Filament Sensor Case w PTFE & Mounting Holes

Loved the original idea of this sensor case, but found that filament would sometimes catch/drag though it, causing imperfect prints. I added holes for 4mm PTFE tubing, so filament can pass through nice and smooth. I also added mounting holes so I can attach it to the extrusions of my FT5 printer more easily.

I didn't bother with a case cover, since it would need to be removed every time filament is changed.

Like the original, this uses a commonly available endstop module as a sensor, such