Prusarduino Nano - Fire Safety System for 3D Printers (miniaturized)

myminifactory

Hello friends! My overall philosophy here was to create a fire safety system that's ridiculously easy to set up, with no programming skills required at all. Everything is plug & play, and you just need to print the parts, download the code, load it on your Arduino board, plug in the sensors as indicated in the code, and you're good to go! The only tricky part is modifying your printer alimentation wire, but that can be done with a simple cutter. If you want a more complete system, just check out this creation: https://www.thingiverse.com/thing:2432366/files I recently released my old version of Prusarduino, which I used to have on my old and awesome Prusa i3 Hephestos. Now that I've got a fantastic new Prusa i3 MK3 (with a heated bed, of course!), I thought it would be great to upgrade the fire detection system to fit this new printer. Here's my latest version! As a short video is always better than a long text, you can see what it does here: https://youtu.be/GDM_EfoJHiU So, basically, it does the same thing as the previous version: If the temperature of the air surrounding your printer is over 75°C (in this case), or if some smoke is detected, the Arduino board switches off the 5V relay, and your printer's power is automatically shut down. This way, if anything starts to burn on your printer, all electricity is removed from it to avoid overheating. This new version fits perfectly with the Lack Enclosure released by Prusa recently! I miniaturized it using an Arduino Nano to make it more affordable – this new system cost me just 10€ on eBay! It's super easy to build, and you don't need any programming skills at all; everything is enclosed here. This new version has an improved temperature sensing range (-40°C to +80°C) thanks to the DHT22 sensor. It'll be more compatible with heated beds. However, if you use it inside an enclosure, be careful not to accidentally shut off your printer's power while printing – it can get really warm in there! It still uses the MQ2 sensor for smoke detection. To act on your printer, I decided to directly cut into two the printer alimentation cable and wire it to the relay. This fix isn't heating up while printing, so no risk there! It requires these pieces: * MQ2 Smoke Sensor (link) * DHT22 temperature and humidity sensor (link) * 5V Relay (link) * An Arduino Nano board (link) The sensors can be mounted on different circuits depending on where you ordered them. If that's the case, I'm afraid you'll have to design a new case for them. Refer to my pictures to see the version I used. The links I attached are the ones I used to purchase the devices – I don't have any relationship with the vendor, or earn any money if you buy from there. So go ahead and find cheaper versions! Useful tricks: * All the instructions concerning the Arduino part are in the .ino file (Arduino script) that you can download here. * You'll find how and on which pin to connect the sensors to your Arduino board, as well as how to change the parameters of the script – including the temperature threshold, the delay before powering on your printer when the Arduino is started, etc. * Be careful not to spray hairspray or isopropanol (when cleaning your PEI bed) close to your printer – it can detect those and shut off your power! * If my sensor cases don't fit perfectly with your sensors, you can adjust them slightly using some pads for furniture that you can buy almost anywhere. I added the .step files for those who want to modify the design. You should be able to open it in Fusion360! Hope you like it! Please share some pictures if you make one – I'd love to see how it turns out! Happy printing!! P.S. If you like the design, consider a small tip – it would help me buy PLA to test my designs