Filament Alarm From Solder Practice Kit

thingiverse

I had an old Elenco soldering practice kit collecting dust in my closet that I wanted to breathe new life into, so I transformed it into a filament alarm from scratch. The filament flows through the hole on the side and when it runs out, the 2 leads that it was separating will connect instantly setting off the alarm with precision. There's a convenient hole in the top for easy access to the volume knob located directly on the board. I had to do some careful trimming to get everything to fit together perfectly and needed to secure the plates together with tape to ensure reliable operation. If I revisit this project, I'd design it so all the parts snap together seamlessly. You can see a quick demo video here: https://youtu.be/nyVRwVZCkmM