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Hi, I'm a newbie and just bought my first stepper and driver (big easy driver).

When I tried to connect the driver to 9V battery the motor was going few steps back and forth and stuttering (see video).

When I connected it to a 12V power supply it worked as expected but the driver was getting too hot and I had to turn off the power supply because I was afraid to damage it.

Please see the videos and image and let me know what I'm doing wrong.

*Note: The only difference between both videos is the power supply (9V battery vs. 12V power supply)


Power supply spec:
9V batteries are for smoke alarms, and are totally unsuitable to power motors of any type.

The Big Easy driver cannot supply the maximum current drawn by many types of stepper motors without overheating. You MUST follow the instructions for setting the current limit properly.

Please post a link to the motor product page or data sheet.
That is a low impedance motor, with maximum allowed current of 1.7 Amperes/winding. If you connect it directly to 12V, it will draw over 7 Amperes and burn up.

However, the Big Easy driver, using the A4988 chip, cannot handle more than about 1 Ampere/winding continuously, without forced air cooling.

There are many imaginative claims for greater current, but they are wrong, so you have to follow instructions to set the current limit to 1 Ampere or lower. The instructions on the Big Easy hookup guide posted by Sparkfun for setting the current limit are bogus, so look around on the web for more accurate and useful information.

The instructions on Pololu's site for their A4988 motor driver may or may not be applicable, depending on the value of the current sense resistor. See ... r-carriers

If you need the full torque from that motor, you need a better motor driver. Pololu has a good selection.