Light Electric Rotorcraft

Hi,

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?

In article .com,
wrote:

Hi,

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?


Of course, they can! All you will need is a really LONG extension cord!

wrote

Somehow this same barebones functional look reminded me a bit of the
Mosquito helicopter, also featured on the same site:

I didn't see what the engine was on the heli, but if you know what it is, do
some calculations. Figure the wattage for the gas engine heli, then convert
it into amp hours for the length of time that you want to fly, then figure
out how much weight of batteries you will have to carry.

My bet is that the batteries will weigh too much, and be too expensive.

I HATE being a pessimist!
--
Jim in NC

("Morgans" wrote)
My bet is that the batteries will weigh too much, and be too expensive.

I HATE being a pessimist!


Diesel turning a generator?


Montblack

"Montblack" wrote

Diesel turning a generator?

And this is supposed to be saving weight? g

Why not just turn the rotor with the diesel? Too obvious?
--
Jim in NC

Morgans wrote:
"Montblack" wrote


Diesel turning a generator?


And this is supposed to be saving weight? g

Why not just turn the rotor with the diesel? Too obvious?

It *might* be possible that diesel-electric system would be lighter than
pure electric or pure diesel.

A small diesel could be optimised to run continuously at its most
economical RPM, producing only a little more electricity than needed to
drive the rotor in level flight. For additional power, electricity from
the battery would also drive the rotor. When descending, the battery
gets charged faster.

"Frank van der Hulst" wrote

It *might* be possible that diesel-electric system would be lighter than
pure electric or pure diesel.

I'm from Oklahoma. Show me!

A small diesel could be optimised to run continuously at its most
economical RPM,

It would already have to have a gearbox for a heli, so it can run whatever
RPM you want. An electric motor would also have a gearbox. Yes I know,
there are low speed electric motors, but they are huge and heavy.

producing only a little more electricity than needed to
drive the rotor in level flight.

There will always be losses, driving a generator, then a motor. You will
have to have at least 10% more power output by the diesel motor, just to
break even, and more than that to charge batteries.

So lets see, we have to have a gearbox both ways, no change in weight
between the two. We will have to have a bigger diesel to take care of
losses, so penalty goes to electric. We would have to have batteries for
electric, so more penalty for electric. Since our electric has gotten
heavier, we will have to have a bigger engine, and more fuel, so BIG penalty
for electric.

For additional power, electricity from the battery would also drive the
rotor. When descending, the battery gets charged faster.

What you are talking about is like an autorotation. The blades in an
autorotation have to go to negative pitch, just to make the blades maintain
RPM, and to get more power to generate electricity than a plain
autorotation, they would have to be at even more negative pitch. You would
have to descend so fast to get the rotor to produce electricity, your
passengers would freak!
--
Jim in NC

Morgans wrote:
wrote


SNIP


I HATE being a pessimist!
--
Jim in NC

Then stop. It's a simple 12 step program... :-)

-Matt

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?

Hi red, thanks for the great ideas.

Hmm, I read about how a coax design can use differential rotation speed
between the 2 rotors for the purpose of turning the aircraft. That'd be
pretty easy to do with a wheelmotor for each rotor.

Here's a link to a new kind of wheelmotor which is attracting
attention:

http://www.wavecrestlabs.com

The company is headed by General Wesley Clark, former NATO commander.
Regarding portable fuel cell for propulsion, here's another link:

http://www.intelligent-energy.com/in...6&artID=3 709

And hydrogen is a lightweight fuel too, for lower fuel load.
But suppose you want some extra juice sometimes, for more
maneuvering/lifting power. Then use the new Toshiba battery:

http://www.dpreview.com/news/0503/05...sh1minbatt.asp

It can apparently discharge and absorb energy at a very high rate. This
might be useful for using regenerative braking to recover energy from
your rotor when you're reducing airspeed/altitude, since a wheelmotor
can convert torque/rpm back into electricity. Once you've landed,
regenerative braking would allow you to quickly bring the rotors to a
stop while recovering energy from them.

I'd also imagine the electric motors would be quieter too, so your
eardrums don't take a beating.