Re: General Stepper Motor Specs Question ??????

Yes, and the reason is intuitively easy. Assume you can generate a
fixed magnetic intensity and this "intensity" is what pulls on the
rotor. The way to increase the torque is:

1) Increase the motor length. Think of a triple stack as three motors
on a common shaft. Stands to reason it will have 3 times the holding
torque.

2) Increase the rotor diameter by increasing the motor frame size.
Torque is force times the length of a moment arm. Increasing the
diameter of the rotor increases the length of that moment arm.

3) Use rare-earth magnets (the new, "square" motors) to increase the
intensity of the magnetic field.

Mariss



--- In CAD_CAM_EDM_DRO@yahoogroups.com, Russ Waters <mycncworld@y...>
wrote:

> First I heard of this, very interesting....... is this because of

more magnetic flex in the square steppers?

>
> Russ
>
> Mariss Freimanis <mariss92705@y...> wrote:
> Holding torque is dependent on motor frame size, stack length and
> whether it's round or "square".
>
> Generally round motors are:
>
> NEMA-23 50 in-oz per stack (stack = 1, 2, or 3)
> NEMA-34 150 in-oz per stack
> NEMA-42 600 in-oz per stack
>
> "Square" motors generally have twice the holding torque of their
> round motor equivalents.
>
> Mariss
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Russ Waters
> wrote:
> > Hi all... been some time now that I had a subject for this
> group........ It's about stepper motor specs and how they relate to
> HOLDING TORQUE.
> >
> > I have found in my own research wheather or not to purchase
> steppers on ebay, that the voltage , amps and resistance seem to be
> related to the holding torque or how powerful the stepper is in
> torque oz./inches.
> >
> > Example.. a stepper (size 23) that I recently found specs on was
> rated 3volts @ 3amps, which by ohms law gave it a resistance of

only

> 1 ohm. The "holding torque" was a good 185 ~ 265 oz./inches,
> depending on how it was wired. So back to my question, can one
> assume with simular specs, there would be a simular holding torque
> for other steppers?
> >
> > Thanks in advance,
> > Russ
> >
> >
> > ---------------------------------
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