As far as stability the slight amount of dihedral in the DGA-5 won't have a huge effect on flight performance, but I think it would look pretty weird without it. Flat wings tend to look anhedraled a lot of the time.

Originally Posted by 3D-Seth

I personally hate wing spars for two piece wings.

Using a wing tube with dihedral is pretty simple. The tube will enter the root rib (one closest to the fuse in that wing half) near the top of the airfoil. The last rib the tube extends through (1/3 span roughly depending on other structure), the wing tube will extend through the rib near the bottom of the airfoil.

In other words, the wing will angle the dihedral amount relative to the tube (level). See photo.

Dihedral makes a decent difference even in small amounts. I'd leave it in the wing myself, mainly for looks since it's a scale model, but a little dihedral certainly will help a scale airplane performance wise too.

Seth

I've got a 2 piece 94" flat wing on a current build I'm doing. I'll probably do something similar to your picture.

First thing is to strip the inboard wing bottoms out to about 2'.
Second would be to mod the wing roots to 1 deg each.
Then rework the wing ribs to support the angled spar tube.