The Chubby Tricorder Project: designing a digital puzzle box

Recently, I had the plea­sure of build­ing a puzzle-hunt gad­get. The cir­cum­stances sur­round­ing this par­tic­u­lar device and hunt were extremely unique. The puz­zle hunt was for an audi­ence of one — a sur­prise birth­day party for my friend Curtis. The gad­get was one stage in an after­noon game. The device itself is a screen and key­pad embed­ded in a sleek laser-cut enclo­sure. Once solved, an inte­grated ther­mal printer spits out an impor­tant mes­sage that fur­thers the plot and adven­ture, lead­ing to the next phase of the puz­zle hunt.


My ini­tial pencil-sketches of the gad­get got tagged with the name “Chubby Tricorder,” mainly due to the thick­ness required by the ther­mal printer. It’s a ter­ri­ble name, espe­cially given that we later intro­duced an actual tri­corder. But it’s a mem­o­rable name. So while my nar­ra­tive will describe it as a puz­zle box, a gad­get, a black box, and so forth, do not be con­fused if you see the phrase “Chubby Tricorder” when dig­ging deeper into the engi­neer­ing files.

But I get ahead of myself. This first blog post is the lead-up to the gad­get. It is the first in a series of three. I assume you’ll hear about the over­all adven­ture in the com­ing days, from Curtis and from the peo­ple more centrally-involved in game con­trol. I first heard about this game about two months ago when Richard approached the Puzzled Pint orga­niz­ers at a plan­ning meet­ing (from which Curtis was absent, of course). Curtis and DeeAnn have put so much time and effort into the local puz­zle com­mu­nity that Richard wanted to give back. On our Puzzled Pint plan­ning mail­ing list, the puz­zle hunt that Neil Patrick Harris’ fiancée threw for him made the rounds. A few of us joked that we had birth­days com­ing up. In this case, Curtis’ 40th was approach­ing. No joke. There would now be a puz­zle hunt for him.

I couldn’t take an active role in build­ing the game. I have too many com­mit­ments already between work, puzzle-based projects, yoga, my fam­ily, and my own “maker” projects with 3D print­ing and laser cut­ting. I really wanted to say yes but knew that doing so would end up with me drop­ping the ball some­where and let­ting some­one down. So I stayed on the fringe, but offered to build a puz­zle or playtest and, of course, to help out on event day.

A lit­tle over a month ago, Matt approached me about build­ing a puz­zle. They needed a phys­i­cal object of some sort, some­thing that could con­tain some paper. I did a lit­tle bit of think­ing and came up with a few pos­si­ble ideas.

CRYPTEX • I could print (or have pro­fes­sion­ally printed) a cryp­tex. There is a pretty decent cryp­tex model on Thingiverse. That ver­sion uses glued-on paper strips for the let­ters (and to cus­tomize the answer to your own word), which seemed a bit lame. Getting it printed at Shapeways meant hav­ing a great res­o­lu­tion for emboss­ing let­ters, so I could tweak the model by putting the let­ters in the right place in the source file for each wheel. I could also replace them with geo­met­ric shapes, Klingon, Romulan, or what­ever. The down­side here is that a cryp­tex feels extremely out of place for far-future SciFi like Star Trek.

HANDHELD COMPUTER • Another thought was to build a small screen and key­pad. It had the down­side of not “con­tain­ing” a mes­sage, as in a piece of paper, but could con­vey one on a screen.

REVERSE GEOCACHE-LIKE DEVICE • Another idea was to build a lock­box that had the screen and key­pad, but that also had a lock­ing mech­a­nism. Like a reverse-geocache, it could unlock itself – though in this case it would be based on an answer, not on a GPS posi­tion. This did not feel like the right answer to me. You could achieve the same result by buy­ing an elec­tronic safe. I had no real expe­ri­ence in man­u­fac­tur­ing a reverse geo­cache and didn’t want to risk a crash-course of trial and error. I had about a month. I trust Curtis to not smash the device, but it still felt con­cep­tu­ally wrong to use some­thing that could just be piñataed open.

PRINTER DEVICE • I had actu­ally wanted to work with a ther­mal printer for a while and won­dered if I could com­bine some of the above ideas into a hybrid. Start with the box that has a screen and key­pad hold­ing a piece of paper, but turn the idea around. Instead of hold­ing the paper mes­sage, it would man­u­fac­ture it on demand.

I liked the printer idea the best, as far as the fun and chal­lenge of build­ing the project and the min­i­mal risk in imple­ment­ing it. Wrap it in a laser cut and etched black acrylic case, and you have some­thing out of Star Trek (admit­tedly, lean­ing a lit­tle more Original-Series-Trek, but trek nonethe­less). I pinged Matt and Richard and they loved the idea. I specif­i­cally did not com­mit to mak­ing the puz­zle that yields the unlock com­bi­na­tion. I thought I would have enough work on my hands in build­ing the box that I could not also focus on design­ing, test­ing, and revis­ing the cor­re­spond­ing puz­zle. They assured me that that would be taken care of.

So I had just over a month to make it hap­pen. Just like Puzzled Pint. Except I had to man­u­fac­ture a piece of high-tech elec­tron­ics.

Next up is Part 2: the design.

Posted in: Dear Diary Gadgets MakerBot Puzzle Games

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Brian Enigma

Brian Enigma is a Portlander, manipulator of atoms & bits, minor-league blogger, and all-around great guy. He typically writes about the interesting “maker” projects he's working on, but sometimes veers off into puzzles, software, games, local news, and current events.

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