shd3920

When you read the measurement for conventional leading edges [example 1/4"x3/8"] http://www.specializedbalsa.com/lead_trail_aileron.php
which measure is listed first, vertical or horizontal?

Also: I am planning on a low-wing scratch build. Which would be a better shape leading edge that would look better and have a better fit when attached to the fuselage? The conventional or symmetrical?

I need to purchase a couple for a scratch build and I need to know before the purchase of the wood.

Thank you

Tony Hallo

I would suggest the first measurement is the thickness. It doesn't take much time to carve your own edge so that's what I would do rather than attempt to make the preformed edge fit.
The wing section you chose will detemine what leading edge you need, i.e. flat bottom or symmetrical. I would just purchase the thicknees of sheeting that you are planning use and carve and sand to final shape after it is glued on. Attached are examples.

Lnewqban

shd3920:

The first or smaller measure is the horizontal (or fraction of the chord of the wing).
The second or bigger measure is the vertical (about 25 % bigger than the horizontal).

Note that the "conventional" leading edge is good only for flat bottom wings, while the symmetrical leading edge is only good for symmetrical airfoils.

Note also that prefabricated leading edges like those need to be selected to match your airfoil, and then sand or carve them in order to achieve a perfect and smooth transition to the contour of the airfoil.

If you start from a rectangular piece of wood, consider that it is critical for the efficiency of the wing that the radius you create matches the specified for your airfoil.
For any airfoil, the very leading edge is always a semi-circle, which transitions to the top and bottom surfaces.

Hope this help.