Scratch build wing question

clolsonus

Well-known member
Are there any size/dimension rules of thumb when creating a scratch built wing in the classic flite-test fold over fashion? I'm thinking about building something on the basement floor (without fancy cad tools or laser cutters.)

More specifically, let's say I am aiming for a specific chord width for my wing. Then presume I'm shooting for 12% thickness. I know the top and bottom layers will be 5mm and I can compute what my spar height should be.

But what I'm looking for is a rule of thumb or guidance on how to properly size the bottom layer (which doesn't go all the way to the trailing edge, how to size the top layer and put the two creases for the airfoil shape? All the while adding enough material to accounting for radius bending around the leading edge etc. etc. I would love to minimize my trips out to the dollar store so I'm hoping to get this right on the first try.

Maybe I'm over thinking this, but I thought I'd ask in case there are some basic guidelines people have figured out already.

Thanks!

Curt.
 

quorneng

Master member
If you can determine the ratio of the top & bottom panel chords used on a Flight Test wing just use the same ratio on yours.
If the finished wing looks the same as a Flight Test wing it will be fine.
 

Grifflyer

WWII fanatic
What I'd do is break out some cardboard or Cardboard Aided Design and draw up a template for the airfoil. Then you can meausure everything and transfer the measurements to fb.
 

Merv

Site Moderator
Staff member
I take a slightly different approach, I make the bottom layer the width of the cord I’m shooting for, and the top layer the cord plus aileron I want. I put a 45 bevel on both the top and bottom LE, the bevel the TE of the bottom layer. The TE bevel is just shy of an inch (15/16) . Similar to this.


1586802425866.jpg