Filament Runout and Binding Sensor

thingiverse

Detects filament jam and entanglement. Mounts directly to 2020 extrusions using M5 bolts and t-nuts. Can mount to either vertical or horizontal extrusions. Filament spool must be mounted below and to the right of the sensor when facing it. Bowden tube mounts to the top of the sensor. In addition to the three printed parts, you will also need: 2x M5 screws - 10 mm 2x M5 t-nuts 2x M3 screws - 18-20 mm long, longer won't hurt anything 4x M3 screws - 10-12 mm long, longer won't hurt anything 2x M3 nuts and washers (or bed adjustment nuts) 2x limit switches - http://a.co/d/1JXC5kr from Amazon 4x magnets - 10mm x 3mm - http://a.co/d/10lAWrz from Amazon 1x bowden tube and fitting - http://a.co/d/ax3PiVd from Amazon 1x epoxy to glue magnets 1x wire and connections Recommended: 3mm tap 6mm tap soldering iron/flux/solder Assembly Print all three parts. Using a M3 tap, tap all 4 mounting holes in the limit switches - you may be able to cut threads with the screws but use a tap if you have access to one. Using a M6 tap to cut threads into the top of the sensor mount for the bowden fitting- again, you may be able to use the fitting to cut thread but use a tap if you have access to one. Push a short piece of bowden tube (approximately 45mm) through the top (runout) guide so the filament easily slides through. The tube should extend slightly beyond the top edge of the guide but not hit the bowden mount. Glue magnets into the upper mount and top guide so they oppose each other. Glue magnets into the lower mount and bottom guide so they attract each other. Assemble the two guides onto the mount with the arrows all pointing in the direction of filament travel. Secure the guides with the longer M3 bolts and nuts. Attach the two switches to the plate using the 4 shorter M3 screws. The arm of the top switch should point up and the arm of the bottom switch should point down. Wire the normally closed terminals of the limit switches in series and connect to your board/octopi/etc. Configure your board/octopi/etc. for the switches and respond accordingly when runout or a bind is detected. Profit! I had some trouble finding the gcode commands for my octopi installation. This is what I used for my FT-5 with a 300mm x 300mm build surface, you will need to adjust the pause commands if you have a smaller bed! After print job is paused: G91; XYZ relative M83; E relative G1 Z+10 E-5 F4500; retract filament, move Z slightly upwards M82; E absolute G90; XYZ absolute G1 X290 Y290; move to a safe rest position adjust this value! {% snippet 'disable_hotends' %}; M106 S0; turn off part cooling fan Before print job is resumed: M83; relative extruder M82; absolute E G90; absolute XYZ G92 E{{ pause_position.e }}; reset E G1 F4000; G1 X{{ pause_position.x }}; reset X G1 Y{{ pause_position.y }}; reset Y G1 Z{{ pause_position.z }}; reset Z {% if pause_position.f is not none %} G1 F{{ pause_position.f }}; {% endif %} Binding: https://youtu.be/NnsKmo40zsc Runout: https://youtu.be/1dtx2eZbmmU - this is an earlier version of the runout but you get the idea