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Old Apr 23, 2012, 10:03 AM
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nick see how comfortable the stuntcat seems IGE...

RC STUNTCAT CRASH! (1 min 53 sec)
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Old Apr 23, 2012, 10:53 AM
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...if u do test urs IGE, maybe you could try adding payload on your cg to test different wing loadings.
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Old Apr 23, 2012, 12:05 PM
What could possibly go wrong?
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Great to see your Stuntcat in action Armour.

It's a terrific plane isn't it? Specially when you consider it's only controlled by a pair of elevons, not in the prop wash. For high alpha I always consider a rudder to be essential, but that plane manages pretty well without. It wouldn't be too difficult to make a pair of fins and rudders just on either side of the prop.

Mine is currently on the back shelf. I've stolen the motor and servos for something else.
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Old Apr 23, 2012, 12:36 PM
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sorry not mine, found vid on the net.
i was waiting to see how urs performs IGE before i built mine.
i think it may b the platform im looking for. i like the fact that it looks like a boat!
its important to know how she handles a higher wing loading.
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Old Apr 23, 2012, 03:47 PM
What could possibly go wrong?
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Market Harborough
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Well, she's a lovely plane with the Polaris style pylon and tail feathers. Fast, slow, high alpha, all terrain. But, as you can see from this video I never really made much effort in Ground Effect. Problem is the field I use for exercising my dog ... all those bumps and dips have an effect on windy days even as high as 50ft above the ground, I reckon.
Polar Stuntcat (4 min 27 sec)
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Old Apr 24, 2012, 07:00 AM
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i think any swept wing may do the same thing.
are any of ur polaris ready to fly?
trim for a very slight descent, just shy of level, then do a take off. as soon as she's is airborne reduce to cruise power and hands off the elevator and see what happens
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Old Apr 24, 2012, 07:41 AM
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Hi Folks

I wondered if anyone can help me track down a video of seabirds flying in ground effect that I need for a presentation?

I have seen sometime within the last year (youtube perhaps) but do not appear to have kept a copy for myself.

From memory the film shows some large seabirds – about 4 pelicans I think. They are cruising very low just behind the surf zone of a bit of coast – travelling from right to left in the film.

Does this ring a bell to anyone?

Any help gratefully accepted as I have already spent some 5 hours trawling through my vid collection and the net without success – that time would have been better spent finishing my new experimental model ! (– more on that to follow).

Cheers

Graham
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Old Apr 24, 2012, 08:56 AM
What could possibly go wrong?
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Market Harborough
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How about this one..
Surfing Birds (0 min 47 sec)

or this one..
"Surfing" Pelicans (0 min 52 sec)

or this..
Sea Movies - Planning Pelicans (1 min 29 sec)


I was searching for "pelicans in ground effect". It looks as if "surfing pelicans" would do it best.

good eh?

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Old Apr 24, 2012, 11:33 AM
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A great big thanks from me! Yes exactly what I was looking for. You have saved my sanity.
Before I wrote out I wasted hours on internet searches trying “seabirds flying low” and similar without any success...... ah the trick is in choosing the right key search words.

So today I read right through this discussion group from the very beginning to see if these videos came up somewhere – all 60+ pages of it. And wow what a fine body of knowledge is contained wherein. I found stuff I missed and even a few bits that were completely new to me. I recommend all reader have a trawl through the past pages – it is amazing what has been covered and uncovered.

Cheers
Graham
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Old Apr 24, 2012, 02:41 PM
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check this bird with no wings, probably creates tons of GE

Wingless Wonders (3 min 2 sec)
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Old Apr 25, 2012, 12:34 AM
BEOWULF
North vancouver, B.C. Canada
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looks like cgs too far forward and a large heavy battery
Quote:
Originally Posted by captarmour View Post
another view of 'tip stalling' as soon as she lifts off.

http://www.youtube.com/watch?v=Y74yv...5fAUAAAAAAAAAA
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Old Apr 25, 2012, 09:50 AM
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thanks david

because of its strong high alpha pitch up tendency OGE any time it slows down she would pull up into high alpha. in a glide test she would pull up into a stall so thats why it needed such a far forward cg. on landing once powers is cut she would drop out of the sky normally with a wing drop.

http://www.youtube.com/watch?v=0iWEp...feature=relmfu

however that model is no more. the one after this had the cg much farther back. it also had the wings closer to the groundand a thicker thickess ratio. im afraid it was worse, it would just veer off to one side or the other and then flip over.

so im incorporating all the ideas i can in the next one. im thinking of sweeping outer wings forward but one reason i like the swept back wings is to have the np as far back as possible so on water it will plane like a speed boat with just aft part of hull in water.
the advantage of swept forward outer wing is that in a bank i get more 'ground' clearance, wingtip pontoons farther forward and closer to cg, and less tendency to tip stall.

btw this design like a bixel, is more of a low flying airplane than a true wig.
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Old Apr 29, 2012, 04:29 AM
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Parboat project

As promised, I share with you a couple of sketches of my latest project - when I get some time I’ll post some pictures of the actual model under construction.

Regards

Graham
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Old Apr 29, 2012, 05:45 AM
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Very nice!

I'm not sure if the name suggest that it will actually leave the water like a WIG? If so will it be stable OGE? Earlier in this forum the general idea was that a WIG would be safer if it were stable OGE.
Is the canard movable?

If I may, the PAR engines look like they may be subject to water ingestion/erosion. same for the canard.

With pontoons so far apart the wing may have to be very strong(heavy) to handle the water loads.

Cheers,

Armour.
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Old Apr 29, 2012, 10:11 AM
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Armour
All very good questions. The canard is also a hydroplane as per my whizzywigs, to keep the water out of the fans. As for the other points - I am only aiming for PAR/XGE.
Graham
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