So if the little ball droid is all practical effects (to the joy of fans), how does it work?
OK then, BB-8 looks to basically be a sophisticated and super-sized Sphero, but what does that mean?
As many have pointed out, the webcomic xkcd may have already solved this one by accident when imagining a hamster ball for a PC.
With this basic design, BB-8 could roll around in any direction while independently turning its head. Number Writing 8 Work Sheet (Color)".

Number Writing 8 image of your choice (if new window does not open-up then you may need to check your pop-up blocker settings.).
Even more eye-catching was the moment that the actual BB-8 rolled on stage at 2015’s Star Wars Celebration in Anaheim, California.
In fact, the filmmakers reportedly worked with Sphero on the mechanics of BB-8, and Sphero’s website looks to be teasing its toy version of the droid. With omni-directional wheels, a gyroscope, batteries, and an adjustable internal arm with magnetic rollers, xkcd‘s hamster ball could roll around just like BB-8 and have a head held in place by the magnets.
In short, the secret to BB-8 surprising movement is likely magnets and some clever engineering, no force required.

Furthermore, a patent submitted by Sphero looks surprisingly similar to BB-8, and the current version of Sphero’s main toy is similar enough to BB-8 that you can make a low-grade version of your own with only slight modifications.
However, assuming that it’s pretty much a Sphero gives us a good idea where to start.

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