14 GeoBender Primary-I
The Oddball is based on a ring of six "Half-Dome" with some elements added.
The setup might look simple at first glance, but the distribution of magnets on the "inside" faces is a real challenge. Only 12 of the 24 triangular faces have magnets, the other half is non-magnetic.
The final assembly still has two units not connected, but getting the other connected magnetically is tricky enough.
The Ball of Spheres build is based on the Oddball.
Just like the Oddball, the Ball of Spheres has a ring of six as base combo. The other key element is a Sphere in the center, where three more Spheres are attached around each of the two poles of the center Sphere. The two structures together make the Ball of Spheres.
Unlike the Oddball, all thirteen elements of the Ball of Sphere are connected magnetically. How is this possible with one element less? The answer is simple: The center Sphere is hollow. For the Oddball consisting of Half-Domes, the equivalent of two units is needed to cross the center. The Spheres offer more adjacent magnetic faces, and can be rotated in an appropriate position. The Half-Domes have to be oriented with the large face pointing outwards. With the freedom in rotation, all of the Spheres can get connected.