Field Derotator for Onstep Telescope Controller

This is compact and low profile field derotator for the Onstep telescope controller. Technical Specs:
1) only 18.5mm backfocus
2) T2 female threads on scope and camera side
3) 57:8 gear ratio
4) 0.9 deg/step stepper motor
6) RJ type connector

It includes a bill of materials and assembly instructions. Wiring of the stepper motor is left to the user as each Onstep controller has its own wiring configuration. For more information on how to set up the field derotator in Ostep please refer to the Onstep Wiki page.
I'm still working on the assembly instructions and BOM, thanks for your patience.

Please consider donating if you like this design and find it useful.

Hardware needed:
6710 RS 50x62x6mm Deep Groove Ball Bearing
280mm GT2 closed belt
Moons stepper motor 14HK0402-143N
4P4C RJ9 Female Telephone Connector
12 M2x6, 2 M3x16 and 4 M3x6 screws (flat head)

I recommend printing the body and large GT2 pulley at a layer height of 0.12mm or smaller, 5 lines for the walls, and 5 top/bottom