Re: Stepper question

Hi,
The 3.3A motor would have almost twice the torque IF it had about
the same number of wire turns as the lower amperage motor (given the
same motor core). The torque is developed from the current AND the
number of wire turns inside the motor. You can have a motor core
wired using thick wire (more current carrying capability) but less
turns, or thinner wire (less current carrying capability) and more
turns, both achieving about the same holding torque. The higher
current motor will get better top end speed, but requires a drive
that can handle more current. The lower current motor can get full
torque at low speeds but will drop off in torque quickly as the step
rates increases (all based on the same drive voltage that is).

Jeff


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@...>
wrote:

>
> >In CCED, Lester Caine <lester@> wrote:
> >>David Micklethwaite wrote:
> >>I have two oldish single stack stepper motors. One is labeled

2.9V

> >>3.3A the other 3V 1.7A. Am I correct in thinking that the 3.3A

motor

> >>will have almost twice the torque of the 1.7A motor?
>
> >If they about the same age, then it's likely but certainly the

3.3A

> >will be more powerful.
>
> I'll be interested in what Mariss has to say here. IME things like
> this are not so quickly or easily answered. Motor designers have

many

> choices...
>
> There's more to a torque spec than holding torque. And "more

powerful"

> can mean different things depending upon WHERE in that torque curve
> you need the "power".
>
> Perhaps even Ray Lin will answer?
>
> Ballendo
>