Anything worth doing is worth overdoing”

Mick Jagger

My first project with the Glowforge allowed me to wrestle with tight tolerances in three dimensions. I wanted to take on an ambitious design, and the end result was an interlocking wooden cryptex with a changeable combination. Fortunately, I was able to get a significant headstart by looking at the brilliant projects of others that came before me. Most designs resembled the one below, with the red inner box holding the prize.

As a new tinkerer, I had lots of ambition but a shortage of materials. I decided to make my cryptex as space-efficient as possible without compromising on the features of the original. First, I made the prize capsule rounded to maximize the volume available. Next, the tolerances were tightened to reduce the waste in the outer rings.

An added benefit of this design was that the treasure capsule is a solid tube held together with pressure-fit slats instead of a rectangular box that has to be cut and assembed separately. The “key” is the slat that is inserted at the 9’o-clock position. This is where the measurements were critical – it’s straightforward to design in 2D, but each of these slices would have to stack to create a disk of the cryptex in 3D. With a 0.1mm kerf on each cut, it was especially tricky to ensure that the XZ-plane letter tiles aligned perfectly with the XY-plane disks.

Time to cut!

Lookin’ good! Now for some assembly. The first step was to peel the masking from the freshly zapped wood, which in turn led to my first case of “laser fingers.” This is the affectionate term for an accumulation of fine soot on the digits that makes them smell like freshly burnt matches. After a significant amount of peeling, I broke out the superglue to bond the rings.

It’s all finally coming together! Next, the rings were stacked and the prize container was assembled. Here’s a cutaway:

All in all, not a bad effort for a first project right? I learned so many valuable lessons about how to draft, cut, and assemble a project while taking on this challenge, and it still stands out to me as one of my favorites!

These days, the cryptex lives at the Belle Mercantile in downtown Bellefonte with a secret treasure inside for anyone that can unlock it…