I made an Arduino Focuser for my William Optics ZS 73 (see my original Orion Astrograph version). The focuser is basically the same as the Orion Astrograph focuser except for the bracket and layout. The bracket is the same except it does not have the tabs in the Orion version. Also, it attaches to the dove tail. I removed the fine focusing knob and attached another belt sprocket.