Beware your 3D printer (They can cause fires) (Page 3 of 8)

Added url for you. That extinguisher definitely looks like a good option. I would like to see one of these actually discharge over a printer.

Also, +1 on Pinhole Printed. Amazing project! I will be buying one for sure to add to my camera collection.

I worked at a injection molding/extrusion facility for 8 years. We melted and reformed plastics of all kinds including ABS 24/7 and there are no rules about fumes or PPE required for breathing. It would take ten thousand printers running constantly to produce the same volume of material. And there were monthly air quality tests (for other chemicals in downstream processes) that showed the extrusion area clear of any health dangers.

Condolences to Skyminer.  With a wife and two kids in my house I am not particularly wild about leaving my printer running.  Especially overnight, but of course that invalidates the whole purpose of a CNC machine.  The intention is a machine that frees up my time, at least in this particular iteration. 

I like the fire extinguisher idea, except for that is quite the serious industrial solution.  Seeing as these are akin to laser printers, etc in my opinion as far as placement in the home... I think there should be a solution that is 99% as effective, but doesn't require a big red canister over head.  Although I think unlike many electronic items in our home a 3d printer has heating elements specifically designed to get very hot, and require active regulation for thousands of hours over the life of the printer. So extra precaution seems apparently very necessary.  But what that is I think is tricky to say.  Either you invalidate the compact nature of the system and create an industrial fire extinguisher solution, or require a compact sensor/relay package.  Not seeing too many other options.

Speaking of laser printers, they use very powerful heating elements, and on large print jobs (I realize are probably rare for most users) the printer seems like it to would need protection from a similar thermal overload situation.  I wonder what their solution is, if any. Regardless of if it's the bed heater, nozzle heater, or bad power supply.  It seems like the necessary solution would be like Daid pointed out, a master cut off relay. 

I am thinking about using a 30 amp AC solid state relay that I have left over from another project perhaps coupled with a smoke detector.  But then would it do any good... It may cut the power once smoke is detected, but that doesn't mean it stopped anything from catching fire.  Perhaps what is really necessary is a miniaturized version of the industrial fire extinguisher built in to the machine itself.  I am thinking about using the 12 - 25 gram CO2 cartridges coupled with the solid state relay and a smoke detector sensor placed on the inside at the top of the enclosure.  When x amount of smoke is detected have a servo release a pin that would puncture the CO2 cartridge flooding the chamber with C02 and signaling the relay to shut off. 

I am thinking this could be a very compact unit. that would be unobtrusive and invisible unless needed.  The extinguisher portion would not need to be much larger than the cartridge itself.  and you could use a nozzle to direct the CO2 directly down.

I realize this is not a very good fit for open air machines.  But could possibly be adapted.

ask firemen about ball lightening or google it. though rare it still occurs and can reach temps exceeding that of the sun for a few seconds and move about even pass through walls etc.

A very interesting topic, but I doubt ball lightening is among the list of primary concerns in 3D printing.
The black hole theory is a good hypothesis, but I think electrostatic is more of a possibility...though possible, very improbably. You have a much better chance of a gas station blowing sky high than a a printer bursting in flames via ball lightening.

these depending what is inside can be dangerous to air breathing life forms if safe for electrical fires plus cost more than printer. made for commercial applications I was trained for similar types as facility engineer for MCI Worldcom and health centers.

Mitch

And thank you for that! I enjoy learning new things.
I, as I am sure many of us, believe the thermistor slipped out of place, then allowing the heater to run wild. It is very possible as the kapton around the block can loosen once heated...which happened to me yesterday when heat cycling for my new hotend. I took the time to wrap more kapton, thinking about this very thread the entire time.

I find Skyminer's unfortunate event is not only a sobering one, but also bares a thread just as important as a beginner's walkthrough on printing.

The E3D v6 addresses this...
http://www.filastruder.com/products/all … -v6-hotend

I tin multicore wires with solder before putting them into screw terminals, usually reduces the chance of escape.

In industrial machinery people use bootlace crimps on the wire ends for the same reason.

In any case, clamping the power cable to the case would prevent any load from being put on the termination; might be a good idea in any case to prevent accidental disconnection (including with the barrel connector).

Ech, stop being precious and get your drill out!
You can get sticky cable clamps from the hardware store too, that could also help with cable tidying in general.

But...but...
ok