🛰️ Hidden Helix

The model features a double-turn helix (2 rotations) hidden within the cylinder walls. You can only catch glimpses of the marble as it passes by the circular observation windows cut into the sides. At the end of the descent, the ball exits the cylinder and rolls freely across your desk! 🏎️💨

⚠️ Important Note on Ball Size Although this was originally designed for 0.5" (12.7mm) balls, the internal tolerances turned out to be too tight, and larger balls tend to get stuck at the entry point.

However, it works perfectly with 6mm steel balls! 🟢 The 6mm size provides a smooth, reliable "hide-and-seek" effect through the windows.