We’ve managed to figure out exactly how last week’s story on an incredible hair entanglement took place. 

The story highlighted this scenario showing a 3D printer operator whose hair had somehow become entangled in a desktop 3D printer. 

Many readers expressed extreme skepticism about this story, suggesting that it “Could Never Happen”. 

But it really did happen.

We now know how, and it could easily happen again. 

Video Footage

We obtained access to security cam footage of the incident. Unfortunately, we are unable to publish it as both the owner of the video and person involved will not grant us permission to do so — we asked! However, I was able to watch it and will provide a detailed sequence of events below. If you read through, you will no doubt agree that this incident really happened. 

The event took place at a public workshop where new members frequently join who may not have a lot of experience operating machines. Although this workshop does take everyone through a very detailed safety orientation program, which must be signed off by all concerned, it doesn’t mean individuals don’t forget what they learned. 

The operator in this case wished to 3D print two items and wanted to use two adjacent 3D printers, seen at top. Here’s what happened in sequence:

• 2019-12-20 09:57:02 Operator is setting up a 3D print job on the Prusa MK2.5S on the left. By chance, the machine’s extruder is positioned at the top of the build volume due to the previous job’s size. 

• 2019-12-20 09:57:26 Operator has inserted the SD card into the MK2.5S and has started the 3D print job. Note that this machine was cold as it had not run for some time. 

• 2019-12-20 09:57:30 MK2.5S is slowly warming up.

• 2019-12-20 09:58:10 Operator now begins prepping the adjacent Ultimaker 2+ Extended for the second 3D print job. It turns out the operator had to change filament spools to ensure the correct material was used. 

• 2019-12-20 09:58:12 Operator leans between the two machines to access the Ultimaker’s spool mount, which is on the back of the machine. One spool must be unloaded and another loaded. 

• 2019-12-20 09:58:15 Operator is having difficulty with the Ultimaker spools, leans in farther, and turns to the right to see the spool mount more clearly, unknowingly laying loose long hair all over the MK2.5S, which is still warming up.

• 2019-12-20 09:58:21 The MK2.5S is now warmed up and begins its homing sequence. Since the extruder was at the top, the controller sends it down to the build plate by spinning the Z-axis rods. The rods are covered with grease, which sticks to some hair and more is quickly wrapped around the rotating Z-axis threaded rod. 

• 2019-12-20 09:59:02 Operator realizes her hair is caught on the right Z-axis threaded rod. Operator powers off the MK2.5S, and attempts to release the hair, but is unsuccessful.

• 2019-12-20 10:00:10 Operator pulls out her phone and calls for help.

• 2019-12-20 10:02:15 Help arrives.

• 2019-12-20 10:04:27 After attempting to pull the hair out unsuccessfully, the two manually rotate the Z-axis to release the hair. 

• 2019-12-20 10:05:15 The operator is released! 

So, to sum up what happened: 

A novice 3D printer operator mistakenly laid loose long hair over an operating 3D printer just at the brief moment when the Z-axis rods were spinning continuously. 

Could this really happen? Yes, because it really did happen. 

As it turns out, there was no damage to equipment, nor harm to anyone as a result of this incident. However, that’s the best kind of incident because we can all learn so much from the experience and safety procedures can be improved. 

Long Hair and 3D Printing

There’s a few things to know here: 

Long hair, beards, hanging strings or any other loose material can always get entangled in operating equipment if exposed at the right moment. In this case, the operator should have secured her hair before proceeding. Always secure all loose things before operating a machine with exposed moving parts. 

Those with short hair may not know this, but people with very long hair often don’t realize something is happening with the ends of their hair because of the length. In this case that effect allowed the Z-axis to capture quite a bit of hair, and the realization was too late. 

There is no blame attributed to the machines in this case; they worked as designed, but were used incorrectly by an inexperienced operator. One who, I should add, is likely never to make this mistake again. There’s nothing quite like a near-miss incident to increase safety awareness. 

3D Printing Safety

To those of you who suggested this was fake because it could not possibly happen, you were wrong. Even worse, your understanding of the equipment and machine safety was too narrow to realize this particular failure mode could occur. If there are moving parts, things can always happen. 

That’s how accidents happen: when everything aligns, the unexpected takes place, especially when incomplete assumptions of the activity are used. Sure, the Z-axis rod turns only very slightly during printing and could not possibly capture hair. 

Except when it doesn’t. 

3D printers are simply machines, and machines can cause harm if operated improperly. Always take a moment to consider all safety protocols when operating any machine, including your 3D printers.