Smart Spool Holder (filament tangle & runout sensor) for Kobra 2 Max + others

thingiverse

The original filament sensor of my Anycubic Kobra 2 Max is not of much use, so I was searching the net for better one. Found this incredibly smart idea, which tackles the problem with a very different approach:https://www.thingiverse.com/thing:3383638Be sure to watch the original makers video to understand the ingenuity of this mechanism – it is very simple using only 2 switches and gravity. A marvellous piece of out-of-the-box thinking, impressive engineering!Best thing is: the logic works with the Anycubic Kobra 2 Max without touching the firmware, just connect it instead of the original sensor. This version of the smart spool holder stops the printing when:Filament is emptyFilament is tangledFilament diameter is bigger then 1,9mmYou can easily resume your printing afterwards, the mechanism of the smart spool holder makes sure your printer has enough filament until the stop signal is really pausing the printer!I had to alter some parts, because the Kobra 2 Max needs the switches to be open or pressed for several seconds, before it stops the printingParts list:Base / Anycubic Kobra 2 MaxUse the two screws of the original spool holder and mount it at the unused threads in the front left. Base / Rocker Arm1x screw M8x50(1x washer M8)1x nut M8Rocker Arm / Swivel Arm1x screw M6x25, countersunk (M6x20 countersunk does also work) 1x nut M6Rocker Arm Switch Housing4x screw M3x12Base Switch Cover4x screw M3x6 Swivel Arm1,5cm Capricorn XS (or similar PTFE tube with 1,9mm inner diameter). This acts as filament diameter sensor. If the filament is bigger than 1,9mm diameter, it won’t (hopefully) fit through the tube and trigger the „filament tangle/jam“ switch2x Mico switch KW12-3 or any other microswitch with roller and approx. 20x10x6,3mm2,35m of a not too thick cable1x standard 2,54mm pitch pin header-strip with 3 pins – only 2 pins are actually used in the anycubic sensor conncector, but the third one offers some extra friction to keep them connected.Axle_v1.2 is longer to take bigger spools, I took it from this remix: https://www.thingiverse.com/thing:3852003Base_Universal_Mounting_Plate is for those who don't have a Kobra 2 Max and want to mount the Smart Spool Holder somewhere else.