It seems that most production foils have a flat plate with screw holes for attaching to the board, though some are now mounting with Tuttle boxes. In my mind, the plate style is easier to build strong, and can be attached to a variety of boards. The Tuttle system is simpler, less draggy, but demands higher strength components.
Can anyone verify my assumptions, or further explain the the pros and cons of each approach?
Two very experienced board builders that I have talked to recommend and prefer the deep Tuttle construction from their point of view.
But the flat plate is perhaps simpler for homemade designs. Certainly the flat plate is heavier and requires more mounting screws and larger reinforced area in the board.
My guess is that a Tuttle type mount will become standard in the future and the flat plate will be looked back on as rather crude.
tuttle is way easier to make then a flat plate if you have molds.
A flat plate has good surface area if the core can handle the load. It has to have a solid core not eps to make it work well.
a tuttle has to have a solid core as well to make it work well. if it doesn't have that it will blow out around the box with your weight hanging on the side of the board.
If you are going to use a tuttle you have to make sure there is at least 1/2" of carbon around the box plus you better make sure the is a good corecell frame around that just to make sure it stays.
Example is all these sectors with boxes that have cracks around them... 5 at my local beach alone. big fins a lot of force on the side boxes start to twist and then a crack shows up.
A little extra in the beginning will save the board in the end..
I have a normal (not deep) Tuttle box on my Spotz foil. It's great to install and for the simplicity of transport.
I think that the sideways pressure on a kiteboard or windsurf fin is much higher than on a foil mast. On the foil you do not push, you stay in equlibrium.
The only advantage that I see for plates is that it's maybe easier to adapt to an existing board.
norcom wrote:I'd love to get a tuttle one so I could use it on a windsurfer or a kiteboard.
The forces are probably a bit different on a windsurfer. You can see that the board is kept level and the mast vertical, so it looks to me like there will be more sideways force when windsurfing.
I think there will be a future for a mast with a plate top. Probably a rectangular plate with rounded corners and a 30 degree chamfer around the perimeter, recessed into the board.
Tuttle is better for dismantling and travelling with.
Thanks guys, sounds like a box is the way to go!
I am inexperienced with board building, but have a lot of composite design time. Any idea which box is typically used in the current boards (or windsurfers)? Online, I'm finding a $60 composite Waterat, or a $10 plastic Chinook option. Either way I'll embed it in an HD foam and c plate sandwich.
lezo wrote:I have a normal (not deep) Tuttle box on my Spotz foil.
My Spotz foil certainly uses a deep Tuttle. For reference here are pictures comparing the standard Tuttle and deep Tuttle. Obviously the deep one is much stronger and is always used with bigger fins or hydrofoils.
[Edit: There are actually even deeper 'deep Tuttle' fins also. The ones shown below and the Spotz are more a medium deep Tuttle]
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Last edited by cglazier on Mon Apr 21, 2014 12:20 am, edited 1 time in total.
the only thing I don't like about a deep tuttle is you have to build a race board for it to fit in. You need a 2 1/2" thick board . But I guess for the race boys and girls they want that for the downwind leg of a race.
After I make my first foil with a plate, I will make one with a deep tuttle as well and see which I like better.
You are correct that a board has to be about 2 1/2 inches thick in the middle to accomodate a deep Tuttle box. But most common kite surf boards are over 2 inches thick anyway.
Ease of transportation is a big factor. I can lay my Spotz foil mast flat on my board in my board bag and it adds very little volume. A plate mast is bulky and harder to pack.
I would not make a purchasing decision solely on this issue, I am just predicting that a Tuttle type box will eventually become the norm. It is lighter, smaller, easier to manufacture, and easier for kiters to use.