Design No. 78-A - Assembly puzzle by Stewart Coffin (STC #78-A)

thingiverse

## ## Design No. 78-A ### Assembly puzzle by Stewart Coffin (STC #78-A) Assemble the six pieces into a 3x3x3 cube. _Design No. 78-A_ is a sort of sequel to Coffin's related design [Pillars of Hercules](https://www.thingiverse.com/thing:4208015). Like _Pillars of Hercules_, it is based on an unusual dissection of the cube into half-cubes, this time with all six pieces containing a dissected component. This design is an obscure one and has rarely been produced. Coffin himself had little to say about it, remarking only that "If the three [composite] pieces are joined together at the start, the puzzle cannot be assembled." Despite its neglect, it's a fine and unique design, and I had a lot of fun solving it. Recommended to anyone interested in exploring the byways of Coffin's catalog. Aside from _Pillars of Hercules_, other Coffin designs that use the same concept include [Pieces-of-Eight](https://www.thingiverse.com/thing:4208010) and [Triple Cross](https://www.thingiverse.com/thing:4230238). ### Printing Instructions Print one copy of `coffin.78-a.pieces.stl`. You may optionally print `coffin.78-a.box.stl`, a display box that can hold the assembled puzzle in place, as shown in the cover photo. This model uses "snap joints" so that it can be printed without supports. After you print it, first connect all the joints before attempting to solve the puzzle. Snap each male connector into a corresponding female connector (for example, the male connector labeled "A" should connect to the female connector with a matching "A" label on the interior). The joints are designed to be tight, and depending on the printer and filament used, you may need to hammer them into place. If they come out too loose, a drop of superglue will make them more solid (in most cases this shouldn't be necessary, but unfortunately tolerances vary across printers and filaments). The snap joint concept is discussed further in this tutorial: [Getting Started with Puzzle Printing](https://www.puzzlehub.org/tutorials/getting-started). I've also included a smaller version, `coffin.78-a.pieces-smaller.stl`, that uses around 1/3 less material. ### The Printable Puzzle Project The [Printable Puzzle Project](https://www.puzzlehub.org/ppp) aims to make available high-quality open-source models of many puzzle designs. All of our models are posted with the generous permission of their designers and are licensed for __non-commercial use only__. Anyone may print copies for their own personal use, but selling or otherwise monetizing them is not permitted, and puzzle designers retain all rights as copyright holders of their work. Our puzzles are modeled using the open-source [puzzlecad](https://www.thingiverse.com/thing:3198014) library. The `.scad` file is included with this model in case you want to modify any of its design parameters; more information on how to do this can be found in the PPP [Puzzle Modeling tutorial](https://www.puzzlehub.org/tutorials/puzzle-modeling). ### About the Designer Stewart Coffin has been called "the most outstanding designer and maker of interlocking puzzles that the world has ever seen". He is credited with over four hundred designs, has pioneered numerous ingenious puzzle forms, and has written extensively about puzzle design and craftsmanship. More information on Coffin, along with many other printable models of his designs, can be found on the [Stewart Coffin Puzzles](https://www.puzzlehub.org/puzzles/stewart-coffin) overview page. Happy puzzling!