This hacked 3D printer-turned-tattoo machine has a built-in panic lever, which I would be hammering furiously at every opportunity

I have precisely one tattoo, which I paid a trained artist an exorbitant amount of money to ink into my pasty skin. YouTuber Emily The Engineer may have developed a more cost-effective solution, however, as she’s cracked open a 3D printer, bypassed its firmware, equipped it with a tattoo gun—and even found a willing volunteer to test it out.

Don’t worry about the test subject’s safety, though—there’s a handy machine-halting panic lever installed for when they inevitably realise they’ve made a terrible mistake.

As Emily points out, she’s printed a “ton of stuff” over the years, not least this world’s largest Benchy boat attempt (via Hackaday). However, “printing” on a human is a brave new frontier, and began with the merciless tearing apart of an old 3D printer frame capable of mapping out the X and Y axis of a 2D design.

Then began a process of convincing the printer to ignore things like temperature and medium variables, before a few 2D pen sketches were drawn on test paper and the back of Emily’s hand.

A small amount of Z-hop was added in between strokes to prevent unintended lines, before the printer was deemed ready for the inclusion of a tattoo machine.

To add to the fear factor, Emily admits that the first time she ever touched a tattoo machine was for the purposes of this build. Still, it wasn’t long before the machine was installed on the print head, and a rough design was inked onto practice material.

A problem soon became apparent, however. The machine can only “print” accurately on flat surfaces, whereas Emily’s (somewhat) willing test subject, Dan, wanted a design on his leg. Legs are not flat. So rather than re-engineer the entire apparatus, a bracket was made to flatten out the top of Dan’s thigh to squish it into a flat surface.

A lever-controlled solenoid was also added, which lifts the entire tattoo machine vertically off the surface if something were to go horribly, terribly wrong. Safety, folks. It’s important.

One last (slightly wonky-looking) material test later, Dan bravely put his leg in the bracket and strapped the tattoo-3D printer hybrid onto his thigh—before the needle finally pierced the top layers of his skin. According to Dan, the sensation “wasn’t bad”, and he’s now the proud owner of… well, this:

Good job, everyone. I’ve certainly seen worse tattoos (some of them on close friends, you know who you are), although it’s not quite the “Rico-at-the-end-of-Starship-Troopers” futuristic tattoo machine we all had in our heads.

Still, I salute the attempt. I’ve seen 3D printers co-opted into all sorts of weird experiments before (this chocolate-printing machine is a highlight), but a full-on automatic tattoo machine is a new one.

And as for Dan? Well, he’ll now be able to stare down at his right thigh for the rest of his life and know exactly what he’s looking at. Rather you than me, Dan. Rather you than me.