Orion XT10 Plus GoTo using OnStep

My Orion XT10 Plus Conversion to GoTo using OnStep: http://www.stellarjourney.com/

My goal was to leave as much of the original mount intact. All parts are designed by be using fusion 360.

The red bracket, and grey stepper pulleys are PLA, the rest is PETG.

The mount is controlled by an MKS Gen L board using S109 stepper drivers.

The steppers are NEMA 17's, with a 100:1 planetary gearbox. The stepper pulleys have 40 teeth, and the larger pulleys for Alt and Azimuth have 320 teeth. The total reduction is 800:1. This yields about 2 degrees/second of movement.

The belts are 9mm wide, GT2 closed loop belts.

The bolt through the middle of the base pulley is 1/2" x 2 1/2", the other 4 are 1/4" x 2 1/2".

There are 2 nuts on the back side of the optical tube pulley. I forget the size, but they match the stock handles used by Orion on the XT 10 plus. I removed the stock bracket, and attached the new one using the original hardware. I had to remove the primary mirro