Ender 3 Filament guide + run-out sensor

thingiverse

This is an improved version of themba's filament guide with roots in the infamous Holspeed's filament guide. IMO this and themba's version are one of the first upgrades you should do to your Ender in order to save the extruder tensioner arm, and then add a sensor later, thanks to modular design Changes: - Sensor now fits standard size switches (20mm in length, I use Omron SS-P series, fits perfectly) - Added length to output tube due to bigger switch (hollow spaces in the sensor are for PTFE tubes to reduce friction) - Fillets for better printing and better material usage. IMPORTANT!!! Ender 3 extruders differ from model year to model year. The sensor, for the time being, best fits extruders without an insert in the tensioner arm. Those with an insert have a hole shifted a bit to the right, and this creates a crease in filament line. Everything still works, but the sensor body may wear out due to friction, and the extruder has to handle a bigger load. I'm planning on reworking it to bend the filament to the right a bit more Guide itself works perfectly on all Ender 3's.