FRO - Filament Runout Sensor with Mount and Lid Ender 3 uses surplus Z limit switch

thingiverse

Filament Runout Sensor for Creality Ender-3 ================================== For use with printers that have the updated BTT SKR Mini E3 board V.1.2 with E0-Stop port. USES EXISTING Z LIMIT SWITCH =========================== This Filament Runout Sensor (FRO) is designed to utilise the "surplus to requirements" original Creality Z Axis Limit Switch (usually leftover after installing the BL Touch). FRO Sensor case / mount - Fits atop the Z Axis Lead Screw SNAP FIT Lid to keep dust out of the filament sensor box IMPROVEMENTS revision 10 (23rd August 2020) ====================================== - Added holes to allow 2 small sections of PTFE tubing at either end for a smoother filament path. Bill of Materials ============ Your "Z Axis Limit Switch" which was removed when you installed a BL Touch. 2 x M3*16mm screw bolts Flexible Silicone Wire (to create new wiring harness) - I used around 100cm (yellow) 24 AWG Electrical Wire Kit,0.20mm² Flexible Silicone Wire - rated 300V Hookup Wire High Temperature Resistance PLUS 100cm (black) 24 AWG Electrical Wire Kit,0.20mm² Flexible Silicone Wire - rated 300V Hookup Wire High Temperature Resistance 1 x 2 pin JST 2.54mm connector (for connecting to E0-STOP on BigTreeTech SKR Mini mainboard) - NOTE : You only connect the wiring to GND and PC15 pins. 1 x 3 pin JST 2.54mm connector (for connecting to Z Limit Switch / Your new Filament Runout Sensor) - NOTE : You only connect G and S pins on the switch. 2 x lengths of PTFE / Capricorn Tube 4mm outer diameter (cut to around 15mm long) - One for EACH end of the FRO box. MOUNT PCB to BOX ================ To attach the Z Limit Switch to the box - you'll require 2 x M3*5mm SCREW BOLT REPLACEMENT ========================= You will need to replace the 2 x M3*10 that pass through the Z rod nut / BRACKET - REPLACE these with longer M3*16mm screw bolts Wiring ===== Connects to E0-STOP header port on the BTT SKR Mini E3. V.1.2. -The Sensor is wired up for G and S only (3 pin connector / 2 pins used) - the other end of the cable is a 2 pin connector (GND and PC15) on e0-STOP header / port on SKR mini board FIRMWARE *must* be configured to allow Filament Runout Sensor FRO SENSOR STATE ================= After Installation - use a gCode Terminal to check - M119 should show FRO sensor as "Open" with no filament loaded - M119 will show "Triggered" with filament inserted (as switch is depressed / triggered when filament is present!)