Question about stepper motors

I have a small stepper motor from a Canon printer, Mitsui modelM35SP-11hpk. Four leads, yellow, black, orange, red. Colors might be slightly off, I'm partially color-blind. I want to experiment with it, but Google was not much help. I'm guessing applying 10V or less should be enough to be able to step the motor. Anyone have any advice?

Reply to
hrhofmann
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4 wires is a bipolar stepper. Here's how it works:

The color codes vary by manufactory:

I suggest you get a stepper motor controller/driver. Something like this:

There are plenty of fancier and more expensive controllers, but this is all you need for a small stepper. If you want computah control, there are others that have USB or RS-232 interfaces.

Plenty more on the various robotics web sites.

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Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Reply to
Jeff Liebermann

10V (DC) will typically be too much. You need lots of voltage compliance to *accelerate* a stepper (to overcome back EMF). But, "holding" (DC) is often just a few volts.

With four leads, you have two coils conceptually orthogonal to each other. You need to be able to drive each coil in each *direction* (i.e., "polarity") to cause the motor to rotate. something like:

+- +-

-+ +-

-+ -+

+- -+

Lather, rinse, repeat.

There is a lot of science (and art!) in good stepper motor driver design -- assuming you want to get the most performance from a given frame size.

Ideally, you want a current-mode driver (you want to push a certain current through the winding regardless of the voltage across the winding) so that the drive can control the motor at varying speeds.

Also, you would (ideally) like a "microstepping drive" (even if you only stop on full steps) for better control. (imagine driving one coil with a sine wave and the other with a "cosine").

Depends on whether you want to *play* with the motor ("Gee, look, mom... it's spinning!!") or if you actually want to *use* it (and, if so, how hard you want to push it).

Google is your friend.

Reply to
D Yuniskis

Jeff:

Thanx for the links, when I studied EE, both Bachelors and Master's, steppers were yet to be invented, and at Bell Labs I was into communications electronics rather than anything mechanical.

Bob H

Reply to
hrhofmann

I never studied much in kollege. I've often suspected that they gave me a diploma just to get rid of me.

Are you sure you didn't blunder into any steppers? They were around starting the early 1960's. Phytron, Superior Electric and other were making them mostly for the space program:

Prior to that, you probably ran into servos, synchros, selsysn, PM multiphase motors, and other analog nightmares. While not the same as a digital drive stepper motor, much of the theory is similar (i.e. damping, acceleration). Some of the early steppers were nothing more than analog servos with digital drivers.

Good luck learning (by destroying) about stepper motors. If you haven't smoked a winding, you haven't learned why steppers use much lower holding current than (peak) drive current. That's one reason to invest in a driver/controller, who's secondary purpose is to keep you from producing smoke instead of rotation.

If you're looking for a worthy project, I recommend a 2 axis solar tracker and solar coffee warmer.

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Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Reply to
Jeff Liebermann

Didn't film use some form of stepper motor from quite early on? The need to synchronise several reels for things like sound dubbing.

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*He had delusions  of adequacy.

    Dave Plowman        dave@davenoise.co.uk           London SW
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Reply to
Dave Plowman (News)

Dunno. I've never worked on film chains, although I used them in college. As I vaguely recall, they used servo motors with tachometer feedback to control speeds, and lots of precision gears.

Google found this site which mumbles something about using steppers with film. They use Superior Electric steppers.

I did a bit of digging with Google Patent search:

Searching for "film stepper motor" yielded about 1958 for the earliest patents. The original stepper motor patent was filed in 1953 and granted in 1955.

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Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Reply to
Jeff Liebermann

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