richg99

When I re-built my latest SPAD wing.. I used 2 mil throughout. Even though I scored the front edge twice..I wound up with a sharp, rather than blunt..leading edge. How important is it to be more rounded? Must I rebuild the wing? Is there a way to add "roundness"? thanks Rich

mclina

I have built a lot of wings with sharp leading edges, and they fly just fine. The Derelict, for one, has a sharp leading edge by design.

I have been told that a sharp leading edge makes the wing incidence more critical, but I don't know that to be a fact.

The best way to find out is to go ahead and fly it.

Good luck

jib

It's fine and much better for a combat plane! <grin>

My Debonair has a pretty sharp leading edge and it flies like a dream.

Jack

draftman1

fly it and have fun!

RLR

Hi
I have seen some photos of planes with really round leading edges made of coro. So how do they then do this? All my wings comes out with shap edges and fly good. For scale I would like to build a round leading edge.

Riaan

jib

You get a fat round edge by scoring several flutes, often 5 or 7. This allows the coro to flex into that big fat curve, but it's a 3D thing. It's not a great wing shape for lift.

Check out the SPA3D on www.spadtothebone.com

Jack

Team_Monkey

Be careful wth that logic. Remember the SPA3D and 3DT are a single piece 4mm wing with flutes span wise. Hard to compare those construction numbers to anything else.

take a look at the Edge 540 plans. that's an all 2mm wing with triple scored leading edge. I think the scores are 3/8" apart.
Good luck.

jib

Team Monkey,

I know what you mean.

From his description "Really round" LE, I can't see the Edge wing fitting the bill, hence my suggestion that perhaps he was looking at a SPA3D type LE, which is Round. I should have been clear on the difference. Thanks for clarifying!

Jack

Villa

The 2MM coroplast wings on my SPAD Biplane at http://www.rcuniverse.com/forum/m_8007330/tm.htm are fully symmetrical. I like the looks of the wing but I doubt it flies different than a sharp edged symmetrical wing. I believe I have read (but I am not certain) that a sharp edge LE wing may stall in a less predictable manner than a rounded LE. The spar is a standard yardstick. There are three score lines 3/8" apart. The plane flies very well. In at least 200 landing I have not had a bad one. This is definitely a record for me. I have had two other similar size biplanes (balsa) , both with rounded LEs, and both would occasionally stall ( drop like a rock) on a landing.

combatpigg

My Feedback: (3)

The higher the wing loading with respect to the Reynolds' numbers, the more critical details like leading edge radius becomes.
Very small and light models need a sharp LE to be considered fast. Their stall characteristics are a non issue.
I don't think this applies to SPADS. I believe a more rounded LE is desireable, but there is no substitute for hands on experience.