3D printer filament sensor

3D printer filament sensor

How about a filament out sensor that is also a smoke alarm. Positioning is adjustable due to it being a fixed to a binder clip.

Download filament sensor switchbox remix from Thingiverse, or design and print your own box.

Next up, make sure your switch fits, modify box if necessary. Now it’s time to mount it to a clip. I used a large binder clip. I drilled two holes in the switchbox and clip and attached with 2 small sheet metal screws. 

Once the switch is mounted onto the clip it’s time to solder on the wires. Using the outer 2 contacts makes this a normally open switch when depressed which is what we want. Use stranded wire, it works best, and you want enough length so it can reach your smoke alarm.

If you don’t want to wire into a smoke alarm you could wire into a low voltage buzzer, or small light. In my example, I am wiring it into a smoke alarm. This serves two purposes – if my 3d printer (in this case an Anet A8) goes up in flames or starts to smoke, I am alerted. I do try to make sure I do not leave my prints unattended but there are times when you have to leave the area especially when your doing a 3 hour print.

I have used a modified (out of date) smoke alarm that I replaced. Once wired up, it was tested with smoke and my filament out sensor. For info on how to wire up a smoke alarm to use in this project or as a water detection sensor take a look at our water alarm post.

So this will not stop your printer but it will give you time to do that, or get your replacement filament ready to install. Plus it’s wise to have a smoke alarm handy as well as a fire extinguisher.

Stay safe and have fun!