RE: [CAD_CAM_EDM_DRO] CNC Parts Selection

The motors are pretty high voltage to get much speed out of them
particularly with the lower cost drives that are limited to 35 or so
volts.

As far as the drives go the Stepperworld is a unipolar system that uses
power resistors for current control. It is a very old technology that
has far less performance than a bipolar chopper drive (Xylotex, Gecko).
Between the Xylotex and the Stepperworld system hands down I would go
with the Xylotex particularly with the high inductance motors you
mention.

Honestly, I think you are trying to get too much torque from too small a
drive. Generally if you want good performance (meaning decent torque at
more than the slowest RPM) you need to use a low inductance motor (look
for a voltage about 3 v and under) and run them at 10 - 25 X the voltage
with a chopper drive. For the torque range you want the low
voltage/inductance motors will have current ratings in the range of 4 -
6 amps or so. To drive one of these motor well the bests bang for the
buck is a set of Gecko G201 drives if you want new. If you are looking
at surplus there are a range of 5 - 8 amp, 60 - 80 v bipolar chopper
drives. I have 2 Oregon Micro System drive I am selling that match that
description and I have a couple of other drives I was testing in ones
and twos. There is also a number of things that turn up on e-bay.

Tim
[Denver, CO]
Sherline products at Deep Discount
Mach1 & DeskCNC with credit card ordering
www.KTMarketing.com/Sherline

> -----Original Message-----
>
> Well I think I found some good steppers, but before I drop my dime on
> them I wanted to run it by the group. These will be used for a
> drill/mill conversion. The motors are Oriental Mmotors
> PH299-02B. The specs are: 2 phase, 2 amps/phase, 6.4
> Volts,611 in/oz torque. Any comments? As for my driver board,
> I'm down to 2 boards the Stepperworld FET3, and the Xylotex
> XS-3525/8S-3. I like the Xylotex, and jeff seems to
> have great support, but the FET 3 can handle up to 15 amps, where as
> the Xylotex can handle only 2.5 amps. Does any one here run over 2.5
> amps? Should I be concerned? I would like to get the Xylotex, someone
> help me out here.
>
> Thanks in advance.
> Fozzyber
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html