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Old Dec 11, 2012, 06:22 PM
Detail Freak
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I thought that I heard that having the aileron NOT extend to the tip caused a drag point where the deflected aileron outer tip met the fixed TE section....
By having curved up wing tips, you can't have the aileron extend all the way, so you have to have that design with the curved tips (aileron stopping short)
I suppose if the last bit of the wing TE swept forward, you could have a trileron extending to where the tip starts to curve up, and try to have the both features. Not sure if that would be better though...
I like simple, and flat tips with ailerons all the way out are pretty simple. I like that on the Maxa and Supra designs, as well as the newer Samba offerings.

R,
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Old Dec 11, 2012, 07:23 PM
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Quote:
Originally Posted by RetoF3X View Post

I hope Joe W can chime in and explain why curved tips have disappeared in J planes too (although they spent most time at positive cl).

Best,
Reto
Sense there are so many Eploder pilots out there, pehaps one of them would be so kind as to cut off their " Hoerner tips" in the name of science, and report back to us on any findings? Maybe Shrederman??? It would really help this disscusion if we had actual studies done...
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Old Dec 11, 2012, 07:24 PM
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Target has like ten sploders maybe he would do it.
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Old Dec 11, 2012, 07:26 PM
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Target?? would you mind? I'd really like to know....
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Old Dec 11, 2012, 07:38 PM
launch low, fly high
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Winglets have their place for some designs. It makes sense if the design is span constrained (e.g. airliner gate spacing), or if it is an after-market performance improvement where the equivalent performance span extension would exceed the wing structure bending allowables. For the case of airliners, spar weight is expensive in terms of performance, it makes sense to "extend the wingtip" via winglets, as the winglet adds only a small contribution to the spar loads. A tip extension adds a lot to the wing bending loads...

As for a hoerner style wing tip, they look cool. They may even add enough performance to offset the increased manufacturing weight (as small as it is), although this isn't at all certain. The cool curled up wingtip is essentially a really low aspect ratio winglet. Due to the really low aspect ratio, it doesn't do much. The performance gain is typically a percentage of the gains if one just unrolled the tip to flat (maybe 70-80%?). How much span delta comes out via the unrolling process for the typical hoerner winglet?
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Old Dec 11, 2012, 07:53 PM
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Thanks Joe, I'm still curious though, Target if your busy I totally understand...just send "one" out here and I'll conduct the tests, and I promise to keep notes so ALL intestested parties will benefit, it'll be a tax deductable contribution on your part T. I'll send the tax "papers'' as soon as I recieve the plane.
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Old Dec 11, 2012, 08:42 PM
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this discussion

calls for some wind tunnel testing
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Old Dec 11, 2012, 11:44 PM
Hugh Blackburn
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Quote:
Originally Posted by alvaro corzo View Post
calls for some wind tunnel testing
The size of differences we are considering would be undetectable in wind tunnel testing.

Hugh
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Old Dec 12, 2012, 12:01 AM
Detail Freak
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Harbor City, CA
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I actually have only one currently flyable Xplorer, and its a 4 meter. If I could heat and unroll the tips, and extend the aileron, I would be your guinea pig.
Until then, I will call it "curly".
R,
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Old Dec 12, 2012, 11:52 AM
F3B and F3K
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Quote:
Originally Posted by IHAVAWDY View Post
Sense there are so many Eploder pilots out there, pehaps one of them would be so kind as to cut off their " Hoerner tips" in the name of science, and report back to us on any findings? Maybe Shrederman??? It would really help this disscusion if we had actual studies done...

In fact Mike Lachowski had cut off the curved wingtips of his Caracho for the 2003 F3B worlds.

I hope he can chime in on his findings. But in short he described the plane as a 2.9m wingspan plane with 0.1m airbreaks on each side when it was flying with the curved tips.

Reto
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Old Dec 12, 2012, 12:12 PM
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Quote:
Originally Posted by RetoF3X View Post
In fact Mike Lachowski had cut off the curved wingtips of his Caracho for the 2003 F3B worlds.

I hope he can chime in on his findings. But in short he described the plane as a 2.9m wingspan plane with 0.1m airbreaks on each side when it was flying with the curved tips.

Reto
I cut off the wing at the start of the curl. This is the extreme case for size. I made a mold for the rest of the wing (flat) and the actual wing was 3.3M when it was finished. Really big improvement in how well it launched. Tom Kiesling also flew one of mine at team selections the next cycle.

The only bad part about extending the tips was the V-tail which was small and too flat to begin with.
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Old Dec 12, 2012, 12:24 PM
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Yup, the Caracho was hugely improved with the removal of the curly tips. It did everything better. In fact Mike had a perfect score for the first round at the 2003 F3B World Championships with that model.

Tom
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Old Dec 12, 2012, 01:33 PM
or F, J, K, or even TD
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And that perfect score included the speed run with a touch and go, snap roll to inverted, and an upside down finish! Oh it was exciting

Wish I had a video replay on that, cuz it would be worth ing

M
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Old Dec 12, 2012, 06:47 PM
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Quote:
Originally Posted by FLY F3B View Post
And that perfect score included the speed run with a touch and go, snap roll to inverted, and an upside down finish! Oh it was exciting

Wish I had a video replay on that, cuz it would be worth ing

M
Oh Man that would have been a great Video.!!. sounds exciting..
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Old Dec 13, 2012, 09:13 AM
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Lots of interesting stuff happened at the 2003 Kirkheim F3B Worlds...
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