The WAVEWING hydrofoil (Florida style)

[Wooddave]

 I was able to get the new setup out into some nice little waist high clean surf on Saturday…

I was really happy with the way it performed That new tail section is a keeper…

It held its line pretty well and I was able to (breifly) get to my knees.which wasn’t even on my list for the day…

The foil positioned all the way to the back of the board was also an improvement.

There was just way too much board hanging off of the front, so on Sunday I rectified that situation.

I cut about a foot off the overall length and rounded the nose a little… 

Apparently these boards are made from a fairly dense foam,(10 lb maybe), it shaped well…

I wasn’t sure how to deal with blending all of the various ridges and concaves but I think it came out fine…

Though I will eventually try a few different shapes and sizes for the tail section,

I will now focus on the new narrower main foil and a more purpose built board.

And maybe a new all stainless strut,and…

[fins]

dave that is a maaad space ship you have there

 

  can’t wait to see phoootage of it in good waves

 

  keep up the experimenting , brett and dave …

 

  cheers

 

  ben

[Surffoils]

Dave, I’m glad you’re getting the same response I am with longer rather than wider foils.

 I found the length is needed to give pitch stability, about 24-25 inches long for prone and about 30 inches for standard surfing. Its easy to ride a shorter shape when it’s submerged because it sits within the wave with the water holding all sides rather than sitting on the water like a surfboard.

 Dave I see you’re using a leash… Ive found that the foils and board don’t get washed around if you bail or get nailed. I initially went out without a leash and thought I’d be doing a lot of swimming but no. Then Ive gone out with a leash and found that it doesn’t help and actually detracts from the sensation of flying. I thjink the shape of the foil and board isn’t streamlined enough to get pushed along by the foam.

[Surffoils]

Latest hydrofoil on a wakeboard.

My God that’s terrible photography !

 I’ll take some better pics and post later.

[Surffoils]

Dave, I followed your idea and modified my kiteboard, just changed the end shapes.

 I’m keeping it at 4’6" for paddling stability but the shorter length is easier to throw around like a skateboard.

[Wooddave]

Hi Ben , Thanks, I will be doing my best to get some good vids too.

My son and I are about to leave for a tour in Costa Rica,(no spaceships allowed),

so my experimenting and documenting will have to wait till I get back…

 

Hi Brett,  

I see how that all works now, wow your foil is getting narrow…

It’s getting closer to the picture that old ski style foil board…

Even though I almost never let go of the board, and I’ve never tested to see if it would get carried away by a wave,

 I prefer to keep the leash, if not for my convenience (it’s not convenient) or safety, then for those around me…

 I’d hate for someone or their board to get hit by THAT thing…

Happy experimenting while I’m gone…

 

 

[Surffoils]

Experimentation is in progress most days…

One of the things I’m looking at is making the foils as light as possible and that means progressing the system with a minimalist design that retains essential strength and flex.

 The ‘black box’ supports in the pictures below are fine but Ive quickly designed a simpler system that’s lighter by a few hundred grams.

Slowly every aspect is considered, tested and improved. I went to see a manufacturer about getting a standard board shaped to suit the foils but it’s such a unique application I think I need to find a kite board maker who builds foilboards (last pic) and then adapt it for the surf.

[Surffoils]

 

Ben asked why the foils are the shape they are so while Daves away I’ll write about about my design. The support/s that connect the board to the foil are there to hold the foils in place at a certain distance from the hull and because the board has no traditional fins, the supports also provide low speed paddling direction.

 I started following the direction of the kite foilboards by trying to make a single support under the board but it requires making a extremely stable platform on the hull and that makes it heavy. Without that stable footing the foil is subjected to lots of fore and aft pressure that tries to break at the single contact point on the hull. Pic 1

 My plan was to have a single contact under the board but to connect with either extremity of the foils to provide stability and control.Some of these earlier ‘split’ supports had a lot of flex and were slow and a bit sluggish to respond. They looked good though. Pic 2 and 3

 The solution is to use 2 supports, Pic 4.   One at either end of the foils, they provide better lateral stability and perfect pitch control and because they share the load they can be made of lighter material.  Made from simple box Aluminum theyre cheap and quick to make and  i dont have to worry about welds or weight. Theyre also massively easier to connect to a fibreglass board. Probably not the final step in their evolution  but better than anything before so I’ll stick with them or variations upon the theme until something better comes along, probably next week.

[Surffoils]

The plan is always to get the foils onto a foam board and with the two supports its possible on any size surfboard or longboard.

Here are the two aluminium supports. Pic 1

I marked out where they will go on the board and resined 4 poly posts thru the board. Pic 2 and 3

Ive got a mate keen to try it on a longboard so that’s next…( last pic)

[Surffoils]

Hydrofoil video…

http://www.worldvideofans.com/en/video/1519296/Tests-Hydrofoil-Laser-20

 and a board ready for the foils to be attached…

 There’s 4 plugs thru the board that are similar to FCS plugs.

 

 

[Surffoils]

The hydrofoils are on the prone board, rode it this morning and its the same easy ride, the connection to the board is rock solid. Next is a 5’10" shortboard and then a longboard. I’m quite stoked that the hydrofoils can be so easily added to any standard poly or epoxy surfboard, I kept thinking that I would have to create a specialised board for the foils but if it all goes well with the shortboard then there’s no reason to create problems.

 The design works fine but I’m not overly impressed with the looks so aesthetics will come to the fore with the next few hydrofoils.

[gordof]

just throwing this thing into the equation - the waterbird…maybe you guys have seen it, but i thought it was interesting. i’m surprised at how easily it seems to float/plane in the video

here’s a video of it in action on facebook - https://www.facebook.com/photo.php?v=1428603960758940&fref=nf

[Surffoils]

Quite amazing vehicles ! Great minimalist design too. You’d need to be quite energetic to keep it going tho.

The main thing I felt from watching the video is that you need to keep the power on and constant which is something that plagues foiled windsurfers and the Moth sailboats. With high aspect foils, the moment the power varies the foil loses lift especially in rough water. Because the foil relies on its contour for lift without power they have little effect without it, no glide, no lift.

.

 The kite foils have an advantage in that they have constant power thru the kite so the high aspect foils maintain lift and constantly win open sail craft races.

.

For surfing there’s constant power from the wave but it varies so much that the accepted thin high aspect foils return erratic lift amounts and if you have a front and back foil, then there’s two foils constantly changing lift and almost always out of synch.

.

 The solution is to stick to a single surfing foil, its so much easier to tune one thing rather than two. Because one foil needs to be long enough to be stable to ride, the length also provides glide, smooths out the power surges and drops and it’s too long to actually ‘foil’ with a NACA profile. This works in your favour because it makes a surfing foil easier to make, it lowers its volume to a minimum and the longer foil works better in the steep wave face and wide angles that you get in the surf. After making more than a hundred traditional hydrofoil sets I changed to longer foils and its only then that the performance jumped exponentially and I realised that the considered wisdom/ accepted knowledge isn’t the only way things work.
.

I’m quite a conservative person so I tried for years to make the ‘traditional’ design hydrofoil theory work in the surf, honestly I agonised over the theory and scientific principles and tried to stick to ’ the rules ’ of hydrofoils, but theyre not relevant in this application, not in the slightest. But I suppose I had to go thru that and keep going to get to the point of doing it differently and better.
.

Now, years later, Ive got some good theories of how surfing hydrofoils work, I don’t know it all yet, but I’m narrowing down the design yet expanding my understanding. Like surfboard building, Ive been thru the romance years of learning what does what, then the harder times of making my own rules and learning the craft inside out, and now it’s just first nature to make and ride hydrofoils in the surf.
.

And lately Ive got a reliable system that attaches foils to a standard surfboard so I may never make a surfboard again, the board is just a paddling platform until the foils kick in on takeoff. It’s been about 8 years doing this, maybe 300 sets and single foils, thousands of pages of theory read over the years and probably twice as many pages of design drawings, gone from foam to vac-bagging composites to aluminium to thermoplastics, for years it’s overtaken the house and midnight thoughts but it’s all been a pleasure. .
.

The only thing Ive missed is having Terry Hendricks as a mentor and his passing a year ago is time to reflect on life and time spent.

[Wooddave]

I have seen those before, I think it would be a really cool gadget if they could find a way to incorporate bouyancy so the rider could rest (or fish) if they would like without sinking…

Having to launch and reurn to a dock seems like a limiting factor…

A friend from the Netherlands described to me what he called a bounce boat that a friend of his had built several years ago ( I goggled it and apparently “bounce boat” means something else now)…

It was basically something like the Aqua skipper but with two very skinny and tall pontoons on each side and as you bounced up and down forward thrust was generated by the foils changing their pitch in each direction…

That shot of them in the wave pool looks like they have a newer version, I’d like to see the video from that to see how it reacts to wave energy…

 

 

[stoneburner]

I found this human powered hydrofoil several years back when I was looking for foil shape ideas. Their prototypes began in the mid- to late 80s.

Video

http://youtu.be/PiH4I3ebyhY

This picture of the Pogo Foil is from 1990:

http://faculty.washington.edu/pmacc/Research/pogo_foil.htm

 

[Surffoils]

Dave, I made a kids toy for my boys a few years ago that resembles a Seahorse.

 They pushed up and down on the green hand and foot pegs and the red vanes move up and down propelling them around the backyard pool.  They rode it everyday and they loved it like an old horse but it was only painted ply so it didn’t survive more than one summer.

[Wooddave]

So after a few months away from my project, I’ve finally been able to do a little more testing and building…

The ridgid aluminum and carbon tail section that I made was very interesting…

It tracked straight as can be (maybe a little too much for riding prone),

The most interesting part though was that it self leveled !!!

** **It didn’t just keep a constant pitch but it actually leveled itself out a few inches below the surface.

It was something I suspected could happen,but the fact that it, did has some real implications for sups and other surf and windcraft…

That just opens up another can of worms that will have to wait a little while…

I was more interested in what this setup told me about the tracking ability…

It proved that my idea of the flexible tails (if properly executed) would work…

So I made a new set of tails these were made by laminating carbon uni down only the length of the tails with a little surfboard cloth to keep it from splitting…  

 

As you can see they have more surface area than the old tails and come further into the center. They are also much more flexible…

They are made to flex upward towards the center when under load (most of the time).

These are screen shots of some gopro vid I made in the pool, as you can see one side opens up more on the turning side,

That effect is increased as the speed/force is increased resulting in more tracking stability at higher speeds…

The whole thing bends upward some which helps redirect the rebound wave rearwards more…

I’ve gotten it out oun the surf a bit and I’m really liking how it feels…

I’m getting tired of carrying that heavy wakeboard/boogieboard monstrosity around so I’m having a custom board made by a local shaper…

I wanted it to be easy to catch the waves so I asked that it be wide (24" at it’s widest) and thick (3") and mostly flat on the bottom…

I will still have to do the reinforcement myself, it will be ready in a few weeks…

 

[gordof]

awesome! stoked for more updates.

[Surffoils]

 More amazing work from you Dave.

Looking forward to hearing what theories you develop from the feedback.

Interesting to hear how the custom board goes too !

[stoneburner]

I like it Dave – especially the underwater shots of the rear stabilizer flexing.

I look forward to seeing the new, improved and lighter design…