I am going to scratch build a 50cc Extra. I have been looking at some wing airfoils. I kind of like the S8035, S1048 , and the Eppler 169. All these airfoils are 14%to14.5% thick. I am wondering if I might be better off with a thinner airfoil? An airfoil that is 12% or 13% thick.
What are your thoughts?
Thanks
Jim

Do you want it to be a psort flyer, IMAC aircraft or hot 3d beast?

thinner airfoils have a higher stall velocity. Thicker airfoils have a lower stall velocity.
Thinner airfoils require more consideration to the wingtip wash out.

Strictly IMAC.

then the 14% to 16% range airfoils should be ok.

Just keep in mind too that thicker airfoils help in creating drag to control downline speeds, which is great for precision aerobatics.

Originally Posted by jim52919

I am going to scratch build a 50cc Extra. I have been looking at some wing airfoils. I kind of like the S8035, S1048 , and the Eppler 169. All these airfoils are 14%to14.5% thick. I am wondering if I might be better off with a thinner airfoil? An airfoil that is 12% or 13% thick.
What are your thoughts?
Thanks
Jim

Why do you like these airfoils? how are they in inverted flight - do they require a higher angle of attack to retain level flight while inverted? Do they produce more lift with airspeed? What are you trying to achieve?

All the airfoils l listed are symmetrical so the airfoil will act the same whether upright or inverted. I wanted an airfoil that had good breaking on down lines and have dependable stall characteristics, It will enter spins and snap-rolls well.
I ended up choosing the S8035 airfoil reduced to 13% thickness. The airplane flies well . As of now I only have about 15 flights on it. I am still in the process of evaluating the performance.
As a side note I am going to scratch build a 40%er and may use the same airfoil unless I come to think something else would be better.
Any suggestions?
Jim

Originally Posted by jim52919

All the airfoils l listed are symmetrical so the airfoil will act the same whether upright or inverted. I wanted an airfoil that had good breaking on down lines and have dependable stall characteristics, It will enter spins and snap-rolls well.
I ended up choosing the S8035 airfoil reduced to 13% thickness. The airplane flies well . As of now I only have about 15 flights on it. I am still in the process of evaluating the performance.
As a side note I am going to scratch build a 40%er and may use the same airfoil unless I come to think something else would be better.
Any suggestions?
Jim

NACA 63 015 or 64 2 015 both laminar airfoils. Important use same profile family for wing and stab. Incidence 0°.
63er is a bit faster as the 64 er family.

Cheers

also remember the thickness of the airfoil and sharpness of the tip will effect roll and snaps. Personally I would try and look at the airfoil thickness in inches as well as the percentage. At least I work better when looking at both.