PDA

View Full Version : ot: mechanical flying bird



Luke55
10-29-2011, 01:10 PM
http://www.youtube.com/watch_popup?v=Fg_JcKSHUtQ

aboard_epsilon
10-29-2011, 01:24 PM
Wow ..is that a first

i can see where that ones going

the next one will be real size..quieter ...and with a spy camera in it .

all the best.,markj

Evan
10-29-2011, 02:22 PM
It's cool but nowhere near being a first. The Smithsonian sponsored a wing flapping half scale model of a pterodactyl in 1986 that flew very well.

Ornithopters are not the future of aviation. There is far more going on in bird flight than just flapping wings. Trying to replicate that with current technology is close to impossible although limited success is possible. Fixed wing designs are much more efficient with large aircraft. That can be seen by observing very large birds. They are not very strong fliers but excellent at soaring. The Giant Pelican is a good example. We have them around here and when they are gliding in a thermal at a distance the look like a formation of ultralight aircraft. They have a wing span of up to 9 or 10 feet. Albatross are up to 11 feet and both birds spend the great majority of time soaring instead of flapping.

Flapping wing flight works well for small flying creatures and mechanical models but it doesn't scale well.

flathead4
10-29-2011, 04:01 PM
...but it doesn't scale well

You know that's probably true for many things unless you are making scale "models." Just making something bigger or smaller doesn't take into account environmental factors like air density that you can't scale. I recall watching a Mythbusters show where they were trying to prove/disprove something with model boat in a tank of water and thinking that waves on the ocean do not move any where near as fast as in that tank. If waves could move that fast, they would smash any conventional ship to bits.

The video was pretty cool. I also found it interesting that their "bird" weighs 400+ grams whereas a pelican with about the same wingspan weighs 10 times that.

Evan
10-29-2011, 05:19 PM
Back in the early 70s when we lived in Edmonton I used to play around with indoor aircraft. These were free flight models and we flew them in a school gymnasium.

We had nothing like the incredible miniaturized motors, super powerful batteries and tiny radio control systems that are available now. Models were powered by rubber bands which have an amazingly high ability to store energy per unit weight. My favorite was a class called the "penny plane". The only rule was that the complete model, ready to fly, could not weigh more than a penny. That is 3.1 grams for the copper penny used then.

That doesn't sound like much and it isn't but models with wing spans of up to around 18 inches were not uncommon. They were flown in competitions for endurance and my longest flight time was around a minute. That is nothing compared to some of the records which were something like 9 minutes in our club at the time.

Penny plane:

http://www.youtube.com/watch?v=vJVOsvqzm_4

When I was maybe 10 I had what may have been one of the very first electric model airplanes. It was made of styrofoam and weighed almost nothing. It had about a 24" span and a very small electric motor. What made it possible was that it used a special salt water/air/magnesium battery. The battery weighed very little and was a primary (one shot) battery. The main problem was that the batteries were very hard to find and very expensive. It really did work though and would fly for several minutes.

My first radio control system was a Futaba single channel with rubber powered escapement. I still have it, somewhere.

Thruthefence
10-29-2011, 06:03 PM
Back in the mid 80's a co worker of mine, a fellow always on the lookout for a "sure thing", ( Amsoil, battery rejuvenatiors, fish carburetors, silver futures, et al) got hooked up with a rubber band powered "wing flapping" plastic bird enterprise. Seems like he had to buy 500 of the things at $ 1.00 ea, and sell them at $5.00 at Festivals, Fairs, flea markets & so forth.

"THEY SELL THEMSELVES" so read the brochures. Guaranteed money back, on any you cant sell!! Which in his case was 495 of them.

He failed to read the fine print, of the inspection & handling charges that were taken out before credit was issued. Seems like it was over $100.00, and THEY had the birds back to resell!

I bought one, of course "for the kids", and it actually worked pretty well, they were bright yellow, maybe 10" long, a little crank in the tail to wind the rubber band, and you could adjust it's tail for circular or climbing flight.

It worked well enough that it flew over a neighbor's house, and we lost it.

Evan
10-29-2011, 09:13 PM
I have a bag of ten of those that I bought for 5 bucks from DX. They were for the grandkids to play with when they visited this summer. While they were here I totally forgot about them.:rolleyes:

Bill736
10-29-2011, 09:30 PM
We had a couple of those colorful plastic flapping birds about 10 years ago . As I recall, they were made in France at that time. They were good for a few indoor flights before collisions with walls did them in. Still, they were fun.

Willy
10-30-2011, 01:29 AM
Interesting video of the "bird".

But after looking at at an owl on final approach at 1000 fps, they still have a long way to go in order to approach the nuances of flight surface control as executed by this bird (http://www.dogwork.com/owfo8/).;)

Lew Hartswick
10-30-2011, 09:59 AM
Interesting video of the "bird".
nuances of flight surface control as executed by this bird (http://www.dogwork.com/owfo8/).;)
That is an amazing video.!
...lew...

Thruthefence
10-30-2011, 10:17 AM
Note at the end of the flight, the disruption of airflow over the inner "leading edges" of the owl's wings, the disturbance of the small feathers. I can't help but believe that something is happening aerodynamically here, vortex generation, or the like, (to the bird's benefit) not just random fluttering of feathers.

Great video! Thanks

Willy
11-03-2011, 11:43 PM
I just received an email from a friend that included a link to some incredable flying and fishing by an osprey.

I kind of thought some here would enjoy it as much as I did.
Once again it shows just how well developed birds are when it comes to the specialized talents and abilities they take for granted.
We can only try to emulate them.

http://www.arkive.org/osprey/pandion-haliaetus/video-00.html