Zaribo MK3 Indirect Filament Sensor Mod

The laser filament sensor included with the MK3 is less reliable than I would have liked especially with shiny transparent filaments. A few brilliant designs have been going around that use a ball bearing as an indirect filament sensor indicator for the stock mk3 extruder. Take a look at the designs here:
https://www.thingiverse.com/thing:3091625 (Firmware modding instructions are on this one)
https://www.thingiverse.com/thing:3129921

I was inspired by these designs to update the new R3 ver