Issues with Stepper Motors

Other Hardware Motors, Mechanics, Power and CNC
1

Hello all,
The issue I'm having has me totally stumped and I think that at this point I have not just 1, but 2 semi-functioning stepper motors.

The stepper motors are right off ebay: http://www.ebay.com/itm/320842713273?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I'm using an Uno R3

The driver I'm using is a DFRobot shield: Stepper_Motor_Shield_For_Arduino__SKU_DRI0023_-DFRobot

I'm using a power supply that outputs 12V and 1.2 Amps.

I am totally at a loss. Sometimes the motors turn perfectly with no issues. Then a moment later (nothing changing) they stop and just sit there and rhythmically buzz instead of turning.

To start with, the DFRobot only uses 2 Digital I/O pins per motor.
That's fine, by using only the 2 pins as follows:
Stepper myStepper(200, 4, 5);
According to DFRobot's info, 4 is the step pin, and 5 is the direction pin.
That's one area that I might be wrong on, but I think I did it right.

The other option is the wiring of the motor to the controller shield.
Pin 1 2 3 4 5 6
Phase B+ X B A X A+
Color Y X R O X Blue
Term 1B X 2B 2A X 1A

Maybe I did something wrong here too?

I'm so frustrated and confused that I think I'm done for the night.

2

The ebay site lists the pins as:
•PIN1= B-
•PIN3= B
•PIN4= A
•PIN6= A-

And looking at your shield I would say that 1A and 1B are a pair and 2A and 2B are a pair, although the documentation wiki is not clear.

Looking at the datasheet for the driver chip:
datasheet

It shows 1A and 1B as one coil and 2A and 2B as the other coil.

3

The Stepper library is not intended for stepper drivers that take step and direction signals. Either use the AccelStepper library or don't bother with any library.

This Simple Stepper Code should be suitable to testing purposes.

Make sure you adjust the current limit on the A4988 driver boards to match your motor.

...R
Stepper Motor Basics

4

BURN51D3:
I'm using a power supply that outputs 12V and 1.2 Amps.

I am totally at a loss. Sometimes the motors turn perfectly with no issues. Then a moment later (nothing changing) they stop and just sit there and rhythmically buzz instead of turning.

Try using a bench top adjustable DC power supply, and see what happens if you use voltages lower than 12 V.... such as 10V or even 9V. If your motor appears to turn nicely for a while, and then suddenly stops, then perhaps some kind of over-heat issue?

5

No, don't bother changing the voltage.

  1. Check the pinout is correct - essential to operation. Multimeter on the leads is the only way to be
    sure - and you get to check the motor is as specified and doesn't have a broken winding.
  2. Check your supply isn't being overloaded, I don't think so, but monitor its output voltage to be sure
  3. Adjust the driver board to 1.4A or less - that's the limit for the motor. Make sure its not tiny
    either.
  4. Use microstepping setting, send about 20 pulses a second and check it moves smoothly and slowly.

Never disconnect the motor from the driver when it is powered up. That's one way to blow up the driver.

6

Nathancamp, Robin & MarkT thank you guys!
You pointed out the obvious a bit, but I sure missed it :stuck_out_tongue:
Robin, thanks also for suggesting AccelStepper, that library will prove much more useful, especially for what I'm trying to work on.
Thanks again everyone!