switching motors (was Re: motor grounding and DB9 conne...

Jan,

I'm in total agreement with you... No relays between the driver and
the stepper.

All one needs is to once "forget" and switch machines while the
drives are powered up... White smoke, cursing and gnashing of teeth
to follow...

Ballendo

--- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
> In a message dated 28-Mar-02 07:12:44 Central Standard Time,
> davemucha@j... writes:
>
>
> > Since this thread mentioned switching from a mill to a lathe and
> > back, why could one not just wire up both and then use a few
relays
> > to determine which machine was being controlled ?
>
>
> Dave: I assume you mean there would be steppers on each machine,
and the
> "electronics" would simply be switched between them, with relays,
when you
> wanted to change machines. This might seem a logical approach for
us po'
> boys, at first, but even very fine relays have more "contact
resistance" than
> good machined, gold-plated connectors, or, perhaps, "mercury-wetted
contact
> relays", if you can find 'em for the currents involved (several
amps). All
> my steppers are SOLDERED to wires, which are "soldered all the way"
until
> they get to the screw-tight terminals on the drives, which "ain't
MY doin's!"
> Oh, I forgot: My lathe's "X stepper" (that's the one that changes
diameter
> of cut, "Z" being the axis! Ain't that dum' !!!) has a 4-
pin "screw-on mic
> connector" with bifurcated pins and solid machined sockets. VERY
low
> "contact resistance", and never any problem).
>
> Relays for such as steppers give me the heebie-jeebies! Lotsa luck!
>
> Would be interested to read others' opinions on this point in
here! Jan
> Rowland
>
>
> [Non-text portions of this message have been removed]