SS Filament Runout Sensor

This is my Small & Simple Filament Runout Sensor (microSD card pictured for scale) My goal was to create a general purpose filament runout sensor that was small, effective, good quality, and built around the cheap and common limit switches that I already had onhand (ordered from Aliexpress). This filament sensor has the following "features" 1) Uses common parts (common limit switch, two M3 cap screws) 2) Screw holes pass all the way through, so you can use longer screws to affix it to something, or shorter screws (9mm overall length) for a "floating" sensor. 3) Small, fast print. Anyone should be able to print this in a half an hour or less. I made it almost as small as I was able to - I did have a smaller version, but it was only held closed on one side which seemed kind of lame. 4) Internals are shaped so that the filament has a lower chance of getting "caught" when pushing it through (tapered cone to guide the filament to the exit hole). 5) Handy arrow on both sides to show the dire