BigTreeTech - Top Rail Mount for Filament-Out Sensor

thingiverse

Revised 11/27/2021: I made it a little shorter to use less rail space. I also mirrored it (when I printed it - not here), moving the pass-through closer to the center, further reducing the resistance to the extruder. I tried different designs, but they were either too brittle, or positioned so there was too much tension on the filament. This design did the trick for me.