Harvesting Stepper Motors

Question

Hi,

I have a question (and may even be suitable for part of a show).

I've rescued some stepper motors from a couple of old printers but the wiring colours don't appear to match any know conventions I can find. Is there a simple method for discovering what order to wire them up to something like a L293D motor controller?

The motor I have in front of me now has 4 wires; orange, black, yellow and brown. I feel like I've tried every combination and tested it using the stepper_oneRevolution sketch on the Arduino but most just appear to make it vibrate and jitter uncontrollably. I understand the leads should be in two pairs but which of the pins in this sketch relate two the pairs on the motor?

Hopre the question makes sense!

Cheers,

Danny.

Former Member · Accepted Answer

Hi Danny,

thank you, you are so kind.

Suppose that you are working with 2 phase step motor. The electrical current throught the phases will something like that, where 1 means the current in one direction and -1 means opposite direction of the current,:

Phase one=> 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1

Phase two=> 1 -1 -1 1 1 -1 -1 1 1 -1 -1

Or graphically:

__ __ __

Phase one=> __| |__| |__| |__

__ __ __ __

Phase two=> _| |__| |__| |__|

You can see that the phase two is going from high to low when phase one is in high level. If you change this for the phase two goes low when the phase one is in low level, the direction of your motor will revert.

Thinking about Arduino, and supposing that there is instructions such as SET BIT (some port) and CLEAR BIT (some port), is possible to write a program that give us the output above:

begin: clear bit x (phase one);

clear bit y (phase two);

delay(w);

clear bit x (phase one);

set bit y (phase two);

delay(w);

set bit x (phase one);

set bit y (phase two);

delay(w);

set bit x (phase one);

clear bit y (phase two);

delay(w);

jump begin

end.

Now you will need a hardware to drive these two phases.

Tomorrow I send you a circuit. Do not connect the phases directly to Arduino pins. You can damage it if so.

Regards,

Guilherme

	Orange	Black	Yellow	Brown
Orange	--	Open	6	Open
Black	Open	--	Open	6
Yellow	6	Open	--	Open
Brown	Open	6	Open	--