Re: AC servos

Graham, I agree with Jon, these motors/drives perform well. The
encoder from the motor connects directly to the drive. The drive
outputs another version of the encoder in quadrature for the
control. This version can be divided down by several ratios, so you
can reduce your encoder resolution if you really want to.

The older SGDA series drives are analog input only from what I
remember. They also come in specific versions like torque or
velocity mode. If I remember correctly, the newer SGDB drives are
both analog and step/dir input. You can usually find the older
drives, and sometimes the newer, for a pretty reasonable price on
eBay. You can order the mating connectors to build cables from
DigiKey. The drives use pretty common high density D-shell type
connectors.

Why not just use something like a Mesa 5i20/7i33 card combo(about
$260 for up to 8 axis) to interface things to an analog drive? Or do
you need something supported by Mach?

~petev
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Graham Stabler"
<grezmos@...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@> wrote:
> >
>
> > Sure, these are really Yaskawa motors and drives, judging by the
> > model numbers.
>
> Correct, it even mentions Yaskawa on the labels.
>
> > Or, you can use step generation hardware to produce the step
> > rate you need. The performance of these drives is somewhere
> > between awesome and frightening! I had one accelerating to 3000
> > RPM and stopping within a single revolution!
>
> So something a long the lines of a G-rex will be needed, and limit
> switches!
>
> Thanks for the advice!
>
> Graham
>