3D Printer Safety

If you own or are considering purchasing a 3D printer you should be aware of the potential hazards involved. Please research your printer or the printers you are considering to find out if it has a higher potential for fire and  if there are ways the community has made the printer safer.

Buy a Printer with Safety Features

Your printer should have firmware (software that runs the printer) which has:

  • Hotend and bed thermal runaway check.
  • Minimum temperature check
  • Maximum temperature check

Thermal Runaway: printer is cooling down faster than it should be or not heating fast enough. This check ensures the thermistor (the device that measures temperature), and the hotend (the part that melts the plastic) are performing as expected. If the hotend is being asked to heat to 215 °C but the thermistor is reporting that the temperature is actually going down, there clearly is a problem. Some printers will simply try to heat the hotend more to compensate and this can actually result in a fire.

Max and Min Temp: If the slicer software requests a temperature of 900 °C it will ignore the command. If the printer detects a temperature below expected cold room temperature or something radical like -600 °C – a sign the thermistor is not working. In both cases the printer should stop printing and turn off power to the heat bed and hot end.

Additional Safety Features:

  • Fans spin up to full blast to help prevent the hotend from overheating in the event that the thermistor is incorrectly reporting the temperature or some other temperature related failure has resulted in the hotend attempting to heat up beyond its usable temperature.
  • Printer that detects fans are not working.

Some cheaper printers come with bad wiring, uses wires that are rated for lower than the amperage being sent over them, or has not fully secured wires either in the power supply or on the circuit board running the printer. Check reviews to see if the printer you have or are interested in suffers from this and usually the community will have a solution available.

If you are building the printer from a kit make sure you follow the instructions carefully. This is most important when it comes to wiring the power supply and heat bed. A loose cable can result in a short which can cause a fire if a printer is unable to detect thermal runaway.

Do your research and make sure you are getting a printer that has safety checks enabled and are proven to work.

Fire Alarm

Please buy a fire alarm and put it directly over your printers. The faster you are notified of a catastrophic problem the better chance you have of getting to safety or even saving your property.

Don’t Rely on Fire Suppression Alone

Some people have suggested using a fire suppression system like those found in kitchens. The idea is if a cooking fire gets out of hand the heat will melt a switch that dumps fire suppression powder or foam. This is usually ok for cooking fires because the source of the fire is extinguished (food) and, even with the burner continuing to heat, typically the worst that happens is smoke damage.

I don’t believe this is as useful with 3D Printers because the problem isn’t that the hotend (burner from the example above) is on, but that the hotend is heating well past safe levels due to a printer malfunction. While the initial fire might be suppressed, another one can easily start from molten aluminum reaching other flammable parts on the printer.

Another option is to run your printer in a fireproof or resistant enclosure (steel or concrete). If it is fully enclosed flames would be better contained in the event of a fire.

You should check with your local fire department for expert advice in regards to handling fire like this with a fire suppression system.

Unsupervised 3D Printers in Multi-Unit Homes or Public Buildings

If you are operating your printer in a location where other people’s lives may be at immediate risk in the event of your printer malfunctioning like at a school or apartment building, you should seriously consider never running it unattended.

At a minimum, you should thoroughly test a printer you don’t have experience with to ensure it is reliable and then regularly test to make sure sensors and safety features are working as expected.

Children and Printers

Make sure children are supervised when using a 3D printer. For those of you with small children you should be aware that the hotend on a 3D printer, which melts the plastic, can get up to 300 °C which is 570 °F. This is typically hotter than your electric oven can heat up. The printer bed, if heated, can get up to 90 °C which is 194 °F. Both these temperatures are capable of causing serious burns.

Many printers, especially cheaper ones, do not come with an enclosure. This is to save costs or, in the case of printers primarily used for PLA, to avoid an enclosure heating up too much and negatively affecting print quality. The printers that do have enclosures do not usually have a lock or child safety mechanism.

Particulates and Fumes and Toxic Materials when Printing

This topic isn’t discussed much, but be aware your printer generates invisible, but often smelly, particulates while printing. Some materials are worse than others (ABS compared to PLA). There is not significant research to show printer fumes and particulates are bad for your health, but you might consider using the printer in a room with decent ventilation.

A lot of what has been discussed covers FDM or FFF printers which melt plastic and put it down in layers. Another type of 3D printer that is becoming more popular are SLA printers that use UV cured resin which is toxic before it is cured. You should not touch liquid resin until it has been washed in alcohol and cured in UV light.

Don’t Take My Word For It

Hackaday –  3D Printer Halts and Catches Fire

Hackaday – Don’t Leave 3D Printers Unattended

Thingiverse – Anet A8 almost burned down my house

Punished Props – Avoid a Fire Hazard

Maker’s Muse looks at safety when it comes to SLS printers that use resin:

Maker’s Muse – Resin 3D Printing Safety – Important for Beginners!

Thomas Sanladerer – Everything you need to know to make your 3d printer fireproof!

Thomas Sanladerer – Testing my printers for fire hazards – results all over the place…

More advanced users can modify the firmware on their printers using Marlin to enable safety features:

Thomas Sanladerer – Maker your 3D printer safer: Marlin configuration!

Damaged thermistor reports the wrong temperature and hotend continues to heat until fire in this test. Example of what can happen if your printer does not have thermal runaway protection:

Chris Bate – Hotend thermal runaway test #2

Building the Prusa i3 MK3

My previous experience putting together 3D printer kits has included splicing wire, soldering, adjusting potentiometers, cutting and drilling parts, and even building small circuit boards.

The Prusa i3 MK3 kit suffers from none of the above. It is a well designed kit that I would compare to building a complex lego set. This is helped by a detailed manual (both printed and digital), properly labeled bags, community discussion, videos, and hundreds of hours of testing.

If you are confident you can properly connect negative and positive wires to the correct terminals and follow a visual guide showing you where and how to connect pre-made wires, then recheck everything, I believe this kit isn’t as hard as it might seem on the surface. With a few tips I think most people, who can handle the above, can easily put together the i3 MK3 kit.

Tips

  • Expect to spend 4-8 hours building the kit.
  • Always read the instructions first before starting. They often include important build instructions that help you understand why you are performing the tasks.
  • I highly recommend using a torque controlled screw driver designed for electronics/delicate-parts and set it to the lowest torque setting. Allen keys are too easy to over tighten and you can end up with cracked parts. I know this is an added expense, but that tool will come in handy in the future so it is not a lost investment.
  • Before you let loose with the power screw driver or even the Allen keys I would hand start any screws to make sure they catch appropriately. This will prevent binding and stripping of threads.
  • Triple check the power supply and bed wires. One of the few things that cannot be fixed is powering up the printer with it incorrectly wired for power.
  • The P.I.N.D.A. probe should be very close to the surface of the print bed while the nozzle is touching. Setting the P.I.N.D.A. too high will result in the nozzle possibly crashing into the bed. The manual recommends using the thick part of the zip tie, however I used the thiner part of the zip tie instead based on my experience with the P.I.N.D.A. probe on the Prusa i3 Mk2.
  • Use the online manual if the print manual images are not clear. I found this particularly helpful for the E Axis and E Axis wire strain relief.
  • A majority of screws and parts are color coded in the manual. The manual will show, for example, a screw boxed in orange then often an orange arrow or box where the screw goes and finally an orange bullet marking in the text that refers to this part and screw.

Problems

Aside from using the occasional wrong screw I did run into two significant issues that you might be able to avoid.

In the right Z part you need to insert a nut into a hard-to-access slot. Unlike other places in the manual where you can essentially pre-seat the nut, this is not possible (see the blue box below).

Right Z nut placement

When trying to insert the screw it ended up binding and I was not able to either reverse the screw or tighten it. The nut would spin and even with significant force trying to hold the screw in place I could not dislodge the two. I did this without the trapezoidal nut installed because I was trying to align the nut and screw. The trapezoidal nut cannot be attached due to the screw head. The solution, for me, was to cut the screw head off:

Z nut fix

The printer works in this setup, however I will print a replacement right Z part to have the trapezoidal nut properly secured.

The second issue I had involved the calibration wizard. I was getting self test error “X-Axis Length” which essentially means the printer is not returning the expected length of the X axis. Often wires or zip ties can cause this, but in my case the Z was misaligned enough that there was minimal binding stopping the X from moving the full distance. To solve this you can exit the setup wizard do a quick Z calibration. Once that was done the self tests all passed in the wizard.

I hope to put up a review of the Prusa i3 MK3 in the next month or so.

The E3D Tool-Changer

How fitting for the first article on a site named “All the Nozzles” to be about the E3D Tool-Changer and motion system.

E3D, the company famous for their high quality hotends, has decided they didn’t have enough to work on, and as a result has come up with a new multi-head 3D Printer design (it is important to note this is not a complete printer – electronics, hotends, etc are not included).

The product includes an improved motion system which has its roots in CoreXY and features a single plate of aluminum with a moving cross-bar, currently made of carbon fiber to reduce weight but keep stiffness and strength. The Z-axis has a single thick Hiwin rail and single high-quality leadscrew motor screwed directly to the above mentioned aluminum plate.

The star of the show, however, is the tool-changing system where a single XY head mount picks tool heads (up to four) and returns them to storage incredibly quickly. This allows printing with multi-color, multi-material, and even use of non-hotend heads.

E3D made a kinematic coupling system that uses a servo to turn a cam-shaft that locks the head into place with better than 5um accuracy. Unused heads are held in place with a magnetic dock.

Right now this system is expected to cost between £1000 and £2000 ($1350-$2700), however, in more recent videos, Sanjay from E3D has said they hope to get the price down as much as possible. They are taking a quasi crowdfunding approach to this product where they hope to get enough £100 ($135) orders, that buy you a place in the queue, to show them this is worth the time to develop into a real product.

As this system does not come with electronics you will have to purchase a compatible board(s) which, at this time, only include Duet3D. In the future, however, it sounds like there will be options from other electronics manufacturers. At minimum expect to pay $275 for the Duet Wifi and Duex5 Expansion boards. You will also need hotends and extruders for as many tool heads as you want to use, up to four. I have yet to find out if the power supply and heated bed are included so keep that in mind as well when calculating costs.

Do you feel comfortable building a custom printer based off this base system and aren’t scared away by the price? Go to E3D’s Tool-Changer blog entry for in-depth information, fill out the survey, and purchase a place in line here!

I have purchased my place in line and will continue to post updates on this site of my progress building a tool-changer printer once I get a hold of one of these E3D systems.

More information:

Tool-Changing 3D Printer innovation: an E3D talk by Sanjay – MRRF 56min presentation on the tool-changing system.

The E3D MegaVolcano, Toolchanger and other shenanigans #MRRF2018 – Thomas Sanlanderer’s video covering the tool-changer.

E3D Toolchanger updates at #3DMS2018 – Thomas Sanlanderer checks in with E3D on the tool-changer and Sanjay gives some updates on what they’ve done since MRRF.