Delt Wing - Looking for some advise....

[jd7792]

Hi guy's,

Still waiting on hardware and electronics to finish this project, but in the mean time I thought I would seek some advise about my wings profile. As you can see in the two photos below the shape is basicall the same as most wings. It has a wing span of 30" a wing depth of 9.5" and a centre length from nose to motor mount of 11".

I notice that a lot of people use pink foam to make their KF Air Foil, but I have been limited with the foam that I have available. So I decided to use two extra pieces of depron to built the density up. While I was playing with the first part of the Air Foil I found a 3rd piece of foam that was thinner than the original foil. I cleaned it up and came up with the idea that is in the attached photo's. As it is I have a two step AF Air Foil, but I am not sure how that will work so now I need some advise before I glue everything together.

So my question is, "Will a two step AF Air Foil work?" If so can anyone tell me how it will effect the overall wing?

Please let me know what you think...

[Rcjim11]

Here is the basic sheet on KF characteristics. Most people use Kfm2 or 4 on their flying wings - 2 because it gives it a floaty feel and 4 because it is locked in for speed with good glide. 3 is mostly for gliders as attached because it generates good lift, but you do not need this for a flying wing. You can try it as an experiment? I would stick with what you got at the mo because you can always add more steps later.




Jim

[jd7792]

Thanks Jim,
I have actually seen something like you posted before, but 1) I couldn't find it and 2) I don't think it had the third foil on it. I really appreciate your help. I am hopeful that someone, somewhere has done something similar and can give me an idea whether to keep going or change it before I make it permanent.

Thanks again

JD

[colorex]

Just remember to sand the leading edge round and put tape on it!

[earthsciteach]

Also, consider covering the entire wing with either poster laminate or something like econokote. It adds a tremendous amount of strenth!

Looks good! The wing sweep looks pretty good for a decent cg.

[jetpackninja]

Search for articles and posts from Schraut5 he has built several similar type wings

[teflyer]

If I may ask, what percentage of the wing chord did you put the steps?
When you fly it, I would suggest putting a little reflex just in case.

[earthsciteach]

Reflex is a good idea, but you can cheat by trimming your elevons up.

[jetpackninja]

Reflex is a good idea, but you can cheat by trimming your elevons up.

Up trim on the elevons is reflex

Some wings (I think this is what you are getting at) cut reflex into the wing profile itself. The effect is the same.

[earthsciteach]

Yep. I find a good ol' Clark Y works just fine with the elevons trimmed up! Now, the one I'm working on at this very moment will have reflex built into the airfoil profile. Just because.