Test005

What would be the best way to get rid of the dihedral on a LT-40 ARF?
I'm gonna put one together now and want a flat wing.
Thanks!

exeter_acres

My Feedback: (2)

is it a Kit or an arf?

if Kit...I'm not sure, but I would think just add a bit of wood to flatten it

if an ARF then just lay they wings on something flat.. cut out some sort of angled plug to fill the gap pretty well, then start filling with Epoxy...

if the wing halves are already glued together, then use a table saw to cut them apart and then do the above...
at least that is how I did it

Tall Paul

Make a wing joiner the same size.. width, depth, length as the dihedralled one in the kit, with no dihedral.
Make an angled filler piece of balsa to fill in the gap between the wing halves.
Epoxy in place.
Use tape to cover the joint.

TexasAirBoss

My Feedback: (22)

There are two basic wing designs. One is a stressed skin wing. There is little or no hardwood in the wing. The strength of the wing comes from the skin of the wing in tension. The second design, and the more common design, is a wing with a hardwood spar for strength. In this type of wing, the wing halves are joined with a plywood doubler that connects the spar from one wing to the spar in the other wing. This doubler is very important in maintaining the integrity of the wing's center section. Cutting through this doubler could be very difficult to repair. Simply wrapping the center section with fiberglass tape and resin will not restore the strength of the center section of this type of wing. The spar carries the load, not the skin. You can cut a new doubler out of plywood that simply doesn't have any dihedral, and replace the doubler in the kit, but this is generally done before the wing halves have ever been joined.

To remove the dihedral from the ends of the wing halves, add a balsa rib doubler, and then sand the doubler to remove the diherdral. Add one to each wing half. The center section will need to be covered with some peel-n-stick covering to seal it against fuel penetration. And the spar doubler will likely need to be slightly longer, but just 1/16 or so.

In a trainer, you may decide to remove most of the dihedral, rather than all of it. Such a plane generally likes a little dihedral.

exeter_acres

My Feedback: (2)

Oh...I forgot to mention...I did make a new hardwood joiner that we cut holes in the root rib and then epoxied it in next to the old one.....