Hydrofoil Wing Build

[RichR2]

Just completed my first hydrofoil wing and very pleased with the outcome.
Not having access to CNC I came up with a way of shaping the wing accurately which others might find helpful. After drawing out the plan shape of the wing I divided it into 3cm strips leading edge to trailing edge. Using the chord length at each 3cm strip, I used Airfoil Tools website to draw a Clark Y (my chosen airfoil) rib. The website allows you to alter the thickness so i could taper it smoothly towards the tips. These ribs were then cut out of 3mm birch ply and glued to 3cm strips of corecell using resin/glass bubbles. The plan shape was cut out and using a router and sanding block, the corecell was removed down to the ply ribs producing a very accurately shaped wing. To achieve the desired anhedral a former was made and the vac bagged wing was pressed down onto it using clanps and sand bags. I first 'skinned' the wing with 200g glass, then added mounting plugs and rear mounting cutout surround (resin/microfibres). The wing was then finished in 200g Carbon, 4 layers centre going to 3 then 2.
I hope the explanation and photos make sense...if you can make boards, wings are even easier.
Dimensions : Span 69cm, Root chord 20cm, Area 1000cm2

[teftelja]

Very nice work. Did you tes it?

[RichR2]

Yes, I tested it before i did the final finishing coats and was very pleased with it. I wanted a wing to complement my Shinn K2 (which I think is a fantastic) so I went for a bit more area but without going full on down the low aspect route like the 633's. It flies at a very low speed and doesn't get 'front footed' when powered up like some of the low aspect wings do.

[Trent hink]

This looks like a really nice technique and outcome!

[qba-epp11]

Super.
I am looking plans to make wing 2500 cm2 for moses Onda fuselage in same technique.
Somebody have file , and can share?

RichR2 Can you share the file?

[RichR2]

Sorry, but there is no file to share. The wing was designed with pencil and paper and each of the aerofoil shapes was plotted according to the chord length and desired thickness at each part of the wing using an online plotter (http://airfoiltools.com/airfoil/details?airfoi). Its very easy to use and allows you to change various parameters for your plot.

[qba-epp11]

r (http://airfoiltools.com/airfoil/details?airfoi). Its very easy to use and allows you to change various parameters for your plot.

Change Chord, Thickness or anything else?

[RichR2]

You can change other things but I only changed chord and thickness

[OzBungy]

Just completed my first hydrofoil wing and very pleased with the outcome.
...

Thanks for the post. It inspires all sorts of ideas, and a few questions.

How did you decide on your plan shape? Did you just make it up or model it on an existing foil?

Did you do anything special to manage the orientation of the wood profiles relative to the outline, and also the pitch of each profile? I'm guessing you glued them in all straight before bending in the anhedral and the flair on the tips.

Did you use any science in determining the angle of attack of the wing to the fuselage and the stabiliser?

Did you wrap the carbon around the edges at all? Or just butt the edges and grind it?

[RichR2]

I wanted the wing to have more area than my Shinn K2 wing but not as much as the 633/Apollo style wings so I aimed for 1000cm2. I also didnt want it as low aspect as the 633/Apollo style. So that was the thinking behind the plan shape although the outline was what looked good to me...so part logic, part guesswork.
All the ribs were glued in the same orientation and cathedral and washout came from the form I bent it on
No science for AOA ... the K2 has a flat bottom aerofoil and mounts flat on the fuselage so I did the same.
The carbon was not wrapped (too difficult to do well ) so the top and bottom are butted together.
As this was my first wing it was very much 'shooting in the dark' design and construction wise, but luckily it all seemed to work