Anderson Li and his team at the University of Victoria have made an amazing Quadcopter from an Arduino, some DC motors and parts printed from a 3D printer. The Quadcopter runs a modified version of the AeroQuad software, and can last a couple of hours in flight.
Using a single propeller causes the craft to rotate in the opposite direction of the prop. This is why helicopters have the propeller on the rear. The Quadcopter uses 4 rotors to control the craft, which rotate in different directions.This helps the stability and keeps a low profile, and relatively simple control.
The Quadcopter cost less than $200 to put together, with a frame that was printed from ABS plastic weighing 176g, a Styrofoam guard for the propellers, and the brushless DC motors. A lithium ion battery powers the Quadcopter, and a 9 degrees of freedom sensor connected to an Arduino.
It’s a great little DIY drone that saves the hassle of buying a Quadcopter and fitting your own Arduino. You can read the entire build on the team’s project website.