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

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