Filament run out sensor/filament guide

Two simple filament run out sensors that double as a reverse bowden filament guides. One includes an optional filament wiper/oiler. They are designed to mount to standard 2020 extrusion and use a cheap optical endstop (https://www.amazon.com/BIQU-Optical-Endstop-Control-Printer/dp/B01FLSA47O) with a M6 PTC connector (https://www.amazon.com/TOOTO-Straight-Pneumatic-Connect-Extruder/dp/B019RQ5EYE)