This is a very simple and effective filament sensor mount I designed to use with the side spool combination. The sensor mounts on the center and is able to rotate freely, preventing filament breakage.
For the side spool holder, please refer to this design:
https://www.printables.com/model/711231-ender-3-v3-ke-filament-spool-side-mount-toolless
For the gear filament guide, please refer to this design:
https://www.printables.com/model/787097-ender-3-v3-ke-filament-guide
The author marked this model as their own original creation.