In my mission to add Onstep GoTo to the Hadley Neumo, I modified the rocker to include a 236-tooth puly. I used a 852mm GT2 belt.
Video showing it working
The stepper motor mount is made with the Rocker frame in mind. This is because this Azimuth for that mount already exists. For that, the following stepper motor mount can be used.
The author remixed this model.
Added a gt2 belt pully to the rocker.