Old meets new

.I want to try it too

Its OK Zoltan , we know each other .
The fuse or safety valve is only when you hit ground.
All the other forces , no matter how extreme or heavy you are should have no pressure on those bolts . None ! OK maybe a smidge in drag through water only. If used in a Tuttle box.
In a Tuttle fin to box connection the tight parallel sides take all the sideways pressure , not the bolts . In a fin or foil this is where the forces are.
The angle on the ends of the fin / box keep the fin / foil parallel to the board. So only a small amount of tension is needed on the bolts .
What your doing is relying on every force , sideways , back , twisting and imaginary , hanging on to two weeny 6mm threads .
So , I believe , if the foil is mounted in a Tuttle box there should be no problem with your weight or radicalness and the 6mm bolts will be fine.

Done some resurch. Surfsail Australia sell Tuttle boxes, $39.
They are 44mm wide . I would machine the sides down to fit snuggly in CB slot. Leaving a 5mm step on the bottom which will stop the box sliding up . If the slot is 30mm it would leave a step of 7mm each side . I would make an alloy plate that slides over the box and would work like a big flange. This would work if the slot is no smaller than 36mm ish.
You could then use your top clamp plate .
I would machine the box and make the plate as a love job, no biggie. And no responsibility
Would like to see how it works

PM you in 3,2,1

Hi Zoltan,

Great video 1 but 2 & 3 says content not found.
Obviously late night editing footage.
Keen to see the flight then touch down.
I agree with using the an actual deep tuttle box machined to fit the center board slot.
Many years ago I was a epoxy board builder, thinking with some plastic and mould release wax you could make custom flanges.
Cheers Greg

Sat 12.1.2019 New Videos: [UPDATED LINKS AT 11:00am Saturday]

1. Speed 250L Race Board + Foil - Passing yacht:

www.facebook.com/100004231339520/posts/1269479619869737/

2. Short flight & touchdown at high speed on race board with foil:

"The short low flight & touchdown are at 1:15 to 1:17 in video 2; it's the part where everything goes completely silent for a few seconds before the obvious touchdown on the long bonnet at 1:17. Very gentle & smooth :D"

Hi Zoltan,

Thanks for that, the silence!
As you said when your not foiling you are getting additional lift to plane faster than without the foil.

Cheers Greg

Hi Zoltan,

Just laugh back at the mockers of your setup with speed raceboard with modified deep Tuttle box within the centreboard slot.

Everyone needs to approach "time on water" value , Enjoy the great moments if life, cheers