I have every axis running smoothly and the correct distances! Thanks again! But I do have one problem with the Z-axis. When I travel down the movement is very smooth, but when I travel up the movement is a little jerky and may be missing some steps. The Z-axis is a 2mm pitch screw (1 start) so at 1/2 stepping I set the Z-axis to 200 Mach3 steps/mm, and set the velocity to 1200mm/min and acceleration to 2000mm/sec/sec. I have also tried the other micro-stepping configurations with their corresponding Mach3 steps/mm, but have the same jerky movement travelling up and smooth travelling down. Any ideas?