Filament run out sensor

thingiverse

Update: I've uploaded a second holder, featuring the same design with additional space between the button and its position on the direct drive. This extra space provides 20 mm to pull out old filament. Another update: Solder connections to the switch and invoke a M600 command (firmware pause) to cool down heaters for a while. Also, set up some form of notification upon pause. Test for continuity from Pi connectors to switch connection, as loose connections may cause false pauses and wasted energy. This project requires an OMRON V-16G-3C25 switch. I salvaged them from an old microwave I disassembled. The holder is designed to force the filament into a funnel shape while keeping the switch actuator depressed. Most of the material is kept out of the path of the filament to reduce friction. PLA was used for this print due to its lubricity. Print multiple holders and keep them handy, as harder filaments will wear through the case over time. Two standard M3x16 screws from my kit are utilized. Note: This design interacts directly with the GPIO pins on the Raspberry Pi 3 I'm using with OctoPrint and the Filament Sensor Reloaded plugin. One leg of the switch connects to ground, while the other goes to your input pin, set in the plugin options. No pullup resistor is required, as the plugin already activates one on the board. I'm using pins 5 and 6. Pinout: https://pinout.xyz/ Set Filament Sensor Reloaded to use a Normally Open switch. Set debounce to 2000 ms if you experience too many false positives. Two seconds seems to work well for me. It's recommended to cut the end of your filament at an angle when changing out.