Re: Stepper Motor Torque vs. Wiring

Chris,

Full winding (6-wire motor)is identical to series in an 8-wire motor.
Half winding is nearly (within 1%) identical to parallel.

Unipolar and bipolar are terms that apply to drive methods. High
performance drives are invariably "bipolar".

Use the motor's "unipolar" rated current in half winding operation.
Set the current to 1/2 that value for full winding operation.

These settings only affect the motor at low speeds. If you set these
currents higher then recommended, you will get a only a little more
low speed torque at the expense of a hotter and rougher running
motor. Rapids will remain unchanged.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "Chris and Dee" <brunoblazer@y...> wrote:
> Hi all,
>
> I was hoping somebody could enlighten me. Just when I think I'm
> starting to understand something, I read something that confuses me
> again....
>
> The following link shows a chart of the torques, etc of some
Superior
> Electric Stepper Motors.
>
> http://www.slosyn.com/ssstepmotors_stndrdnema34.html
>
> I have some M092-FD09 motors that I'm in the process of
connecting.
> Last night I hooked them up in 'Full Winding' mode according to
> Mariss' explanation in the Geckodrive papaers. My understanding
was
> that the full winding mode corresponds to what Superior Electric is
> referring to as 'Bipolar' in the above webpage and that the half
> winding configuration is what is referred to as unipolar. (My
primary
> indication of this is that the inductance on the bipoar section of
> the table is 4X that in the unipolar section which corresponds to
the
> statement made in the gecko papers if I'm not mistaken).
>
> However, two questions come up.
>
> 1st, The Geockodrive instructions indidcate that the current should
> be limited to half of the unipolar nameplate rating on the motor
but
> the Slo-Syn says that the current for bipolar is not quite 1/2 the
> amount. Is 1/2 the current a conservative theoretical number and
the
> slo-syn chart is likely giving a more accurate empirical value for
> those windings?
>
> 2nd (and most confusing), the geockodrive instructions indicate
that
> a motor connected in parallel (or half winding, since a series
> connection is associated with a full winding connection) will have
> twice the power of a motor connected in series (or full winding).
> This directly conflicts with the information on the above website
if
> bipolar refers to full winding and unipolar refers to half winding.
>
> Please help! :-)
>
> Thanks,
> -Chris