28BYJ-48 Celestron C8 Focuser

thingiverse

This motor controller is based on a small and affordable 28-BYJ-48 stepper motor. I use it with an Arduino Nano board and a simple USB battery pack. It works flawlessly on my Celestron C8, the motor is extremely precise and has sufficient torque to move the mirror. The motor wires can be hidden under the cover and there's a small opening to secure them in place. You will need some M3 screws and one bolt: * 3 short screws (20mm long or longer ones that you can cut down) * 2 longer M3 screws to attach the motor and its cover (at least 30mm long) * 1 nut * 1 small M3 screw (10mm long) I recommend using a tapping threading tool, M3 size, as PLA is not particularly hard. The cheapest option will suffice. The design is also available on Tinkercad so you can customize the screw hole sizes: https://www.tinkercad.com/things/4LjwJ2PkdNM-28-byj-48-celestron-c8-focuser WARNING: If using PLA, make sure to turn all the coils of the stepper motor to a low state (OFF, 0v) after moving to avoid heating issues. Stepper motors can become extremely hot if you keep the power on and may melt the PLA. Turning off the coil will eliminate this concern. If you're using custom code, ensure that all output pins are set to low after each move. If you're using a different project's code, refer to its documentation or contact the developer for guidance. For "Arduino ASCOM Focuser Pro", check the documentation for "Set Coil Power" and turn it off (default is ON).