THIS IS THE OLD VERSION. TAKE A LOOK TO THE NEW IMPROVED VERSION OF THE B-ROBOT:

B-robot EVO

B-ROBOT is an OPEN SOURCE remotely controlled self-balancing arduino robot created with 3D printed parts. With only two wheels, B-ROBOT is able to maintain his balance all the time by using his internal sensors and driving the motors. You can control your Robot, making him moving or spinning, by sending command through a Smartphone, Tablet or PC while he keeps the balance.

https://www.youtube.com/watch?v=V-_uxpX9aFQ

Here are the 3D parts. Print them and if you need any help take a look to www.jjrobots.com (@jjrobots)