Gould servos--maintenance question

[Tom Curran]

Hello all, I have a Tree Journeyman 320 with Gould servos (ser. 985-393, 12.5 amp stall).

My X axis has been acting funny, like chugging, not running smoothly after the machine has been running for a while. It runs OK in one direction, and chugs in the other.

What kind of maintenance does this motor need?
There is some carbon dust from the brushes, I presume. Commutators on servo and encoder look OK.

Any help or wisdom much appreciated.

Thanks, Tom

[Al_The_Man]

Could be the drive, swap two axis drives over, if possible to pin it down.
Al.

[Tom Curran]

Al, Thanks for your quick response. I have to tell you up front, I am an electronics dummy, and will err on the side of being overly cautious.

The drives are Gettys 360 drives, and look to be about nine or ten circuit boards in each drive section.

If I could get the problem to switch to another axis, then I could pin it down a little better. I am not sure exactly what I am supposed to switch around. Should I pull all boards out of the X drive, and switch them with the Y drive boards, for example?

I think that's what you mean.

Thanks, Tom

[Al_The_Man]

That seems like alot of boards per drive?
Make sure you identify them and that they are in fact identical, I would swop the boards one at a time, if the drives are all the same, the settings may vary from drive to drive, but a temporary swap should show if it is in fact the drive.
It helps if you have the documentation on the drives, which should show individual board locations etc.
If the encoder/tach/motor leads were all plug in, you could swap just the connectors between drives, but I suspect they may be terminals for the most part.
Al.