Julien who has been a kyte world champ asks me to design his SUP foil board, so I took my computer and done a Shape3D file which has been cut out and finally built.
Here, Its 3D viewer from Shape3D www.shape3d.com/Viewers/Viewer3D.aspx?Board=7843

And the video I've recorded during a session where I missed most of the waves he gets.

Below here some pictures of this successful process.

The file on which I took off of my hat some design tricks I know

The board is 5'7" 25" and 85 litres as JUlien is 73 kg .




Some pics from the blank 20 Kg/m3 back from CNC. As my drawings is rigorous the KKL operator cut it with high definition cutting and finally get out as a precision shape.








The building with bagging carbon lamination, nice coloured from the man of this art.

Nice board and design!

What are your thoughts on tail rocker for foil boards? I've shaped zero boards, but wouldn't it change the angle of the mast when it's attached?

db541 said..
Nice board and design!

What are your thoughts on tail rocker for foil boards? I've shaped zero boards, but wouldn't it change the angle of the mast when it's attached?

I would be basically on paper with overall flat rocker for reactivity and also stability in waiting periods as well as driving to take off. If I pull up curves on rocker i'm doing concaves in the same time...
so to answer you further about mast angle attached to the rocker curve I would say that it would be think from the entry rocker or from the overall of the front board but not from the tail rocker. While designing I'm following a virtual line between the overall curve of the board and the flying plan. So I can't do a tail lift without leaving my virtual straight line.
To have a flat plan shape and having a lifted tail in the same time, the solution is to make a 3 hulls concept board as The board of Julien is.
In the picture below, you can see in yellow colour the concave bevels at the tail curving the rocker tail while the flattest part is holding the mast straight.
In the same time note that the entry rocker is flattened by the concaves on both sides of the bow.


In another project I've designed, I though to give curves on the tail and still have something flat and straight to have the hull and the flying plan in the same line is to design aI bevels vee at tail. Like this one.
www.shape3d.com/Viewers/Viewer3D.aspx?Board=7701

Looking like below still the concave Vee bevels lifting the tail...

Always been a big fan of yours Kami you really do make some amazing stuff . Couple of questions. I'm really starting to reevaluate the value of a large cut away tail . Is the loss of litres & stability really worth the supposed release and the sunken deck in principal I like but it just doesn't drain when you are loaded on your front foot trying to launch and just adds weight to the board. The new Armstrong boards addressed this by putting a Handel right through the board to drain but this has it's misgivings as well shooting water up between your legs on touchdowns. Love your innovation , I could be right or wrong just some feed back on your latest design. Big fan mate love your work and sick tint job BTW.

warwickl said..

Piros said..
Always been a big fan of yours Kami you really do make some amazing stuff . Couple of questions. I'm really starting to reevaluate the value of a large cut away tail . Is the loss of litres & stability really worth the supposed release and the sunken deck in principal I like but it just doesn't drain when you are loaded on your front foot trying to launch and just adds weight to the board. The new Armstrong boards addressed this by putting a Handel right through the board to drain but this has it's misgivings as well shooting water up between your legs on touchdowns. Love your innovation , I could be right or wrong just some feed back on your latest design. Big fan mate love your work and sick tint job BTW.

Armstrong just need to redesign the fluid flow of the handle, its not a new design idea.
Kayak/skis already have had this design for many years ie suck out.
Just thinking further all handles in the bottom of boards need to be refined.

Yes I agree it's very old school and the complex drain design to make it work far out weighs the advantages of a sunken deck . OK on a prone but any Stand up board just becomes a bucket to hold water at launch. Re a sealed handle on the bottom really has little drag like a 5+ one set up on a short board when only using 3 fins are used. IMHO

Nice Kami but I'd pull the nose in a bit more . This is just how I like it because I've gone off the square boxy nose . Just grabs too much on touch downs and picks up the corners of the nose on an unbalanced reach trapping you on the rail . Again these are my preferences , maybe not for everyone.