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

Rodger,

I didn't think I should start turning pots just yet. I bought the
machine not working. I don't know who has done what to it before I
got it. I'm thinking the controller is at fault and have indentified
the input voltage wires from the controller. I'm going to give your
battery test a try. The controller also controls the all of the
power supplies, when you turn off the controller it shuts down the
whole works dead.

Thanks,
Jim

--- In CAD_CAM_EDM_DRO@y..., vrsculptor@h... wrote:
> Jim,
> I would mess with pots yet or the wiring if this was a working
> machine that suddenly stopped working. The servo dynamics are
tough
> and I can't imagine 2 failing at once. The only multipe amp
failure
> could be caused by the rail voltages and all 3 use the same power
so
> this is real unlikely.
>
> If you shut down the controller and the run away stops it is the
> controller. If you look at the Westamp board (should be 3) edge
> connector you will see a two wire shielded cable that runs from
the
> board back to the CNC controller. There is another pair that runs
to
> the motor which is the tach which you shouldn't mess with. If you
> disconnect the wire from the controller and the axis stops running
> away or does so real slowly you have isolated the problem to the
> controller.
>
> The wires from the controller supply 0 to +10/-10 volts to control
> the axis speed and direction. If you connect a 1.5 volt flashlight
> battery to a working servo amp and switch polarities you can make
it
> run back and forth.
>
> If it is the CNC controller you better talk to the EMC people
about
> servo to go or some such. I ended up installing Gecko's and used
> CNCPro.
>
>
> Roger
>
> --- In CAD_CAM_EDM_DRO@y..., "Jim Montgomery" <jimbomont@y...>
wrote:
> > 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