Infrared safety device (thermal runaway protection)?

I'm new to 3D printing - so new that I'm still waiting for my kit to arrive - but I've read a bit about the safety issues as I'll be using mine in my home and don't want a fire, and I got to thinking (which may be a dangerous thing!).......

It seems that one major fire concern is thermal runaway in the hot end. Perhaps from a faulty thermocouple or wiring issue and that this can lead to uncontrolled heating with disastrous effects.

Infrared thermometers are common so I was wondering if anyone has added one to their printer as a safety device. If not, I think I'll give it a go. Use a separate Arduino, driving an IR thermometer and controlling the power to the printer through a relay. Something like this should do the measuring part, I think [interface.khm.de]


The MLX90614 sensor reads a surface temperature of -70°C to 380°C in 0.5°C steps so should cover most plastics. I would imagine that it would be fairly easy to modify one of the cooling fan ducts to contain a mount for the sensor so it can read the temperature right near the nozzle.

Is anyone aware of this being done?

Richard

I like the idea.
A simple, low cost circuit to catch hot spots on the printer, to alarm or cut the power at say 20 deg C above the hotend temp?
I think it would need a wide angle of view to take in the whole printer. A spot temperature would not be much use.