Flybrix: "rebuildable, crash-friendly drones" made from Lego

Flybrix kits allow you to turn a variety of Lego builds into little copter-drones that you can fly with an app or a Bluetooth joystick.

The kits come with up to eight motors and a variety of reference designs that fly well, but the manufacturer encourages you to experiment with variations to find stronger or more maneuverable airframes. The firmware and control software are also available to modify on Github.

Kits start at $149 (4 rotors) and go up to $249 ("deluxe" eight rotors).