unipolar stepper question

Other Hardware Motors, Mechanics, Power and CNC
1

Hello! I recently acquired a pair of 5v 5 wire unipolar steppers. I am trying to test them to maybe implement them in the future in a plotter or laser etch project.

I have an adafruit motor shield, external 5v power supply, and I cannot get the demo code StepperTest to function properly.
There are, as I mentioned earlier, 5 wires
1 A Blue
2 B Pink
3 C Yellow
4 D Orange
5 E Red (midpoint)

The way I understand the wiring, 2&4 and 3&1 are the coil pairs.

Every combo I have tried produces only jitters, no rotation.

Any help would be awesome.
thanks
-e

2

maybe try lower or higher speed

3

Controlling the electromagnet intensity through arduino;

Check that this is correct with a meter.
Check that each coil is being energised by disconnecting on coil and seeing if you still get the feel the remaining one is being pulses. Then try pulsing it slower.

4

Hello again!

Thanks for the speed tip. I uploaded the example and I guess had no idea how slow and finite 10rpm and 100 steps was.(actually moving although a slow and insignificant amount)

Oops and thanks.
-e

5

So searching this forum I stumbled upon a thread that pointed out the steppers I own (28BYJ-48 5V) are 64 steps with 1/64 reduction.

So I changed the adafruit StepperTest code:

AF_Stepper motor(64, 2);

and then 2048 steps gives one rotation not the 4096 someone indicated.

Can anyone demystify this for me?
-e

6

Dear -e,

and then 2048 steps gives one rotation not the 4096 someone indicated.

I made the same obervation when controlling the motor from an arduino program example. Maybe differences in coil addressing (microstepping vs. normal stepping)? In the datasheet http://www.yoonitrading.co.kr/doc/step-geared-fulling/(10)28BYJ48-12-300-01.pdf, I noticed a sequence of 8 triple signals applied across the 4 leads. The arduino stepper library seems to address 2 coils at a time, what I conclude from some LEDs attached to the ULN2003 driver module I'm using.

Anyway, it runs quite smoothly, especially for that price and weight :slight_smile:

Can you make a suggestion about how to connect the motor mechanically to something?

/Wo

7

Can you make a suggestion about how to connect the motor mechanically to something?

You need a shaft coupler. There are several in this project:-
http://www.thebox.myzen.co.uk/Hardware/CNC_Conversion.html

8

Agreed. These cheap steppers are the only ones I currently own and are worlds smoother, quieter, and lighter than servos in my "quiver". Thanks for replies!!
-e

9

Hi
Just for help others like me that have get here from google.
If you just change the sequence in Arduino Stepper Examples Stepper myStepper(stepsPerRevolution, 8,9,10,11); to Stepper myStepper(stepsPerRevolution,8,10,11,9); this motor will work.

10

This is just the same as swapping the wires over. In other words you had it wired up wrong in the first place.