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The 'daydreamers' thread...post your craziest designs and concepts here

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Swampyankee

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I'd love to see almost any non-helicopter VTOL approach come to life as viable homebuilt. I have always like the tailsitters, so maybe something along the lines of a scaled down Convair XFY-1 Pogo, perhaps with prone position pilot (so basically standing up for takeoff and landing).

View attachment 50283

Something like the Hirth H30ES (102 hp, 45 kg) two-stroke should work for power. I have sketched out ideas for trying to address the obvious safety issues with a 360-degree crash cage around the pilot, prop brake or explosive destruction of the blades in an emergency, and a ballistic chute in the oversized spinner. Even simpler, but less attractive, would be a ballistic chute launching at 45-degrees up and forward with a guard to keep the lines out of the prop. There would still be an envelope in VTOL mode where you'd be too low for the chute, so that would have be dealt with as a crushable structure or, even better, airbags like a Mars lander. ;-)
I think that a tilt-wing or a tilt-rotor could be viable homebuilt projects, with a lot of ifs, not excluding somebody willing to design and built controllable pitch propellers with flapping and (probably) lead-lag hinges, either real ones or virtual ones (hingeless rotors have a soft-in-bending section in place of mechanical hinge). (Check out the VTOL Wheel for more fun homebuilding ideas; I rather like this one: 40.jpg). Once one leaves out helicopters and compound helicopters, VTOL becomes hard, and for many of them, I'd want to have a zero-zero ejection seat, not just a ballistic parachute.

Neither the tilt-wing nor tilt-rotor configuration is particularly easy, and both have disadvantages. I suspect (which means that I've not done a full-blown analysis) that the structural issues of a tilt-rotor are easier (for one thing, the wing doesn't need to move) but the aerodynamic ones of the tilt-wing are easier; it ends up being a trade study. Bell Helicopter had a lot of experience with tilt-rotors, so the V-22 was a tilt-rotor; had Hiller or LTV been major players, the JVX may have been a tilt-wing.

Bluntly, I would not trust my life in any kind of tail-sitter, especially one powered by a piston engine. Give me a robust, well-proven gas turbine engine any day!
 

RPM314

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There's a class of aircraft in RC called a "hotliner", which is basically what happens when you take a competition sailplane and put a motor on it more typically found on pylon racers, with a folding prop. They're built for energy retention at high speeds, vertical climbouts, etc. I highly recommend Youtubing it.

I know of course that there are power loading limits as you scale up, but I wonder how far you could get at general aviation scale, using the peculiarity that composite wings get lighter as AR goes up. Maybe a 2 stroke to get in as much HP as possible, and easier starts/stops?
 

delta

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This one stems from pedal powered crafts I've seen turning a very large slow turning prop. Decavitator and Aug. 23, 1977: Pedal-Powered Gossamer Condor Flies Into Record Books | WIRED I figure a 20hp Briggs with a massive reduction would keep it in the air longer than I could. An electric motor on the rear wheels for ground operation would get me to a restaurant or service station. If I could keep the weight down, I'm sure the top speed would not exceed part 103. Using bicycle wheels instead of motorcycle wheels might help it be street legal but a reverse trike configuration would be easy enough. Air cylinder/shocks, would adjust the ground angle of attack to facilitate take off or hugging the road. The thing would be so quiet the park service might not even hear you when you buzz the Grand Canyon.
 

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Tiger Tim

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This one comes from an older sketchbook but I don't think I've posted it here before. The idea started with the thought of jazzing up the basic concept of the Affordaplane and one thing led to another, finally settling on the Afforda-Stang:

Don't dig too deep into it, it's only a concept.
 

Floydr92

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This one comes from an older sketchbook but I don't think I've posted it here before. The idea started with the thought of jazzing up the basic concept of the Affordaplane and one thing led to another, finally settling on the Afforda-Stang:

Don't dig too deep into it, it's only a concept.
Nice sketching skills, wish i could do that. I can do good engineering drawings, but i find sketching difficult. Frustrating with so many 'napkin sketches' in my head. Haha. So, a napkin sketch for me is usually a computer rendering of some kind. Usually x-plane comes first.
 

bifft

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Apr 17, 2011
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Utah
Since this thread is still alive, thought of another impractical one. "The ellipse" Elliptical wing, with elliptical polyhedral. Elliptical full flying ruddervators. Would be way too hard to build, and how would you hinge any control surfaces on the wing? Would look kinda pretty.

ellipse.jpg
 

Tiger Tim

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Nice sketching skills, wish i could do that. I can do good engineering drawings, but i find sketching difficult. Frustrating with so many 'napkin sketches' in my head. Haha. So, a napkin sketch for me is usually a computer rendering of some kind. Usually x-plane comes first.
Thanks Floyd, that's the result of spendingyears doodling. I always found it was too hard to pull out a laptop and design in X-plane during math class...
 

delta

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I've often wondered if this ring wing ever flew
View attachment 51429
I saw that one at Oshkosh I believe in 2004. I didn't see it fly and haven't heard a word about it since. I didn't look real close at the time, but I'm also curious now how he hinged the curved control surfaces. The F4U Corsair flap system may contain some ideas in that regard, but it's probably not very simple or light.
 

Swampyankee

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A ring wing would be nice structurally and aerodynamically (maybe), but talk about a nightmare to build...
I've seen some proposals for ring-wing airliners, but, like a lot of these designs, there are a lot of practical problems, including where to put things like landing gear and fuel.
 

delta

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The "What replica warbird would you like to see" poll didn't allow the p-38 because it had two engines... not fair... I would love to see a reasonable representation of a p-38 in the works. The configuration is sound, and with a couple of turbocharged vw's it'd scoot pretty good at altitude.
I had to add a couple of delta delta wings just for drill.
 

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BJC

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I saw that one at Oshkosh I believe in 2004. I didn't see it fly and haven't heard a word about it since. I didn't look real close at the time, but I'm also curious now how he hinged the curved control surfaces. The F4U Corsair flap system may contain some ideas in that regard, but it's probably not very simple or light.
IIRC, it had control surfaces only on the strut/wing that supported the back half of the ring-shaped wing.


BJC
 
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