After having my used Epilog Mini for over 2 years I decided to purchase the rotary attachment. I found a "almost new" used one and purchased it. It's one with the Lin Engineering stepper motor(5609-11-01RO). I was disappointed to find that it did not work on my machine. At this point I did not know if it was the stepper motor or something in my Epilog Machine. I searched the internet for the motor specs and found the method to test the stepper motor with a 9v battery. The test appeared to indicate that the unipolar stepper motor was good. I contacted Epilog Technical Service for help and was informed that a new stepper motor was $126.54. I told them that I would like a pinout of the motor molex connector and the matching machine connector and I received the very unhelpful picture of the rotary plug. Nothing technical... just a picture. I then asked for a schematic of the motor driver circuitry. More useless help. "I don't have those and I don't think I could sent them out.... Motor is 126.53." Is there someone out there that could help me debug this problem? From my poking around the electronics... I believe that the rotary stepper is driven by one of the LMD1845(Full Bridge Motor Driver). I assume when the rotary is attached the y-axis bridge is switched to drive the stepper motor of the rotary. It's output appears to be switching(stepping) when the rotary is working. Is the rotary stepper motor run in a unipolar mode or bipolar mode? I'm stuck.