I mean thick compared to the leading edge.
You could make the leading edge thicker without increasing drag or you could make the trailing edge thinner and reduce drag.
It is all relative.
The image I posted gives you an idea of how the contour would look if you would use the profiles displayed on the right side of the image.
PS: I’m only trying to improve where I can. The results you have are really incredible, a lot of respect for that! You are really pushing it forward!
Thanks Huck, its a moment that’s been coming for quite a while,
Starting off with a thread here years ago with all the usual suspects involved.
And then just plugging away at the theory, making prototypes to test the theories and then test riding around 90 versions for the past 9 years.
I’ve already shaped and started glassing Alex’s next board…
40/60 rails.
The first board is 3.5 thick with only nose rocker. This second board is 2.5 with angled rails and the front half is thinned out like a standard shortboard.
So the journey of experimentation continues.
More boards to build, definitely more foils to test.
Hans, I’ll have a go at your fin software and see what comes of it.
All thanks to Alex Budlevskis for riding the boards and coming back for more.
Hans, I can’t get the software to download on iOS but it looks like it might be the perfect solution to getting the design refined for replication on a 3D printer or similar.
Back to the foils…
A singe foil rides very smoothly, gliding thru a wave, Alex was able to turn and stall with it but id like to find a more aggressive performance.
Moving to a twin foil setup, where at the front is a pitch sensitive lateral foil. And the rear foil provides a more stable ‘back foot’ platform.
It’ll be in the surf tomorrow…
There is no version for iOS yet.
Currently, there are Windows and Linux versions for finFoil v0.x and for the pre-alpha releases of v1.x
I know of Mac users that succeeded in compiling and running the pre-alpha v1.x code, but didn’t succeed to find a way to package the binaries for distribution.
Once I release v1.0, I’ll make sure to have a version for all desktop platforms. Tablets will follow later (don’t know when), because I’ll need to buy tablets for that.
So , how did THEY go ?
DID you mount them on Alex’s test board , brett ?
cheers
ben
Hans, I’ll have a go at work tomorrow with your software as we only have iOS at home. I design the foils on Apple products so it will be good to try your program.
Ben, the surf was tiny today so I spent the day with the family.
I’ve had more than a few emails from people asking if the foils would work on SUPs or knee boards or longboards and yes they would, the shape and length of whatever board you use isn’t a problem. I’m happy to answer questions here where everyone can get the answers.
Split (dual) level foil placement or single level (same plane)?
I am thinking, fuse the spitfire wing with the V into a single foil with smooth clean lines and no sharp corners. >}
You are very generous Brett when many would be secretive.
May your generosity and trailblazing be rewarded with continued success …
BTW the bird is a Scissor-Tailed Flycatcher. It is common on the rural Texas coast.
Its About time you coughed up some evidence of your claims but Im truly amazed at the photographs, the board is clear of the water, the board is balanced level and moving forward quickly and the surfer guy looks totally stoked. Thats got to be a BIG MOMENT in surfing right there !!!!
Its not another board with a new fin or a new tail shape or new laminating material, its not an evolution in design either, This is a freakin REVOLUTION in surfing.
didnt think you could do it
but you did it,
onya. wheres a pic of you with the foils ?
this
The following is a quick sketch of a Flycatcher inspired, uni-body Scissor-Tail Foil concept I have in mind:
Scissor-Tailed Flycatcher
Looking at the angle of the face and the difference in distance from the board to the water…
It seems like rider weight could be easily accomodated by changing foil size.
The sketch was quick, and the spitfire wing had similarities to the Flycatcher wing. I think the spitfire wing would be highly responsive for slower/smaller to medium speed/size waves. I think front foil shape will need to vary with peformance (desired responsiveness) and wave type/speed (mellow shallow angle wave faces versus steep dredgers).
Bird wing shapes differ – flycatcher versus falcon – according to needed performance. Birds can individually alter wing shape too (pulling wing tips in). I think streamlining (wings swept back) can be used to reduce sensitivity and improve speed.
Apparently the Scissor-Tailed Flycatcher is very agile and maneuverable.
**Scissor-Tailed Flycatcher Performance:**
"They are agile in the air, spreading their long tails wide to make abrupt turns and stalls.
The tail proves useful as they expertly catch insects on the wing with sharp midair twists and turns.
The Scissor-tailed Flycatcher flies in straight lines with fast wingbeats, its tail folded. It also often hovers with its tail spread or makes abrupt turns in midair."
I look forward to your continued innovation Brett.
I’d be curious to know of any reactions from others at the beach during testing - its gotta be mind blowing, or are most just oblivious?
I found people were interested and curious to see more, people always paddle over and ask what Im riding and wanted to know how it felt, where did I get it, was it easy, would it work on a longboard, did I make it or buy it...
People definately noticed it but didnt want to show that they were surprised, but I can feel the looks especially if I take the fourth wave of the set when eveyones paddling back out... you surf down the line past 20 or 30 guys and when you get out the back again theres a buzz in the lineup.
Ben said he and Alex were stopped on the beach by guys who were sailors and knew a lot about the Moth hydrofoil concept. All the reactions and comments have been positive but Im guessing people didnt think it would drop straight into a wave and ride along as smoothly as it does.
The next step is to use struts that double the height so the board will be completely above the wave from nose to tail.
Thanks for the Question Huck. ;-)
Just a word about foil curve from tip to tip,
a flat horizontal foil gives maximum reflection of the power of the wave
a full concave foil gives less power, and as the craft rolls the angle of the inside tip increases towards the vertical and gives even less lift, but it gives more hold as the tip turns down into the wave.
a fully convex foil has less lift than a horizontal foil and as the craft turns the upward tip of the convex foil becomes more horizontal giving better lift and drive. Previously I have used concave foils but I’m testing a new foil that’s flat thru the middle with upturned tips.
There’s 2 layers of 10 oz and 1 of Innegra in between the two layers of ply.
I’ve got to foil it and then put 2 layers of carbon over the tips.
There’s also the chance of combining the benefits of concave and convex tips by making a flat foil with a Y at either tip…
but I’ll get to that later after I work out the best angles and tip areas.
As I read your insights about foil angle (good points btw), I was thinking the same thing about Y tips, LOL. But Y tips begin to violoate the principle of design simplicity.
Another thing to consider when angling foils downward (angular or concave) is the reduced vertical lift as a function of the foil angle (cosine of the angle) while the board is in parallel-to-surface mode. This is the same effect experienced as the horizontal foil leans into the wave at an angle. However, centrifugal/centripetal forces also factor in. The foil lift vector is in the same direction as it was in its horizontal (parallel to water surface) position.
BTW This is the board I plan to offer up as a sacrifice on the altar of hydrofoil experimentation after I play around with a few foil designs:
I am still working my way through reading all 20 pages of this thread. It is so inspirational! All of the broken image links from photobucket are breaking my heart, though. What is causing this to happen?
I am all ready to start experimenting with hydrofoils now. The big design challenge that I will have is in creating a foil that will shed kelp so the rig won’t come to an instant stop when it runs through a patch. I imagine that you don’t have much kelp in the waters where you surf. It is pretty thick around here on the central coast of California.
Stoneburner, I will heed your scientific advice and for any new foils the front foil flat area will stay the same so the added angled tips will add area but minimal lift due to their angle. Good luck with the shortboard , looks like a perfect selection.
Swied, I keep all the pics on photobucket so if there’s any particular photos missing I can supply them.
That kelp is a real issue, we don’t get it here often at all, maybe once every 2 or 3 years for a week and only at certain beaches. That Alaia looks like a good candidate for conversion too, please post your progress so we can all learn from your work as well.