Here’s a great tutorial on building your own quadrotor helicopter. This build isn’t necessarily less expensive than others we’ve seen since quality motors, propellers, and control circuitry aren’t cheap. But the design and assembly is well documented and presents a well-planned building procedure. The carbon-fiber tubes that make up the frame have extensions to protect the motors and propellers in the event of a crash. The Arduino, IMU, and transceiver are all tucked away between two aluminum body plates as well. They only thing missing is a solid methodology for tuning the four motors, a critical procedure that is just touched up at the end of the article.