Re: 6 wire motor running bipolar

Hi Gerry,
With the Xylotex drive, and 6-wire motors, you have two choices.
Bipolar series winding, and bipolar half-winding.
With bipolar series winding (end to end, center tap unused), when
running in microstepping mode (preferable), you actually want to use
HALF the rated unipolar rating, as you will be driving DOUBLE the
number of wires turns. The probelm with this winding mode is that
you increase the inductance, thus the time it takes to fully energize
the coils. Becasue of this, you can end up loosing torque at higher
step rates
With bipolar half winding you use one end and the center tap. You
would then run the drive at full amperage (2.5A/phase). Although
this is not quite the full rating of the motor, you can still get
good performance at lower speeds, and MUCH better performance than
series winding mode at higher speeds.
You never want to run a motor at more than it's specified amperage
rating, but almost always run it at higher than the specified voltage
rating. The most common voltage used for the Xylotex drives is 24V.

Jeff
http://www.xylotex.com

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "notoneleft" <ger21@c...>
wrote:

> I'm building a small CNC router and I have a question about 6 wire
> steppers. I plan on using a Xylotex driver. I've been doing a lot

of

> research, as this is my first CNC project and I've come across a
> conversion chart for unipolar and bipolar ratings. I'm looking at
> some Vexta PK266-03B motors, rated at 3amps 2.3V unipolar. If what
> I've read is correct, when running these on the xylotex board "end

to

> end", do the motors then actually draw 2.1 amps @ 3.22V? And do I

see

> a 40% increase in torque. Thanks.
>
> Gerry