Feb 17, 2011 at 1:23 pm #1269311
Here's a video about rubber band airplanes. It inspires me because these guys are so focused and so into lightweight. Makes my gear look like heavy duty truck parts.
They talk in grams and partial grams. I think they said they have airplanes that can fly for 1/2 hour on a single rubber band winding. I read elsewhere, but don't know for sure, that the propellers actually move as slowly as shown in the video.
DarylFeb 17, 2011 at 1:39 pm #1697957
That's a pretty cool video, thanks for sharing.
I'd be interested if the propellers do indeed spin that fast, as it looked like the footage had been slowed down – especially towards the end when the gentleman was pushing the tail down of his airplane. Incredible, either way.
Good find.Feb 17, 2011 at 7:23 pm #1698112
@socal-nomadLocale: North San Diego county
I use to I like free flight gliders and rubber power planes. Takes me back to my childhood days.
About 10 years ago I use to compete in Radio Control Hand launch glider contest with Torrey pines gulls club. I was in it when we drop from a light glider was 7.5 oz to 9 oz. By the time I got out of it because of micro radio gear and lithium battery technology. Using free flight technology like they use in R/C gliders. We got down to 4 oz and wing tip launch planes instead of javelin launched.
The field I would fly at you could see the thermals coming down the field in the tall grass. We would throw the plane in it to and hook a thermal akin to fly fishing and speck the plane out for 1 hour flights from a simple hand launch.We called it specking out because a 60" wingspan plane would turn in to a dot in the air.
The AMA has a annual national competitions at it's home field in Indiana every year in all kinds of discipline of model aircraft flight from Free flight to Radio control gliders and gas planes. Also indoor free flight and r/c flight.
Here's a link if you want to make a freeflight gliders:
If you want to see something cool and will blow your mind look up R/C Dynamic Soaring and check out the videos of the gliders reaching over 100 mph plus flown on the backside of a slope in Santa Ana condition winds. Planes even blow up from structural failure.Feb 17, 2011 at 7:31 pm #1698113
Wow, a 1.5g plane! that is about the same weight at the top parts of a small bic lighter (as we learnt from earlier posts), but oh so much more useful. Do you guys know what fiber they are using?
It's always nice to see something a bit different like this.
Jeremy.Feb 18, 2011 at 7:59 am #1698281
My engineer friend says he believes the props are moving as slowly as shown because:
"I believe the slow velocity of the propellers. Thrust is the mass of air accelerated times the velocity increase. The energy required to create the thrust is proportional to the mass of air accelerated times the velocity squared. So to get the greatest thrust for least energy expenditure you need to have a big propeller engaging a large mass of air so you can use a smaller velocity increase."
I can't verify the accuracy of this statement………heck I can barely understand it.
DarylFeb 18, 2011 at 3:17 pm #1698477
@socal-nomadLocale: North San Diego county
Your friend is correct the on the slow moving props. I have seen the indoor plane like in the video flown at a hobby show in Pasadena,ca. back awhile ago. They are like butterflies floating around for long time around the convention center.
The indoor micro r/c stick type prop planes are really neat also to watch. The indoor micro R/C guys were the one that pushed the envelope in micro R/C equipment to weigh a couple grams or less.
The materials they use are balsa wood and carbon fiber with a ultra light weight mylar type film for wing and prop coverings. I use to buy the film from a guy who sold it to cover my Epp foam wings and tail feathers on my r/c hand launch glider that I designed that weighed in at 5.5oz called The Cetan.
Here's a link to freeflight.org if you want to start play around with micro flight
Plantraco offer ready made planes and the best radios for micro indoor R/C gear,Plus they make micro blimps that I have owned that are pretty cool.
TerryFeb 18, 2011 at 6:33 pm #1698549
Thanks for the info.
I checked out the links. There's a whole world out there that I was unaware of.
I'd better stick with my hobbies of backpacking and gardening, however. There are only so many hours in the day.
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