M2 Fire Report

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rpollack
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Re: M2 Fire Report

Post by rpollack » Mon Jul 24, 2017 6:27 pm

We analyzed the machine and we have not been able to reproduce the cause of the fire. The heater block did not melt. We have also tested many failure scenarios over the years.

We do not know what happened with this machine.

Bratag
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Re: M2 Fire Report

Post by Bratag » Mon Jul 24, 2017 6:31 pm

rpollack wrote:Here is an updated on what we know:

Prior to the fire, the printer was shutting down with a temperature error - this means there was a problem in the temperature regulation system. The owner did not contact us for support but did order replacement parts (thermistor, cartridge heater and some other parts). While waiting on the replacement parts to arrive, the owner continued to use the printer and run it unattended.

We have analyzed the printer and attempted to reproduce the fire but have not been able to reproduce it. We do not know what happened. We have contracted a 3rd party specialist to help with the investigation.

We'll post updates as they are available.

Rick
"Driver noted doors had fallen off car, ordered replacement parts but continued to drive without doors. Bad review left regarding falling out of moving vehicle."

I know this isn't a witch hunt but eventually people have to take some responsibility for their actions.

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rpollack
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Re: M2 Fire Report

Post by rpollack » Mon Jul 24, 2017 6:32 pm

@insta - running the cartridge heater at full power just produces smoke.

hybridprinter
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Re: M2 Fire Report

Post by hybridprinter » Mon Jul 24, 2017 6:38 pm

why not just have a temp monitor on the aluminum block, if the block exceeds for instance 375 C then shut down the main power to the machine.
jimc wrote:Thermistor goes bad, hardware component on rambo board goes bad, glitch in the firmware. Any one of these items would have to fail in a way to keep power on constant to the heater cartridge. I have watched a forced failure video awhile ago. The cartridge will melt the aluminum heater block and catch the filament drive on fire and anything flammable around it

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jimc
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Re: M2 Fire Report

Post by jimc » Mon Jul 24, 2017 6:48 pm

Yes, an i dependent over temp circuit is what is needed. A temp switch on the block that will shut down the power supply. Problem is lack of a temp switch or sensor that is small enough at the right temp to work. Last time i looked was about a year ago and there is just nothing on the the market. The whole fire hazard thing is hardly a makergear issue. Its every 3d printer out there. If something was available then everyone would be using it.

hybridprinter
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Re: M2 Fire Report

Post by hybridprinter » Mon Jul 24, 2017 7:51 pm

how about one of those handheld laser temp guns pointed at the aluminum block (mounted to a bracket which attaches to the extruder carriage), the temp gun could probably have an output cable that feeds real-time temp into the 3DPrinter electronics (or whatever can control the power supply on/off function).

or how about a temp sensor which is like a sticker that can be stuck to the side of the aluminum block, nothing made like that?

jimc wrote:Yes, an i dependent over temp circuit is what is needed. A temp switch on the block that will shut down the power supply. Problem is lack of a temp switch or sensor that is small enough at the right temp to work. Last time i looked was about a year ago and there is just nothing on the the market. The whole fire hazard thing is hardly a makergear issue. Its every 3d printer out there. If something was available then everyone would be using it.

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jimc
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Re: M2 Fire Report

Post by jimc » Mon Jul 24, 2017 8:34 pm

You cant get a true reading on the hotend with an ir gun. Its too precise of an area that needs a measurement. No small sensor is available for the block. You would need a second sensing unit maybe using a thermocouple attached to the block connected to a purpose built board

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Tim
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Re: M2 Fire Report

Post by Tim » Tue Jul 25, 2017 1:25 pm

jimc wrote:You would need a second sensing unit maybe using a thermocouple attached to the block connected to a purpose built board
That does lead to one possible and fairly cheap solution: Redundant temperature sensors. If the temperature sensor is known to be a part with a high failure rate, then double them up. Works for a single extruder, at least, since the RAMBo has three sockets for thermistors.

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jimc
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Re: M2 Fire Report

Post by jimc » Tue Jul 25, 2017 1:46 pm

Yeah i would also get it on a small dedicated board completely off the rambo.

hybridprinter
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Re: M2 Fire Report

Post by hybridprinter » Tue Jul 25, 2017 2:10 pm

Can the stock M2 power supply even be turned off and on with an electrical signal?

Our M2 power supplies are plugged into WeMo devices for remote control, maybe there is a temp sensor which can interface with the WeMo software and that software could turn on/off the M2 PSU?

Also good idea to have a smoke/CO2 detector with loud alarm sitting next to the printers (which of course would only be beneficial when running the printers when on-site).

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