Customizable Parametric Planetary Fidget

Get ready for a mesmerizing mechanical spin. This isn't just another gear toy—it is a fully parametric, self-capturing planetary gear system engineered to print flawlessly right off the build plate.

Powered by MakerWorld's Parametric Model Maker, this customizable fidget gives you total control over the geometry. Want a massive sun gear with tiny orbiting planets? Done. Want to change the center cutouts to hexagons or triangles? Easy. I've even included five distinct outer ring profiles, ranging from a smooth ergonomic scallop to a fully articulated, 3-axis gyroscope that acts like an aerodynamic spinning top.

Configure your print in place gear assembly, drop it in BambuStudio or your favorite slicer, and give it a spin.

Technical Challenges Overcome: 

Building a mathematically sound involute gear generator that users can safely modify in the cloud required solving several complex kinematic hurdles:

• Carrier-less Mesh: By utilizing a 30-degree double helical (herringbone) gear profile, the opposing V-angles naturally lock the planetary gears on the Z-axis. This eliminates the need for an external carrier, drastically reducing internal friction for a much longer spin time.
• Anti-Collision Math: Allowing users to blindly change gear teeth counts usually results in broken meshes and overlapping parts. I've implemented a dynamic anti-collision algorithm that auto-corrects the planet sizes to guarantee a perfect mechanical fit every time.
• Kinematic Phasing: Meshing internal and external involute curves requires perfect alignment. The script calculates the exact fractional degrees of rotation needed to phase the sun, planets, and internal ring gear perfectly before rendering.
• The "Shrink-and-Grow" Grip Fillets: To ensure the outer grips (like the Scallops and Sunbursts) don't have sharp edges, the script uses a 2D offset chain to simultaneously round over every peak and valley on the perimeter before extruding the final 3D shell.

Open Source Attribution:

• Powered by BOSL2: A massive thank you to the creators and maintainers of the Belfry OpenScad Library, v2 (BOSL2). The core gear kinematics, involute curve generation, and profile shifting in this parametric model rely entirely on their incredibly robust library.

Pro-Tips for Printing:

• Clearances: The default configuration is tuned for modern FDM printers with a 0.12mm backlash gap for the gear teeth and a 0.4mm clearance for the gyroscope gimbal pins. If your printer runs a little loose or tight, you can adjust these directly in the customizer!
• Structural Integrity: When hollowing out the center of the Sun or Planet gears, keep the cutout under 60% (the customizer safely caps you here). Anything larger threatens the structural backing of the gear teeth and could cause shearing under heavy use.
• The First Spin: When pulling the Gyroscope Grip version off the build plate, gently crack the 45-degree gimbal pins loose on their axes one by one before trying to spin the main gear assembly.