Spinning Sphere Inside the Octahedron | Print-in-Place Fidget Toy

This 3D-printed fidget model features a sphere inside an octahedron. The sphere has just enough room to move freely inside, allowing you to spin and rotate both the sphere and the octahedron in a few different ways.

For the best visual effect, I recommend using dual-color or tri-color silk PLA, or any co-extrusion filament, to really make the sphere and top/bottom layer patterns pop.

The included 3MF file has all the recommended settings already dialed in, so I strongly suggest using it to save time and ensure the best result.

If you prefer to use the STL files instead, be sure to center and merge the sphere and octahedron in your slicer before printing. You’ll also want to adjust the settings for each part individually. I’ve included two versions of the octahedron: one with a Hilbert curve pattern and one with a simpler top and bottom. Feel free to choose whichever suits your style.

Just a heads-up: don’t expect long spin times. There’s a decent amount of friction, and the sphere almost never prints perfectly round. That said, it's still a super satisfying little fidget toy to mess with. It’s more about tactile interaction than smooth, continuous spinning.

It’s worth noting that you could theoretically print the octahedron in two halves and print the sphere separately (also in halves) using variable layer height for a smoother result, then glue everything together. I haven’t tried this myself, though, since the goal here was to make something print-in-place.

Print Settings I Used (Bambu Lab P1P):

• Nozzle: 0.4 mm
• Layer Height: 0.2 mm
• Infill: Octahedron uses 10% gyroid, sphere uses 5% gyroid
• Supports: Octahedron doesn’t need supports, but the sphere does (included 3MF only adds supports to the sphere)
• Top & Bottom Patterns: Octahedron uses Hilbert curve, sphere uses Archimedean chords

If you want to turn it into a “rolling octahedron,” try printing the sphere with a heavier infill percentage, around 50 to 100 percent. I haven’t included print profiles specifically for that, but it’s an easy tweak. On the other hand, if you want better spin performance for fidgeting, go with a lower infill around 5 to 10 percent.

If you have any questions or run into issues, feel free to reach out. I'm always happy to help.

Enjoy the print! 🌀

Also available: I have a similar model that features a spherical shell instead of an octahedron. If you're interested, you can check it out here:

License Information:

This model is licensed under Creative Commons Attribution-ShareAlike (CC BY-SA). You are free to share, copy, redistribute, and adapt this file for any purpose, even commercially, as long as proper credit is given to the original creator. If you remix, transform, or build upon this model, you must distribute your contributions under the same license as the original.

*Selling physical prints of my other designs is only permitted if you are an active member of my Authorized Seller tier on Patreon, Printables, or MakerWorld.* To learn more, visit https://www.patreon.com/c/endlessdesignlab

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