Re: FS: New 4 axis microstepping driver $45.00 USD

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Mariss Freimanis"
<mariss92705@y...> wrote:

> I think regulating the power supply does not address the bigger
> problem of returned energy and in fact, will make it much worse.
>
> Those of you who have scopes may want to try a little experiment

that

> could destroy your drive.
>
> 1) Place the scope probe across your DC power supply. Set the input
> coupling to DC, 10V / div vertical scale, 100 milliseconds / div on
> the timebase. Trigger set to AUTO.
>
> 2) Spin up a NEMA-23 or NEMA-34 motor to 2,000 to 3,000 RPM.

Maris, this would be 100-150 inches per minute on a Sherline or Taig
mill (.050 pitch lead screws) and is not representative of the kind
of operating conditions that are encountered for these machines.
What happens to back EMF if the motor spins around 400-600 rpm (20-30
ipm) and you stall it?

Fred Smith - IMService

> > >> On Wednesday, Mar 17, 2004, at 17:40 US/Eastern, Fred Smith
> wrote:
> > >>>> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Fred Smith"
> > > <imserv@v... wrote:
> > >We have a limited edition, 4 axis, microstepping driver
> > >available for $45. Based on
> > >the Allegro A3977 chip. The board is rated at 2 amps per axis
> > >and maximum of 35vdc. This is a promotional item and is subject
> > >to prior sale. Quantities are very limited.
> > >>>
> > >>> Info at: http://www.cadcamcadcam.com