Filament Runout Case

Simple case for filament runout. Best to chamfer the inside of the exiting PTFE tubing so it is more forgiving to load. Place this as close as possible to the extruder. I have multiple printers and extruder setups and use this on nearly all of them. A couple of hemeras and an ender 3 with a bowden tube setup. the PTFE tubing holds everything inline easily, no mounts to machines necessary in most setups but feel free to modify for your use case.

Hardware:
(1) Ramps switch like this
(2) M3x8 screws
(2) M3 nuts
(1) metal ball bearing (3/16" imperial or 4mm metric will work)
PTFE tubing, standard 4mm diameter for 1.75mm filament