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Paducah said..Francone said..Paducah said..
Francone, I'm confused what you are looking to do. Do you want to make a fin with a wing on it or an actual windfoil like Naish, Slingshot, NP, etc?
Sorry for the confusion: Just the wing to be attached to the fin. The fin is already there.
Thanks
Francone
Things to consider:
1) You have a US box which can only take limited loading. I'd think a swept fin like a weedie would mean the wing would constantly be trying to pivot the fin out of a not-so-strong box. If you go with this, a bit of reinforcement might be wise. Virus seems to say that a 38 cm fin is the limit for even a Powerbox version of their fin if there was one.
2) Foils work by creating lift under the rider - between the front and back straps. Take a look at the post by barbarian above and you can see the blue wing under the rider. Fin foils generate lift under or even behind the back foot which, while lifting the back of the board, effectively forces the nose into the water. You'll have to compensate by either moving back, lifting hard on the front straps, etc. to keep board trim. By putting the wing on a weedie, you are exacerbating this tendency. The idea that you can magically float above the water like you would on a foil has been pushed by spiralbevel here and elsewhere without any real evidence.
The Virus fin seems to consider this and extends the wing forward of the fin.
I'm not against anyone having a go at something and proving me absolutely wrong. :) Just some things that you might think about. Something like a Slingshot foil with a short mast, while not ideal, might be a lot more fun and less frustrating in the long run even if more expensive to start.
www.facebook.com/theviruscarbon/posts/2005028389783992 The length of my weedie is 38 cm and the vertical depth from the fin box 28 cm. AS it is ,and at the speed I usually go (light winds) I don't think that the stress on the US box is an issue.
My aim, as I said earlier, is to have the board just rise off the water enough to plane or skim a few inches above it.
As I see it, the only way to do it ( theoretically!) is as large a wing surface as possible.
My project, with 70 cm ( 28") wing span and a 25 cm max center width tapering down at the tips . should give me a decent 875 cm2 wing surface, with enough lift ( I hope!) to pull me out of the water .( The minimum recommended wing surface is 600 cm2, from what I read.) .
I was thinking at first of building the wing with a 3D printer, but it looks easier to do it manually out of a 1 1/4 " " plywood board.
At
there is a YouTube video showing how to shape the plywood board into a wing by progressively whittling away, tapering and sanding the wood. A long process, but with power tools it is not too bad.
I am aware that without a rear stabilizer fin I might experience drag or stability problems, but I can always add it later on, if necessary.
May be it won't work, but I'll try, keeping in mind your advice to reinforce the wing at the insertion point on the fin in order to prevent the fin from swaying and pivoting on the fin box under the hydrodynamic stress of the water .
By the way, you say that the lift would be created between the front and the back straps . Do you think then that it is better to invert the direction of the fin so that it points forward? This should also advance the wing more forward, especially with a weed fin which is already coinsiderably back swept. .
I'll post the results on the Forum next summer, because we still have ice here!
Thanks to you all for the comments and suggestions.
Francone