9 wire stepper question

Using Arduino Motors, Mechanics, Power and CNC
1

Hi, new to the forum, and definitely a newcomer to this subject!

I'm hoping I can get some advice on running a 9 wire stepper motor, pictures attached,
Code 57SH-52A9D 22.5? 0.9deg, JAPAN 16 May 86 DB

I have successfully got two 4 wire steppers running, using a Uno plus a stepper shield,
but I have no idea of where to go with this motor which I'm hoping will have a lot more torque.

I think I have identified the pairs on this motor using the 'easy to turn' test.
All other combinations lock the motor.

Nine wires...
White 1
Mauve 2
Orange 5
Blue 6
Green 4
Brown 3
Yellow 8
Red 7
Black ?????

I'm scratching my head over what the 12th wire is for?
Will I be able to hook this up to my '2 servo - 2 stepper - 4 DC motor' Arduino shield?

Your help would be appreciated!

Thanks

Chris

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2

Given the 0.9 degree label I would guess it's a 9 wire unipolar motor. One of those 9 wires (probably black) will have half the resistance to any of the other 8 wires.

Do you have an ohmmeter? Create a chart and start writing down the resistances between each of the wires. The arrangement should become clear pretty quickly and should be much more reliable than your "hard-to-turn" method.

As far as driving the motor goes you just need 8 transistors. You can find lots of examples of 5 wire stepper wiring (usually using a ULN2003); you just have twice as many coils.

3

Thanks for the suggestion; I've created the chart but I'm not sure what it's telling me?

Can you see a meaningful pattern?

Thanks

Chris

screenshot.1.jpg

4

Yes, it's a unipolar motor. The white wire would be connected to ground and each of the remaining wires would be energized (connected to ~5V) in sequence to make the motor turn.

Take a look at this tutorial on 5 wire steppers to understand the internal layout. For the stepper in the example, the red wire would be the same as your white wire.

5

Chagrin:
Yes, it's a unipolar motor. The white wire would be connected to ground and each of the remaining wires would be energized (connected to ~5V) in sequence to make the motor turn.

Alternatively (and probably easier), connect the white wire to your positive supply, and use transistors or a ULN2803A to connect each of the other wires to ground in turn.

6

Thank you!

There are moments when I ask myself why I am going down this path.
Than goodness I'm retired and have the time.
I feel as though I'm starting a marathon while I'm still learning to crawl!

Cheers

Chris