Craig,

Lets see if I have this right. I was hung up on the encoder and trying to factor the 4 into the equation. Apparently the items factored into the calculation are: Motor Steps / rev (200), Microstepping (16), and distance moved per step or rev.

My calculation: 200 X 16 = 3200 Steps per revolution. (Belt 3mm pitch, pulley 24 tooth)

(3200) / (24 X 3) = 44.444 pulses per mm Is this correct??

You mentioned previously that 8 is the preferred microstepping factor. Is there a reason to not use 16?

Thank you much for your help, it is much appreciated,

Roger