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Old Mar 31, 2012, 04:49 AM
.....till the wind drops.
Sean Oelofse's Avatar
Port Elizabeth, South Africa
Joined Oct 2006
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"Kevlar for durability and 2.4 friendly!"......but 35 megs does'nt have a problem with carbon! ;-)
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Old Mar 31, 2012, 04:56 AM
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Fubar 123's Avatar
Whitchurch,Shropshire. UK
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Do you mind if I tag along for the ride ?
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Old Mar 31, 2012, 05:00 AM
Stirring the pot
johannlochner's Avatar
Port Elizabeth South Africa
Joined Jun 2008
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Quote:
Originally Posted by Fubar 123 View Post
Do you mind if I tag along for the ride ?
Hehehe
What took you so long Chris!!!

This is not a Genesis aka "Flying Fish" thread!
I do wonder....
Probably more my thing!

I really should stop going to the slope Cafe!
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Old Mar 31, 2012, 06:01 AM
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Quote:
Originally Posted by johannlochner View Post
Hehehe
What took you so long Chris!!!

This is not a Genesis aka "Flying Fish" thread!
I do wonder....
Probably more my thing!

I really should stop going to the slope Cafe!
I have a confession .................
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Old Mar 31, 2012, 06:45 AM
Stirring the pot
johannlochner's Avatar
Port Elizabeth South Africa
Joined Jun 2008
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Here are a few more thoughts or rough sketches...

What are the other "team members" up too?

Sean, as the M-stab is your department,
Check out Paige's thread!
http://www.rcgroups.com/forums/showp...8&postcount=22

Bakkie,
Get out that hammer you bought the other day!
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Old Mar 31, 2012, 09:13 AM
Feeling FrSky
surfimp's Avatar
United States, CA, Santa Barbara
Joined Feb 2003
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That fin is pretty close to being right on the CG.. might work more like a dive brake than anything

There are adherents to various varieties of the "nose rudder theory", but I am not one of them.

We already know that a suitably sized surface with sufficient travel located at the end of the tailboom will initiate an airframe flip... why should yaw work significantly differently than pitch?

Obviously there are issues around getting the wings to behave nice as they rotate in a way that they were never intended to, but the nose rudder theory doesn't help there, does it?

Steve
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Old Mar 31, 2012, 09:30 AM
let's FLY!
JimZinVT's Avatar
United States, VT, Castleton
Joined Dec 2007
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I think Steve is assuming the "dorsal fin" is a functional control surface. I was seeing it as a fixed, but removable part of the fuselage, to get at the removable wing....just additional side surface area, the better to knife-edge with?

I don't really buy into the "nose rudder" idea either. If a flat 360 spin is the goal, it's going to spin around the CG. So the control input should be as far from the CG as possible....i.e. at the tail.

(just adding my 2 rand worth.....;-)
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Old Mar 31, 2012, 09:38 AM
Feeling FrSky
surfimp's Avatar
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Quote:
Originally Posted by JimZinVT View Post
I think Steve is assuming the "dorsal fin" is a functional control surface. I was seeing it as a fixed, but removable part of the fuselage, to get at the removable wing....just additional side surface area, the better to knife-edge with?

I don't really buy into the "nose rudder" idea either. If a flat 360 spin is the goal, it's going to spin around the CG. So the control input should be as far from the CG as possible....i.e. at the tail.

(just adding my 2 rand worth.....;-)
The latest sketch shows what looks very much like a hinged surface... my comments pertained to that

Steve
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Old Mar 31, 2012, 11:19 AM
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Very good eye, there, Steve. I missed that detail but believe you're correct. Biggest issue I see with a truly flat pirouette type spin is the loss of lift from the wings as airspeed drops and reverses, especially across the wing that is pivoting backwards.

Here's a top view of a real flying fish.........possibilities???

http://animals.nationalgeographic.co...h/flying-fish/

And here's a nice side view drawing.

http://upload.wikimedia.org/wikipedi...flyingfish.jpg

These views got me thinking all kind of weird thoughts.....a probably low performance but visually cool "Fish" with a fairly standard build wing but all-moving tail surfaces built by using monofilament titanium wire for the leading edges and a straight film covering from wire to wire with no structural filler similar to a hang glider wing. They would be light and flexible, very forgiving on ground contact and although the flex factor would probably prevent tight precision flying it just might add a bit of oomph coming out of dives and turns.

(and I swear I haven't been smokin' nothin"!!)

Ken
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Old Mar 31, 2012, 11:28 AM
Feeling FrSky
surfimp's Avatar
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Quote:
Originally Posted by Snewk View Post
Very good eye, there, Steve. I missed that detail but believe you're correct. Biggest issue I see with a truly flat pirouette type spin is the loss of lift from the wings as airspeed drops and reverses, especially across the wing that is pivoting backwards.
I don't know if think a true heli-style pirouette is very likely, but we know that conventional airframes can enter flat spins.

With appropriate flying technique, we should be able to unload Gs from the plane and kick it into a couple rotations at least before it drops into recovery.

Envision doing this with a glider, where the surfboard is the glider and the wave is the cliff face... very do-able, I think.

The Kaoli Kahokuloa 360 Spin (0 min 28 sec)


Steve
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Old Mar 31, 2012, 11:33 AM
Missing you too FB!
Bakkie's Avatar
South Africa, Eastern Cape, Port Elizabeth
Joined Sep 2010
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Quote:
Originally Posted by johannlochner View Post
What are the other "team members" up too?


Bakkie,
Get out that hammer you bought the other day!
We been out training Had a nice fly ay Maitlands
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Old Mar 31, 2012, 11:38 AM
Missing you too FB!
Bakkie's Avatar
South Africa, Eastern Cape, Port Elizabeth
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"dorsal fin" is just the name for the "saddle" that's gonna keep the wing in place....
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Old Mar 31, 2012, 11:50 AM
Stirring the pot
johannlochner's Avatar
Port Elizabeth South Africa
Joined Jun 2008
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You guys are probably giving me credit for more lateral thought than I intend
The "Dorsal fin" was only a replacement for the lost vertical surface above the wing.
I would really like the wing to be a one piece removable item both for strength, weight and convenience.
It would also afford us the opportunity to test some different wing plan forms and sections.
I'll have to get to shaping the fuz to see what it looks like!
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Old Mar 31, 2012, 12:32 PM
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Whitchurch,Shropshire. UK
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Hows about plug in wings for a change ?
Just a idea
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Old Mar 31, 2012, 02:09 PM
.....till the wind drops.
Sean Oelofse's Avatar
Port Elizabeth, South Africa
Joined Oct 2006
3,537 Posts
Quote:
Originally Posted by johannlochner View Post
You guys are probably giving me credit for more lateral thought than I intend
Flat spin?
I've seen one of those Parkzone Strikers doing an inverted flat spin. It goes for as long as you like and does about 3 spins per second...(guess), like a "frisbee"
I beleive it prefers inverted to upright. OK!.......it has twin rudders and is a delta wing.

Just a question!
Do the wings need to generate lift in a spin?
How many spins is enough?
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