Ender-3 filament runout & jam sensor / guide

thingiverse

Filament runout sensor - jam/snag sensor - filament guide ============================================ inspired by: All in one - Filament Jam - Cleaner & Runout Sensor by 3D-Muc This has 2 parts: 1. The runout sensor (based on laubed's design) attaches to 2. The jam sensor (my design) The runout sensor guides the filament and can pivot on the jam sensor, which gets pulled in when the filament gets tangled. Both switches are simply wired together in series with the runout normally open and the jam normally closed. I included an STL with both parts closely together to reduce the supports needed. I also included an all-in-one combo design that I originally planned, but never printed it since I think I like it better in 2 pieces. The combo also looks harder to print, but I included it anyway. If you already have laubed's runout sensor you can simply print my jam sensor and attach it with a longer screw or bolt. EDIT1: I elongated the jam switch mounting hole to allow adjustment of how soon it actuates without having to bend the switch arm. EDIT2: After using this for over a week almost non-stop I got my first false alarm. I discovered that PLA might not be the best material for this design. Apparently PLA looses it's elasticity after being compressed/bent for extended durations. Because of this I would suggest using PETG. I will remake it with PETG and report back later. Also, later I plan to make a version that uses PTFE tubes to reduce the friction in the runout sensor holes. I believe this would allow PLA to work since the spring tab won't be under continuous stress. EDIT3: I reprinted this with PETG and it works better than PLA. Also I recommend mounting the runout sensor higher (using the lower hole, like in the 3rd picture). I also made a new version (v2) of the runout sensor that guides the limit switch roller better. This prevents the roller from getting along side the filament and causing increased friction.