Re: Stepper motor speeds

Hi MArv,

check post 45509. I think that covers it pretty well.

The small section that may be direct is :

quote :
(2) Steppers have lots of torque at low speeds and very little torque
at high speeds. This is a good thing. Work is done at low speeds
where you need a lot of torque; high speeds are usually "rapids"
where little torque is needed.

As a rule of thumb, steppers are pretty much out of torque (rapids)
at:

Size 42, 300 to 600 RPM, 800 in-oz or more low-speed torque.
Size 34, 600 to 1,200 RPM, 150 to 450 in-oz low-speed torque.
Size 23, 1,200 to 2,400 RPM, 50 to 150 in-oz low-speed torque.
Size 17, 2,400 to 4,800 RPM, less than 50 in-oz torque.
end quote

There is more on gearing and stuff.



Dave

--- In CAD_CAM_EDM_DRO@y..., "Marv Frankel" <dcdziner@p...> wrote:
> Guys,
> I have a pretty good handle on sizing stepper motors with
respect
> to required torque, but I haven't heard any discussions about speed
> ranges and how they're controlled. I'm in the preliminary stages of
> designing a CNC retrofit for my Enco full size mill, and would like
> to use the smallest motor possible, to motorize the fine feed on
the
> quill. My down feed requires almost no torque, but retracting
> requires about 120 to 150 oz/ins. I have enough room to gear the
> motor to feed at 1:1, 2:1, or 3:1, but I don't know the RPM range I
> can expect from the motor. Help please!!
>
> Marv Frankel
> Los Angeles