FIRE!

That's it im done, I have had enough now.
The new heater just set fire to the protective cover on the hotend.
I can't be bothered now!

There is a Safety section with some really good information. Fire is a real fear with these DIY printers, so be careful and watchful.

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madmike8
There is a Safety section with some really good information. Fire is a real fear with these DIY printers, so be careful and watchful.

I work in the fire industry so always have a fire extinguisher close to hand
The cause was the sensor coming loose!

O.o fire is bad mmmmkay

got pics?

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My creations/2020 aluminum parts/FolgerTech i3 upgrades [www.thingiverse.com]

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mel0n
O.o fire is bad mmmmkay

got pics?

No

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GRAYWOLF
I work in the fire industry so always have a fire extinguisher close to hand
The cause was the sensor coming loose!

What electronics and firmware were you running? I thought most firmwares had protection mechanisms to guard against that sort of thing.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

They do but it relies on the temperature probe which and fallen out when the hot end was reassembled.

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GRAYWOLF
They do but it relies on the temperature probe which and fallen out when the hot end was reassembled.

So the probe fell out but remained connected. This shows the importance of securing the temperature probe. E3D provide a screw to secure the leads, and RepRapPro in their instructions say to cable tie the thermistor leads in place.

Edited 1 time(s). Last edit at 07/15/2015 04:57PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

It happened to me. I had a close shave when the hotend thermostat got pulled out by a print that went awol. It filled the house with smoke.

I fitted a smoke detector that cuts the power to the printer. Not absolutely failsafe but should catch majority of problems.

Don't give up. Re think the way you do things. Don't print unattended. Printing overnight is particularly dangerous imho.

This is a problem that affects all of us. If 3d printing is seen as high risk by insurers, conditions may be imposed.

Edited 1 time(s). Last edit at 07/15/2015 05:35PM by dave3d.

As mentioned by madmike8 above, fire risks, incidents and prevention are better discussed in the Safety section. Which makes reading through the various threads in the Safety section a good idea, before you even get started on any RepRap build.

It's times like this where facebooks like function would come in handy.

That smoke detector with a cutoff is a seriously good idea. I'm going to check online for something small that can be attached to the x carraige. Thanks.

And here it is. Cheap with relay onboard.
[www.aliexpress.com]

Interesting module! It says it has adjustable sensitivity - I wonder if it could be used inside a printer enclosure without producing too many false alarms. The upper limit of the working temperature is a bit on the low side though. Otherwise - a really neat safety addition!

I have ordered one of these modues, when I get it up and running and tested (part time alarm engineer!) I will report back.

I bought one of those modules but have never used it.
I ended up using an Aico Ei141 ionisation type smoke alarm with an integral Ei128R base unit that houses a switching relay. An external latching relay is required for the circuitry and I housed this in a separate box. These are commercial quality parts not cheap, possibly unreliable, electronics. It has been in use now over a year and it works well when tested, but not used in anger yet.
I also invested in a CO2 extinguisher.

This is the very tip of the iceberg. An unregulated industry is inherently unsafe. For all the futuristic, almost utopian aspirations of the 3d printer movement, there will be consequences. No good deed goes unpunished.

Insidences like this are like ants on your kitchen floor. If you see one, you can bet there's 10,000 that you can't. The reason for this is the willingness to believe that the first to the market is trustworthy. Standing on the cutting edge of inovation rarely means that safety is the first thing on your mind. Unscrupulous vendors are abound.

This is the price we pay for the developement of new ideas; new ways of doing things. If the cost of finding out which printer is B.S. and which is reliable is your house burning down with your family in it, I say that cost is too high. People like this should be driven out of the market. We need a vetting process of some kind to take dangerous products off of the market so innocent people don't get hurt, or God forbid, killed.

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dr.hunter s. thompson wrote:
This is the very tip of the iceberg. An unregulated industry is inherently unsafe. For all the futuristic, almost utopian aspirations of the 3d printer movement, there will be consequences. No good deed goes unpunished.

I could not agree more. Repraps are by definition home built DIY printers that are built by a wide range of enthusiasts but all with different abilities. A knowledge of electronics, mechanics and materials of construction is required. In addition a lot of experimentation goes on.

When you read through these forums a lot of reprappers on here have had incidents of one sort or another, including me.
A few big claims for house fires and insurers may refuse fire insurance if a 3d printer is used in the house or limit it to commercially made printers built to an agreed standard or code of practice. This will affect all of us.

How do you wire a smoke detector to cut off the printer. Is it connected to the kill switch?

The relay cuts the mains power supply to the printer so everything is shut down.

IF (Heater == ON && TempRise != 1-10)
Switch OFF

Marlin people, could you look at this and implement. It does not rely on an accurate thermistor or thermocouple reading. If you need more info or to discuss as to the logic of implementation, come find me in irc.
Note:
If a temp probe falls out, temp will not increase if the heater is on. This is a good indicator.
If a temp probe shorts to 0 degrees or max temp, this will be a sudden temp rise. The temp rise in the algo can be set as a gradual increase, ie if temp rise is not between 1-10 degrees, this will discount the shorted or fallen out temp probe scenario

HTH

Edited 1 time(s). Last edit at 09/22/2015 08:54AM by Mutley3D.

That already exists in Marlin.

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greenman100
That already exists in Marlin.

Does it? for one thermistor, or for two thermistors cross checking for a difference between them?

Is the some date on the marlin ranaway function?

just a quick comment here. i would think the best method to reduce concerns of fire would be a mechanism that is not tied to the firmware. the firmware in theory could crash and that could be a possible cause. you want something also that relates to the direct issue. excessive heat, i would think that by the time smoke is detected damage is already done and a fire potentially started. I have always been a fan of thermal fuses or thermal cutouts, that require replacement when something goes wrong. that being said any extra precautions are welcome, as long as there reliability is not based on the tool that could be failing. for example using firmware to have the only software cutoff (it is still a good idea in firmware but it is not 100% reliable), smoke detector is a good idea as well, but if a fire has already started then it might be too late. a bolted on thermal cut off seems like the best approach along with any reasonable protection one feels is needed. It seems like a good idea to not plan to leave a machine unattended. this is not always possible because of the extremely long jon run times. but at very minimum have a fire extinguisher within 3 feet of machine, and have a fire alarm in the same room.

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jamesdanielv
just a quick comment here. i would think the best method to reduce concerns of fire would be a mechanism that is not tied to the firmware. the firmware in theory could crash and that could be a possible cause....

You can protect against firmware crashes by a combination of proper hardware design (so that all heaters are turned off when the microcontroller is reset) and using the watchdog timer built into the microcontroller hardware. Any decent 3D printer firmware ought to include such a mechanism, but sadly some firmwares don't.

I agree that a backup mechanism independent of the firmware is desirable. In my case it is a smoke alarm in the room with the printers, linked to other smoke alarms in the building, and a fire extinguisher outside the door. I never leave the building while a print is in progress.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].