How to run 5 wires hibrid stepper motor with arduino uno?

Question

I have a question. How to run stepper motor (Nema 17) that has 5 wires with arduino and stepper driver. Here is the driver, stepper and Arduino when stepper has 4 wires. http://jdreyer.com/projects/Arduino/ArduinoEasyDriverStepperMotorv1_Resize.png

I need help identifying the wires on my hibrid stepper motor. I will provide picture of dissasembled motor.

Questions are:

1. Wires identification?
2. How to connect it to ArduinoEasyDriver?
3. Code example desired.

UPDATE

I am now thinking of making it bipolar (4 wires), because now in 5 wires configuration motor is unipolar. I did some research and this motor is HIBRID. It can be driven as unipolar or bipolar. I will try to troubleshoot the wiring and find the common wire. Ill keep you informed.

Answer 1

1) it is probably something like A1, A2, Common, B1, B2. You could confirm this with an ohmmeter. Common to any of the others would be a certain resistance X, while between any of the others (A1-A2, B1-B2, A1-B1, A1-B2, B1 A2) would be 2X.

2) You can't. It is a unipolar stepper.

The EasyDriver faq number 5.1 at http://www.schmalzhaus.com/EasyDriver/ says: "... The only kind you can't use is 5-wire stepper motors. (They need uni-polar drivers.)"

The difficulty with the 5-wire steppers is that they short the middle of the two coils together, which makes it hard to drive the coils independently.

Since you have the motor open, you might be able to do some surgery and disconnect the centers of the coils from each other, but you'll probably be better off getting a 4, 6 or 8 wire stepper instead.

Answer 2

On stepper motors there are a few types of wiring, but essentially there are two coils inside the stepper motor. To figure out where the wiring is you need a way to test if the coils are being connected. On your setup I would suggest to connect two of the wires together at a time and spin the shaft. If the shaft offers resistance then you have found the two wires for one coil.

For your stepper motor it looks like it may have three coils, but out of the 6 wires you may also only come up with 4 wires; which would equal 2 coils.

As far as connecting it to an easy driver, the easy driver only takes two coils. you would need to find a driver that can take three coils, or just connect two coils out of the three and hope for the best.

Answer 3

Finding the ground pin

We should start off by finding the Ground/GND pin.

Do you have an Ohm-meter? I believe one of the pins should be GND/ground, and should have low resistance when referenced to the other pins.

Wiring the stepper

Steppers have a coil and thus are an inductive load, you should really check your wiring with sources, to be sure they're valid. (At this point I can't give you a 100% accurate wiring diagram, but it should be easy to find, as wiring steppers is quite common.) You could use a pre-assembled stepper-driver. Having such a thing is usefull when you want to design the circuitry yourself.

Driving the steppers

You should generate a signal like this: https://en.wikipedia.org/wiki/Stepper_motor#Phase_current_waveforms

(The source/link describes the different forms of stepping. Like "Wave drive (one phase on)" in which each coil is activated/deactivated in a rotary fashion, making the core turn around.)

Extra

Adafruit always has extremely well documented tutorials for beginners: https://learn.adafruit.com/all-about-stepper-motors/types-of-steppers

The wiki of RepRap should be a good source, since steppers are the hearth of 3D printers (RepRap is a 3D printer brand): http://reprap.org/wiki/Stepper_wiring

Answer 4

Instead of doing surgery on your unipolar stepper, you can use it like a unipolar stepper. Some transistors to hook the motor to power (just get a darlington array chip), and four output pins on the arduino. Works fine.