Forums > General Discussion   Shooting the breeze...

Foils - wanted broken, wanted ideas, etc

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Created by Mark _australia > 9 months ago, 8 May 2020
Mark _australia
WA, 23517 posts
8 May 2020 11:50PM
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I'm looking at building an experiment foil, I'm thinking why not a low speed one for SUP and on a wing foil setup. Probably build a wing foiling board too.
The building will be easy but I'm not really finding any sites that talk about foil design. Manufacturers all reckon theirs is the best of course, and published wing areas / span / chord are helpful but I see massive differences in draft (presume thicker for slower speed use)

Has anyone got any links for foil design that isn't uni research papers? All I'm finding is how to shape 5 ply and glass it, not actual design talk or plans.


Then - thinking about busted foils that are worth repairing, there must be plenty of buggered stuff out there that people want to part with? Anything....

mazdon
1198 posts
9 May 2020 12:16AM
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You tried the foiling section in kite forum Mark? Pretty frothed and proactive crew in there from what I can tell. Worth a post there also maybe.

Good of luck with next builds!

Mark _australia
WA, 23517 posts
9 May 2020 12:33AM
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cheers will do
EDIT nah gone to the the SUP foiling forums as that's closest to what I'm after I think

Ian K
WA, 4163 posts
9 May 2020 8:16AM
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Go to the moth web sites if you can't find one to copy. They're less mystical about the sources of their design than "surf" types.

The NACA 63412 curve scaled to 12% seems popular. The thickness going back from the leading edge specs for all the NACA curves are all over the web.

airfoiltools.com/airfoil/details?airfoil=n63412-il

tarquin1
954 posts
9 May 2020 1:32PM
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finfoil.io/blog/
I saw a guy design one with this. You can design them on Shape3D as well.
You could try efoil homebuilding websites too.
There a quite a few people that have 3d printed foils to use as the core.
As far as the actual design and theory go I think it's a bit of a black science and anything I have read seems to be written in another language!
I think by reading ride reports on sites like here you can get an idea. But yes thicker gives more lift but more drag so slower.
Have a look at the Gong foil range. There new foil is a lot thinner.

mazdon
1198 posts
9 May 2020 6:56PM
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Actually that's a good point, some of the gong gents post in the sup forum so you should be sorted.

Post pics of build later please

Mark _australia
WA, 23517 posts
9 May 2020 10:25PM
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Select to expand quote
Ian K said..The NACA 63412 curve scaled to 12% seems popular. The thickness going back from the leading edge specs for all the NACA curves are all over the web. airfoiltools.com/airfoil/details?airfoil=n63412-il


Glad I looked as you're showing a foil that is not flat on the bottom - I was going to go flat......
Hmmm I might need to rethink my mould and process I was going to employ

Mark _australia
WA, 23517 posts
9 May 2020 10:27PM
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Select to expand quote
tarquin1 said..
finfoil.io/blog/
I saw a guy design one with this. You can design them on Shape3D as well.
You could try efoil homebuilding websites too.
There a quite a few people that have 3d printed foils to use as the core.
As far as the actual design and theory go I think it's a bit of a black science and anything I have read seems to be written in another language!
I think by reading ride reports on sites like here you can get an idea. But yes thicker gives more lift but more drag so slower.
Have a look at the Gong foil range. There new foil is a lot thinner.


Interesting, I have used Finfoil to design some windsurf fins and it was super easy - but I could not add a base to the foil which is not much good.
Nor could I export just a plan shape to CNC just the outline and then hand foil (what I really wanted to do)
But I am pretty dumb with CAD stuff so was I doing it wrong?

tarquin1
954 posts
10 May 2020 12:37AM
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It was awhile ago. I just saw someone had used it. Maybe he just used it for the outline.
I wouldn't get too confused between sailing foils and sup foils,from your other post on here.Different speeds weights etc involved.Look at what works and how they have evolved.

515
874 posts
10 May 2020 6:03PM
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It's interesting I caught up with an old mate that wind foils and wing foils says he uses the same wings but different mast/fuselage set up.
Yes I am biased to Axis, but I do like the alternative Armstrong mast/fuselage connection with a structural carbon pipe at bottom of round fuselage but then with wings of top and bottom layer of plywood sandwich foam makes it easier to shape the profile and layers of carbon reinforcement would make a one piece foil setup stronger and lighter but without the adjustability of commerciall setup

Ian K
WA, 4163 posts
10 May 2020 6:30PM
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Select to expand quote
Mark _australia said..

Ian K said..The NACA 63412 curve scaled to 12% seems popular. The thickness going back from the leading edge specs for all the NACA curves are all over the web. airfoiltools.com/airfoil/details?airfoil=n63412-il



Glad I looked as you're showing a foil that is not flat on the bottom - I was going to go flat......
Hmmm I might need to rethink my mould and process I was going to employ


Just going back to that NACA 63412 and comparing it by eye with the first Neil Pryde pinkie front foil, I'd say that's what it is. Haven't measured in detail ,( apart from its thickness, 11.8 %) but the convex to concave bottom surface and its proportions to the top curve seem to match. Not surprising I suppose that the first stab at a windsurf foil just went with what the moth sailors had settled on. Not that the NP pinkie was highly regarded.

Imax1
QLD, 4926 posts
10 May 2020 8:56PM
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Select to expand quote
Mark _australia said..
I'm looking at building an experiment foil, I'm thinking why not a low speed one for SUP and on a wing foil setup. Probably build a wing foiling board too.
The building will be easy but I'm not really finding any sites that talk about foil design. Manufacturers all reckon theirs is the best of course, and published wing areas / span / chord are helpful but I see massive differences in draft (presume thicker for slower speed use)

Has anyone got any links for foil design that isn't uni research papers? All I'm finding is how to shape 5 ply and glass it, not actual design talk or plans.


Then - thinking about busted foils that are worth repairing, there must be plenty of buggered stuff out there that people want to part with? Anything....



I love experiments .
Please post pics and associated waffle.
Im sill working on RB foiling.
I bought a stronger than average mast from a Wasp foiling boat thing. It was a rear foil mast.
The interesting thing while browsing in their factory was they had a simple front and rear foil. The front wing was a simple straight design , the rear was the same thing only less wide with an adjustable rear flap that self regulated with leavers from a paddle flap at the front of the boat.
So the thing self levelled all on its own.
These small waspy boats are very small and have no controll of body weight and work perfectly.
Im still thinking I can do this on a windsurfer .
Why not ?
Im thinking it can and will be done on a self levelling kit for all foiling applications.



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Forums > General Discussion   Shooting the breeze...


"Foils - wanted broken, wanted ideas, etc" started by Mark _australia