Mariss's Mystery Motors ( was Re: Driving unmarked steppers

--- In CAD_CAM_EDM_DRO@y..., "mariss92705" <mariss92705@y...> wrote:

> Hi,
>
> Here's what I use for "mystery motors":
>
> size 23, 1 stack -- 5W
> size 23, 2 stack -- 8W
> size 23, 3 stack -- 10W
>
> size 34, 1 stack -- 8W
> size 34, 2 stack -- 12W
> size 34, 3 stack -- 14W
>
> This applies to 6-wire round motors. It does not apply to the
> new "square" motors, but being new, they probably are not mystery
> motors either.
>
> When you measure the resistance, be sure to short the ohmmeter

leads

> together first. Subtract the lead resistance resistance reading

from

> whatever you read for the winding resistance.
>
> To improve accuracy a little more, measure the resistance of the

end

> wires of the winding, subtract the lead resistance, then divide the
> result by 2 to get the center-tap to end-wire (unipolar) resistance
> of the motor.
>
> Mariss
>
>
>
> --- In CAD_CAM_EDM_DRO@y..., Hugh Currin <currinh@O...> wrote:
> > Mariss:
> >
> > This sounds like a "rule of thumb" number. I think it was for a

34

> frame
> > stepper? Do you have similar numbers for other size steppers? I'd
> sure like
> > to have this data on the shelf. :-)
> >
> > Thank you.
> >
> > On Thursday 14 February 2002 01:21 pm, you wrote:
> > >
> > > Figure 12W per coil. Knowing W=(I*I)/R ,then solving for

current,

> > > I= square root (W/R). Plug in 12/0.8 and take the square root.

The

> > > answer is 3.9A or more likely 4A per phase, 3 volts.
> >
> > (typo in repost W=(I*I)*R)
> >
> > Hugh Currin
> > Klamath Falls, OR