Hi Robin. What a brilliant idea. When you get it right you will have solved one of the major issues with using steppers. i would be interested in the outcome.I had another thought that if i had the knowhow would be worth pursuing. What if you had a PIC counting pulses sent my Mach 3 and then the PIC moved the stepper motor using the encoder to go to the correct position? Its probably complicated, and you would get some lag,but i would gladly put up with lag for accuracy.