Re: Driving unmarked steppers

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