Quote Originally Posted by 109jb View Post
The theoretical max current of a microstepping drive is 141% of the current setting. For example a 3 amp per phase current setting would mean the drive would draw a max of 4.23 amps.

At full step setting it is exactly what the current is set for. This is because at full step one coil is on and the other is off. When in-between full steps each coil is partially energized and it follows a sine-cosine type curve. At exactly 1/2 step each coil gets 70.7% of the full current setting, but there are 2 coils energized, so 70.7% x 2 = 141.4%

If the drive has the motor positioned at 1/2 step position and the drive is not set to reduce current at idle, then the idle current will also be 141% of the current setting.
This is very true. I am though not sure if the motors I have are 3A peak or RMS, so currently I have the drivers set to 3.32A peak current, which is of course 2.36A RMS. It is also true that the current is per coil, so we must find an intermediate step position where the motor should be put to hold at full current. Currently my drivers are set for half current holding, but that's only for a second, if within that time no step pulses are sensed then the current drops even more.