manofsan,
That's an interesting idea. Now put another lifting rotor on top of the
main shaft, counter-rotating, and you can forget the tail rotor, with all
of its' complexities. Use spider gears idling between the rotors, so both
rotors will turn at equal rates, even if one motor fails.
Pivot the entire rotorhead like a Benson autogyro, and control that with a
joystick. Steer it with a large rudder behind the pilot that can tilt (for
yaw axis control in hovering flight) *and* swing left-and-right (for
directional control in forward flight). You could do that very simply,
with a rudder hinge line angled 45 degrees back from the main rotor shaft,
and rudder cables that pull the lower end of the rudder directly.
The flight control system at the pilot's position could be identical to an
autogyro. You would need rudder pedals, throttle, and joystick only.
There would be no cyclic controls, no collective pitch controls, and no
tail rotor controls (because there is no tail rotor). This is *much* less
machinery than the AirScooter:
http://www.gizmag.com/go/3056/
Feed it with fuel cells (aviation ain't cheap).
Watch out for birds... Don't forget the BRS :-)
http://brsparachutes.com

My ASCII art:
____
| |
|BRS |
\ /
counter-rotating ||
-------------------(motor)--------------------
lift rotors *||* --spider gears
-------------------(motor)--------------------
______||-----\
_____/h\.....|| \ autogyro
( i\....||\ \--joystick
( n\...|| \ \
(rudder g\..|| \seat pedals
(__________e\.|| \______ /
/----------------------------/--\
/ main frame w/fuel cells \
/-----------------------------------\
o O
--
(Replies *will* bounce, unless you delete
the letter A from my email address)
Cheers,
Red

wrote:
I was looking at pictures of Yamaha's recently announced Deinonychus
motorbike, and was struck by how functional and light it looked, due to
having been designed around electric wheel-motors:
http://www.gizmag.com/go/4686/
Somehow this same barebones functional look reminded me a bit of the
Mosquito helicopter, also featured on the same site:
http://www.gizmag.com/go/4628/
And so it made me wonder whether some of the same elements used to make
the Deinonychus motorbike couldn't be rearranged to make a light
electric-powered mini-helicopter.

Ugh, here's my ascii-art pic ;P

--------=======-------
|
|
|
|
||
||
_||____
| \
__ /
/ \
| |
\__/

So the top part is the rotor and the = signs are the wheel motor that
turns it.
Then you have the shaft with the seat coming off near the bottom of it.
And the circular shape at the bottom is supposed to be a tire for
landing gear, meant to take the main shock of landing, but the pilot's
legs are supposed to provide lateral stability on landing and takeoff.
Some Segway-style control logic on the bottom wheelmotor could be used
to provide stability on the forward-backward axis during
landing/takeoff. This would include allowing the swivel-arm, on which
the bottom tire is mounted, to move and change its angle.

So the tire underneath is supposed to have fan-blades as the spokes,
and is spun by its wheelmotor to provide the counter-rotative thrust
like a tail-rotor. After takeoff, the swivel arm slowly swivels the
tire back and up to position it at the rear. Likewise, during landing
approach it swivels down and forward to serve as the Segway-style
landing gear.

While landing, the wheelmotors will use regenerative braking to stop
the rotors as quickly as possible.

What do you think? Comments, critiques, suggestions?