Here is my prototype I 42" Wingspan with kFm3 Airfoil(Well almost   , by mistake i had a extra little small step) for glide test. It glided very well.



Oh yes, 'Watch out for that coconut Treeeee !!!!!!'  .

nice i love pvc and coro

I don't understand why folks would want to put a step when they can just extend the top surface all the way for a neat clark-y shape.

for the fun of trying new things i guess

HEHEHE. Not for fun SLS. That the speciality of kFm easy to contruct and also more efficient(based on your application) then the normal ones.

Azhagu
Hope our discussion was of some help

Quote from: azhaguvel on April 11, 2011, 12:26:08 PM
That the speciality of kFm easy to contruct and also more efficient

I don't think Kfm are not more efficient than conventional airfoil, they are comparable only to flat plate or UC airfoil at best.
Easy to construct and weight saving 

Ps: I just love the "i agree" smily

@SLS
 
        yes 

@Augustinev

Ya augustinev it was very helpful.thanks . I am re-designing the plan. I am little worried about sticking the horizontal stabilizers on the top of vertical stabilizers. Cos now I have to stick the vertical stabilizer, vertical to both the boom & the horizontal stabiliser. I am going to try with kFm2 for my prototype II . After it works fine then i will try kFm3.

KFm3 easy to build? What is so difficult the way I construct mine?

The lower surface is a flat plate, the spar runs across the half span of the wing at approx 30% from LE, the upper surface is joined first at the spar, then at the LE and finally at TE.
In this construction, the small foam bit at the TE is just a 1/2 inch width to help the two halves to be glued together.

Personally, I feel this offers a much smoother curve for the aerofoil than the KFm wing

Pankaj

nice one Pankaj. I would construct one if i get bio-foam here in trivandrum. Can this be done using coro also. Wont it will add more to the weight?

See if you look at the KFm3 design, with all the steps involved, the material needed would probably be the same. While I do not have much experience with coro, but it might be a good idea to slice the inner layer of coro at appropriate length and after giving the bend, put a dash of super glue to stick the tear (if you understand what I mean).

@ SLS
That is not PVC, Its a aluminium tube. sounds heavy na. Ya it was a test for how heavy the plane can lift and glide. Also the tail is just inserted there on the tube so that i can change the tail dimentions & check for stability.

@pankaj
I didn't get what you are saying. Are you saying to split the coro at the flutes or insert coro strips of required length vertically inbetween two layers to get the airfoil shape?

Split the flute or bend the upper coro sheet a bit to get the shape. If you split, then be sure to touch up with CA. Also remember the flat plat at the bottom would provide the necessary strength.

looks good to me
best of luck