Skelestruder micro switch filament sensor

thingiverse

Still a work in progress! This is NOT for Prusa firmware printers. You could use it for Prusa printers but you would have to modify the firmware. I am using this on my i3 Duet 2 Maestro build. I really like having my filament sensor on my Prusa i3 MK2.5 in case my filament runs out during a print in the middle of the night. I do like how it auto loads as well, but since jltx did a great job on the Skelestruder it's too easy to load by placing your thumb on the cartridge cover while pulling up on the filament idler and then just pushing filament down through the hotend until you're satisfied. So to me, the only reason for a filament sensor now is for detecting filament runout. I used the filament runout sensor that I linked as a remix to modify the cartridge design of the skelestruder. These are the switches I bought and designed it for https://www.amazon.com/gp/product/B073TYWX86/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1 I've printed this and fit it, but I have not yet hooked it up (but will report back when I do.) I did hook up the C (common) and NO (normally open) leads to my multimeter and tested that it was triggering correctly. To install the switch, I twisted the metal leaver off of the switch and oriented the switch with the red trigger to the top. I don't like using those small M2 screws so what I did was I took an allen wrench of the same size as 1.75mm filament and I ran it through the holes that hold the switch in place. Once I cleared out the holes I then cut some PETG 1.75mm filament at an angle and used pliers to push it through the holes and clipped off the excess on either side (if it went all the way through.) I haven't tried to get it back out yet, but I'm thinking I might be able to use the allen wrench to push the filament back out. I'm including the Fusion 360 files in case someone has a better way to make this work. It's a tight fit! You will need to download the remixed filament runout sensor's "Filament_Runout_Sensor_piece_thick.stl" file and print it for use with this. I will add it at a later time so that it can be done from here.