Ornithopter ?? For real?

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DarylP

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This link shows a crazy plane. It is like what you used to see in the old films when people were trying to invent the plane.

Project Ornithopter

DP
 

rtfm

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Haq ha. What a laugh... And to think people spend good time and money on this sort of thing. I was amused by the almost equal down and up thrust of the wings. A mighty down sweep of the wings, and the craft lifts off. An equally mighty raising of the wings again, and the craft is pulled back to the ground. Even at a most basic level one would have thought that swivelling wings so that the upsweep would not produce as much "lift" would have been mandatory in the design. As it is, each down/up cycle would seem to cancel each other out.

Weird...

Duncan
 

DarylP

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I KNOW!!!:grin:

It just goes to show....get stoned enough and anything is possible. Well, er....in your mind anyway. :roll:
 

BDD

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I think it's interesting. Take a look at the video of the concept model in flight. If it developed equal forces but in the opposite direction with each wing stroke the model wouldn't have flown and the full size version wouldn't have lifted off of the ground. The up and down movement is probably from inertial forces of the wing.

It's interesting but not practical for a man carrying plane. I think it can be done however. There would be a lot of forces and fatigue stresses on the wing that you don't need and can easily avoid by not making it an ornithopter. Changing wing geometry with a fixed wing though probably has uses. I think these wings need to go through an elliptical path at the wing tips and birds actually move their wings forward not just up and down.

You could propel a small boat or submarine this way. I saw some video years ago of a kayak that had a short, delta shaped underwater flapping wing that propelled it. Very neat.

There are some very interesting websites for rc model ornithopters. They've been making model ornithopters since the 50's but rc only recently.

I'd say interesting, very unique, maybe useful for some things, not practical for a large or man carrying airplane (on Mars or a very large space station you could make it human powered), but not laughable, and not really like the old news reels. Some of those used actual feathers and chicken wire and they didn't work at all. They are funny. There are some funny ones in a movie called "Gizmo" I think from the 80's. I especially like the pushy woman who taught her students how to fly like Icharus by "utilizing the power of the solar plexus". That was the key. That and the canvas duck covered wings she designed and had a local handyman make for her. The students, not she, were forced to jump off of rocks and out of trees to prove her principles. If the failed (if?) it was always all their fault. Priceless. I have the feeling she was very difficult to get along with. I think Thurber must have had a run in or two with her. She is at about 3:03 in the first video but the rest is worth watching too. The grandiose claims and 1930's nasal delivery (the movies and talkies had just been invented and before that everyone probably sounded, well......funny) are great. The last one is great from about 3:58 on. Shouldn't miss the woman's speech on great inventors. Watch and learn.

 
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mz-

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Probably potentially much more efficient than a wing and a propeller. A lot harder to build.
 

BDD

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As odd as it seems, in the 70's I had the idea that something along these lines might even be a quieter way to propel a submarine as opposed to a propeller that is close to cavitating, vibrates at high frequency, etc.
 

DarylP

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Thanks guys,
Well I just assumed that just because you could make a toy that can fly, did not mean that it would work when up-scaled. If you could make one that handled the stresses and carry a person, well that would be amazing. I am sure that all of you have seen the flying dragonfly, where the wings move the way they are supposed to in nature, hence it flies. Now lets say that you could overcome the stresses, find a material light enough, then what would the power plant be?
The kid in all of us wants to believe it is possible.

;)
 

mz-

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That one uses a regular spinning crankshaft piston engine that then is attached to a cam and rod arrangement that pushes and pulls the center section up and down. Since the wing is attached away from the center, the tip goes up when the center goes down. Etc.
Of course you need to rotate the foil to have a different attitude in down and up strokes but some passive flex does a little of this quite easily.

You could do pneumatics or hydraulics like air muscles too for example for the wing flappers, there's probably many ways to do it. Even electromagnetics though you might need something advanced to avoid too much weight.
 
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