Filament Runout Sensor Enclosure (Micro-Switch)

This is filament sensor enclosure. The filament sensor use a PTFE tube to guide the filament. A cut in the PTFE tube expose the filament to a micro-switch with ball bearing. This should keep the friction to the filament to minimum even during retraction.

This is thought to be mounted on a BMG extruder with the PTFE tube going in the PTFE coupling. The sensor is light enough to not cause any trouble.

2nd version: switched to OpenSCAD and added the source. Added a blocker for the PTFE tube so it does not slide out of the box.