That is a good question I get asked a lot at school. A lot of students wonder if this style of movement is sci-fi, or magic, or some mystical physics law they know nothing about. Well, it’s not that hard to answer actually, and it’s a combination of the three mentioned above, ha-ha.

Sphero works surprisingly similar to many other robots that are being manufactured, except it is encased in a plastic ball. It uses two wheels to push itself around inside the ball (the wheels are touching the sides of the ball), controlled by the electronics and circuits inside of it.

The robot has a center of gravity that is not the middle of the ball, but is actually on the bottom (a big metal weight you can see on the picture below), so it always stays at the bottom of the ball as it rolls and moves. So, it rolls (and moves) by spinning its wheels and moving the external plastic ball part.

As for the Sphero BB-8 robot, modeled after the famous (and very cute!) droid from Star Wars, it works very similarly – it also has a metal weight at the bottom, keeping the robot’s main part on the bottom of the ball, except that BB-8 also has a lightweight metal part that reaches up to the top of the sphere, helping the ‘head’ (which has a magnet inside) stay on the top of the ball while it’s moving (magnetic force and stuff 😂 physics! I told ya!).

This informational post was lots of fun writing, I hope it helps you understand Sphero’s mechanisms better, and I hope that now you can explain to your students the ins and outs of this cool robot!

Happy teaching!

Grace