Redlined

Hey,
I like the idea of building with coroplast, but now I have a question. I found the Wonda plans, and that one turns my key. Looks like a good first coroplast plane, since all the rest of mine have been balsa or Depron. The plans say to run the internal channels (grain) from leading edge to trailing edge of the wings. Seems like the wing would be stronger, if the grain ran from root to tip. Am I missing something here?

Red

Villa

Hi Redlined
You may be right, the wing may be stronger. Unfortunately the wing will then crease where the top of the wing goes over the spar. I have built more than 10 planes with Coroplast wings, and have always run the flutes in the direction of the wing chord. I get a beautiful air foil.

mustangman177

More like 100 ?

PatrickCurry

My Feedback: (20)

+1 on the LE to TE flute direction.  You could then glue a piece in between the top and bottom with the flutes in the opposite direction for your ailerons and take it all the way back to cut for an elevator if you're going that route.  You might try a Sickle. Very similar to a Wonder, just a little shorter in the tail feathers.

OzMo

My Feedback: (3)

The flute direction can sometimes be tip to tip on the wing,s BOTTOM when the bottom is 4 mil and the top is 2 mil BUT the top still has the flutes running front to back.

PatrickCurry

My Feedback: (20)

You're right on that one OzMo, I forgot about the old RedNeckAirFoil.  

aspeed

I read on a forum somewhere many moons ago, that the chord way fares out better in a crash, limiting the damage to a smaller section.  Combat forum likely.

marmalade1

I found the spar caused the 4mm coroplast with flutes in the direction of the cord to fold sharply and create a triangular aerofoil. Do you score/cut the underside of the top of the wing to allow it to curve smoothly? I may be remaking a wing...

Villa

Hi marmalade
I have built many SPADS. I always place the flutes in the direction of the chord. The spar has NEVER caused a crease in the Coroplast. If you place the flutes in the direction of the span, then the spar will cause the Coroplast to crease at the SPAR.

Cloudsoarer

Both ways can work.
I am afraid I dislike edicts to do it one way. A bit like Burt Rutan, at model scales it is good for me to experiment rather than follow the crowd, just like Kraut and Tattoo did. You will learn a lot more and become an innovator, but that is a more difficult path...
Anyway, look at the Armin wing construction. Especially on a wing with taper, you will get a lot of torsional strength on a span-wise wing and little need for a structural spar. The ailerons can be cut flutes on the bottom surface.
And who said a crease on the top surface was a problem?

coro kid

I love it redneck airfoil!!!!!! that wing work great
corokid

draftman1

draftman2 on youtube. the video will show you how