The setup we have is for a specific diameter of dowel but with a little time it could be turned into a roller setup. I simply unplugged my X axis and plugged in the stepper rotating the dowel normal Gcode will move left and right burning the image and when the CNC thinks it is going up (plus X) it rotated the dowel and burns the next line. We determined that the dowel my buddy needed was almost the exact diameter as the gear used to drive the belts so we did not make any scaling changes. THe image is slightly compressed but on the dowel it is not noticeable.
I will get it out in the next few days and get you some photos.