This project is about exploring uses of a commercial toy helicopter equipped with a video camera. I am looking for someone to try a fuel cell in this thing, to try to extend the flight time from 15 minutes to say at least an hour. Butane, methane, compressed gas? The requirements and constraints for commercial applications differ from those for hobbyists. (Internal combustion engine is an option but may require elaborate mechanical design.)
Instructions for use of HAK635C RC helicopter
The HAK has two counter rotating propellors sets, hence no horizontal pushing tail rotor. Power to the rotors is controlled by the left hand joystick on the controller. The vertical pushing tail rotor is used to control orientation and is controlled by the right-hand joystick.
Do not fly indoors. You will need plenty of space as control is touchy. Believe me. The control range is 150'. The flight time is about 15 minutes. Be careful to maintain constant line of sight.
Plug inboard battery cable into chassis. Power on helicopter. Power on controller. The red light will blink. Toggle left controller handle up fully and back all the way down. The red light will be steady the controller will be controlling the helicopter. Gently move the vertical control forward to power the rotors. The copter will rise faster than you think and you will overreact and crash it. Use right hand controller to navigate horizontally.
The spare battery may be charged while the onboard one is in use then swapped out by removing the plastic fuselage.
To use the video camera, install micro card in base of chassis. Use camera controls on the right-hand-side of the controller to power the camera on and off and take stills. The micro card inserts into a USB plug and that into a laptop. The stills and videos will be in separate files.
Fuel cell powered RC car http://www.gizmag.com/horizon-fuel-cell-technologies-hrover/26037/
Horizon minipack http://www.horizonfuelcell.com/store_us.htm#!minipak/c156u
Choosing quadcopter motors and props http://oddcopter.com/2012/02/06/choosing-quadcopter-motors-and-props/
More links are on the Diigo page with tags "quadcopter" and "drone" and "fuel cell."