Drone racing is a fun, new and FAST sport.  Drones whip through urban environments like football stadiums at lightning speeds.  I’d imagine in practice and competition, just like car racing, some wrecks are inevitable.  Well, if you want to take the sport up maybe 3D printing can help.  You can print your own drone with this great kit of files and parts (motor, battery and the such) from Robo 3D.  With this you can print your own spare parts when you wreck.  Of course perhaps it may be best to start virtually.  In that case checkout the great video game!