Sierpiński Cube-Octahedron Compound Fractal - Level 3

While learning about geometry, I came across a Wikipedia article on duality, which used a cube-octahedron compound as an example. Intrigued by the shape, I modeled it in CAD ( https://www.printables.com/model/1166563-compound-of-cube-and-octahedron ) and realized it could be used as the base for a Sierpiński octahedron. Instead of a single octahedron, this structure follows the same recursive method but is built from the cube-octahedron compound.

This is Level 3 of the Sierpiński Cube-Octahedron Compound series. If you'd like to see more, you can find Level 2 here: https://www.printables.com/model/1172404-sierpinski-cube-octahedron-compound-level-2

Print Settings:

Supports: Manually Painted Snug Supports (Use Pre-Painted 3MF – Support Painting Guide Coming Soon)
Infill: Gyroid, 10%
Brim: You'll want to use a brim to avoid adhesion issues.
Ironing: Recommended on the top surfaces for a smooth finish but not required.

I’ve included a 3MF file for printing two halves as pyramids that need to be combined. To capture the full fractal design, print both halves and glue them together.

Alternatively, you can print just one half as a standalone pyramid—it offers a unique perspective on its own and looks great with tri-color filament and a fancy bottom surface pattern like Hilbert Curve or Archimedean Chords. (A separate 3MF for the single pyramid is also included, along with the STL.)

A Quick Note on Supports - I put a lot of effort into minimizing supports, testing multiple approaches—including organic tree supports—but after several failed attempts, I found that snug supports provided the best balance of stability and clean print quality.

Most overhangs print fine without support, so I’ve manually painted supports only where absolutely necessary rather than relying on auto-generated ones. The included 3MF file reflects this optimized setup.

Feel free to leave a comment or reach out in a DM if you have any questions. I’m here to help.

Have fun! 🥳

License Information:

This model is licensed under Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA). You may share, copy, and redistribute the file for non-commercial purposes with proper attribution. Modifications must remain under the same license. Selling this model or modified versions, either digitally or as physical prints, is strictly prohibited.

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