Re: [CAD_CAM_EDM_DRO] Newbie question: determining Stepper Motor Specs

Find two (coil wires) that show a low resistance. That will be the same
for all coils.
Come to think of it, if you're using Geckos, you don't need to know the
motor resistance,
since you use a resistor to set the current on the drive according to a
legend printed
on the drive.

If I'm not mistaken, you get the best performance running two coils and
leaving the other two unconnected (it's called half coil). You can find
the correct two coils to use by experimentation. Just ohm all the wires
out and keep the pairs of wires together. Connect one pair, then pick a
pair and connect those, if that doesn't work, pick another pair to use
as the second pair. Of course you /always/ power down when connecting
of disconnecting a motor.

Power supply voltage can be anything up to the max for the Geckos. See
their website for advice.

Regards,
JJ

On Monday, December 15, 2003, at 10:46 PM, dk32544 wrote:

> I'm trying to figure out exactly what the specs are for 2 stepper
> motors I have. I bought them for a CNC plasma table at what I thought
> was a good price. They have brakes and 5:1 gearheads. The labels
> state: Bipolar series: 3.4 amps; Bipolar Parallel: 6.7 amps; Torque
> hold: 265 oz-in. They doesn't state the resistance which I've read is
> critical for selecting the right power supply. They have 8 wires
> each: 2 black wires for the brake. 1 orange, 1 yellow, 1 white/red, 1
> white/orange, 1 red, 1 black. So which wires do I need to ohm out?
> And what voltage power supply is correct?
>
> These are API Motion/Positran units if that makes a diff.
>
> BTW: I'm planning on running these on rack with a 1" pinion and Gecko
> 210's. What IPM should I expect? Guess I need about 100 IPM to cut 16
> ga.
>
> Thanks for the help so for the dumb questions this is all new to me.
>
> dk
>
>
>
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