Direct Drive DIY Filament Runout Sensor (Ender 3 / 3 Pro)

thingiverse

Direct Drive DIY Filament Runout Sensor (Ender 3 / 3 Pro) * This project uses the V-155-1C25 microswitch with roller.. After upgrading to direct drive, my side mounted filament runout sensor became useless to the point I had to disable it. I have since bought an eSUN filament dryer, which came with a feed tube from the dryer. As the tube fits nicely over the spare bowden tube i have, I decided to design a filament runout sensor that sits on the top bar instead of the spool holder, which is no longer needed.. The small piece of bowden tube is glued in place and is used to guide the filament across the switches roller. Without it, the filament will bend and it will be difficult to feed the filament through the unit. For the wiring, I used common on the side of the switch and normally open (the pin nearest common), so when the filament runs out and the switch closes, the printer will act. Depending on how your marlin is set up, it may be the other way round for you - in this case, simply wire to common and nc (normally closed). I have the btt tft35 e3 touch screen and wired to filament (DET)ect. The switch can also be wired to the main board - pin 15 on the skr mini boards I believe. You may want to google 'diy filament runout sensor' for information on your paticular board.. Anyway, I hope this is helpful for otheres and so share it with you here..