Filament Runout Sensor for Titan

thingiverse

**Update 2018-03-05:** A new thicker shim piece is available (`Filament_Runout_Sensor_piece_thick.stl`). It's designed for use with a limit switch that has the metallic lever removed. Remove it by squeezing and twisting it off with pliers. The thicker shim is highly recommended over the original piece. My limit switch started to wear out and became slightly unpredictable, but removing the lever and using the thicker shim fixed the issue right away. I wish I had thought of it sooner. A [filament runout sensor](http://marlinfw.org/docs/configuration/configuration.html#filament-runout-sensor) is created using a simple micro-switch that attaches directly to the Titan extruder. Unlike simpler designs, this setup allows the filament to be inserted from either direction. This means the printer can push out the filament during an [M600 Filament Change](http://marlinfw.org/docs/gcode/M600.html) operation. The design also includes a viewport to watch the filament, but it's not necessary. This sensor is specifically designed for 1.75mm filament. I had to revise the sizes several times while prototyping, and now they're perfect on my end. To configure the sensor, refer to your firmware's documentation (here's [Marlin](http://marlinfw.org/docs/configuration/configuration.html#filament-runout-sensor)). **Additional Items Needed:** * A micro limit switch / endstop (KW-1 2A? I used a spare from my TEVO Tarantula kit, which is about 13mm wide and 6mm thick) * 2x M2 screws + nuts to secure the switch