Quote Originally Posted by irving2008 View Post
You can run steppers below their rated phase current, you just derate the torque by the ratio of the currents. So a 4.2Abipolar stepper rated at 1.8Nm will, on a 3.5A drive, give 1.05Nm RMS instead of 1.27Nm RMS
Whoa ... way over my head, although I am led to believe that matching drive/stepper is far better rather than adjusting to suit .... Remember MESSENGER