Re: [CAD_CAM_EDM_DRO] Re: Stepper Motors

cadcamcenter wrote:

> Just posting the ratios of the figures provided by Mike Cheney for
> the convenience of those who would like to respond to his questions.
>
> U unipolar 4.3 3.0
> S series 3.0 2.1
> P parallel 6.0 3.5
>
> ratio P/U 1.4 1.2
> . P/S 2.0 1.7
> . U/S 1.4 1.4
> . S/U 0.7 0.7
>
> >From previous posts, I thought that the rated current of 6 wires
> steppers is the unipolar (U) current which is the same as bipolar
> parallel (P), ie. P/U = 2 and the bipolar series (S) should be the
> same as the rated (unipolar) current, ie. S/U = U/S = 1 ?

Not quite. Many people use just one half of the winding on a 6-wire
stepper when running it with a bipolar drive. The S rating is with
BOTH halves of the winding in use. (I don't know why someone
would do that, I guess it works for drives limited to the lower
current.) The parallel connection is only available with 8-wire
steppers, and has current going in parallel to both parts of the
winding. You get just a little more torque this way on some motors.

Jon