Re: Please help!!! I have run away servos on X and Y

OK, It's starting to sink in but, now let me show you how little I
know about servo systems. It seems like if I reverse polarity on only
the motor, that the position loop would get a huge error count and
shut things down. I won't know till I try.

Also, there are six trim pots on the amp AUX, SIG, TAC, TC, CLM, and
BAL. First what do they do and second, If any one or more of these
pots are "out of wack", Could this be causing run away.

This amp is a WESTAMP marked module: 30060-75

Thanks again,

Jim

--- In CAD_CAM_EDM_DRO@y..., "Eric Keller" <keller137@h...> wrote:
> I submit that you just have the motor polarity reversed. The stop
and
> go runaway suggests that the amps are working fine. The reason that
> I say this is that there are 2 control loops -- one is around the
tach and
> the other is on the position. When the position and the tach
polarity are
> out of whack, they fight each other, thus the stop and go. If the
motor
> polarity is wrong, you get a straight runaway.
> Eric
>
>
> > Hi Roger,
> >
> > I have tested the tach voltage at the servo amp past any
connectors
> > that could be causing resistance or false readings. Everything
checks
> > out OK. I've even swaped polarity at the tach, the result was a
run
> > away that paused about every 3", kind of a stop and go run away.
I've
> > not tried swapping polarity of the motors, that was suggested in a
> > couple of other replies.