Re: Going home / more stepper speed!

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.

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

Alan KM6VV

Jon Elson wrote:

>
> Alan Marconett KM6VV wrote:
>
> > Nice idea Mariss,
> >
> > Like a pitmann (pittman ?) motor? It would also provide some load. Is
> > Kv linear? So I could empirically determine the voltage at some known
> > stepping rate (function/rate generator), and "calibrate" my motor? And
> > add your dynamic brake circuitry? I like that!
> >
> > Alan KM6VV
> >
> > mariss92705@... wrote:
> > >
> > > You can also couple a small DC brush motor to the step motor shaft,
> > > place the scope probes across the DC motor, set coupling to AC and
>
> This has to be a high quality servo motor, so that it has minimum ripple
> when running at a constant speed. Most small motors, like toy motors,
> have LOTS of ripple. Ironless, or at least slotless, rotor motors are
> often designed to avoid this problem. Maxon motors, specifically, are
> just about all made this way. I'm not sure about Pittman, but I would
> suspect lots of ripple from most of them.
>
> Jon