A4988 Stepper Driver Current Concerns

Hi,

Just wondering how the current limiter affects motor output. I have a 7-35 V 1.6A stepper but am only drawing .7 A or so, but would like a bit more torque. How can this be achieved? When I increase the current flow to the motor it flips out.

Thanks,

Hello.

What is a 7-35V stepper motor? Typically, the rated voltage for a stepper motor is the voltage that produces the rated current (e.g. 1.6 A), so it is a single value, not a range.

I’m not sure what level of of response you are looking for. Simply put, it limits the current through the motor coils. If you want a more detailed explanation, I think your best resource is the A4988 datasheet.

How are you measuring your 0.7 A current draw? I don’t know what it means for the motor to “flip out”, but the driver could be overheating and missing steps. If you really want to get the full torque out of your motor, you will need to add a heat sink to your board.

- Ben