Quote Originally Posted by irving2008 View Post
There's a big issue with those drivers - the current setting is not via switches but by twiddling a variable resistor while measuring the current in the windings. That's not easy to do without appropriate test equipment, a cheap digital multimeter on DC Amps setting will be wildly inaccurate as it cant sample fast enough
One might be better off in that situation measuring the supply current and voltage to the driver, then since you (should) know the resistance of the motor at low speed, the required supply current can be estimated fairly accurately by considering the rated power. Adjust the potentiometer to get that current. The supply current should be measurable accurately using a cheap meter due to the filtering effect of the DC-bus capacitor.