Re: [CAD_CAM_EDM_DRO] Re: Looking for a servo amplifier.....

dougrasmussen@... wrote:

> Jon & Matt,
>
> Thanks for the excellent and knowledgeable responses and suggestions.
>
> Jon, good idea to watch Ebay, you never know what'll show up there.
>
> Matt, I went through the SD's recommended tuning procedure and the
> results were so far off that the axis was not functioning. Their
> tech suggested matching settings to the axis with the closest
> loading, X. That worked very well. I noticed in matching, some of
> the number of pot turns were off by large factors from the initial
> recommended settings. Again, the BAL pot on the Y axis seems to have
> no effect, the other axis BAL pots function correctly. That's the
> main reason the SD tech suggested replacing the board.

One possibility is the pot is simply broken. If you turn some of these
trim pots too much, the will occasinally break inside. I've seen that
before. If it doesn't click no matter how many turns you turn it, that
may indicate the worm follower has broken inside. It is not too hard
to replace these pots if you have decent (de)soldering equipment.

If you can get a meter on the center terminal of the pot, it should go
from -12 V to +12 V as you turn the pot. If not, it has to be bad.

If you don't feel confident in changing the pot, you could take it to
a local electronics repair place, and they could probably replace
the pot for $15 or so.

Jon