I’m not going to drop in with my hydrofoil plans but I did notice that Gdaddy mentioned Roy’s Tunnel Fins.
Now I’m a big fan of everything Roy does, mainly because my teenage boys think he’s freakin awesome, which is how all teenage boys describe everything…
Anyhow, here’s my latest Tunnel Fin, with all respect to Roy for his inspiration and technical knowledge.
Now I’ll drop in…
Here’s my latest WaveWing, Australian Style.
I’m following Daves lead and making a simpler strut for the next version.
cool !
… that certainly looks a BIG improvement on the one Al stood up on , Brett.
does it overhang the rail , much ? It’s a little hard to tell , from that angle …do you have a shot from the tail , looking forward to the nose , please ?
I’m sure , once you do the second stand up surfboard for Al [ based on his board[s] ] , that he will get it out of the water , and turning , no probs !
… A finboxed version [of that one you just posted ] , so you can have a few inches forwards and back movement [ … if needed ?] would be the next step , in my books , mate !
keep up the experimenting , Dave and Brett !
cheers !
ben
Tremendous experimentation and innovation here.
wooddave, look up a ‘reflex camber’ foil. You’ll see that it incorporates what you are doing with the aft ‘hooks’ in the main foil itself, generating a more stable platform in the pitch axis.
The vid showed you are actually ‘flying’ the hydrofoil, not just using it as a smaller planing surface. Great use of anhedral to ventilate the outside half of the wing on banked turns.
JSS
This is the only drawing I’m working off, its on a paper napkin.
Because my foils are longer than Daves Ive split the strut into two arms to get a better spread of control. Front is on the RHS.
At the top of the strut is a square plate to attach to the board and at the bottom of the struts will be lateral arms to hold the actual foils.
thanks for the tail to nose view , showing ? minimal ? overhang
q:
…is there a way to make the winged bits [? and struts too, maybe ? ] from wood , and / or thin fibreglass layers , Brett ?
[two reasons… 1. to avoid metal slicing flesh , is why I ask … and , 2… ? to bypass the need for screws or bolts , too ? The metal base plate is still fine though , eh …]
cheers !!!
ben
( zzzz time nowwww … 11pm monday )
Ben, at the moment I think Aluminium is probably the quickest and easiest material to use for struts and the rest of the frame but I’m working towards keeping the ‘frame’ as hydrodynamically invisible as possible and just focussing on riding on the design of the foils. Custom vacced foils will probably be the way to go later.
Getting rid of any screws will be something to do once I get a better idea of how well the current setup works in different wave shapes. For all the visual variations of wave shape and speed there’s a lot of similarities when it comes to the internal forces within a wave and this basic foil shape works in every wave so far.
Dave commented before that lift isn’t a problem and that’s true, it’s not hard to get airborne, it’s all about flying smoothly through the swirling wall of power.
Surffoils, That quasi tube fin looks pretty cool,is it pvc? , I wonder if a bamboo version could be made…
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maxmercy, I looked up reflex camber, from what I can tell it is used in aerofoils to get a little extra lift in the trailing edge…
I figured there are technical terms for the things I’m building and knowing them is helpful .
I work with and around engineers and I know most of the basics, but I tend to glaze over when they break out a lot of those two dollar words lol…
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I’ve cut the mdf for my new mold,
but I seem to have lost the ability to post pics from my Flickr acct.
It seems they’ve “improved it” again.
Dave, keen to see the new mold !
Yes the tunnel fin is PVC, just attaching it to a paipo and then its testing time.
“maxmercy, I looked up reflex camber, from what I can tell it is used in aerofoils to get a little extra lift in the trailing edge…”
Actually, the back of the foil ‘pulls down’ and stabilizes what the front of the foil wants to do - lift up. Without reflex camber, a single foil will want to keep doing ‘loops’. That’s the reason most aircraft have a tail. Front wing pulls up and lifts the aircraft, small wing in the back pulls down and stabilizes everything. The trick to a proper hydrofoil is designing one that has enough stability and can be ‘steered’ with simple weight shifts. Not as easy to do as it first seems. It’s like trying to design an aircraft with no control surfaces (like a hang-glider) that can fly inside a tornado (the wave).
Surffoils…nice! What is the decalage?
JSS
I met Dave Saturday to try out his foil. The surf was not too exciting, about 2 ft. but with offshore winds cleaning it up. After some pointers from Dave I kicked out to the line-up to give it a go. It took a few tries to figure it out, as you would expect with something new, but when I got my first wave it was a revelation. Once I got it nose down and into the wave the foil lifted me up like magic and it flew. It was like being a Pelican skimming just above the water being pushed by the wave energy below. Even though the surf was marginal it did not take that much effort to get going and once on the wave it was very easy to control. Even after the wave closed out the foil would just run ahead of the whitewater without any loss of speed. I had to purposely turn it out of the wave to keep it from running into the sand. I was so jazzed by the thing that I completely forgot to break out my camera and get some photos of it.
I am so stoked to be able to try something like that. Thanks, Dave. I think you are really on to something. Any time you need a test pilot, give me a call.
Well done Sensei and Dave.
That’s just how it is, flying above the water, in touch with the power of the wave. Its like the Fourth Dimension of surfing. I’m waiting for Dave to get into some hollow waves with his foil.
Brett,
I’m sure you’ve explained the tunnel fin before, but is it intended to provide lift akin to the hydrofoils?
Bob
Bob, with the foils being just a flat surface there was plenty of lift but I started to look for some grip. As I put fins on the outside edge of the foils I noticed even more lift. So I’m guessing that the wave side foil with an edge that’s down rolled is scooping the water as it rises up the face and that extra volume of scooped water is adding lift. The orange tunnel is to see if a longer tunnel gives a multiplied effect.
Here’s some more foils to test…
Why are these foils shaped as they are. I don’t see why wave foils are different to the established laws of hydrofoil boat design over the past 100 years.
I call, bullshit , on this whole surf / wavefoil / Lifting/planing shit. I think you guys are faking it, Laird did it in huge waves but its nots possible in smaller waves. It’s just stupid to think you can lift a surfer out of the water on a bit of beach break froth.
lairds a hero but youse guy are wankeers
Yes it’s all a lie,I can’t beleive you saw through it…haha
Thanks for being my first troll I’m flattered…
