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Old Oct 06, 2012, 12:52 PM
flying since 2000
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I guess we are all speachless

What were you trying to achieve again? Stable flight IGE and OGE? To me it looks like it's flying quite good...
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Old Oct 06, 2012, 08:43 PM
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Haha. Easy to control in all regimes would be a worthwhile goal.
To do that we need a design that counters the rearward shift of the AC IGE.
that was my goal but I exceeded it so that it actually gets too nose heavy OGE.
if it is balanced for OGE it gets tail heavy IGE. As you can see it needs no tail. I am doing trials with a canard. We'll see how that goes.
Cheers.
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Old Oct 09, 2012, 10:23 AM
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South Africa, WC, Cape Town
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Busy building a remote control ekranoplan currently, stripped the guts out of a double horse super sonic 2 channel which was unrepairable after its first flight attempt. When I started researching hovercrafts and GEVs I thought they would be perfect for a two channel, so I looked at the pros and cons of different WIG configurations and I chose one based on the Lun-class Russian Ekranoplan. Would also like to make a ground effect aircraft capable of free flight, but think the Bixel configuration and 4 channel controls would be better for that.
The current one I'm building has a cambered wing, somewhere between a rectangular wing with floats on the wingtips to trap air and a reverse delta.
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Old Oct 19, 2012, 09:04 PM
What could possibly go wrong?
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Dave:
Quote:
Haha. Easy to control in all regimes would be a worthwhile goal.
To do that we need a design that counters the rearward shift of the AC IGE.
Here's a thought... I've been fiddling about with this little gyro. Single channel, you put it between the Rx and the servo. I've had some good results using it in the aileron channel for high alpha and hovering. As you probably know, if you were to put it in the elevator channel, it would automatically correct for any changes in pitch except for those sent by the pilot.

As you might remember, I got fed up with WIG experiments after these efforts:
Flightship variations (1 min 41 sec)


As soon as leaving GE, the Flightship pitched up uncontrollably, unless the CoG was so far forward that, in GE, she wouldn't get her nose off the ground. If I moved the CoG back enough so that she could get her nose off the ground, she quickly reached the speed where she would leave GE.

The gyro would allow you to move the CoG back to a point where you can fly in GE and, hopefully, still maintain pitch control out of GE. A bit like a pellican, you would have an on-board computer. Don't forget to move the "centre of lateral area" back by increasing the fin size.

How does that sound? Cheating you might say, but they probably told the Wright brothers that when they invented a system for roll-control.

Nick
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Old Oct 25, 2012, 02:35 AM
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Thanks nick, I haven't been on this page for some time. I'll order gyros and try it out. So far I've got good results causing aft migration of cp with height gain as opposed to the normal fwd migration which causes pitch up with height and not wanting to take off. As it is, without tail, myWIG is tail heavy on takeoff and trims(with no control input or movement) itself noseheavy as it climbs until by the time it is OGE it wants to dive. I am testing now with camber and close coupled canards but so far its not working as well.
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Old Jan 14, 2013, 05:04 AM
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Flying IGE on snow

It's been a long time that I didn't post. But tests on water were so far not so efficient. Could not release from water suction. So winter is here and snow is definitely the best type of floor to test our WIG. Need some tuning on stabilization when it comes out of GE, but I think we can say it works well OGE.

Enjoy the video!

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Old Jan 26, 2013, 04:57 AM
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Could not see if it got airborne except where it goes vertical. The predicament of WIG is if they are balanced to fly like an airplane then they stick to the ground, they don't want to lift off. Maybe with more wing incidence more prop wash could get under the wing and then with a forward CG and less incidence on tail than wing, she may fly stable and still be able to lift off.
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Old Jan 28, 2013, 04:57 AM
What could possibly go wrong?
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Market Harborough
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Quote:
Could not see if it got airborne except where it goes vertical.
I wonder if a gyro on the elevator channel would help to control the sudden, unintended pitch upwards?

That's what gyros do: make corrections for any changes that were not instigated by the TX, I think.

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Old Jan 29, 2013, 05:03 AM
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Ok some new capture of it getting out of GE. You guys may be right, a gyro would help. But from our last tests the elevator does not have enough efficiency, as I tried to counteract the lift off but it always jumped up. Anyway, the elevator is broken so we'll build a new one with probably a setting possibility of the aoa of the whole horizontal stabilizer.

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Old Jan 29, 2013, 09:33 AM
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Ok that's classic too aft CG. Try flying it like an airplane first so you can trim it out nicely. To do that you need less incidence, about 2 degrees on tailplane than main wing and the cg forward like an airplane. The goal is too get it trimmed for a very slight descent OGE and getting a pitch up in GE and a pitch down OGE. Easier said than done. What may work is to have the leading edge higher so more engine thrust can go below the wing. At the very least the angle of your props should be in line with your wing so it is not pushing down the wing. Better still if the wing incidence is greater than the thrust line incidence it would be blowing the wing up not down. Also the thrust line will help lift the nose to get it out of extreme GE and as it climbs the slight nose down trim may prevent it from leaving GE.
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Old Jan 29, 2013, 09:40 AM
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I may add that what I said above will prob work if as soon as it lifts off you reduce to cruise power for IGE tests. The reason is the thrust line will assist in countering the usual nose down trim IGE and if the power is too much it would over power the OGE nose down trim. Hopefully after a few trials you might figure out the correct power setting. Trimming down to counteract power induced pitch up may result in instability. Because of this it may be a handful OGE because any power increase may cause an abrupt climb, so a set and forget power management style might be best, at least until your muscle memory is tuned.
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Old Jan 29, 2013, 01:10 PM
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I took a look at one of your pics. The wing incidence looks like close to zero, and tail about +3 to +5 degrees suggesting a very aft CG. Thats a lot of camber. Is the underneath hollow (undercambered)? For some reason symmetrical with a thick round LE seems to do well IGE. Maybe you could try one with less camber at about +7 degrees incidence. Leave some clearance between the TE and the ground.
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Old Feb 01, 2013, 12:28 PM
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Quote:
Originally Posted by nbrophy View Post
This is a great thread.

Here are two unique wig layouts that I've always wanted try to build RC models of.

Harry Schoell’s Canard flarecraft (patent 5,566,775)

http://www.schoellmarine.com/flarecraft/flarecraft.htm

A.I. Pietsukh’s PAI-67 (Diamond winged, tandem, and Lippisch Reverse Delta!)

http://brunodemichelis.com/Images/Russia39.gif



some similar devices





http://www.sunny-boxwing.de/Greenwings.html
http://www.patent-de.com/19860710/DE3500575A1.html
http://www.sunny-boxwing.de/wigwings.htm
http://www.youtube.com/watch?feature...&v=T1U7TIT0Png


http://www.youtube.com/watch?feature...AMZCiW6jA&NR=1




Quote:
According to information of Zhenmin of military reporters, "Xianglong high-rise pilotless scout plane length of 14,33 m, scope of a wing of 24,86 m, height of 5,413 m, normal take-off weight of 6800 kg, payload of 600 kg
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Old Feb 03, 2013, 11:03 PM
TheyreComingToTakeMeAway!
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USA, ID, Coeur D'Alene
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that last one is crazy looking!
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Old Feb 05, 2013, 12:33 PM
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Joined/Box wing

If you are interest in the joined wing, I know there was some early posts on the Yahoo Wig group concerning utilizing joined wing configuration in ground effect.

Search for discussions on Bruno De Michelis's Twiny concept or joined wing in the Yahoo Wig group:

#822 [wig] Joined wing concept
#819 [wig] Re: [Bruno's Model
#901 [wig] Sweet tweeny
#3465 TWINY DESIGN


While I have no direct experience, I have read on a few occasions that joined and box wing configuration similar to Ligeti Stratos and FlyNano (relatively high aspect ratio box wings where the lower forewing is swept back joining the tip of a straight upper aft wing) showed remarkable gliding/floating characteristics in ground effect upon landing.

http://www.rcgroups.com/forums/showp...5&postcount=10
http://www.rcgroups.com/forums/showp...1&postcount=24

I also believe this is same characteristic is described for the Delta M5 glider design "Big Wing Paper Gliders" book by Michael Johnson (http://us.macmillan.com/bigwingpaper...MichaelJohnson).
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