Re: new stepper motors wiring mess...

Erie, I have read the paper and discussed in detail the wiring,
jumpers, capacitor, resistor size, Nema 42 jumper, multiplexer
settings, standby, frequency compensation, slow speed pot
adjustment - etc with Mariss at Gecko and still not working. I have
motors rated when wired "Series Bipolar" of 4.9 amps. Using the
calculation in the Gecko manual requiring 110 kOhm current limiting
resistors. With the original Bridgeport motors I had been using
340KOhm resistors as set by Mariss and he finally said the motors
were bad. Now about $2000 later and I am in the same boat. Any
ideas would be appreciated as I am a sponge at this point.

Keith Clark

--- In CAD_CAM_EDM_DRO@yahoogroups.com, erie <erie@s...> wrote:
> ok, start from the beginning, are you saying you have resistors in
> series with the motors??
>
>
> If so, Geckos are "Chopper" type drives, they limit current and
any
> additional resistance
> will give you exactly the symptoms you describe. Download the
white
> paper from the
> gecko site, print it out and READ IT!!!! Use the appropriate
current
> setting resistors on the drive and
> then let us know how you make out.
> erie
>
>
> Keith Clark wrote:
>
> >Harvey, the motors are functioning now but still limited in terms
of
> >maximum speed to 20 ipm. They are bipolar in series as
recommended
> >by the motor factory with resistors to limit the power to 4.9
amps
> >per the specs. I don't think the wiring is the problem plus
these
> >are high inductance motors. I would like to try to rewire but
after
> >cooking two Gecko drivers, I am quite reluctant except as a last
> >resort.
> >
> >Thanks
> >Keith
> >
> >
> >