Help to identify this stepper.

[Konstantin]

From industrial garbge I have salvaged a couple of motors mounted on the same plate, later I realized that I had only one motor because the other thing was a General Electric Control Plugging Switch. The stepper had no labels on it and was heavily painted with two coats of (doh) paint, one in blue the other one white. I have removed all the paint, unfortunately no labels or marks underneath.
Any suggestion on what to use as primer and paint?


Here are the stepper measures:


shaft diam 8 mm
shaft lenght 20 mm
motor diam 86 mm or 3.4 inches
motor length w/o shaft 110 mm or 4.3 inches
229 Ohms between each pair of leads
Original wires are colored : White_blue and white_yellow, white_green and white_red.

What I have found inside is a permanent magnet rotor and a stator with 16 slot in it.
So I guess 16/2 = 8 coils. Motor has 4 wires so I guess bipolar then is has 4 coils each winding, right?
How many steps would this motor do per revolution? 8?

Must have high torque then, isnt it?

[Konstantin]

mo pics

[Konstantin]

inside

[Ferenczyg]

Um, you've pretty sure demagnetized the steper opening it, so the torque will never be the same as original, non opened. On other side, 229 ohm seems a pretty high value for me, not very usual and talks about high V low A.

The number of the steps is not easy to guess from the coils, because every one of the rotor slots create two magnetic poles independent of the others and by that way with less coils they can provide more steps.

[Konstantin]

Too bad the motor maybe be damaged. It still has some magnetic energy because it is heavy to turn while the leads are crossed. At least I havent paid for this motor.

Will anyone help me on what voltage and amperage to use to test this motor?

[bunalmis]

This motor must be squirell cage asynchron motor or variable reluctance type step motor.

If you send to picture of rotor i can say the type of motor.

[Konstantin]

Cannot be variable reluctance (I think) because it has ALNICO magnet as rotor. I dont want to dissasemble the motor anymore.
The rotor looks like a cilinder whit a shaft in it, thats all. Color is like stainless steel just a tad darker. Motor is definately a bipolar.

Thanks for helping though.


Konstantin.

[bunalmis]

Ferenczyg,

You can open and close all motors, this is not problem.

And you need very big magnetic field or need high temperature. If you want to demagnetize any magnet. (Try it not simple)

[bunalmis]

Ok, if rotor has a magnet this must be permanent magnet step.
This motor dont gives high torque.

If you have scope, turn the motor by external source and look the waveform and find the frequency of protuced coil voltages.

This gives idea for revolution. (You know shaft rpm and frequency of waveform).

[Konstantin]

Unfortunately no scope or access to one.

[Ferenczyg]

Originally posted by bunalmis Ferenczyg, You can open and close all motors, this is not problem. And you need very big magnetic field or need high temperature. If you want to demagnetize any magnet. (Try it not simple)

Of course the motor can be opened and put at work before opening, but the torque is lower than original. At least this is what my teachers teached to me

[Konstantin]

I guess what we and more important me, myself and I learned the morale of the Permanent Magnet Motor

PUT DOWN THAT SCREWDRIVER AND STEP AWAY FROM THE MOTOR!