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

Can't hurt swapping polarity of the motors. Although my controllers
are different than yours ,Gecko's ... Your controller is going to swap
polarity based on what the encoders tell it anyway. If your motors are
wired wrong then this is commom. Wish I could tell you why it happens.
I think the encoder is seeing say a clockwise rotation, the controller
commands a counter clockwise rotation but your motor rotates clockwise
because the motor polarity is not correct to start with.

--- In CAD_CAM_EDM_DRO@y..., "Jim Montgomery" <jimbomont@y...> wrote:
> 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.
>
> If I disconnect the controller, every thing stops.
> If I just disconnect the encoders, I get an error and everything
stops
> until reset.
> If I could find information on the amps I think I could apply the
> proper +/- Voltage and move each axis back and forth. So far, The
only
> good axis I have ( the "Z" ) measures +/- 1.0 volt on one certian
pin
> on the servo amp. I really don't want to take a chance of ruining a
> good amp so, I'll wait until I can get specs on the boards.
>
> Thanks for the reply,
>
> Jim
>
>
> --- In CAD_CAM_EDM_DRO@y..., vrsculptor@h... wrote:
> > Jim,
> > I'm not sure if any of this applies in your case but the only time
> > I've had this happend is when the servos don't "see" the tack (an
> amp
> > run away) or the controller doesn't "see" the encoder". If it was
> > only a single axis I might be able to believe and output
transistor
> > failure. Can you disconnect the controller to eliminate the
> > possibility of an encoder problem?
> >
> > Roger
> >
> > --- In CAD_CAM_EDM_DRO@y..., "Jim Montgomery" <jimbomont@y...>
> wrote:
> > > Please Help,
> > >
> > > I'm able to jog and adjust feed rate on the "Z" axis.
> > > The machine is a Southbend Mill, 9" x 42" (Bridgeport Style).
> > > The control is an older Anilam Crusader II , circa 1983 I'm
> > guessing.
> > > The motors are SEM, 100v, 30a "X" & "Y" and 20a on "Z".
> > > The servo amps are Westamp 30060-75
> > > The linear encoders read find as a DRO at the control.
> > > The tachs output good voltage.
> > > When I switch the amps from axis to axis I get the same results
> so,
> > I
> > > assume they are OK.
> > > Limits check out OK.
> > >
> > > I've built a few stepper systems but, I'm just learning servo
> > systems.
> > > I'd really like the tech specs on the servo amps so I could
trash
> > the
> > > Anilam controller and upgrade to PC control. The "Servos To Go"
> > board
> > > looks good to use with the Linux/EMC project along with other
> > options
> > > like using products from "http://www.rutex.com".
> > >
> > > Any help on why I might get run aways or any info on what my
servo
> > > amps may like as far as voltage inputs and what pins would be
> great.
> > >
> > > Thanks,
> > >
> > > Jim Montgomery