The 32 Crystallographic Point Groups ("didactic" set)

Models of all 32 Crystal Classes (= crystallographic point groups) for teaching or practice, with spoiler-free, randomized file names. Pre-oriented for best adhesion and overhang quality. 

There are no overlaps with the other sets, you can freely mix&match shapes or use them interchangeably. This new set is also now suitable for multicolor printing.

Note: This is a really tough exercise. It is harder than the original "minerals" set, because guessing will not get you anywhere. You really have to understand and exclusively use the symmetry elements. With colored faces it becomes a lot easier but is still hard. Don't cry if you fail, you're in good company.

There are 33 files, because one example exists in D- and L-configuration (I didn't bother to do that for all chiral symmetries - you can just mirror the models). The pdf is just a printable A4 game board to help with sorting. Feel free to drop me a message if you would like the solution, I will not post it here as it's not meant to be available to my students.

Check out my other symmetry models:

Minimal set
(Pseudo-)Minerals set
Molecules set
Real Life Set
Simple Set
Spheres (Pac-Man)
Spheres (rings)
Teddys

Things I designed differently in comparison to the other sets:

- no real minerals/crystal shapes were used: this allows better printable and generally simpler shapes
- shapes are generally more blocky and isotropic: makes it much harder to spot the crystal system and forces students to use only symmetry, which is the proper method
- made cubic symmetries not look like cubes, and trigonal/tetragonal/hexagonal not look like rods with 3/4/6 axes (again to force students to check systematically for symmetry)
- less faces: some symmetries are easier to spot, makes multicolor printing or painting feasible
- added extra faces: 1-2 unneccessary indices were added wherever it improves printability or removes pointy edges (I carry them in bags, edges chafe off)
- generally larger faces: easier to identify equivalent faces, better build plate adhesion, much easier to identify on fotos (for scoring)
- generally low h,k,l indices were used, including any extra faces (with two exceptions for better overhangs): makes shapes more recognizable and face indexing easier (if students are interested)
- all models scaled to the same volume (saves some filament and looks better)
- all models designed with print quality in mind and preoriented in the best orientation (tested): corners should all be straight
- now multicolor-enabled: pre-painted project files are provided for XL(5H) & MK4/S+MMU3, where I painted equivalent faces in the same color. Since only 5 colors are available, I had to use some colors twice for a handful of the lowest symmetries. In these cases I made sure that inequivalent faces that were assigned the same color are very clearly not identical. Of course other coloring schemes are possible and might make more sense for you, e.g. use 2 colors and only mark a crucial axis or face (pair).

Notes on printing:

Best stick with the print orientations I provide. I tested several for the more difficult models and these were the best (the Prusa XL has relatively poor print cooling and my final results are great, so other printers might do a bit better). If you have an enclosure and print with PLA, leave the door open, or the lower edge overhangs will sag heavily if you print a full plate. I provide project files for multicolor printing (Prusa XL and MK4/S), where I have given equivalent faces the same colors.