would still not move.
I replaced the cables back to their correct positions and ran service code 100 for open loop test. I ran this test on X and Y. The X worked fine. The Y did not move at all.

E-Stop is not pressed, machine is lubricated, ways are loose. Pins in both cable connectors look good.
Are there any other tests I can do to figure out where the problem is? I'm going to go mess with it some more. Thanks for reading.

 

[ps15]

I think I figured out why the "good" axis faults when I switch cables. I believe since the sensor wheel isn't moving (I didn't swap sensors) it thinks its blocked and cancels the jog. Which isn't weird after all. 90% sure my motor went bad but why?

 

[Billtodd]

Could be a dead motor (I have replaced them in the past) . I'd remove the motor and bench test it. From memory they are 100 and something volts . I can't recall now if they are the , not so permanent magnet type or not (i think they are) . The magnets can get erased by the switching motor current .

Last machine I fixed , I swapped the Z for the faulty one and replaced the Z motor with another slightly smaller motor purlioned from ebay, replacement swi motor's being unavailable.

 

[ps15]

Thanks for the reply.
I'm all for buying a replacement motor but the cable from the drive to the motor is hardwired into the motor. If I bought another servo motor I don't know how to make sure the connection is compatible or any issues with the encoder.

 

[Billtodd]

The motor is just a dc servo motor so two connections (if you get them the wring way 'round the motor spins like a loon - don't ask me how I know 8⁠-⁠))

I had to drill the motor shaft and attached the encoder to the replacement motor , but other than that it was fairly straight forward.

 

[Mrw]

It is more than likely the servo driver. You can easily test by swapping it from the other motor.

 

[mcorbett]

I just had this problem after we swept the floor and lifted the servo motor cable. The wires inside the servomotor were moving and lost contact to the encoder board. Moving the cable cause the encoder data to be lost. The way to see this is by entering service code 101 for X axis and 102 for y-axis. This will allow you to see the glass scale and encoder data at the same time. It shows the glass scale date on X or Y readout and the encoder data in the Z readout.

BTW I have an MX2 servomotor that has a burned out encoder. I have been meaning to fix it so that I have a spare. If you are interested in buying it let me know.