Re: [CAD_CAM_EDM_DRO] Re: Going home / more stepper speed!

Alan Marconett KM6VV wrote:

> Hi Jon,
>
> I also have a small pittman motor w/tach end. I think it was for a
> floppy disk drive. Any better? The pittman I was originally thinking
> about is fairly big, 1/4" shaft, 1.5" dia, 5" long, approximately. No
> idea of specs.

Well, if it is used for a sensitive speed control application, it would be
a better class of motor than for spinning a fan, for instance. The tachs
on most of the floppy drive motors were AC. Anyway, the best way of
finding out is to spin it with something that runs at a constant speed
(drill press or mill spindle comes to mind) and see if you get waves
or a straight line.

> And I'll try a current probe on a motor winding...

It will take some analysis to figure out what you are seeing, but if you have
it stepping at 50 - 100 steps/sec, you should see little wiggles after the
steps.

Jon