3D Printable half-size BB-8. Motorized and remote controlled via an Arduino platform. Also have functional LEDs and sounds!
It's powered by an Ardu...ino board and remote controlled via RF. This droid self-balance on two wheels, play sounds, and has several programmable LEDs.
Printing the whole body and head takes about 200 meters (656 feet) of filament, and 50 hours on a regular PLA 3D printer. No support required.