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How to Solve the Problem of Stepper motor only turning in one direction Answered

I've finally had the time to start putting together the electronics package for a CNC machine, and already need to do some debugging. ;)

I'm trying to get one stepper motor going with the v2.58 board, a RPi 3, Popolu DRV8825, and one of these stepper motors.

I've used the Pololu FAQs to tell me how to hook up the stepper to the RPi CNC board. On my stepper motor A is black, C is green, B is red, and D is blue. I'm getting this from examining the documentation that came with the stepper motor, and I used an LED to verify which wires were connected to each other. I examined the traces on the underside of the board to tell me how things connected to the stepper driver through the screw terminals. The green connector should go to 2B, 1B, 1A, and 2A in that order if you're looking directly at them.

I can get the stepper to turn in one direction, but not the other. It acts like it's trying to move by jerking around, but doesn't actually start turning. If I move it in the other direction there's some jerkiness at the beginning, but it'll start spinning, jerk a bit more near the end, and stop. I've put a short video of this on YouTube.

I've tried using another stepper driver, and gotten the same results. I've tried various different wiring options, but all I've managed to do is change the direction of the issue. I've also tried moving everything over to the Y-axis, and gotten the same result. I'm convinced this is something to do with my stepper motor wiring, but I'm needing some help on figuring out the right way to do it.

Any help?

Discussions

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liquidhandwash
liquidhandwash

5 weeks ago

Make sure that the Pi and stepper driver are grounded together and your power supply has enough current to drive the motor.

0
Downunder35m
Downunder35m

5 weeks ago

A stepper motor needs enough current and the correct voltage for starters.
Best to test this with and without any load on the output of the motor.
The direction is done through the code and assuming you use the correct code I assume power issues.
You might want to start simple with full or half steps and work your way up to find the correct settings on your driver board.