A post that was shared in a Facebook Group today sparked an interesting conversation in another group that I am in when I shared the images of a charred 3D printer with reminders about 3D printer safety. Any electronic device carries risk, but some devices more than others. This is true for 3D printers because of their moving parts and use of high temp heat.
We've compliled a list below to help get you started in making your printer safer and understanding some of the basic maintenance that can be completed to reduce your chances.
(Source: Facebook)
Fire Extinguisher
Make sure that you have a class C fire extinguisher nearby. Your extinguisher should be easily accessible and NOT placed next to the printers in case of a fire.
Smoke Alarm
Make sure that you place an additional smoke alarm directly above your printers. The faster that you are able to detect a problem, the less damage is likely to occur.
Replace tinned wires with "shoe string" ferrules
A ferrule is considered to be any kind of band or clamp that will secure an object to each other, but in an electrical application have a more specific definition of being a soft metal tube that can be crimped onto the end of a stranded wire to improve the wire's connection. Most of the ferrules on the market are made with copper plated with tin and is sized specifically for each gauge of wire in regards to diameter and length.
Here in the US, it's not common to see ferrules in use because they are not required under any regulation like they are in other countries to obtain a CE certification. Without the use of ferrules, the stranded wire connections compressed into screw terminals eventually will seperate, reducing the number of strands that maintain contact with the terminal. In that scenario, the resistance is much higher than it would be with a ferruled connector in use.
Another reason to utilize ferrules is to reduce the surface oxidation on the strands using properly applied pressure on the strands which in turn increases the longevity of the connection. Ferrule kits are easily obtainable online and usually cost $20 or less and include a variety of ferrule sizes and a crimping tool.
Want to learn more? Watch https://www.youtube.com/watch?v=8F4zQVzDRww
Replace knockoff XT60 connectors
Sadly it is well known in the 3D printint community that many of the Ender 3 printers were shipped with knockoff XT60 connectors. If the inside of the Xt60 connector doesn't have a good solid contact inside the connector, it will act like a resistor and heat up, possibly enough to catch fire. You can usually tell the difference between a "good" XT60 connector vs a "bad" connector by checking to see if they are soldered, or crimped. In large scale production it makes more sense to crimp thousands of connectors rather than soldering them. The "real" XT60 connector cannot be crimped.
Want to learn more? Watch https://www.youtube.com/watch?v=4yDp9frWkcg
(Image credit: reddit)
Keep flammable objects away!
Where you place your printers in your home or office is important. The work surface should be clear of clutter, flammable objects and should be flame retardant/resistant. While there are a lot of parts on a printer that can/will burn, you don't want to add fuel to the fire by placing the printer near objects that will combust along with the printer.
Turn on Thermal Runaway and make sure it works!
Thermal runaway is a scary possibility with 3D printing and is a safety feature designed to cut power to the heaters in case of a thermistor malfunction. Thermal runaway is considered to be the most dangerous problems that can occur with 3D printing and can easily cause your printer to catch fire. Thermal runaway can happen for many different reasons but the most common is where your temperature sensor (the thermistor) is unable to properly sense that the nozzle or bed temperature is at the correct temperature and the firmware on the printer will continue to raise the temperature in order to reach the target temperature.
Not only does thermal runaway need to be enabled on your printer, but you should test to see whether or not thermal runaway works. To do so, you would need to unscrew the thermistor wire from the heat block, and carefully remove it and allow it to hang in the open air, not touching the heatblock. Set your printer hotend to 185C and wait for about a minute. The thermal runaway error should either pop up on your printer display screen, or create an audible warning (beep) to alert that thermal runaway has occured. If your printer didn't bring up an error or stop the heating process then thermal runaway is not activated in your printers firmware. You can choose to change or update your firmware to include this feature if not available by default.
For more info watch: https://www.youtube.com/watch?v=z5s2iXBpnrc or https://www.youtube.com/watch?v=eGUPBoDxmKk
Upgrade your powersupply to a "certified" brand.
Sadly, a lot of powersupplies that come with printers are not UL or CL certified. This is a simple fix, as it is easy to replace a power supply like-for-like with a UL certified (or CL) brand off of Amazon or other internet shopping site of your choice.
In conclusion
It is rare, but 3D Printer fires do happen, which is why every single manufacturer out there tells you to never leave your 3D printer unattended. No mitigation strategy is every 100% but we hope the information provided helps get you started on reducing the chance of it happening to you. We're always here to help too!