The other day, I caught the Brain Cell.

I presume most of you are familiar with my Rockhopper 3D printable utility knife balisong thing, and for those of you who aren’t I will use this opportunity for yet another shameless plug.

It’s fully printable, it’s got a spring latch, a reversible deep carry pocket clip, and it’s wholesome and easy to make at home.

I designed this by using the screw design from my marginally more popular but considerably less interesting (in my opinion) Adélie Axis locking Wave Opening utility knife jobbie. Those screws were designed with no particular specification in mind other than to be totally 3D printable.

But I realized that due to laziness on my part the thread pitch is precisely 1.0 mm, and the diameter is tantalizingly close to the same as a standard commodity M6x1.0 screw. But not quite.

So why not just make it an M6 screw, you say?

Why not, indeed.

One minor redesign later – which has been up on Printables for a couple of weeks, actually – and now there’s the option to use either printed screws (for the lazy, purist, or impatient) or 12mm long M6 set screws (for the stylin’, swanky, or possibly paranoid).

I will point out that I have never managed to break one of my printed screws once I got the design nailed down. I’m sure it’s possible if you try hard enough, but clearly they’re not the actual weak point. Even so, I understand that they skeeve some people out on general principle.

Going with metal hardware also makes the final product significantly heavier: 42.8 grams, versus 26.3 with the plastic stuff. That makes the knife feel more substantial and less like a middle schooler’s science fair project.

This also enables stronger bushings with a slightly increased thickness, which means a more solid action and increased positivity to the lockup when latched. I made a few other minor design changes as well, like making the pocket clip mounting significantly less of a pain in the ass.

I’m also showing this off with one of several scale pattern variations, in this case my Replicator set. Astute readers may find them reminiscent of a certain knife. Don’t you worry about the Chinese; I can make knockoffs of my own, right here in my own basement.