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Old Apr 12, 2010, 05:52 PM
MAD MEN QCRC
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Here is a vid of Del flying his Roto-Four at PERF on Saturday night. Very neat to see flying Bill
RotiFour.avi (0 min 42 sec)
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Old Apr 12, 2010, 06:05 PM
Storm Runner guy
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A delight to watch
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Old Apr 12, 2010, 06:20 PM
del
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Fun video, Bill!

I crashed, repaired, and learned to fly the thing at PERF. By accident on my part, you got a vid of the best flight of the evening.

Thanks a bunch.

--del
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Old Apr 12, 2010, 06:35 PM
MAD MEN QCRC
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Sure looked neat flying Love the name "Roto-Four" Bill
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Old Apr 15, 2010, 10:04 AM
MAD MEN QCRC
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Cody Kite

Here is a short vid of Del flying his Cody Kite at PERF also. Bill

codykite.avi (0 min 22 sec)
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Old Apr 15, 2010, 07:25 PM
del
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Thanks a bunch Bill!

Amusing to see it in the air.

--del
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Old Apr 15, 2010, 07:33 PM
MAD MEN QCRC
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Sorry I posted it in the wrong thread Bill
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Old Apr 16, 2010, 11:34 AM
SlingWinger
San Bernardino, California, United States
Joined Oct 2004
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I've seen single-bladed props and helicopters. I wonder if a single-bladed autogyro would work?

An idea that fascinates me (yeah, I know, I should get a life) is a plane with a single-blade autogyro rotor mounted on each wing tip.
At high AoA they would rotate, but when the AoA is reduced sufficiently they would stop and just streamline with the airflow, and the plane flies only on the wing.

It seems to me this might actually have a practical application. The wing could be very small, allowing higher speeds. But the autogyro rotors would allow slower flight for take-off, landing and manuevering in a small space.

Maybe I'll call DARPA. Ya never know...

I got this idea while playing with an F-111 semi-scale catapult glider I made from sheet foam, the same stuff I make the Sling Wing from.

This glider has a "spring" loaded elevator. When catapulted, the high speed acts on the trim tab of the elevator, "blowing it down", so the glider has a zero-lift AoA. This keeps the wings swept back into a delta configuration. When the glider slows enough the "spring" (actually just a piece of elastic thread from old underwear) pulls the elevator up, the AoA increases and the wings automatically swing forward to the soaring position.

So I got the idea the wings were behaving like autogyro rotors, but weren't allowed to spin.

Hey, now, there's an idea! A catapult launched single bladed autogyro glider!

Ok, where did I leave that hobby knife...it's around here somewhere...I just saw it yesterday....
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Old Apr 16, 2010, 01:27 PM
Playing with AutoCAD!
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United States, ME
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del,

I'm interested in the quick, vertical landing of the quad-motor. Could you please explain it a little further.

Thanks,
PC49
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Old Apr 16, 2010, 02:29 PM
SlingWinger
San Bernardino, California, United States
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Does anyone know what the best L/D is for an autogyro? I'm thinking about the same as a tumble wing, maybe 2:1.
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Old Apr 16, 2010, 06:00 PM
del
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Quote:
Originally Posted by RCBilly View Post
Sorry I posted it in the wrong thread Bill
Heck, Bill, I'm just thankful that you posted it..

--del
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Old Apr 16, 2010, 06:13 PM
del
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I don't think it would work.

Let's say you have a 2 blade rotor. The blade that's advancing into the relative wind will create more lift than the retreating blade. That's why I went for 4 blades. It evens that out. A single rotor will be really squirrely.

But, heck, ya never know what DARPA will fund....

--del


Quote:
Originally Posted by dayhead View Post
I've seen single-bladed props and helicopters. I wonder if a single-bladed autogyro would work?

An idea that fascinates me (yeah, I know, I should get a life) is a plane with a single-blade autogyro rotor mounted on each wing tip.
At high AoA they would rotate, but when the AoA is reduced sufficiently they would stop and just streamline with the airflow, and the plane flies only on the wing.

It seems to me this might actually have a practical application. The wing could be very small, allowing higher speeds. But the autogyro rotors would allow slower flight for take-off, landing and manuevering in a small space.

Maybe I'll call DARPA. Ya never know...

I got this idea while playing with an F-111 semi-scale catapult glider I made from sheet foam, the same stuff I make the Sling Wing from.

This glider has a "spring" loaded elevator. When catapulted, the high speed acts on the trim tab of the elevator, "blowing it down", so the glider has a zero-lift AoA. This keeps the wings swept back into a delta configuration. When the glider slows enough the "spring" (actually just a piece of elastic thread from old underwear) pulls the elevator up, the AoA increases and the wings automatically swing forward to the soaring position.

So I got the idea the wings were behaving like autogyro rotors, but weren't allowed to spin.

Hey, now, there's an idea! A catapult launched single bladed autogyro glider!

Ok, where did I leave that hobby knife...it's around here somewhere...I just saw it yesterday....
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Old Apr 16, 2010, 06:36 PM
del
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pc49 and dayhead..

Autogyros, like helicopters, don't glide worth a crap. The Roti-Four is worse than most. The drag from the four rotors reduces the L/D to dang near zero. Close the throttle and she just plops down on the floor. In fact, the drag on the Roti-Four is so high that the flight in Bill's video was done, mostly, at 80-90% throttle..

Not the most efficient flying machine, fun to see it fly though....

--del
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Old May 10, 2010, 11:06 PM
del
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Roto-Four: An update..

Friends,

While I did manage to get the little gyrating beastie to fly at the PERF meet in Toledo, I was not all that happy with it. So I hacked it...

I moved the canard/rotors up by putting them on a boom above the fuselage to get the thrust and drag more in line.
I lengthened the horn on the rudder to calm down the turn.
I replaced the PZ Cessna drive with a Vapor drive and prop for more thrust.
And I moved the CG back by moving the battery to make it more pitch stable.

Now y'all might be thinkin' "Whoa, buddy. Too many changes at once!" Yep, OK, normally I'd agree. But sometimes test flights tell ya more than one thing....

And this time multiple changes worked. Now it's ground-hugger tendencies are gone. She accelerates smartly and climbs nicely. Turns are nice and controllable, even for my poor flying abilities, with little tendency to spiral in. The formerly wild beastie has become fun to fly.

But coolest of all is power-off auto-rotation. By the end of our session in the gym today, I would fly it up to about 15-20 feet and chop the throttle. It would stop forward progress instantly and, with all 4 rotors spinning wildly, float down flat and level to the floor; ready to go again. Which i did! More than once.

Needless to say, I'm tickled. What was once a rather weird bugger to fly has become a docile favorite fly-toy.

--del
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Old May 10, 2010, 11:14 PM
Bringer of lasers
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United States, MA, Greenfield
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really cool Del, got plans for that one, I have a spare RX and drive set just like you are using (I think)

Cheers, Dill
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