NEMA17 planetary Gearbox

Planetary gearbox for a roller blind.

I added the bracket for a ceiling mount + a body to hide the stepper from sight.

More info & ESPHome yaml file are available [here](https://community.home-assistant.io/t/motor-on-a-roller-blind-esphome-version/116179/73)

*DISCLAIMER:*
I would **really** recommend to design this yourself, there are too many variables. The chances are pretty slim this will be what you want if you just download and print it. This is designed for:
- The tolerances of my printer
- The location I wanted it (ceiling mounted, also an impact on the screw holes of the mounting bracket)
- Material used (I reused the M4 screws, and since I wanted to use a cable tray it was moved a couple of millimeters so it would fit, …)
- My roller blinds, there is a small difference on inner diameter of the tube where the blinds are mounted on. This won’t fit on the Ikea blinds I had lying around
- Gear reduction I needed for the best speed-torque ratio