After scouring 3D models to find the perfect solution for my Celestron 130 SLT telescope, I finally gave up and just built what I needed, but I did leverage multiple other projects to help me complete the work, so thank you community!

This design incorporates a 28BYJ-48 focus motor mount with engaging/disengaging gears for manual focus using a 3:1 gear ratio since that focus motor is only 5V and struggles to drive the manual focusing knob directly. It also has a contoured platform for mounting the motor and securing a raspberry pi with storage bay for one standard 1.25" eye piece. I included a case I built for the raspberry pi HD camera, with threading to support attachment of a 1.25" eye piece sleeve.

Assembly:

1. 4x M3x12mm bolts to attach the camera cap to the base.
2. 1x M4x30mm (w/ locking nut inside telescope tube) to attach the mount to the telescope (you will need to remove one factory housing screw). WARNING: TILT TELESCOPE DOWN TO AVOID DROPPING THE NUT ON MIRROR!
3. 2x M4x40mm bolts (w/ nuts) to attach the 28BYJ-48 motor and housing to the telescope mount, I recommend 2 fly nuts to make engaging/disengaging the motor gears for manual focusing easier.
4. 2x M3x16mm bolts to attach the driver case cap (I recommend using thread inserts for a better hold).
5. Lastly 1x M5x12mm to attach the raspberry pi 4 case to the telescope mount.

Part List:
4x M3x12mm bolts
2x M3x16mm bolts
1x M4x30mm bolt
2x M4x40mm bolts
1x M5x12mm bolt

2x M3 heated inserts
5x M3 nuts
2x M4 lock nuts
2x M4 fly nuts
1x M5 lock nut

NOTE: I also included the STEP file for the gears in case you need to modify the focus motor fit.

I use the raspberry pi 4 as my focus motor control and Astro Camera control, I do not have all software details online, but the Astro Camera setup is my fork of the public project below, which leverages the amazing NDI protocol with any ribbon attached raspberry pi camera...

https://github.com/IrPgFKS0/raspindi

Camera I am using (I removed the lens for this application):
https://www.uctronics.com/raspberry-pi-high-quality-camera-autofocus-motorized-focus-imx477.html

Thanks to these projects for their contributions...

• 28BYJ-48 motor housing: https://www.thingiverse.com/thing:3552339
• ULN2003 Case: https://www.thingiverse.com/thing:2317662
• Raspberry Pi 4 Case: https://www.thingiverse.com/thing:3723561