3D Printers catching fire? Is this true?


Is it true that we have 3d printers on fire? Unfortunately yes, they can be dangerous. take a look on our tips to make sure your printer is safe.


Think of your beloved 3D Printer, it is printing flawlessly trough the night while you sleep.., and then suddenly.. Theres a nice cosy fire!! why is this happening? how can we prevent it, and more important, how dangerous can it be?

Did this ever happen? Is there a real danger?

“Yes, mine did!”, Here we see some images from Claudio Luis Marques Sampaio, His printer’s thermistor came out of the heating block, which caused the fire. He also suffered from ABS inahalation, even using a gas mask!, so this is really dangerous!.


Claudio was suffering from ABS smoke inhalation

You can see more photos of the accident HERE

What are the most common errors that lead to a fire?

It always comes down to, who you bought it from, or how you assembled it. There are a few things that are likely to cause a fire hazard, as:

  • Bad connection on the RAMPS board (power input pin)
  • Bad power supply quality
  • Not using a proper cable
  • Poorly fixed thermistor
  • Not using a cable holder

Lets talk about each one of them, Before we begin, notice that those are not isolated cases, they have been around since the first reprap designs.


Bad connection on the RAMPS board

mau contato 3

This is more common then all the other, and it has even happened to me.

Remember those green connectors with screws? you NEED to screw it properly. do not go over this step!, also, on cheap ramps boards they will have a poor quality and are likely to fail, imagine that you need to pass a high current (20+ amps) trough a small wire, it will get pretty hot and burn the insulation, this is exactly what happens, there are a small contact area to a lot of current pass through when you don’t screw it properly, you can already imagine the outcome…

On the Sunhokey 3D Printer there is a similar problem, that you should check out here



Bad power supply quality

brand1Ok, i was tempted to buy a 10$ 500w chinese PSU, but guess what? after a research of 3 minutes i found out that they only deliver about 140w RMS. What is RMS? it means the real power, how much can it handle for a long time. Why its so low? cheap components were used, for a low end computer it could work, since most computers dont even go above 150w rms with spikes of 300w. but if i used it for my high-end cpu, powering the water-cooling systems, GPU, CPU, etc,  it would fail, since it really need those 500w, but we are not talking about computers, we are talking about 3D printers, so what is would mean for us? slow heating on the bed / noozle, motor fails, a lot of trouble, and, if we have a bad luck, the PSU will fail and possibly burn, causing fire.



Low quality cables

Screenshot_6This is another  common issue, cables can break over time (if they are not on chains or cable holder, their life will be even smaller).

You should always use flexible cables, fire resistant if possible, and always with cable chains or holders, this way, the service life is greatly improved,

DO NOT USE RIGID CABLES ON MOVING PLACES!, they will break and cause problems!,



 Thermistor moving off the hotend

300px-Reprappro-hotend-thermistor-fittedThis is by far the biggest mistake that people make, the thermistor is not properly fixed at the metal body, and with time it just moves away from the heated block, which them make the software read a lower temperature, set the hot end mosfet to ON and powering it without control, the nozzle heats and is just a matter of time to the heat burn itself and then the ABS /PLA supports,  this is extremely dangerous and there are a lot of registered cases where this happened! If your nozzle do not have a proper  place to insert the thermistor just make a small hole for the thermistor and second one for a screw (to secure it in place)

Not using cable holders.


Cable chains are standard for most CNC’s and Robots on the market, it can avoid a lot of problems, like the cables going in wrong places, break  and a lot of bad stuff, so why no should it be on our printers? we can even print one!, so, its cheaps, printable, and will improve you cables lifetime, so what are you waiting?






Now that you know what are the most common and dangerous mistakes, check if there is any issue with your printer,  If you have any doubt or suggestion, please feel free to comment it below, or go to our forum ask for the experts!

Comments 10

    • All the fires that have happened are due to operator error and lack of maintenance. Followed by Operation without being monitored. It doesn’t matter what printer you own be it built or bought if you don’t maintain the machine just like your car it will break down. A visual inspection should be done of all components at least once every 100 hours of operation. Fast moving parts cause screws to vibrate loose and wires to Frey. People hear the word printer and assume they can abuse it like that HP printer collecting dust on the corner of your desk. This is one reason why i always recommend build it yourself printer it makes you stay on your toes. and at the very least do maintenance checks.

    • The possibility of 3D printer catching fire usually DOES NOT depend on a particular manufacturer of printer, because most manufacturers are using the similar parts. Instead, the possibility of fire depends on the version of firmware that is installed ! More recent firmwares are more advanced and have the additional protection measures – like against a thermistor coming off place. For example, below you can find a commit message 43c298a (dated Jun 30 2014) from a Marlin Firmware repository. My cheap Chinese 3D printer had a slightly older firmware version installed, so I had to update its’ firmware to enable this “Thermal Runaway Protection”! Always update a firmware of your 3D printer!!!

      /*================== Thermal Runaway Protection ==============================
      This is a feature to protect your printer from burn up in flames if it has a thermistor coming off place (this happened to a friend of mine recently and motivated me writing this feature).

      The issue: If a thermistor come off, it will read a lower temperature than actual. The system will turn the heater on forever, burning up the filament and anything else around.

      After the temperature reaches the target for the first time, this feature will start measuring for how long the current temperature stays below the target

      If it stays longer than _PERIOD, it means the thermistor temperature cannot catch up with the target, so something *may be* wrong. Then, to be on the safe side, the system will he halt.

      Bear in mind the count down will just start AFTER the first time the thermistor temperature is over the target, so you will have no problem if your extruder heater takes 2 minutes to hit the target on heating.*/

  1. Man, I just got a 3D printer the other day, our first. Great tips here. Thanks for the heads up….we’re going to try to set it up and start trying to use it this coming week. It’s always good to know these small, but very important details. Great job man.

  2. Overall good article, it happened to me too. However, in my case I had a different problem: The software got stuck and the nozzle overheated which caused the filament catch fire. Luckily this was huge room (3.5 ceiling height) so I was able to extinguish the fire without inhaling the smoke.

    So I would add software and electronic failures to the causes of 3D printer fires. Here you can find some discussion on how to prevent these problems https://groups.google.com/forum/#!searchin/machinekit/fire%7Csort:relevance/machinekit/jkl0SZttLk8/bfq8wxb4CUIJ
    I also can recommend a smoke detector and automatic fire extinguishing system. Better be safe than sorry.

  3. It is so easy to take it for granted. There is no one brand or model to blame, and it can happen to any device, not just printers. We are surrounded by electronics that we let run overnight while we are sleeping.

    Proper care and maintenance, visual inspections and following the tips in this article which are applicable to a lot of devices are what we should all be doing. Most home fires are avoidable. With our printers, and especially with kits or homebrew, we should be even more cognizant and careful.

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