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Everything you need to know to make your 3D printer fireproof!
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- Опубликовано: 6 апр 2018
- It doesn't take much for a 3D printer to catch fire - but it's easy to prevent! Here's how you can make your own 3D printer safer and keep it from causing more harm should it start to burn anyways.
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As a firefighter myself this is a good topic to be covered. With things being made cheaply to keep cost down safety is the part of the trade off. It's always a good idea to do routine inspections of your equipment to make sure there's no problems before it becomes one.
Agreed, plus a good idea to situate the printer away from combustible materials if possible to prevent a fire escalating. Not a good idea to leave it unattended either. I've seen adapters and plugs on high power appliances such as electric heaters go into meltdown because of bad spot welds holding the internal bus bars and pin contacts together.
Do you think it's a good idea if I inspect my printer from a stream webcam with octoprint while I'm away? Pause my print or simply use a remote socket to unplug it! I can stay for the first hour maybe or something
thank you for being a hero! :) THANK YOU SO MUCH!
Gypsum board/drywall... there's a REASON it is used in structures. So instead of making a wooden box, build a drywall box with the wood frame OUTSIDE the panel; any flames that occur can only come in contact with drywall. (Note drywall will not contain a raging fire, and the "seams" are a weak point but you can use angle bracket framing to help prevent any flames from leaking out)
This was actually one of my biggest concerns when I designed my 3D printer. Here is a list of all the things I did to prevent fires.
- Lots of fuses. My bed and my hotend have there own fuse. The board also has its own fuse
- All heaters currents go around the board, not through the board. The bed has an SSR
- All Marlin safety features used
- When SSR's fail, they stay open all the time. Therefore I use a relay which can shut off the current going to the bed and the hotend. The relay is operated by the firmware and is turned on when the printer turns on, and turned of when the kill procedure is activated.
- There is a mechanical bimetal switch on the bed which switches the bed of at a curtain temperature in case of a firmware error with the bed heater.
- My printer prints inside an enclosed frame. I have a smoke detector inside the printer frame. Smoke will be detected at a very early phase.
My printer actually failed once because the connector switching the safety relay got lose. It is always funny when your ridiculous amount of safety features cause problems of there own.
In response to your last line, I work on military helicopters doing electrical work. The engine fire detectors, that tell you when your aircraft is on fire, go bad and set off the warning quite often. I've changed dozens of those sensors but have never seen an engine fire. I think it's to the point that the pilots assume it's a false alarm every time it happens
I got one from that same brand. If I remember correctly the brand was "Self Fulfilling Prophesy"
I would like to see a series on this where you review a few board components and which connectors are in which printers.
Many of us do not open that cover to even know which board (connectors) we have and which type of MOSFET or even if we have fuses. If we don't have fuses, which two wires on our board do we fuse, etc.
and thank you very much for taking the time and care to post us this informative video as a start. 👍🏼👍🏼
Products get revised all the time. This would be a huge job, and there's the "send one with name brand connectors to the reviewer" scam.
I've been thinking about picking up some "Stove Top Fire Stop" fire extinguishers for my 3D printer enclosure. I made an All-wood enclosure (even though you discount it, having an all-plastic enclosure is just as bad, maybe worse) for my printer. There are a number of automatic fire extinguishers that rely on a fire melting something to release the retardant. I think this is something we need to see in the 3D printing community.
Maybe its an overkill but in somecasses its should be usefull. I think its more importent to recheck everything in 3 months or so. maintenance
I was thinking about getting something like this too, but my concern is that it's designed to be mounted on a metal stove hood, which isn't going to burn or melt. It only goes off after sustained and direct contact to fire, so If you put it on a wood or plastic mount, it's possible that it falls off and fails to trigger.
Yeah you can get those online @wildrosebuilds has a video testing them out. They're not the cheapest but the peace of mind is definitely priceless.
My printer is a Ender 3 v2 Neo, and I’m kinda glad you talked mostly about kits because that’s less stuff I need to worry about I guess
My machine is in an IT rack that ended up being just the right size for it and its accessories, it's extremely cheap second hand, it's sturdy metal with a glass window and has plenty of mounting points for cameras, raspberry pi, spool holders and whatnot, it keeps the ambient temperature predictable and avoids drafts, keeps everything dust free and it looks badass. ^^
If you’re printing in a basement or garage that has exposed ceiling with pipes, it’s pretty cheap to have a plumber add a fire sprinkler. Several years ago I had a plumber add a couple around our gas hot water heater and gas furnace and that cost about $150. I run my printer on the other side of my furnace a few feet away but still under the sprinkler and have no fear.
I run 34 printers in wooden enclosed shelves right now. Just bought some of those stove top fire suppression devices. Going to put them in a couple to make sure there are no false positives and then put them with every printer. Going to be about $1000 but will absolutely be worth it.
There is a company in the UK called Jacktone who sell "Auto fire extinguishers" the just have a hose connected to the valve.
When the hose ruptures from heat, the extinguisher releases its content.
These are great and work without triggers, cable or other moving parts which have been known to fail and not trigger the fire extinguisher.
Don Mega he said contents not water
Fire extinguishing also should cut off power supply first
Don Mega you can get auto co2 extinguishers, problem solved
Really great video! Something you might have added, when talking about improving your printers safety are external mosfets: They are designed with more current in mind, so they will have reserves, but they also come with connectors that are capable of dealing with higer current than the stock connectors on the control board. And by using an external mosfet you lower the current going to your contol board, lowering the danger of using the bad connectors for power supply of the control board. And it will allow you to add a fuse just for the mainboard with a rather low value, because all the big currents will run on the external mosfets. I think it is a major safety upgrade for a 3d printer to use external mosfets for hotend and heatbed and use 3 fuses - one for the headbed, one for the hotend and one for the controlboard (without heatbed and hotend current).
The only time I've had a thermal runaway is when my layer cooling fan shroud was poorly designed and cooled the nozzle.
Also, if fire is a huge concern, there's likely a way to wire up a fire alarm to main power of the printer.
By the time there is a fire, cutting power won't matter.
@@janbroz4681 thats so true! cutting power makes no sense if there is a nice little fire going on
@@janbroz4681 it will smoke before it burns (I think)
@@korodo7599 fair point
@@janbroz4681 Actually it very much matters. There is no point in a sense on putting fire out, when heat source is still creating more heat, ie shorting wires etc, so first cut the power and then put out the fire, if possible both at the same time. Also helps to prevent getting electrocuted if metal frame is on contact with the wires or something like that. After power is off, you should be able to put it out even with some water(?), if there is no fire extinguisher around, witch there should be one and it should be inspected one for that.
I love this video. Ive been advocating so many of these safety tips for so long. A few more things I may suggest:
Cork pads/mats. Cork dosen't burn like a yoga mat or rubber mat can. Makes for a great insulator for a printer to sit on to help limit sound vibrations, Can be easily gotten and used to help insulate mountings of electronics from metal frames.
Sheetrock. Another good, non-flamable material you can set your printer on top of to help keep a table top from spreading a fire, this is the same reason it is used on the interior walls of a house or gun safe.
Another idea I have seen people do with RC batteries that may work for a 3D printer if there is a large enough rack over head of it, A large plastic bag full of sand. The basic theory is the heat from a fire melts the bag, dumps the sand and smothers the fire. The sand also can help to limit spread of any melted plastic to help stop the spread of anything burning.
KNOW WHERE YOUR GAS LINES RUN IN YOUR HOME!!!! Dont print next to gaslines. Should a printer fail, it being near an even bigger fuel source can make the situation worse. Yes, gaslines are rated to deal with some degree of flame to help stop failure, but dont blindly trust it on its own.
Just a few ideas for v2 of fire safety video :P
Actually, another point about nearby gas lines is if you do get a gas leak, and there is a heated nozzle and bed nearby, that heat could ignite the gas.
I plan on using a smart smoke detector. I'm almost finished with my enclosure. One of my other hobbies is automation. I personally use Smartthings to control lights and doors. I already have a power switch that my 3d printer runs through. I can power off and on the printer remotely if needed. It comes in handy when that one print is almost done but I have to go to work.
With the smoke detector in the enclosure, I plan on setting it up to automatically turn the printer off if it detects smoke. That way, if the smoke is electrical in nature, it should prevent a fire if is detects it early enough. I would expect it to also work for catastrophic print failure that balls up on the nozzle and causes any smoke.
Awesome Video Tom!!! I own an Anet A2 I have two small children at home, and the first thing I did was upgrade the main wiring for the heated bed and from the power supply with 12awg silicone wires, also bought spade connectors, auxiliary mosfets, a 33amp power supply, smoke alarm, changed the connectors on the heated bed, and managed the wires properly... now I just bought inline fuses for both the hotbed, and hotend!! Thank you for this, one more thing that I can add to my printer for some more peace of mind!
How great! I have learned so much from watching you. You pointed out a fault on the Creality CR-10. I bought one. They must have watched your video because they thought they solved that with a plastic strain relief attachment. The only problem is, it prevents the bed from leveling because they attach it under the bed the a leveling lug. I sent mine back, after making a video pointing it out. Personally, after taking mine apart, I would never own a Creality. They are assembled poorly. It printed 1/10 of the Cat before shutting down with Thermal Runaway. I took the heater block apart and they had bent the thermistor wires right at the base of the bulb, breaking it; not to mention tightening it too much and squishing the insulation. I replaced it with a Winice M09, slightly smaller, but I love double Z screws, not to mention assisted bed leveling.
I also own an Anet A8, for roughly a month now. Today has been a very weird day for my relationship with it. I received the recommended mosfets and a soldering iron in the mail, got really stoked about how well it's lasted and started taking it down. When I took the bed connector off, it wiggled right out of place and had a nice scorch mark on the side next to the 12v pin. After following the community's suggestions of "fixing it", I see Thomas has released a video with even BETTER suggestions about this very issue!
I can't recommend enough that if you buy one, get the electronics and do some soldering... I really don't think these are complete right out of the box.
That being said, it works quite well. I've binged hours of different 3dp content before and during my ownership, and i'm really happy with the quality of what little I have made. I would still recommend it to people, with the stipulation that you treat it like it needs to be treated. Like a cheap piece of miniature chinese industrial equipment. lol.
I had the cheap ramps connector melt on me once. I ended up buying a bag of 12v barrel jack connectors for it instead and just pressed it in the pins. Works like a charm and it hasn't melted or shown any signs. Good stuff.
I have an Anet A8, which is notorious for being dangerous. It's pretty much stock, but I did double check everything during assembly and took my time to do the wiring as well as the design and my equipment allowed me. It's been printing really well for almost 6 months now, but I will do some temperature checking with an IR camera this week, just to be sure.
11:30 you can also use an old tape measure to add support to wires. It works well with braided wrap. Not sure about spiral wrap.
I read a lot of comments that the A8 is "Always the one to set itself on fire. "
I know this isn't true.
But part of the problem is that the Anet A8 is a home build printer.
So the quality of hiw it is put together can have a huge bearing on how safe it is to use.
The tips in the video are all valid and I would also add that a 3D printer should be 'serviced' at regular times.
Chect the wires for problems.
Check nuts and screws are tight etc.
Lightly oil the rods etc.
But yes.
Treat these items with care and respect.
I'm 3D printing in an old house, in a closet in an office that's off of another room, none of which have fire alarms. So, something was telling me to be careful... I'm glad my intuition kicked in. Definitely will not run my printer overnight
Thanks for making this, you have really helped a lot of people.
+Thomas Sanladerer
That smoke detector is in a BAD spot you should have it in the centre of the ceiling - putting it on a corner like that means the airflow could keep smoke from going through the detector. I'm a former firealarm technician and I have seen smoke alarms fail in locations like that.
was looking for this comment
basically all the firealarms i bought had a 0.5 to 1m recommendation for wall distance on the box
Notice all the fires are Anet A8? Hmm.
Quite a bold claim..
All the fires aren't the A8, but I'll admit it's safety out of the box is pretty poor. I thankfully got some advice from the A8 community on facebook before I got mine so I was aware about all the mandatory safety mods it needed. But anyone who just rocks up to gearbest slaps their cheap Chinese printer kit of choice together and leaves it running overnight unattended is asking for trouble.
Some of the 'mandatory' mods I've seen advertised for the A8 are just creating other obvious points of failure, or merely introducing complexity for no benefit.
The biggest problem is the assembler, not the parts.
Monkeh might be right - but a kit requiring perfect assembly and at least some mods to run safely isn’t the real deal either.
The most essential upgrade is human supervision.
As for Marlin safety features, if you're having issues, rather than disabling them, you can slightly relax, how strict they are.
If I remember correctly, there's a time period, and heat offset. If the heat reading stays off from target for longer than given period of time, the print will be stopped, and all heaters shut down. So basically you can increase the allowed difference, or increase time period, or both.
design is a factor as well. Some hot ends can get hot enough to set plastic on fire under a run away conditions. other appear to top out at smoldering point. I had a thermistor failure that resulted in a call for max temp for a very significant time to an e3dv6 - no fire or smoking occurred. (The 3d printerrs original firmware did not have safety checks. I am now running repetier with checks enabled.)
Tom, your smoke detector is mounted wrong. There should be at least 50cm space to a corner, wall or lamp. The smoke does NOT reach your detector. Placing the detector on the ceiling is allways better. Most detectors aren't even rated for wall mounting. Many electrical shop's are certified by the TÜV, you should ask them to mount your smoke detector. If you want to do it yourselfe check out the DIN 14676. Please fix it. Right now your smoke detector is just a piece of plastic without any use. Would be nice if you can make an update to show the propper mounting.
Strange then, that googling the subject immediately shows approved placement for wall mounting. Equally, I've never observed that smoke stops dissipating at 50cm from a wall. It's possible (but impossible to say from the viewpoint in the video) that it's not in the optimal position, but it is most certainly not "just a piece of plastic without any use."
Andy Chaplin sorry, "googling the subject" is like saying "i don't know what i'm talking about".
Just for fun i searched "smokedetector placement" and it says "wallmounting acceptable". You can place them there, but you need a smokedetector that is rated for wallmounting, 95% (in Germany) are NOT. Those that are rated for wallmounting are expensive, the one used by tom looked more like a cheaper one.
About those 50cm... there are cold/hotspots (depending on the situation) a difference in temperatur = airflow and blocking the smoke.
Sorry if i'm rude right now. I'm a firefighter and TÜV-Certified for DIN14676, i mount and maintain smokedetectors for a living.
There are so many cheap 3d printer out there, most of the cheaper ones are a fire hazard. I don't want anyone to end up in a dangerous situation and not beeing warned by a misplaced smokedetector.
@@Pa_No123 dog chillllllll you're missing the point
@Don Mega You don't want a chance that it is working. There is a chance that somebody nearby will extinguish the fire too... You MUST be sure that it is working. It is a safety equipment. It should also be checked routinely. Your house and your life worth a 'little bit' more than 'there is a chance that it works'...
It would be pretty cool if the smoke alarm was connected to the power of your printer so that when it goes off, it shuts off the printer. (kinda like a Ground fault power outlet, but smoke alarm tripped)
Not really hard to achieve. I could quite easily rig that to mine - I already have a massive relay on the 12V side. Wouldn't be hard to do the same on the input of the PSU.
You can certainly get optical and heat alarms as modules, I wouldn't be surprised if ionization is available - not that I'd pick it for this application (or most others).
All this of course requires people doing their own mains voltage wiring, which itself is one of the potential risk factors for fire and other hazards..
Smart Home is the answer :)
Arduino is your friend 😄
Arduino?
Fire safety?
The door's over there.
Monkeh arduino connected to alarm as input and relay as output. Super safe (worst case it false triggers if you have proper relay) and really effective ...
You just cost me $1,000. After seeing the FireStop I like the idea so much I bought 32 of them to go over my printers (1:1). Thanks Tom! Great info!
Well, thank you I guess?... Just checked on my cheap Prusa clone sitting inside of a wooden box. Heatbed cables just fell out of the connectors. One of the RAMPS power cables as well.
Wouldn't the best engineering solution be to put thermal cut outs in series with the hot end and bed heaters? They're cheap and will work even if the controller has crashed or the mosfets have failed short circuit.
Tinning wires also creates a rigid point of stress for the wire isn't allowed to flex, and eventually individual wire strands will break. I suggest using crimped ferrules.
I doubt there is any significant difference, because the ferrule is not flexible, creating a flex-to-solid point exactly as solder does. If heat shrink is applied you essentially create a "strain relief." I can tell you in my experiencefrom many years experience connections - crimped/soldered/other - have always been more reliable when covered with heat shrink. JME...
Just a quick one. Octopi with Temperature Failsafe and Smartplug plugins Plus a smoke alarm hacked onto an Arduino and a 433mhz remote. That way, if there is smoke then the smoke alarm and Arduino will shut off the power via 433mhz and if the temperatures start going out of bounds then the Pi will shut off the smart plug. Did that on my Tevo Tornado a couple of years back. Would also suggest a GFI device. Did a vid on it all showing setup too.
The one key thing is regular maintenance - monthly, quarterly, whatever fits your bill. Check loose connectors, measure circuit resistance and voltage drop (for oxidation), tighten all screws, visually check the PCB for delaminated pads, etc. The vast majority of failures and accidents are caused by neglect, in any engineering discipline.
Regarding thermal runaway protection - if your board triggers it and you don't want to disable it completely, look for THERMAL_PROTECTION_PERIOD / THERMAL_PROTECTION_HYSTERESIS / WATCH_TEMP_*. It's still a hack for a faulty hardware, but better than nothing.
Awesome video, I'm always paranoid about electrical fires. Another safety measure would be to (if you can) have your 3d printer on a fire retardent surface. I do this with my lithium ion cells whenever I leave them unattended just in case.
Fantastic safety video! Wish I knew this stuff when I was building my first printer
The thermal runaway doesn't stop that instance of a slow wiggle out of a heater cartridge. It lit up because it was supplying the right temp to the thermistor, but when it fell out it was super hot, lighting up the fan shroud. Thermal runaway will cut the power once it falls out after the timer expires, but until it cools, you still have a super hot cartridge touching flammable plastic.
Joe wouldn't be a problem if people actually did any form of stain relief!
Creality seems to have paid attention to the forums and emails from customers because my CR-10 arrived with the heat bed strain relief already installed and the heat bed was insulated as well.
I suspect that Creality will eventually honor the GPL license agreement since they are listening to their customers.
electronron1 totally agree. They are on of the few companies that actually listens to consumers.
Donovan Morgan I agree. Although they had a slightly shady start, CR is improving and being very responsive
Creality is the best
Great video, I installed a power relay with thermal fuses on my printer that shuts down all power if anything gets warmer than I want it to.
Firstly, solder melts at over 200 degrees C so I think you're in trouble if that happens already. Also, another thing to check is not only if the wire comes out but to check if the connector is getting hot then you know there's a bad connection or too high current through the connector.
The problem is that, given enough time and pressure, solder will flow even at room temperature.
Wondering what kind of time and pressure we are talking about here? Glass flows technically, but it will take about 10,000 years to form a drip.
I guess creep may be a better word than flow? Anyway - it's soft and may yield over time.
2:52 i just looked over to my very own wooden-box-with-styrofoam-insulation-printer Situation and giggled a little
I got excited when I saw the CR-10, thinking Tom would be fire-proofing it in the video. Then I'd just use the video as a guide to do the exact same things, step by step, to my CR-10. But I'll just suck it up and do it without that extra help. Still very useful video, thank you.
Finally a new how-to informational-tutorial like video! This is the content I subscribed to. More like this please!
Very good video!
You should always use wire end caps/ferules/cable shoes which are properly crimped. They also prevent single strands of the wire to stick out or shorting with neighboring cables.
These are good tips. I really need to install the strain relief on my original CR-10 (my CR-10S came with it). I haven't had any emergencies yet and do a lot of multi-day prints...but I always worry a little bit!
Good point on mentioning not to put 3D printer inside wooden create. I have seen lots of printer put inside plywood crates to create heat enclosure since it’s easy to make. If you can make another video on how to make proper fire safe enclosure , that would be really awesome!
Actually a totally sealed crate of any material might be good so long as it can't draw a draft from anywhere. Last I knew, fire requires oxygen to burn. Once it is all used up the fire will go out.
Also another good one not mentioned was external mosfets they are a must on all budget printers espically for heat bed takes all the power strain out of the board
I agree with the suggestion but the quality of the external mosfets most people will go for is no better than the ones on the cheap control boards and they tend to fail 'on'. I'm not dismissing it as a part of fire protection (though as the video says a board with properly spec'd mosfet and connectors isn't any safer with another external mosfet) but it worries me the number of people who add a $8 board from ebay on the back of advice from Facebook and then tell the world their printer is safe - a false sense of security can be more deadly than a 3d printer :)
regmigrant All mosfets tend to fail on though, even better ones. In these semiconductors there isn't much physical insulation to stop that. If you want safety, you need a mechanical relay in series with the mosfet.
sure, I wasn't trying to suggest that only cheaper ones fail on but i phrased it really bad; I meant cheaper boards are more likely to use the 'wrong' spec (bin ends etc) and therefore more likely to fail. It was a commentary on the 'you bought a cheap printer so buy a mosfet to protect you' - 'ok, I bought the cheapest mosfet I could find so now I'm safe' fallacy.
Yes, that's true. It'd be especially unfortunate if someone got a good board with a good mosfet and then used a cheap external mosfet with it o.o
@@warriormes6012 That's just what I was thinking: why would you use an external mosfet instead of a good relais and fuses. Seems so strange to me, actually I think in many cases good relais will be cheaper then the whole external mosfet-configuration. And in 'Fail' a relais will basically be 'off' in most cases.
seriously, the firmware one is really nice. it helped me figure out my thermistor was garbage. now, if i hadn't know the printer could have caught on fire without the thermal run away protection.
I didn't know about those auto fire extinguishers, so thanks for that.
I just invested in nine smoke alarms that interconnect so when one goes off they signal each other and all go off. Great since I have three sheds and a garage that if one went off during the night when we were asleep we would still notice in time to possibly do something about it. Decided to get them as a mate had a fire when he left his laser cutter alone in a shed (two weeks ago) whilst he went to peel some potatoes. I also invested in some fire extinguishers as well. Was about £250 altogether but worth it in the long run.
I have an acustic fire alarm mounted on top of the printer (and a second one on the ceiling of the room). Another simple and cheap idea to stop the fire from spreading in the first place is to put a large ceramic tile under the printer. And keep a minimum distance between the printer and anything flammable (curtain, desk, paper etc.) of at least 1m.
One could use a thermal camera to identify hot spots in electrical connections, especially at the points where wires/cables flex the most.
It would be a good way to check for hotspots, but decent thermal cameras often cost more than the printer itself.
This Should be a mandatory video for anybody who opens a package with a 3d printer. Kit or ready assembled.
Why would anyone down vote this video. This is great info that anyone should listen to.
Holy crap, did not know any of this. I'm getting my first filament printer, a Prusa I3 MK3S, which I feel more confident doesn't use cheap components and is engineered better, but still getting connected fire alarms and automatic fire extinguisher.
Thomas- just finished building a plywood enclosure for a printer. I have one of those "range hood fire suppressant" devices in it, and I think I will also paint the inside of the enclosure with high-temp paint (often used in a BBQ or to paint a car engine). Anyhow, sounds like we're on the same track.
Look into intumescent paint not high temp. The wood can still burn with high temp paint.. intimecent paint actually expends into a flame proof insulation keeping the wood cool and blocking the heat. You can paint cardboard with intimecent paint and put a torch to it. Its cool stuff and required in building codes in some instances.
Also worth mentioning: Power mosfets turning into shorts (probably due to ESD damage), had this happen to me twice on a "ancient" RepRapPro Huxley (Melzi controller).
Both times i happened during the heating phase for the hotend where I remove any ooze with a pair of tweezers (metal ones)
No fires as I was next to it, but the first time around I spend too long considering my options, resulting in having to "rebuild" the hotend.
After the second time I have switched to an e3d v6 clone hot end, hope its heater cartridge insulation might be better than then wirewound resistor in the older original hotend design.
Anyway as the hotend (and steppers) now runs off 12V I'm considering switching to an ATX PSU to allow Marlin to switch off the power if it detects a problem.
I learned a lot from this, thanks. Especially about the wire relief on the bed. I didn't know about the strands breaking down over time with movement. Had to solder new wires to my A8 bed as they used insanely thin wire which you would use for LED lights on the back of a TV, not for heating up a bed to 110C! I thought those printed chain cable management designs were just glorified cable tidies. Didn't realize they were for strain relief.
I don't agree with the "don't tin the wire ends" part though... Tinning the end is not to make it look neat. It is to make sure that all the copper strands gets the maximum contact surface with the contact in the screw-in connector. Otherwise use a ferrules. Check electrical guide book. Note that copper will also deform under pressure if that was a concern
I was particularly keen on the Sea-Fire FG50A auto-extinguisher, as it uses the FM-200 Halon-replacement and has a pressure switch to cut off the ignition (it's meant for the engine rooms on small boats). I've been emailing various fire system manufacturers for weeks trying to find out if it's possible to get something similar with a mains-rated switch that could cut printer power when triggered. I want to stuff the whole bundle in a steel enclosure as last-resort mitigation. I figure a cheap 12U server rack should do a good job.
I went with the 12U server rack along with a thermal switch and an SSR to cut power. Also put a BlazeCut tube in it. Hopefully I never need to find out how well it works.
There are smoke and heat detectors with relay outputs that can cut the power via SSR or contactor.
Thankyou harles255, it looks like BlazeCut have a UK office so I'll look into them as an option. It certainly looks very compact! How much did you pay for yours, and did you go for the relay option?
I also want to add electrical thermal cutouts, but an actual "mechanical" extinguisher is final and reliable line of defence. Hopefully temperature monitoring and IR detection would cut power before it reached a point of no return.
The six foot BlazeCut tube was $100 on amazon, sadly it does not appear to be there in the US anymore, but it may be in the UK store. The temperature controlled relay is actually an inexpensive Sous Vide controller. My enclosure is not insulated and should never exceed 100c, so it has been working quite well. I have a smoke detector in the room with the printer, so I have not tried to place one in the enclosure itself. All in all, I really don't worry about it much at this point.
Hmm, there's a single Blazecut T3 on Amazon UK. Doesn't spec a length but says it's 499g in weight. Priced at £207, so roughly $292USD. Auto-extinguishers are proving to be both expensive and hard to get in the UK.
Thank you for this video Thomas, I was already planning to use those automatic fire suppression cans in metal enclosed case with some simple power shut-off sensor but all the electronic parts informations are excellent for electronically inept people like myself (I can make stuff work but doing it by the book is out of my league). Regarding safety I have few questions that I need to answer before I get into 3D printing. My problem revolves around extremely limited working and living space and health and safety concerns. I can't dump my yet to be acquired Prusa Mk3 into the garage I don't have and call it a day. My current apartment that fits my needs perfectly well (single big room with kitchen annex and small bathroom) and I can't really relocate either way. With Prusa Mk3 eliminating noise problem as well as all the little quirks that let it be fire&forget solution the last concern I'm having is about fumes. We know at this point they're toxic and keeping a printer in your bedroom is a bad idea hence why I didn't pull the trigger on any printer yet despite following the subject for quite some time already. Taking into account limited living space I'm dealing with I was wondering if some DIY airtight enclosure with fumes extractor consisting of a system where air has to be filtered through some active charcoal and HEPA filters would do the trick or whether can you recommend some ready, reasonably priced solutions to address my problem. While some people would ask why I just don't open the window and call it a day I'm just gonna say that where I live it's rather cold thorough the year and given the limited space it would be equivalent of filling my bed with ice cubes which I'm not really thrilled about. I believe I'm not the only one with such a problem and video on the subject would find some target audience if you ever decide to expand on it. Thank you in advance!
same! i just got a closet for enclosure and am looking for a good fire alarm + fireproofing to put inside
Your smoke alarm is placed suboptimal. It needs to be on the ceiling 0.5 - 1m meter away from the wall, there smoke always gathers first.
yeah was going to comment the exact thing
6:50 You should not tin also because you are making contact area smaller.
For High current application I suggest using XT connectors - Amass XT60 can take between 30 and 60 Amps :D. Also is reasonably cheap and disconnec force is very reasonable. Only backside is that it is hard to solder - but this is due to high cooling speed, which gives this one such high amperage.
7:30 heatsinks are probably because there is no copper polygon for cooling here. But too many designers forget that plastic case thermal resistance is very high and TO-220 without heatsink will be still cooler than DPAK with incorrectly mounted heatsink. Funny thing is: if they added price of placing heatsink, they would probably have already good enough MOSFET with low resistance.
The wiring behind the power switch on my printer started smoking. I'm glad I was standing right there when it happened.
Thank you greatly for this information, it has certainly changed my mind about which 3D printer to purchase.
Thanks for the tip about tinned wires. I did that while adding a MOSFET board to mine, going to go and fix that now!
What did you add a MOSFET board to anyway and why? People assume that they must need one because the ones on the controllers are crap without ever looking at what parts are in use.
Thanks very good video everyone with a 3D printer should watch. At 5:18 those connectors melted on my first printer and almost caused fire. I removed them and soldered decent gauge wires directly.
intumescent paint. Paint the inside with intimecent paint, its amazing stuff.
Or Rockwool comfort board would also be insulation for a heated enclosure.
It would be a fraction of the weight of drywall
We had a discussion on the Anet A8 Facebook page a short time ago. We discovered that using these external Mosfet board upgrades that are very cheap and work well in removing the AMP's out of the main board connectors and mosfets, but when they fail they typically fail ON. So even if you had the software upgrades because you have bypassed the printer main board using the Mosfet, if it fails on it will not turn off even if the printer is off. Because these cheap printer PSU's do not switch on and off by a controller from the printer main board like a computer PSU for example they can cause the exact problem we were trying to prevent in the first place.
What is needed is a relay controlling the PSU's supply determined by the printers safty features and if its actually on and in use/ printing.
From the ideas we had a extra Arduino would be required to control the relay as the printers main board doesn't have the IO pins spare or be controlled by a Raspberry Pi octoprint setup.
I have had my 3D printer catch fire. I was so lucky that I was looking at it as it caught fire, and simply switching the power off was enough to stop the small flame that had started on the stepper motor driver. and I didn't have to use the fire extinguisher i had grabbed after flipping the power switch. what was concerning was the smoke detector inside the room with my 3d printer didn't go off, but the one on my landing did go off.
A tip: a nice encluser is a polycarbonate type. it has a great fire resistance. i have my two printers surrounded by it. Its also a good noise reducer...its an extra.
Gee you make it sound really scary. I have run plenty of 24 to 36 hour prints on my Ender 3 V2, day and night, whilst being away and everything. Never thought the house could burn down.
Well this was great reminder! Just checked my printer over and noticed beds connector negative lead having some color chance indicating it has went near combustion temp. Strain relief was earlier on my list of to, but could not figure how to install it since heat bed is one of those aluminum elements, but yeah will be replacing the connector and developing something before next print, since that was way too close to comfort.
This is reason why i never print anything while i'm away. I rather cut larger peaces into smaller ones and print them when i have guaranteed time to stay and supervise the thing, or i have someone around to supervise it while i check into store or such, only leaving it alone for going for smoke etc under 5 minutes.
This was a great Video, far better than your "overclock your Powersupply and set your house on fire" Video !
This video should be pinned at the top of ALL Anet facebook and reddit groups!
Thomas PLEASE keep up the amazing work. Every video I think you have hit peak quality levels in video and audio but nope you keep improving and I don't understand how. I know quality will plateau at some point but now its a question of when.
x9x9x9x9x9 He could wave his hands a lot less. Yah, I know, three years late.
Anet and some of its siblings ship with Repetier-FW, which has thermal protection, but it's disabled by default. So they haven't enabled it probably by negligence.
There has also been a simulation published on reprap wiki that the inductive spike off the bed, simulated with measured parasitic inductance of wiring and bed, can easily exceed MOSFET's rating, so a free wheeling Schottky diode across the outputs would be nice. MOSFETs are fairly temperature resilient, they're too hot to touch at 65°C but you expect them to live a long and healthy life at 80°C too, so chances are, it's more the spiking than temperature killing off the things. Of course they fail short, and then there's no reason for the fuse to trip, because it's as if the MOSFET was simply turned on intentionally.
Would the firmware updates or change altogether help this? Or would people be ok just installing outside mosfets for both heating elements? I wanna be sure it doesn't make a fire. I'm prepared for it, but i don't wanna ruin 3dp's credibility in my house. lol.
Official firmware updates, for Anet and its siblings (Tronxy, Zonestar, etc) - i wouldn't hope, they have no idea what they're doing. Alternative firmware distributions from the user community are generally safer and better tuned up.
I don't have an Anet but from the rumours i heard it seems that the official firmware also might not have a working watchdog. Watchdog is an internal peripheral of all relevant microcontrollers which runs a timer, that the firmware should re-start regularly after checking its state, that it seems to run fine. Once the timer runs out, which happens if the firmware is locked up or not delivering the necessary performance for its realtime tasks, if watchdog is enabled, the microcontroller will reset to bootloader and turn off all outputs, hopefully (in case of semi-sane board designs) turning off all heaters in the process, after which the firmware will boot again. Why i suspect this is because some people describe their printers locking right up occasionally. That is one of the worst things that can happen - if the heaters were on when it happened to lock up, they will stay on.
So it's very much advised to use someone's better developed firmware.
Having an external MOSFET doesn't fix the potential thermal runaway issues if you're running stock firmware. Furthermore i suspect that in case of one of the recent fires, various hardware upgrades have exacerbated the issue - more powerful power supply was installed, an external MOSFET for the bed was installed. But that just means you have THAT much more power to go around if things go wrong! There was effectively not a single electrical fuse on the thing, not one that was anywhere near sensitive enough. Anet and Melzi already don't come with fuses on the board, which is bad, and with those printers which do, circumventing the fuse and installing an external MOSFET without giving it another fuse is outright criminal. Plus look at those MOSFET kits, they are generally Chinese ICs, the specs on them seem... fine, but there's no telling how good the production consistency is, and how they behave just outside the specs such as on occasional spikes, how well designed the whole board is, there's still no protection diode to cap the voltage spikes, there's always more things to go wrong.
Once the MOSFET fails, it fails short and there's no control. Firmware can detect thermal runaway, and if it was on an ATX power supply and had PS_ON control, it could cut off the power to the complete heater/motor portion, but the way people normally build stuff, it's not the case. Also thermal runaway detection takes maybe 20-40 seconds to engage, and by then, you might already have a self-sustaining fire. Janky printed cable chains that people installed to make things better sometimes made things worse because they did rub the cables in a spot and hindered inspection. Beefier wiring sometimes made things worse. Most things you can do will have benefits and potential drawbacks.
Unfortunately i'm not good enough of an engineer to give you much specific advice (and i do have electronics engineering university education), i can just list some potential problems but i don't have the data to back up how important or prevalent all these issues might be, and to give a solution which would be easy to grasp and implement for a typical builder without introducing further issues. This is something where we need to put out heads together and dice out as a community, pooling from various experience fields.
So in repetier, is it the watchdog timer that is the protection, or is there other settings required?
I'm not very familiar with Repetier, but their lingo for thermal runaway is "decoupling", so look for that in the configuration file. In particular you should probably enable KILL_IF_SENSOR_DEFECT, which is weird that this is the only one that jumps out and doesn't use the same wording, but it controls the sensor decoupling test feature.
Also the feature might be faulty, see issue 737 on their Github filed a couple months ago - "v1.0.0 Firmware does not detect defected thermistor (-200°C and still running)" - weirdly no response from the maintainers AT ALL. I mean, when there's a security or safety relevant issue being filed, wouldn't you rush in to treat it at priority and at least request more information and triage it? I don't know, this kind of conduct (or lack of any) leaves me speechless.
FEATURE_WATCHDOG is enabled by default, but it's kind of tricky to get right, who knows whether they ever actually tested it - it's difficult. Also it's not thermal runaway protection, it's protection against the firmware locking up and losing control over heaters altogether - it can result in thermal runaway which thermal runaway protection could no longer catch, because it would no longer be executed. Similarly, Watchdog is enabled by default in Marlin.
Dragonslayer.Bob If you want extra safety a seperate mosfet won't do, you need a switch that fails open... like an electromagnetic relay.
I had a connector on my Hictop Prusa i3 3DP-03 catch fire. Burned a hole in the acrylic frame and the MKS base board. Now I use a solid state relay, 24V supply and peripheral, and the better rated MPX.3 board.
The 24V power cable for my Ender 3 (Bought Nov 2018) came loose at the PSU mid-print just last week. The increased resistance heated up the wire quite a bit, luckily I was in the room and noticed. Could have easily caught on fire.
Propper awg and use of RC plane/cars garded wires are best way to go cuse they are designed to take high amps and burst, that said fuses and propper setup overall is a must.
PLA and it's parts are highly flammable. Use PETG for flame resistance.
Damn, I'll have to stop pumping my printer full of pure oxygen
Probably wouldn't hurt to put the wires going into those screw connectors on the left side of the screw so the screw pulls them in instead of pushing them out as you screw. If there's space you could even curl the wire so it wraps around the screw for maximum contact.
Well my ender 3 has 3 cameras that stream to 4 services and two machines. One of those cameras detects the beeping sound of nearby smoke detector and pushes alert. They are not connected though.oh yeah it runs marlin bugfix with pretty conservative sanity thermal checks. Always go open source
maintaining the wires - you can drop in there a small carbon fibre flat (got some advantages) or round (no edges to chew on the wires), you find these in any decend RC model shop and they cost 1-3 bucks.
Strange I saw the notification for this video on my phone but can't seem to find it on your yt channel on my desktop on a fresh tab even after cleaning my cache an everything
MOSFETs also change according to their current internal temperature. High quality MOSFETs usually have their specs also listed at an internal temperature of 125°C.
I would also add thermal fuses around the printer. Over the top of connectors and such. They'll blow at a set temperature and cut off power to the printer.
Great video. Please do a video comparing CNC routers or anything about them and give us all you know I’m sure many people would like it. Thanks you’re the best.
Great wealth of Info Tom, Thanks for putting this out ! Happy Extruding !
Please make an video on all ramps 1.4 mod like MOSFET change , Changing connectors or replacing them completely with soldering changing fuses and also external mosfet if it is needed for safety
One of your best videos so far
I love the automotive fuse idea. Brilliant! Oh yeah and put a battery powered smoke alarm on top of the printer itself. BTW is there a smoke/combustibles alarm that will cut the power automatically? Electrical equipment usually smokes for a while before it combusts so killing the power immediately could save the printer and/or your house.
You should also mention that the wires going to the heatbed can corrode, mine have corroded so bad it broke off the bed and they are getting hotter due to the wire not efficiently transfering power to the bed
That's why I never set the bed of my Anet A8 above 60C.
And then switched to a Prusa i3 MK3.
Jonathan Kayne didn’t save my Anet - the connector to the heatbed smoldered anyway despite having installed a proper mosfet. My smoke detectors would have saved the day anyway, but fortunately nothing happened, even the print went fine.
There's nothing wrong with the MOSFET on the A8 controller anyway!
Monkeh that is just not true, especially on the original A8 boards.
Which boards? What MOSFET? There's nothing wrong with the parts on mine.
Monkeh there have been at least three iterations of A8 boards that I know of. And are you implying that because your parts _might_ be okay that there are no quality control issues with Anet? If that’s so, that’s surely a bold statement.
love the idea of installing a kitchen fire extinguisher above the 3d printer.
I'm missing the tip for more beefy external mosfets like a MKS Mosfet boards and the general tip for crimped connectors
Please improve your soldering technique.
Make a good mechanical connection first. This helps hold the wire still, and ensures a more reliable connection. For example, my wife just bought an electrical spinning 'wheel': didn't work at first, because one of the power connector wires had not been mechanically attached, had been poorly soldered and had fallen off the connector.
Heat the wire / joint, then melt the solder onto it. That way, you know you are less likely to get a 'cold' solder joint and the flux (that generates the smoke), which is a chemical cleaner, cleans the wire and joint instead of burning off on the soldering iron.
Keep the wire still while soldering and until the joint has cooled. Otherwise you end up with a 'cold' solder joint, the solder can get crystallized and have voids in it and makes a weak, poor connection.
Clear and concise, like all your videos.
I have a doubt, my printer lost the connection to the raspberry a few days ago, it never happened before, but I could see that the heaters remained on. Is there any configuration in Marlin that turns off the heaters when it does not receive commands for a certain time? Thank you.
What filaments do you store in dryboxes, or dry before printing, and what filaments do you just print without worrying about moisture?
Yikes! I had a Monoprice Maker Select V2 that started to melt the heatbed connections. Luckily I caught it and replaced the machine before anything really bad happened. Scary how many companies play it fast and loose with safety.