Star Wars: The Force Unleashed, the seventh movie in the venerable space opera franchise, has already won fans with a cast full of new as well as familiar faces and a striking, post-Imperial aesthetic. It also features a brand-new robot, the sphere-with-a-head BB-8, who captured hearts at Popular Science from the first moment it appeared on screen. We’ve already seen working fan-made BB-8 replicas. Now, a site explains just how the rolling, bouncing, head-toting ball works.
The site, “How Does BB-8 Work?” helpfully hides spoilers unless readers choose to click through to read them. In the fictional universe, BB-8 fits into the same spot of an X-Wing as R2-D2. In the real world, BB-8 is a physical object, in sharp contrast to the Star Wars prequels’ heavy reliance on computer-generated images.
To get the working body, the production team turned to Sphero, a Disney-funded toy rolling ball robot. (It’s no surprise that when a fan tried to recreate BB-8, he started with a Sphero, too.) Here’s how Sphero, and the ball part of BB-8, works:
A different patent filed by Disney discusses at “dynamic mast”, which functions as a sort of internal magnetic arm that holds onto the head while allowing it to move on the outside of the sphere.
“How Does BB-8 Work” was created by Carlos Sánchez and Emilio Gelardo, two self-described Star Wars geeks in Spain. Their site features a couple of really cool animations of the likely BB-8 mechanisms in action. While their description remains a hypothesis for how BB-8 actually works, in true Star Wars fashion they expect the secret to eventually leak, saying: “Because let’s face it. If the Death Star plans were leaked, so will BB-8 plans.”