Adélie 3D Printed Utility Knife

The Adélie is the utility knife that makes it all worth it having to remember how to type the ` over the E like that. There are box cutters in the world, but none of them snap open automatically off of your pocket, and they're for sure not shaped like a penguin.

You can trust me on this one, that never gets old.

Thus the Adélie is not a switchblade — It's even better than one! No springs or other gimcrackery are required. This also means that the Adélie ought to be broadly legal in various locales, unlike switchblades or even spring assisted knives in some locations. I'm not your lawyer, though; don't quote me on that to the judge.

Now that the patent on the Axis lock is expired, anyone can have a bash at a crossbar knife lock design. And when they say "anyone," we're not kidding around. The Adélie is my fourth design for a 3D printed utility knife and the second that's any good. It also has what may just be the most robust locking mechanism on any 3D printed knife ever. Flip the blade carrier open and it locks automatically, positively, securely. Simply slide the nub to the rear to unlock.

And just like the very best crossbar lockers, e.g. those from brands whose name begins with "B" and cost $180, you can hold the lock back and easily "Axis flick" it open or closed. A bushing pivot inside ensures a freely pivoting action, while the crossbar mechanism lightly detents the blade in the closed position. Otherwise you can thumb the blade carrier open manually using the beak on the penguin head that's sticking out of it. (Hey, everybody needs a shtick. I'll give you three guesses what mine is.)

The Adélie sports colorful textured scales and includes a reversible deep carry pocket clip. Weighing just under 30 grams, it's ready to be your ultra lightweight daily companion. Why pay for carbon fiber and titanium? Those fancy materials are for chumps. 3D printed plastic is totally where it's at.

The core conceit here is my by-now-signature 3D printed "impossible" screws. These are precision engineered, I say while doing my best to keep a straight face, and headless. A single continuous thread passes through the entire assembly and locks it together, providing what I conjecture is the strongest 3D printed fastening method available without resorting to cheating and using storebought screws. (Which you can do, if you like; ordinary M6x1.0 screws will also fit.)

It should go without saying but the cutting edge on the Adélie is not plastic. Rather, it accepts standard Stanley style trapezoid utility knife blades. One blade is included; the rest you can find at any hardware store. The Adélie will be your package opening, cord cutting, box flattening companion. Using it as a bushcraft knife is not advised.

The mechanical components are all printed out of ABS so they'll be heat and broadly impact resistant. The heat resistance is important — you'd be surprised how quickly friction against a long run of cardboard against the very tip of the blade holder can heat it up to temperatures easily capable of melting plastic. ABS will stand up to this better than PLA, and there's a good chunk of material you'll have to work your way through over time before it'll cause you problems. The colorful components are printed in PLA for their, well, colurfulness. Believe it or not, PLA also has a higher layer adhesion strength than ABS which makes the screws hold up better. I was surprised as anyone to learn that, but learn it I did via the expedient of prolonged testing (read: printing several of these in various guises, taking them to work, and using them heavily to see what makes them break.)