Wing shape and why. Advantages of each shape.

[Snoopy1]

Making a new wing for a plane. I know the profile needed for the root and the tip but undecided on the leading and trailing edge relative to the fuse.
1. Do I make the leading edge straight from the fuse ie at 90 degrees.
2. Do I make the trailing edge at 90 to the fuse and have the leading edge trail to the back. This is how we used to do it many years ago for pattern planes.
But with todays 3D machines which is preferred and why. Or split the difference and have the leading edge and the trailing edge taper in the same amount.
Thanks for your help

 

[Terryscustom]

Wing shape depends on what type of plane and the type of flying you anticipate doing. Also the airfoil / wing shape combination plays a roll. Many people will use one airfoil at the root, one airfoil at the tip and a tested wing shape to get the desired flight characteristics. It's all a game of balance, give and take.

 

[Terryscustom]

......Or split the difference and have the leading edge and the trailing edge taper in the same amount.

NO, sorry forgot to answer that part of the question.

 

[Snoopy1]

The airfoil on the root will be NACA-63A012A and the airfoil on the tip will be NACA-63A010A. It will be for 3D plane. Converting a sport plane with a 15 % airfoil and rectangular type wing.

 

[Snoopy1]

In the attached picture you can see the wing layout for a pattern ship. Just finished building the plane do not know if I will get the time to fly it this year. It is a 50cc size and my own design. Flew a few pattern ships a number of years ago and thought it would be nice to fly one again accept little bigger and nice 50cc engine in it.

 

[Terryscustom]

In the attached picture you can see the wing layout for a pattern ship. Just finished building the plane do not know if I will get the time to fly it this year. It is a 50cc size and my own design. Flew a few pattern ships a number of years ago and thought it would be nice to fly one again accept little bigger and nice 50cc engine in it.

Nice work

If you are drawing it out in CAD try to sketch it up at about 11-12% of the root chord = LE sweep at front of tip chord and see how that looks. I design mostly 100-120" wingspan stuff and have found that to be a sweet spot for super 3D stability and still be able to snap pretty decently. Increase that if you want better snaps as well as sharpen the leading edge. Also keep in mind the wing area and tip chord so you don't create a tippy or snap happy monster. If you have a rectangle wing now and you angle the tips you will have to come up with more wing area via chord or span.

 

[Snoopy1]

Hi Terry thanks for taking the time to help. Yes I made sure that the wing are is still the same. The size of the wing panel is root cord is 32 inches and the wing tip cord is 16 inches and the wing length for one side is 57 inches. So if I understand what you have explained above is 12% of 32 = 3.84 inches. Therefore the leading edge of the wing tapers backwards 3.84 inches at the wing tip.
Great that helps a lot.

 

[Snoopy1]

Man am I getting excited about this wing to see the difference it will make to the plane.
One more question about 3D plane wings. When I built a wing it was always built on the table upside down flat on the table. This makes the wing flat on top and the bottom of the wing have very small amount of dihedral. (The difference between the cord thicknesses). How are 3D wings built?

 

[Terryscustom]

Do it without the bottom dihedral and you will loose the wing rock you likely had. Well, should I say you maybe didn't if you had a constant cord wing but you will now with a tapered wing. The dihedral will induce stability and the wing tip will want to stall and unless you have several other things just right it will wing rock like a mutha.

You have picked a very nice place to start with on airfoils because they have an extremely broad range of CG (very friendly) and you will be very happy.

Here is the problem I see with this......... You described a hella big airplane wing and I DON'T SEE A BUILD THREAD YET!!!!!

 

[Snoopy1]

This is the wing I am going to replace with the new one we are discussing. Built the plane last winter. But I will be duilding a THE VIPER ST this winter.