Spheromino

Spheromino — sphere-packing puzzle segments

Print these coloured segments and assemble them into a tetrahedron of 35 close-packed balls. It's an open puzzle about how spheres actually pack (FCC): fit the pieces so every ball has its place.

🧩 Free puzzles to solve, the maths behind it, and more ways to build a set: https://spheromino.com
Each puzzle has a single, verified solution and prints on one page (colour-coded, with a letter on every piece so it's colourblind-friendly).

Made by me — feedback and remixes welcome!

Puzzle

Folding segments from spheres into planar ones (square, rectangle, triangle, star, etc.) or three-dimensional shapes (tetragonal pyramid, cube, tetrahedron, etc.) is a popular puzzle. Currently, there are various "disposable" puzzles (usually made of wood or plastic) or sets with a number of tasks (IQ and Quadrillion from Smart Games, Leu, Klikko, Lonpos etc.) on the market.
This project offers every imaginable component from 1 to 5 balls with straight or right angles between ball center connectors. It can thus serve as a source of spare parts for the aforementioned games, as the basis of a completely new game or perhaps as an aid for teaching crystallography 🙂

Printing

Material

We print from PLA; although the density is lower, the individual segments are comparable to commercially available balls.

Printing method

We print on the hemispheres, glue the pairs of halves by briefly immersing them in acetone and then pressing both surfaces together, or with cyanoacrylate (secondary glue).
For a smooth surface, we print in 0.1 mm DETAIL quality.

Coloring

The easiest way is to print each segment with a different filament. However, it is possible to color white PLA (just use tempera paint, then spray with clear varnish).