“Hey! This was a weekend project of mine. While stuck in Covid lockdown in the U.K. there’s nothing much to do except create and make things. Using some spare parts which any hobbist will have I was able to create a sensor which warns me when I’m low on filament for my 3D printer.
As any 3D printerist will know, running out of filament mid print is one of the most painful experiences to have to watch. (Ok maybe I exaggerate a bit).
This simple circuit sets off a buzzer when the filament passes through this system using a little limit switch pressed against the filament.
Disclaimer: I’m not responsible if anyone causes injuries or death to themselves or others, nor am I resposible if they cause damage to objects after building a project identical or similar to this instructable.
For this project you will need:
A battery (I used an 18650 however with the right holder anything smaller can fit in this)
A limit switch
Double sided stickypads (to attach to the printer)
3D printer for the case (and filament)
Glue gun (and glue)
Soldering iron (and solder)
A second switch”