**** me Macro's gonna have his surfcat in the stratosphere in no time, imagine if you made the blades out of solar panels AND had nutri grain for breakie!!!

Not picking.

Its a multi-rotor not a true helicopter.
Good on them for their hard work and effort.

IMO the record is still unbroken as a few fellow enthusiast will know what I mean.

Leonardo just had an orgasm.

Macroscien said..

As a proof of concept two counter rotating wings could be enough.

Theoretically if human could power airplane why not small helicopter. (?) We could generate 700W of power for an extended time.

Well, in that video, it was in a controlled environment with a really efficient setup, with a very strong cyclist, so I am not sure it is really very easy at all.

I can't remember the exact figures, but trying to continuously provide an reasonable amount of power for a long time is very difficult. A quick google tells me that your guess of producing 700w for an extended time is way off.

The cycling machines at the local gym tell you how much energy you are using and I remember thinking that the output a good cyclist can produce was way different to what I could do.

Macroscien said..

FormulaNova said..


I can't remember the exact figures, but trying to continuously provide an reasonable amount of power for a long time is very difficult. A quick google tells me that your guess of producing 700w for an extended time is way off.

Normally we could output 1/3 to 1-2 of that 700W but as you could see on the video guy doesn't look like during Olympic sports event.;

Another one the flew over English channel also managed to deliver over extended period of time.
So 150-250W would be appropriate, but if you are properly motivated I guess we could produce much more for longer.

75W is average useful output for laborer in 8 hour shift.

Peak power for 30 second for normal healthy men 909W , and double that for pro athlete.

Good physical exercise : 500W including produced heat and you could sustain is for an hour.


I wonder how much energy if cost me sailing for 1 hour on slalom board On ordinary free ride I could sail for hours but on slalom I am completely flat out after just one

I even doubt the abilities of most people to put out 200W for a sustained period. I can't quite understand your comment about Olympics, but that guy is certainly a cyclist and not some random guy chosen off of the street. He has the legs of a cyclist.

Where are you getting your figures from for peak power? Are they the total energy a person expends or just the amount of energy they can put into a bike? They sound way too high.

Also, the amount of energy needed for a helicopter would be way more than for an aeroplane.

youngbull said..

Not picking.

Its a multi-rotor not a true helicopter.
Good on them for their hard work and effort.

IMO the record is still unbroken as a few fellow enthusiast will know what I mean.

Yep definitely not a true helicopter. but a really good multi-rotor. If they were to be able to store the energy by attaching to a flywheel of some sort he would be able to take a short break between cycling to conserve his energy.

FormulaNova said...

Also, the amount of energy needed for a helicopter would be way more than for an aeroplane.

Not necessarily? It's all about optimising lift, drag and the speed of the wing. No good having great lift to drag if you have to move the wing too fast. Power = drag X velocity. It's also a battle between the size and weight of the wing vs. fragility. Maybe that's why regular helicopters go for small wings and high power. Fast planes also have small wings, but that doesn't matter because they get there quicker. The regular pedal powered plane loses because you have the drag of the wing plus the drag to turn the propellor. The helicopter wins because it doesn't need the propellor but loses because some parts of the wing move faster than optimum and others slower. The pedal helicopter also loses because it doesn't go anywhere. But maybe that's not important, it's the getting off the ground that matters.

(And of course it's a helicopter. Saying a helicopter stops at 2 rotors is just being sexist)

Ian K said..

FormulaNova said...

Also, the amount of energy needed for a helicopter would be way more than for an aeroplane.

Not necessarily?

I agree.
IMO, Flight will be trade of air resistance and lifting force.
All power is provided by human muscle. Say 500W. Some is spent on fighting air resistance and one small component on fighting gravitational force. Because plane needs wings plus needs also propeller the total air resistance should be much higher as the total surface and weight, plus things that make some parts of machine less effective.
IMO properly design two long wings counter rotating on the rotor should do the trick of being the most efficient flying machine ( unfortunately for lifting only not horizontal flight) .
As to helicopter blades - because angular speed is always the same some parts work at optimal ratio - lift to drag, the rest doesn't and create more drag then lift.
If I could built such helicopter I would strip whole thing to two wings attached on extension boom . This way wing -blade will operate at the distance of center but just transfer forces will be designed to minimalism drag.

pweedas said..

In an aeroplane, the rider has to continually overcome wind resistance to maintain forward speed.

that valid observation too.

In order to avoid turbulence in counter rotating blades I could see few option:
-separating blades at the vertical distance - say one set 1 or 2m meters above another
-separating blades in horizontal distance - on set longer then other
-Such asymmetrical blades that the one on the bottom further utilize turbulence and flow caused by upper one ( what actually frying insect do with big advantage and birds possibly too ) . In such design the upper one is design for laminar flow, the bottom one for turbulent, alternated flow.

Advantage of single axis counter rotating blades / wing is safety. In the case of engine malfunction still should allow for relatively safe landing. In two or more configuration malfunction of single rotor will cause asymmetric lifting force and crash landing ( unless you multiply rotors for 6 or more.

IMO good designed helicopter should allow for flying platform above the city that could stay days and night over same spot. Thin tether cable could supply electricity from ground or solar panels.

Macroscien said..


If I could built such helicopter I would strip whole thing to two wings attached on extension boom . This way wing -blade will operate at the distance of center but just transfer forces will be designed to minimalism drag.

I think you need Barn to help you out with the drawing... this one is not very convincing...