Viel spas fûr schmales geld - lots of fun for a little money.
I'll tune in with some thoughts for a start, I know that I may be repeating myself, but after Delmenhorst I feel even stronger that a very simple design will be the design that will get most people "tricked" into this project. I was in Delmenhorst last weekend, and heard Christian Behrens talk about the aerodynamic design tool XLFR-5. He likes the tool, but what is more interesting is his conclusions about minor design changes.
According to Christian there is only 10% gain from going from a simple rectangular wing to a double tapper planform.
According to Christian there is even less gain from making minor airfoil adjustments.
Compare this to the 25% gain alone in flying time, from learning to launch 50 meters instead of 40 meters!
In my ears this tells me that a very simple design will fly very well, if it is built very good and designed and build strong enough to withstand a powerfull launch. In my oppinion this should make the RCN09 as simple a plane as possible, because complexity doesn't really pay of before you can launch really well and find lift very well.
In my oppinion molds, multiple cutting guides for wings and tails are complex for a beginner.
In my optic this gives me:
- a single tappered wing made in vacuum bag / possitiv bauweise - 49 grams glass and UD carbon as mainspar
- a one piece fuselage made as a foam plug with UD carbon and glass around - lost foam method - no fuse mold
- sanded balsa fin and tailplane glassed with 25 gram glass
Airfoil? The thickest airfoil possible which still has a good performance, is the airfoil that is easiest to build strong and stiff -> HM51
This is not very different from my crude drawing in the first thread about RCN09:
http://www.rc-network.de/forum/attachment.php?attachmentid=333469&d=1250686169
make the tailfeathers more rounded and nicer looking
What do you need for this design:
cutting guides for the wing
1,5 meters mylar
1,5 meters 120 gram UD carbon 300mm wide
2 meters 49 grams glass
1 meter 25 glass
500 grams epoxy (more than enough)
1 p 5mm light balsa (40-45 gram)
1 block of foam
vax
bag for vacuum
pump from a fridge, with a manometer and a falls air valve (?), if you can't borrow one for the one evening build ;-)