Watching Grant M. on a 10M kite ripping upwind on his self made hydro-foil (12 knots of wind @ most !!!) board I realized that there is still a lot to learn for the rest of us: http://www.extremeboarders.com/hydrofoiling/ http://www.skyski.com/shop/index.php http://www.airjunky.com/ http://www.jimmylewis.com/mainframset.html (No. it's the real J. Lewis...click on 'foil photos') http://foxxaero.homestead.com/indwig_014.html ground effects http://foxxaero.homestead.com/indwig_012.html Russian tech. http://www.sentex.net/~sxing/wig/wig.htm China http://www.se-technology.com/wig/index.php

I love the story that goes behind Jimmy Lewis.

Turtle.

Truth is stranger than fiction !!!

Hey Jim, thanks for starting this thread. I thought I might take the opportunity to say a bit about my foil project in case anyone's interested.
Frist, it's a riot. Fun doesn't really come close to describing the sensation. Second, I suck pretty bad at it, mostly I just teeter around at about 10 knots until I fall off, and it still seems fun. Third, I didn't invent it, I'm just following the lead of others.
Hydrofoils have been around for a long time, there's a bit of history available through links to the sites that Jim posted. I saw a guy named Aaron Sales kiting on one at the Gorge Games in 2001 or 2, and he was ripping. I didn't really appreciate it at the time, but later I thought about it, and it started to make sense that it would feel a lot cooler than it looked. Somebody else had one at Squamish in 2003, and I wish I'd taken a better look at.
I figured I could build a better one, so I made something out of plywood and glass. It was right next to useless. But it did push me up out of the water once or twice, and that kept me thinking about it. It's about $2000 US for the production Rush foilboard, so model number one went up in my workshop rafters, and model 2 started in aluminum. Model number 2 is as close as posible to a copy of any photo I can find of the thing on the net. (Airchair and Skyski build slightly different variants of exactly the same configuration, and Rush takes the Skyski and adapts it to a board and adds snowboard boots, I think.)
To my total surprise my setup works, kinda. It's slow, but it goes upwind like crazy, and gets up at really, really low speeds, but it's opened up a huge low wind range of fun. I'm going to stick with it, and search for more speed and stability. I'd be happy to talk about design and constuction if anybody wants to jump on this bandwagon. The funny thing is... (I ought to know by now) that by the time I go through material and welding costs, plus an old board, and snowboard gear, and a zillion hours grinding and polishing, $2000 US doesn't look so bad. In fact it seems pretty good. Remember mine doesn't work too well. The point is, I think if you shelled out and bought one, you'd probably have fun. Anybody else interested? It's lonely at the beach when it's only blowing 10 knots. Plus, I could have a chuckle as I heard YOUR board clanging into the reef at Dallas road... cause I know I'll never hit that thing... least not more than, let me count the dings, 2 or 3 times anyway!

Thanks Grant. It doesn't look like you 'suck' on your hydro-board from down wind where I'm walking back up the beach !!!

No, your not the only one grant.
I've been coveting foilboards ever since I saw one about a year and a half ago.
I hadn't been able to see one untill yours.
I find the physics of it sooo interesting.
And I have a feeling, using one would be fun as hell, especially with a kite like mine.

I would love to get one myself, but I have a feeling it could be a while.
I haven't got a shop and welding, grinding, sanding tools laying around at the moment.
Or 2000$ in pocket change. I'll have to start saving pennies.
I'll just covet yours for now, and live vicariously through you.
Watching the progression of the foil shape.
I've been keeping track of what kind of wind you've been flying in, and what kite you've been flying to.
I have a few small very short clips of you a few modifications ago.
I'll put them in the next vid I make.

http://www.moth.asn.au/pictures.html These guys are working with foils as well. links: http://www.fastacraft.com/links.html Go to gallery & enjoy the videos...

There was a really interesting looooonnnngggg technical pdf on the web by a Calif windsurfer who makes foils for windsurfers. Big thing seems to be a canard for automatic pitch control. I think he was manufacturing them for a while, but gave up and has made his patents public, plus gives away the plans I think. I'll see if I can find the link, I never finished reading it.

Yes, good paper from a generous guy. Seems like he's giving up his plans and patents so others might make further developments. His canard setup is another interpretation of the same principle that the moths use, with their surface sensor and control flap. Single point strut systems like the airchair and my version need constant input from the rider. Just like the difference between a bicycle and a unicycle, but not quite as hard. They're far less sensible, but maybe more fun? Here's the paper:
http://www.foils.org/miller.htm btw, how do I turn that into a real link?[/url]

looks like it worked

In the forums cut & paste is enough to add a link...Once in a while it fails because it adds some of your text...I find if I add the link on the end of a line & leave a few blank spaces I have no trouble.

Yep, thats the paper I remember - the 28 page fine-print one. It sounds like an intriguing system, with the surface-seeking canard angle trimmed to produce the appropriate board roll. From the description, it seems MUCH faster than conventional boards in most winds - and probably faster/easier than the Rush Randall system. The acceleration and reaching sounds very scary - and the method of dealing with it by close reaching then quickly turning deep downwind sounds like Formula methods.

Solar powered cat.: http://www.slyasafox.com/SVN/combinationcreativity.html