[Geschlossen] Fire hazard  

Re: Fire hazard

Maximum (peak) power consumption in worst case will be about 300W (all heaters and motors under permanent load). PSU is not 100% efficient, so let it be 400W. That is 1.7A from 230V or 3.3A from 120V.

Re: Fire hazard

Here's my two cents on the subject of 3d printer safety, some of the suggestions I make will already have been mentioned by others:

FFF printing is not yet in the stage where 3D printers are safety-wise like common household objects you can leave running without anybody around like say, regular inkjetprinters or a dishwasher.

As such, better safe than sorry so you should get the following equipment:

- smoke detector (They're so inexpensive these days there's no justification not to have them around the house. The fire chief & your insurance agent will love you for having them)
- portable fire extinguisher (If something does catch fire, you've got electrical equipment right by it so don't use water.) Note these things have an expiration date, so don't shell out the big cash and just get a small one like for your car.

Also do the following:
- store your flammable materials away from the printer. Perhaps even in a different room (Bottles of IPA, limonene D, ...)
- don't leave the house while you're printing something, somebody needs to be able to hear the smoke detector go off.
- point a camera at your printer. Some of us here use Octoprint with a raspberry pi, that's a suitable solution. That way you can leave the printer somewhat unattended and you can check on it from other parts of the house or yard.

Also take note when choosing materials, i.e. for an enclosure:
- paper can catch fire at temperatures of 233C. That's well within the temperature range the hot-end will reach depending on the material you're printing. This means you should be careful with cardboard objects as well.

Re: Fire hazard

Hi all,

that's interesting 🙂

Actually, I'm considering to use a home fire detector to trigger a relay to switch off the PSU in case of smoke detection.

Something like that: http://www.instructables.com/id/Modify-a-6-EUR-smoke-detector-for-use-with-microco/

And using 2 relays, for both neutral and phase wires, wired in a way so that on normal condition the PSU is plugged to AC, and disconnected in case of smoke detection, in addition to the sound alarm. However, I need to do some test to ensure it's not triggered in normal condition and to find the 🙂

Still at early phase of thought but it should be a good additionnal security solution.

Re: Fire hazard

Here is a simple DYI solution.

1) Make a printer box like this one:
http://www.3ders.org/articles/20150726-new-ikea-hack-lets-you-create-a-3d-printer-enclosure-for-cheap.html

2) Then plug everything into a power strip like this:
https://www.adafruit.com/products/2935?gclid=Cj0KEQjwqfvABRC6gJ3T_4mwspoBEiQAyoQPkVgogQxNHa5fIkZWIaeMZ1sPxnAu7ixqDbd2sZAal6AaAjQv8P8HAQ

3) Hook up an micro controller to detect a danger state: temperatures out of range, smoke detector triggered, etc. Here is an example setup.
http://www.raspberry-pi-geek.com/Archive/2014/04/Build-a-WiFi-enabled-remote-temperature-sensor-with-Arduino-Yun

4) If the micro controller detects fire / smoke / temperatures too high then have it turn on a DC fish pump that push water into a contain that has dry ice.

The micro controller will also power cycle the MK2. When water hits the dry ice it will create CO2 and with will be vented into the printer box.
It is important to turn the printer back on because the ABS parts may melt if the fan is off too long.

This system can be tested without destroying the electronics of the MK2 since CO2 is a gas, not a liquid. The only downfall is that you must have enough dry ice to last the whole print. You could just throw dry ice into the system when you are going to bed. If the system is triggered, vent the CO2 because it will suffocate both fires and humans.

For Dry Ice plan on using 5 to 10 pounds for each 24-hour period depending upon the quality of the insulated shipping container. This will keep everything frozen in a container up to 15 quarts. For larger containers and greater shipping times multiply dry ice quantities by this rate. The best shipping container is a two-inch thick urethane insulated box tested to lose only 5 pounds for a 10-quart storage volume every 24-hours.

Update: They make electronic C02 valves, no need for dry ice:
- https://www.amazon.com/AQUATEK-OF-CALIFORNIA-Regulator-Mini/dp/B008TJCPSY/ref=sr_1_1?s=pet-supplies&ie=UTF8&qid=1478482300&sr=1-1&keywords=c02+solenoid
- https://www.amazon.com/gp/product/B016NGH4M6/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A3M104HT1W8RYK

Also, even if the system is not triggered, dry ice will produce CO2 so proper precautions should be considered. It would be best to set this up in the basement or shed, not in the main living area and definitely not in the sleeping area.

Thoughts?

Re: Fire hazard

Also, this would do the trick but would be super messy:
https://www.amazon.com/Fire-Extinguisher-Ball-Auto-Off/dp/B01MFX2XWN/ref=pd_sim_sbs_60_4?ie=UTF8&psc=1&refRID=NZ5QX4G2AJ92DD3SVDYX

I would use this as a secondary fail safe. It you place the Rambo and power supply outside of the printer box then it you only have to clean up the parts attached to the frame.

But the above is not as bad as this:
http://www.soliforum.com/topic/6608/beware-your-3d-printer-they-can-cause-fires/

Re: Fire hazard

Another possible DYI solution is to use baking soda and vinegar to generate CO2.

You could put the baking soda in a balloon over a pot of vinegar in a printing box. Once the heat inside the box gets too high the balloon will pop over the pot of vinegar and put out the fire.

You could also place the baking soda over the pot of vinegar in a paper bag suspend by a string that has been cut into two piece and rejoined using wax from a candle. If the heat gets to high the wax will melt dropping the paper bag of baking soda into the pot of vinegar producing the CO2 to put out the fire. The bag could attached to some sort of spring loaded switch that would kill power to the system.

You could also use a mercury switch thermostat that would ignite the fuses use in model rocket engines to pop the balloon of baking soda.
This thermostat could be used as well: https://www.amazon.com/Lux-T101141SA-Mechanical-Thermostat-Sterling/dp/B000E7PZUY/ref=pd_sim_sbs_60_1?ie=UTF8&psc=1&refRID=0KMRH2AMCFMGB9DGGC7N

The rocket ignition fuse runs on a self contain 9v battery and is affected if the power system or controller board gets toasted.

Re: Fire hazard

...
Reminds me of this: https://en.wikipedia.org/wiki/The_Incredible_Machine_%28series%29 😆

Re: Fire hazard

I agree. One could make a 3D print of a box with two chambers to keep vinegar and baking soda separate. Put the device in the printer box and if there is a fire the 3D print will melt and release the CO2.

Re: Fire hazard

If the print is full of vinegar it will not melt until the vinegar has heated up a lot.... I suspect this would be too long to be useful...

the vinegar would essentially be a heat sink...

the baking soda might allow the chamber to melt...

best to give it a try in a simulated overheating situation...
best wishes Joan

Re: Fire hazard

...or hire the a neighbor's kid to sit and watch your printer for you. 🙂 Seems much less complicated. 🙂 🙂 🙂

Re: Fire hazard

Some of my prints run 24 hrs which rules out humans.

In thinking about this more, the first sign of fire will be smoke. Therefore I can have a closed loop system that runs off a battery.

The system will trigger when the smoke is detected us this device with an arduino: https://www.amazon.com/gp/product/B01F2X3VY6/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=AUUCM4D6XGJ7T .

Here is a sample setup: http://www.instructables.com/id/Smoke-Detector/?ALLSTEPS

Once the system is triggered it will power cycle the Octoprint which will halt the current job, but keep the fans running on the hot end of the MK2.

The system will turn on a dc fish pump that will combine vinegar and baking soda to product CO2. The mixing chamber will be outside of the printing box and will be connected with a tube.

The second fail safe will be Stovetop Firestop ( https://www.amazon.com/Williams-Pyro-675-3D-Stovetop-Firestop-Venthood/dp/B00FL6VU3Y/ref=sr_1_5?ie=UTF8&qid=1478634111&sr=8-5&keywords=fire+suppression+system ) mounted inside the case.

This should handle all scenarios that I can think of.

Re: Fire hazard

I'm not sure why I didn't think of this before, but I have a home automation system that is z-wave based.

I will purchase a z-wave smoke detector ( https://www.amazon.com/gp/product/B00KMHXFAI/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1O77D5UJY7IVU ) which kills power to the octopi.

I am using a VeraLite-US Smart Home Controller Hub which has a REST API and Arduino plugins, so I can still trigger a CO2 based suppression system.

The fail safe will still be one these balls:

Re: Fire hazard

To my knowledge there has only been one actual house fire caused by a printer, (it was a Solidoodle) There have been plenty of burnt and melted printers, but other than that one, no actually house fires.

But it can never hurt to implement any protective measure you want to implement.

Re: Fire hazard

This might be an option to place on the inside Of any enclosure for ABS printing.
https://www.amazon.com/gp/product/B0758P49HV/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A1SEW4ZO2ZFJZI