Ender 3 filament guide and sensor

thingiverse

A single device combines a filament guide and runout sensor, featuring an M6 fitting that enables the use of a section of bowden tube as an inlet guide. It perfectly aligns with the stock extruder's or aluminum extruder's inlet hole, making it effortless to insert filament from any angle. The cap fits over the top, creating a continuous tube from the bowden coupler to the extruder. I utilized the factory Z limit switch, flipping the microswitch and adjusting the lever slightly - in hindsight, I could have thickened the base and mounted it upside down, but that's a lesson for next time... 02/09 Edit: After using this device for several weeks, changing filament has become significantly easier. No longer must you stick your head behind the printer to guide the filament through multiple holes. 03/16 Edit: I've uploaded the fusion 360 file for use and reference.