Concerning wing tips........

[Beemerider]

How does the shape of a wing tip affect wing performance? I guess specifically I'm trying to decide if I should put effort into fashioning proper wing tips for an older 2M sailplane I'm rebuilding and covering. The original tips were formed plastic. This is just a lazy flier for a nice day. I'm not after performance, I guess I'm trying to be lazy and wanting someone to say it's ok!

[dgjessing]

It's OK with me

[mclarkson]

Me too!

[solentlife]

Wing Tips ............

For years and still now ... we have plain tips. For general flight there's nothing wrong with them.

Then we have shaped form tips to overcome tip vortex's, tip losses, to try and direct airflow.
My Cessna 182 has tips that are shaped with a definite 'tuck under' .. this is supposed to reduce air bleed round the tip ...

I think in model sizes - the benefits of shaped tips is questionable. Look at full size - it took Boeing / Airbus years to get around to added Winglets to the tips and still many are built without.

Go fly as is !! I would.

Nigel

[Beemerider]

That's what I wanted to hear. Thanks!

[rreid7]

I read somewhere recently (I've forgotten the exact source) that Cessna's engineers experimented with drooped wing tips back in the 70's. They concluded that they didn't do much unless they were quite exaggerated, so they dropped the idea from a performance stand-point. However, the marketing guys thought they looked cool and most single engine Cessnas (150, 172, 182, etc.) since have worn molded, modestly drooped wing tips.

[cyclops2]

My love... The real A-10 had wing tips. Then took them off. Says you must need to be moving pretty fast to justify them.

My 3 cents.

[CHELLIE]

It's OK with me Too

[stuart]

ITS NOT OK WITH ME SO DON'T DO IT!!!! I WILL FIND YOUR WINGTIP LESS GLIDER NO MATTER HOW HIGH YOU FLY AND DESTROY IT FOR NOT BEING RESTORED TO THE ORIGINAL PLASTIC TIPS!!! THIS IS A CRIME OF UNPRECEDENTED PROPORTION'S AND MUST BE REPORTED TO ALL,YES ALL THE WATTFLYER MODERATORS!!!!

THERE WILL NOW BE AN OFFICIAL VOTE DISCOUNTING THE PREVIOUS POSTERS AND THEIR BIAS,INCONSIDERATE OPINIONS OR CONSIDERATIONS OF THE DISCUSSION ON WING TIPS.




opps,sorry about that,just took a sip of my coffee and feel better now...................it's ok with me too.

[mclarkson]

I'm confused now. Are we talking about wing tip shape? Or winglet shape?

[Beemerider]

My question was concerning tip shape, not winglets. As in squared off vs tapered (probably wrong terminology).

More specifically---lazy shortcut vs doing it "the right way".

[mclarkson]

I suspect that the differences between a square and rounded wing tip are minimal in subsonic flight with a 12oz foam plane.

Looking at fast planes, I see that many of them have rounded wingtips, but just as many have square wingtips. Look at the 'Rare Bear' (Grumman F8F Bearcat) or the Mustang. OTOH, the Spitfire's wings are lovelier.

[Beemerider]

Originally Posted by mclarkson

I suspect that the differences between a square and rounded wing tip are minimal in subsonic flight with a 12oz foam plane.

My 2 meter sailplane weighs in around 32oz, I expect I'll get fairly close to supersonic in a full power on dive so maybe I should think about rounded wing tips?

[rreid7]

Rounded wingtips are purely cosmetic. Everything from Cubs to Spitfires have have had them clipped off to reduce weight and drag and increase speed and roll rate. There is no loss of lift, just of prettiness.

[stuart]

plus 1+ on it cosmetics. even full scale cubs and bipe had clipped wing designed into the wings.

i built the greatplanes rv 4-40 that had plastic molded wing tips that were very curvy and cool looking . i left them off as they would also be a weak spot if the wing tip ever touched on landing or take off. it still looked beautiful as a clipped wing rv 4-40 until my cheap esc cut out to cause total failure on its first flight from building a new wing. it was a total loss. i hate to say this,but i want to build another one someday and hope to get the wing not to warp due to the dumbest design i ever had the displeasure to build...lol.....man i wish i had used a castle 100amp ice esc with the eflight power 60,she might still be around to enjoy.

RIP:

[TLyttle]

A buddy flew an Aquila in competition, but he noticed that it tended to wander on high-speed runs (F3B), and we tried everything to cure it. Finally we sawed off those lovely upswept wingtips, and (1) it was faster and (2) the wandering disappeared completely and (3) it was more manoeverable at any speed. We even tried a few other tip shapes, nothing we tried improved the Aquila's performance. My guess is that the Reynolds Numbers were simply not high enough to make a difference.