hybrid stepper/servo system

Dave -

I just ran across a company called Bearing Engineers
http://supersite.net/semin2/bearinge/home.htm (see the Press Releases)
that sells an impressive step/direction controlled servo system. What does
everybody think about this approach for a low-cost servo system? It's all
digital and they make some big claims as far as following errors and
performance. I think they're doing something fancy with "sinewave vector
commutation" or the like, but even the step/direction approach for
plain-vanilla servos sounds like it could have alot of potential with a fast
enough steprate.

Carlos Guillermo



David Howland <dhowland@...> wrote:

>
> The diamond in the pile of possibilities (on my front) may be
> open loop stepper motor programs, driven through a higher speed
> interface into a black box which turns a DC motor and encoder
> into a higher performance stepper motor (a hybrid). This may be
> realized, if surplus DC servo motors offer more bang for the buck
> and can be identified and used easily. Some surplus servo motors
> are neither easy to identify, or appropriate for this use.
>