Nema 17 with A4988 Power Supply Issues

[theeric]

Hi guys

I am trying to run a Nema 17 stepper with 1.7A, 12V together with an A4988 driver and an Arduino Uno.
The only power sources I have available right now are 12V, 1A and 12V, 2A. Somehow the motor is only running when the driver is connected to the 1Amp power supply. When I plug it into the 2Amp supply, nothing is happening.
The problem is I would rather use 2A since with 1A the motor is not always doing as expected. I guess this is because its current rate from the datasheet is 1.7Amp?!

Any ideas where the problem lies?
Have a great day!

[jremington]

The A4988 driver can handle at most about 1 Ampere/winding without overheating. What did you set as the current limit?

The motor power supply should be rated at the very least for 2 A, when setting the current limit to 1A/winding.

[theeric]

Thanks for the quick reply!

What do you mean by current limit? The reference voltage is set to 0.8V.

[jremington]

The reference voltage is meaningless, unless you know the value of the current sense resistors. See the A4988 data sheet for the details.

For the Pololu version of the A4988 breakout, click here and scroll down to "current limit".

[theeric]

Ok, so the current limit of the driver is 2A per phase, and the sense resistors 0.1ohm.

[jremington]

The A4988 can handle 1A maximum, per channel. More, and it overheats and shuts down. Adjust Vref accordingly.

[theeric]

Well, this is kind of embarrassing. This is the first time me dealing with steppers, and I wired the stepper the wrong way. I was frustrated and just switched the cables, now it is working flawlessly.
Nevertheless thanks for the great tips about the current limit @jremington