Puzzle Box

UPDATED VERSION HERE

This Hellraiser themed puzzle box, The Lament Configuration or Lemarchand's box is the latest in a series of previous attempts. What started as a contrived application of a gearbox design has evolved into it's own puzzle with a completely new internal locking mechanism. Pictured in Prusament "Mystic Brown" PLA.

Print in place, fully assembled - optimized for 0.2mm layer height. I've only printed one so far, so still refining the post-processing technique - I might do a video on it later. Optionally add support (it should bridge) with a high overhang angle and a 100% support interface for a solid disk under the dial. Random Z Seam Alignment may help alleviate binding issues caused by a vertical seam.

Start by running a razor or sharp edge through the outer seams, then pushing the fingers out from the center by hand, working your way around slowly. Crack, crack, crack is the sound of layers de-laminating and moving parts freeing up. Take your time and the box should slide open. Finally free up the dials, I used a hobby knife to wedge in the crack and then slide a sliver of Coke can into the gap and work it around.

Don't be worried if it's a bit tight and binding at first, it will quickly work itself in. Friction creates heat which softens PLA quickly. Just work it back and forth. Warm soapy water may help. Press the heels of your palms firmly on opposite dials to really work them back and forth until they move freely.

As for the locking mechanism, it prints in the "unlocked" position. Without giving too much away, to lock it turn the top dial 180 degrees before turning the bottom dial to engage the "maze" mechanism. Entering the maze is deceptively easy, escaping not so much.

I have included the negative volumes so the design can be applied to your own artwork cubes (eg. Crashjensen's work). I find Tinkercad to be quite adept at complex boolean operations. Import your cube, scaled to 76.2mm, then import the negative, make it a "hole" and combine the two objects. Finally, include the core (might have to translate 38.1mm up).

https://youtu.be/H0MJJPkx5ls

Here's an exploded view.

04/03/2021: Updated dials to reduce overhang angle to make them easier to free up.
06/01/2021: Added telescoping spring guide for 0.6x10mm x 150mm spring
02/04/2022: Updated embossed version with uniform 0.6mm emboss and thicker top and bottom face detail.

All the fiddly bits on the top few layers seem to be quite susceptible to over-extrusion. I found best results from dialing back flow rate to the point of causing under-extrusion elsewhere (75%). There are a lot of retractions so settings like ‘Retraction extra prime amount’ will also add unwanted material. A trick to getting this right in Cura is to add a support blocker cube positioned over the top few layers and change it to ‘Modify settings for overlaps’. This allows the flow rate to be tweaked only for the detailed layers as described here.