Re: [CAD_CAM_EDM_DRO] Compumotor Plus stepper drive

"Carey L. Culpepper" wrote:

> Ron: Thanks for your reply. Here is what the user manual has to say
> about their resolver:
> A brushless resolver made of the same rotor and stator components used
>
> in the motor was developed. This resolver is magnetically similar to
> the
> motor itself, and is manufactured as an integral part of the motor.
> The
> result is a sensor with the same number of poles as the motor( which
> makes control straightforward) that is always properly aligned with
> the
> motor and can be operated in high noise, high temperature
> environments."
>
> This is what led me to believe that a motor might be wired to do the
> same thing.

This is not really a resolver, but a permanent magnet encoder. Yes, if
you turn a stepper
motor by hand, you will get voltages out. The only problem with the
stepper-"resolver"
is that, since it is excited only by the moving magnets causing flux
lines to pass through
the windings, very slow motion will not register. So, if you use a high
microstepping
resolution, and program extremely slow motion, whole steps could be
lost. If you
use fairly low microstepping, I think it should work fine.

There have been some stepper drivers that detected stalls and missed
steps
by detecting either the current fluctuations or voltage excursions when
the motor
was moving, using the motor's own windings and magnetics.

Jon