[spuds]

In researching stepper motors I became a bit confused so I'm hoping the collective knowlege on this board can set me straight.

I'm looking to convert my X3 mill and am considering using 3 Gecko G201's with a PMDX131 Breakout with a PMDX 135 PSU. I was looking at the steppers on homeshopcnc, the 260's for the X/Y and the 600 for the Z. My question is the voltage.

I read that the voltage supplied to the steppers should be between 20 and 25 times the rated voltage and when using these values and the specs for the steppers I'd have to run the 23's between 64 and 80 volts and the 32's between 46 and 57.5 volts. Since these two ranges don't overlap they don't appear compatible for use on the same machine?

The output of the PMDX 135 is based off the VA of the transformer so there is some tuning you can do once you find motor that will work (and keep the voltage of the G201's in range).

Is this all correct, if not what should I be concerned with when selecting steppers?

Thanks!

[rexstep]

Rick from homeshopcnc here.

You can with confidence run the 260's together with the 640 from a single power supply from anywhere between 48-68 volts with excellent results. If you want to get as much high speed torque as you can, go 68V. I know because we've sold enough of these w/Geckos to have a sense of the result.

The 640's for example are often run at over 30X rated voltage.

Mariss, though he can beat me with one hemisphere of his brain tied behind his back, likes to see steppers run cooler and at lower voltages, but when pressed, will concede that steppers were made to run hot as long as you don't exceed 85 C. 68V won't get you anywhere near that.

RHT23-260 should probably be on a 2:1 ratio for the X3.

Let me know if you have any questions at: [email protected]

Regards,

Rick LaLonde
www.homeshopcnc.com