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Old May 04, 2012, 02:02 AM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
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Armour:
Quote:
nick pls tell me a little more about "wind got underneath". was it before or after take off? how soon after take off?
. It was a crazy idea even to try. She was still in the water. The wind was about 10mph and gusting, probably not straight on when she flipped. That's why I'm frustrated with GE flying, you need a calm day and a large flat space.

Nick
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Old May 04, 2012, 07:30 AM
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Lol without risk we won't get very far.

So I'm understanding it was on the take off roll while doing a water take off?

Did u have similar wind at anytime in dry or hard ground?

In water the wings are closer to the surface, I am trying to determine if that could be the difference. In the rcpowers video of the 'hydro' she only dropped the wing on water take offs in same conditions as dry take offs.

My last models wings were much closer to the ground than previous one and it was terrible.

The be 103's wings r very close to the water and has slats.

If my observations make sense enough dihedral could raise the wings to allow les stagnation under and better flow over the wing.
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Old May 06, 2012, 05:15 PM
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Our RC model design

Hi all!

I would like to get all your comments and advices about our model. We made a few calculations about the wing, thruse, CG and so on. The challenge of this Ekranoplan is to fly above grass field and water. For the transition we will see later. So let me know about your thoughts of our configuration, difficulties and so on. We have all the material and we will start to build it up in a weeks.

Thx! Keep all the fun!
Sirglider
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Old May 06, 2012, 08:32 PM
Sorry, but they're all toys.
Eric Odle's Avatar
United States, WA, Bellingham
Joined Jun 2009
292 Posts
Static thrust on those EDF's might be an issue. You might need to go with an open prop design that can move more air at lower speeds.
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Old May 07, 2012, 05:01 PM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,796 Posts
Sirglider - here's a thought. Have you ever considered powering your plane with a fanwing, like this

I wonder if a stubby wing like yours would lend itself to being powered by a fan designed to direct faster air over the top surface. Here's something I tried. The fan blades need to be able to cope with a 1200 Kv motor, separate motors for each side, using differential thrust instead of ailerons.

When I build it all has to be off the peg, inexpensive stuff. the fan shaft can be cf tube glued onto the motor shafts and the blades can be 8mm x 1mm cf strips, if you can get that size. I tried using balsa blades but they couldn't stand the speed.

I'd be interested to know your thoughts..

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Old May 08, 2012, 11:47 AM
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My thoughts r

Resist balancing it for GE, try balancing it as an airplane.

In GE it will be nose heavy so you need a big tail to get it to rotate. Tail should have less incidence than wing to accomplish.start with an oversized tail, u can cut it down later to see what size works.

Many disagree about having tail in prop wash, but in my experience if the thrust angle and incidence is set up so power changes don't cause too much pitch changes it may give u a shorter take off run as you will be able to rotate sooner. Like the Polaris.

U also need a big enough step so that it can rotate.

Strakes or LEX may give u a little lift up front in GE to counter the normal rearward shift IGE.

Looks real nice, all the best

Armour
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Old May 08, 2012, 11:57 AM
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hi all

this looks like a type C WIG.

love the double sweep design! does anyone know anything about this Russian(? design?

rgards

armour
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Old May 08, 2012, 02:06 PM
Is the sky the limit?
Joined May 2012
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Card mock up

i am building a balsa RC model WIG craft, though I am an amateur when it comes to the aerodynamics of GEVs, i know the basics but thats it.

heres one of my ideas, it flys in PAR when held in front of a blow dryer.

Thoughts? Improvements?

Its for a science fair project

and yes, you will have to turn your screen upside down to view the pictures
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Old May 11, 2012, 07:57 AM
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Originally Posted by ConorBergin View Post
i am building a balsa RC model WIG craft, though I am an amateur when it comes to the aerodynamics of GEVs, i know the basics but thats it.

heres one of my ideas, it flys in PAR when held in front of a blow dryer.

Thoughts? Improvements?

Its for a science fair project

and yes, you will have to turn your screen upside down to view the pictures
I'm not a lippisch expert but if you haven't, earlier in this forum, some lippisch reverse delta models were built and tested. Some of us realized as I posted that a large tail, large step and stable OGE flight would make life a bit easier. If its simply a hand launch model then you may need a more aft cg as you would not be able to rotate it.
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Old May 13, 2012, 01:20 PM
Is the sky the limit?
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Thanks, I looked

Does anyone have a sensible angle of attack for a lippisch
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Old May 13, 2012, 07:25 PM
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Originally Posted by ConorBergin View Post
Thanks, I looked

Does anyone have a sensible angle of attack for a lippisch
Do you mean incidence of main wing when in its normal upright stationary position? The minimum should be about 4 degrees fom horizontal for a symmetrical airfoil. For a cambered it from the zero lift line, but 4 degrees to the chord line may be a good start. The tail could be 2 degrees less. Start with an oversized tail, u can make it smaller and smaller untill it starts to misbehave then go back to the last size that worked well.

BTW what do you want to do with this? Unpowered or powered? Radio controlled?
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Old May 14, 2012, 02:28 PM
Is the sky the limit?
Joined May 2012
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Thanks a lot!
Its powered RC, I'm using a cambered wing ( its a lippisch )
Does a difference in the angle of the tail and main wing improve stability or something?
Should be able to draw up a plan soon
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Old May 14, 2012, 11:34 PM
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The forward wing on aircraft generally need to have a higher load than aft wing for stability. Because of the downwash behind main wing if the aft wing has same incidence the effect is as if it has less than forward wing.

-2 Degrees may b a good place to start.
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Old May 25, 2012, 08:01 AM
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Hi,
I'm new to the page, lack all but the most basic understanding of aerodynamics and haven't built anything more advanced than paper planes. Being a bit fascinated by ekranoplans I read through this excellent discussion and was left wondering what became of Gabriels model with a Lippisch-style canard wing inspired by the Baikal 2/M-6. Did anyone continue to investigate?

The japanese Kaien-3, although obviously made of a very light foam material and therefore maybe not a realistic model of a full-size manned craft, showed some promise in my humble opinion. I've been trying to mentally extrapolate a model with stepped planing hull, Lippisch canard, twin PAR engines, main wing in ground effect and OGE dihedral wingtip stabilisers. Has such a design any fundamental flaws?

-Adrian
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Old Jun 04, 2012, 11:00 PM
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Originally Posted by nickchud View Post
Armour!

You were wondering about my different experiments with swept wing planes. This is what I've been up to since last week. It's made from the wings of a small flying wing that has given me a lot of fun over the last couple of years. The motors, pylons and the fuse all come from my failed attempt to build a scale model of the Flightship.

I've had a couple of very successful flights, but the weather has been terrible - rain and strong winds, it was 38mph on Sunday.

Quite a few unsuccessful flights before I got the thrust line, incidence lines and the CoG right. Length is 900mm, ws is 850. All the controls are at the tail, elevator and rudders in the prop wash. Those canards are static.

You'd have had a laugh today... after all that rain we have several fields under water, but today was sunny though still windy. I couldn't resist an experiment on the water. However the wind got underneath and turned it over. So, you could have seen me with my socks and shoes off, and my trousers rolled up to recover it.

Nick,

Any video yet?

Regds

Armour
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