Why don't they just put a flange on the foil so it doesn't bottom out in the box but rather spreads the load over a greater surface.

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DarrylG said..
The phantom should fit just fine in a starboard board.
The standard that cobra / starboard are trying to introduce with the flat top Tuttle box and foil head is a better design. Better load support and easier trimming. the flat top boxes will also fit sloping top foil heads. Ideally the front edge still bottoms out in the box to take the load. And if you have a sloping top box and new starboard foil then you will have to trim to the line marked on the head.

Yep. You can actually see from the photo that the phantom foil will fit, given what you've said about the starboard.


I actually like starboards idea of a sawable deep tuttle head. It fits thd box that a lot of manufacturers seem to be going for. But they have presented a solution If you want to fit it to a deep tuttle box that matches a deep tuttle angled head profile. So you know theyre good to go either way.

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cammd said..
Why don't they just put a flange on the foil so it doesn't bottom out in the box but rather spreads the load over a greater surface.

Flanges work ok, but have issues as well. 1/ they will dent the board when people lever the foil getting it in and out.
2/ they don't fit flat if board has any vee, or you have trimmed the rake of the mast
3/ unnecessary if foil correctly fits box

I have foils with both systems, neither one is a perfect solution. ( both still better than track system , flame suit on :)))))

Alex Udin of Phantom said that Patrik D. requested they not use a flange for the same reasons as DarrylG mentioned

www.windsurfing33.com/forum/viewtopic.php?f=42&t=120891&p=863756&hilit=Patrik#p863756

I use both flanged and non-flanged foils in deep tuttle boxes.

Yes, the big "beak" flanges that Moses provided on their 101 and 111 masts were famous for denting the board when users rocked them to remove. Moses has ceased making those masts. They now make flange-less masts. My Race 105 is flange-less.

I also use the small flanges found on LP and Slingshot foils. I have not found them to be any problem with denting the board. I like how they set the mast to board angle with no variation. Even a board with some centerline V will show an infinitesimally small gap along the side of the small flange. No biggie.

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I pasted below something I found on the IWA website. I wonder if that will be driving prices down. I also wonder when (if ever) Starboard and new IQFoil manufacturers will start pushing this product to the general public; after all, they are promoting it as one board, one sail, one foil (with two fuselages) solution for 6-30 knots.

From the IWA website ( www.internationalwindsurfing.com/windsurfing_competion_0001v01news1932.htm ):

Starboard invites new industry partners to participate in the "iQFOiL White Board" Programme.
By applying the "white board" concept, the iQFOiL class, IWA and Starboard have fast tracked the opportunity for industry partners to apply for iQFOiL hulls to be branded in their own unique way, allowing the industry as a whole to be part of Olympic windsurfing - the first time since the sport was introduced as an Olympic discipline in Los Angeles in 1984.

This programme will run in addition to the Class implementation of the World Sailing Olympic Equipment Policy which will allow other manufacturers to produce certain iQFOiL components - more information on that soon to be released.

Interested parties can contact whiteboard@iq-foil.com for more details on how to apply to participate in the White Board Programme and its eligibility requirements.

Svein Rasmussen
Starboard Windsurfing

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WillyWind said..

I pasted below something I found on the IWA website. I wonder if that will be driving prices down. I also wonder when (if ever) Starboard and new IQFoil manufacturers will start pushing this product to the general public; after all, they are promoting it as one board, one sail, one foil (with two fuselages) solution for 6-30 knots.

From the IWA website ( www.internationalwindsurfing.com/windsurfing_competion_0001v01news1932.htm ):

Starboard invites new industry partners to participate in the "iQFOiL White Board" Programme.
By applying the "white board" concept, the iQFOiL class, IWA and Starboard have fast tracked the opportunity for industry partners to apply for iQFOiL hulls to be branded in their own unique way, allowing the industry as a whole to be part of Olympic windsurfing - the first time since the sport was introduced as an Olympic discipline in Los Angeles in 1984.

This programme will run in addition to the Class implementation of the World Sailing Olympic Equipment Policy which will allow other manufacturers to produce certain iQFOiL components - more information on that soon to be released.

Interested parties can contact whiteboard@iq-foil.com for more details on how to apply to participate in the White Board Programme and its eligibility requirements.

Svein Rasmussen
Starboard Windsurfing

I am not sure why my post above looks like that. It should be one post, not quotes over quotes...

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snides8 said..

RichardG said..
How competitive is a JP 150 PWA foil board v a JP 190 or JP 175 ? Assuming everything else is equal (same foil) is a 95 kg sailor using such a 150 litre board in a club race or similar outclassed on such a board vis a viz a lighter say 80kg sailor on the latest bigger volume foil boards. I notice, excitingly the volume is now increasing in the arms race, for example, Exocet have a 220 litre and JP a 230 litre hydrofoil board for course racing.

Richard
I used to have the 150 and traded to the 190.
It's funny but upwind I felt the 150 held the groove better than my current 190 perhaps because it didn't get blown around as much as the 190,
but all in all they where similar IMO.
Off the wind however I found the wider 190 had more control And as such slightly faster as it meant the straps where further outboard.

Thanks Snides.

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cammd said..
Why don't they just put a flange on the foil so it doesn't bottom out in the box but rather spreads the load over a greater surface.

I'm not sure people understand how a fin box actually works.
The tapers are what should hold the fin/foil & theoretically should not bottom out but if it does it should be when the tapers are fully engaged.
I have seen a lot of people butcher fin heads to make them fit without knowing what they should be trying to achieve.
There was some talk about shimming under the head of the foil to adjust the mast angle, this is a bad idea as the tapers then will not engage.
With fins it's probably not as important but with the long foil masts the leverage is huge & loads up the box.
If the tapers are not doing their part then you are solely relying on the bolts & the top of the box to take the full load.
Maybe the reason the Super Cruiser bends bolts.
A flange may just load up the bottom of the board without engaging the tapers or top of the box which would really load up the area around the head of the bolts.

That's my view & totally from an engineering POV, I personally use the track system, although not by choice but better than a standard Power Box.
My PB is now much stronger now so I could use it if required.

From the Phantom foil manual.

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AUS 808 said..

cammd said..
Why don't they just put a flange on the foil so it doesn't bottom out in the box but rather spreads the load over a greater surface.

I'm not sure people understand how a fin box actually works.
The tapers are what should hold the fin/foil & theoretically should not bottom out but if it does it should be when the tapers are fully engaged.
I have seen a lot of people butcher fin heads to make them fit without knowing what they should be trying to achieve.
There was some talk about shimming under the head of the foil to adjust the mast angle, this is a bad idea as the tapers then will not engage.
With fins it's probably not as important but with the long foil masts the leverage is huge & loads up the box.
If the tapers are not doing their part then you are solely relying on the bolts & the top of the box to take the full load.
Maybe the reason the Super Cruiser bends bolts.
A flange may just load up the bottom of the board without engaging the tapers or top of the box which would really load up the area around the head of the bolts.

That's my view & totally from an engineering POV, I personally use the track system, although not by choice but better than a standard Power Box.
My PB is now much stronger now so I could use it if required.

There's a video of Tiesda You (Starboard lead design) talking about this, however, he says that due to the angles used in deeptuttle boxes the forces get amplified. Tapered walls ensure snug fit with normal fins, but with foils the walls alone cant take the force.

Nothing really works well, even the reinforced "foilboxes" everyone at cobra puts in their boards break under the loads of really good sailors racing (I know some PWA guys had their board or box replaced 3 times during last season), I hope the IQ boards are even stronger than regular ones.

I use a lp windfoil in an old starboard 161. So far so good the fin box is hanging in there. After seeing the Starboard race foils chew out fin boxes I figured a flange was a must if I want to use a older formula board as a stepping stone into foiling.

I agree with WOH
the tapers work for normal fins, not for foils. The loads need to taken on top of box

No, I disagree with DarrylG. Since foil forces are ALL fore and aft and not much side to side like a fin, those tapers are CRITICAL since they carry ALL the fore and aft loads along their entire curved surfaces. When Tuttle designed the box, he intended for full and intimate contact to the tapers, both ends. And he did this long before anybody even thought about foils.

Tuttle never intended to have any contact inside the top of the box. This is why you see deep tuttle tops with varying heights. Recall all those formula fins. It's all taper.

Custom foilboard builders use deep tuttle boxes that are taller on the inside than any expected foil deep tuttle top, intending to ensure a gap between the top of the foil and the inside top of the box. They intend for all the fit to be to the tapers. That's how Tuttle designed it and how formula boards for the last 20 years have implemented it.

Flanges are nice, but it's the for and aft tapers that matter.

When I first purchased my no-flange AFS-2 foil from Sailworks three years ago, Bruce Peterson was adamant about not changing or sanding the deep tuttle top. Fit it in there. Use McLube if necessary and rock that puppy into place. After tightening the screws, keep rocking and tightening until it does not move anymore.

If you shim the inside to change the mast angle, you defeat the purpose of the tapers. That will destroy a finbox because shimming introduces point loads inside.

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segler said..
No, I disagree with DarrylG. Since foil forces are ALL fore and aft and not much side to side like a fin, those tapers are CRITICAL since they carry ALL the fore and aft loads along their entire curved surfaces. When Tuttle designed the box, he intended for full and intimate contact to the tapers, both ends. And he did this long before anybody even thought about foils.

Tuttle never intended to have any contact inside the top of the box. This is why you see deep tuttle tops with varying heights. Recall all those formula fins. It's all taper.

Custom foilboard builders use deep tuttle boxes that are taller on the inside than any expected foil deep tuttle top, intending to ensure a gap between the top of the foil and the inside top of the box. They intend for all the fit to be to the tapers. That's how Tuttle designed it and how formula boards for the last 20 years have implemented it.

Flanges are nice, but it's the for and aft tapers that matter.

When I first purchased my no-flange AFS-2 foil from Sailworks three years ago, Bruce Peterson was adamant about not changing or sanding the deep tuttle top. Fit it in there. Use McLube if necessary and rock that puppy into place. After tightening the screws, keep rocking and tightening until it does not move anymore.

If you shim the inside to change the mast angle, you defeat the purpose of the tapers. That will destroy a finbox because shimming introduces point loads inside.

I agree about point loading the top, And the foil does need to maintain intimate contact with the box all over. But the game really has changed with foiling. If you rely only on the tapers fore and aft, the box can crack/bolts can (and do) snap with the sudden pitch loading the Foil puts on the box. I'm sure thats well outside what Tuttle would have imagined one of his boxes would have to cope with.

there's also a heap of side force put on the sides of the box (its why foil boxes are re-enforced wider than a normal deep tuttle) when the rider manipulates the board leeward/windward.

this is all putting aside the fact that board manufacturers and foil makers seem to still be struggling to make a tuttle head and a foil box fit together snugly. All the boxes seem to be standard, but foil manufacturers seem to have their own ideas about shapes and sizes a foil head should be, including the shape of the tapers. Some are a match for a tuttle box, and seat snug and solid, just the way they should. Some are too big and absolutely require sanding as they don't even come close to fitting.

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segler said..
No, I disagree with DarrylG. Since foil forces are ALL fore and aft and not much side to side like a fin, those tapers are CRITICAL since they carry ALL the fore and aft loads along their entire curved surfaces. When Tuttle designed the box, he intended for full and intimate contact to the tapers, both ends. And he did this long before anybody even thought about foils.

Tuttle never intended to have any contact inside the top of the box. This is why you see deep tuttle tops with varying heights. Recall all those formula fins. It's all taper.

Custom foilboard builders use deep tuttle boxes that are taller on the inside than any expected foil deep tuttle top, intending to ensure a gap between the top of the foil and the inside top of the box. They intend for all the fit to be to the tapers. That's how Tuttle designed it and how formula boards for the last 20 years have implemented it.

Flanges are nice, but it's the for and aft tapers that matter.

When I first purchased my no-flange AFS-2 foil from Sailworks three years ago, Bruce Peterson was adamant about not changing or sanding the deep tuttle top. Fit it in there. Use McLube if necessary and rock that puppy into place. After tightening the screws, keep rocking and tightening until it does not move anymore.

If you shim the inside to change the mast angle, you defeat the purpose of the tapers. That will destroy a finbox because shimming introduces point loads inside.

Exactly, the best fit would be that the tapers are in full contact, contact at the top of the box is not really required. The addition of a flange could be beneficial at the front of the box but elsewhere is pointless, the sides are parallel so should not move & all forces are for the mast to go forward.
It may be that the Deep Tuttle is just not up to the job at all as Starboard are reporting, poor fitting foils & shimming would not be helping.
Shimming as per Nico's advise above just makes things worse, it may work as a quick fix but goes against the principal of the tapered box.

Tiesda You's theory about the angles in the box has nothing to do with the breakages, it's simply the leverage from the length of the mast & the force of the foil being applied to a box designed for a fin, even a Formula fin reacts differently to a foil.
Maybe there needs to be something designed specifically for the forces of the foil which are totally different to a fin, after all a fin with simple side loading was the original design brief for the Tuttle Box
This is where real engineering needs to be applied like in F1 racing, board manufacturers are simply out of their depth & rely on R&D, trial & error alone.
There is one foil brand with a flange and gusset at the front to counteract the force, not sure if this is enough though.
If the flange came forward the same distance as the length of the box then theoretically the forces would be halved.
Alternatively the box needs to be much longer to reduce the leverage affect and then properly connected to the bottom & deck of the board.
Then you will have foil only boards, good for the board companies probably bad for the sport.

Someone will come up with the answer & all will fall in line, in the mean time the best you can do is ensure a good fit & hope for the best

I've done hundreds of hours of foiling with flanged foils in unmodified boxes. Even shallow Tuttle using a DIY load spreader.
At the very least I'd like to see a small front plate like Horue and others use but ideally a plate which contacts the sides as well.

Personally I think that recreational foils will all be using a plate mount within a year or two. If the need to run a fin wasn't there I don't see why race foils wouldn't do it as well.
So much easier to tune the equipment to the sailor and conditions.

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Subsonic said..
Some are a match for a tuttle box, and seat snug and solid, just the way they should. Some are too big and absolutely require sanding as they don't even come close to fitting.

I had to take sandpaper to a friend's brand new carbon mast. Using digital calipers, it was easy to see why the foil head didn't fit into his brand new board. Scary taking a $900 mast that's still in the plastic and hitting it with the 100 grit. Yeah, it was far enough off to require that. He had more trust in me than anyone should have.

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Grantmac said..
... Personally I think that recreational foils will all be using a plate mount within a year or two. If the need to run a fin wasn't there I don't see why race foils wouldn't do it as well.
So much easier to tune the equipment to the sailor and conditions.

Track mounts aren't without their problems

www.seatexboards.com/future-track-mount-tips-and-consequences/

Of course they need to be tied to the top laminate just like any other foil attachment system.
Much like how foil boards really need some sort of stringer from the foil mount forward to the mast base. We've all seen pictures of formula boards break in half right between the front and back straps because of the forces put into them from foiling.

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Paducah said..

Subsonic said..
Some are a match for a tuttle box, and seat snug and solid, just the way they should. Some are too big and absolutely require sanding as they don't even come close to fitting.

I had to take sandpaper to a friend's brand carbon mast. Using digital calipers, it was easy to see why the foil head didn't fit into his brand new board. Scary taking a $900 mast that's still in the plastic and hitting it with the 100 grit. Yeah, it was far enough off to require that. He had more trust in me than anyone should have.

Yeah, i've had to do the same. It wasnt anywhere near the same shape as the box.

It's just not something you want to have to do.

Reading all the the above about foil to board connection issues you can't help but wonder what will happen when the Olympic guys and girls really start to train on this gear hard, its a different level to weekend warriors, I think its a different level to PWA. Perhaps these things should have been solved before windfoiling became Olympic.

I don't image too many issues.
it will be starboard foil to starboard board. Most issues are with old style boxes
it's not really that complicated.
below is some info supplied with starboard foils. As it states, flat bottom for best support

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DarrylG said..
I don't image too many issues.
it will be starboard foil to starboard board. Most issues are with old style boxes
it's not really that complicated.
below is some info supplied with starboard foils. As it states, flat bottom for best support

From the above I would assume that Starboard have simply beefed up the bottom of their boxes to take the load through the bolts in the worst case.
Not ideal but they are obviously confident with that solution.

Best case would be the tapers plus the top of the mast are in full contact with the box which takes the load off of the bolts & distributes it evenly through the box.

It's really only the weekend hacks mixing & mismatching gear and using boards with older FIN boxes that creates issues.
Hopefully brands that state "Foil Ready" actually are and not just using a standard FIN box.

There are two or three sources of deep tuttle boxes with greatly thicker sides and ends. I would presume the thicker ends would stand up to the concentrated stresses placed onto the tapers by the fore-and-aft rocking forces from foils. I bought the bullet and purchased a custom foil board from a long-time board builder in Hood River. They use a thicker-walled deep tuttle box AND add 16" long stringers forward to beef up the strength of the box to carry cantilevering forces from foils.

I believe that side to side forces on foil boxes are miniscule compared to the days of formula 70 cm fins. To go upwind and downwind on foils, you just tip the whole thing to windward or leeward and let the wing do all the work. When tipped the wing exerts a side lift as the sine of the tip angle. Yaw forces exerted by foil masts are, I believe, quite small.

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segler said..
There are two or three sources of deep tuttle boxes with greatly thicker sides and ends. I would presume the thicker ends would stand up to the concentrated stresses placed onto the tapers by the fore-and-aft rocking forces from foils. I bought the bullet and purchased a custom foil board from a long-time board builder in Hood River. They use a thicker-walled deep tuttle box AND add 16" long stringers forward to beef up the strength of the box to carry cantilevering forces from foils.

I believe that side to side forces on foil boxes are miniscule compared to the days of formula 70 cm fins. To go upwind and downwind on foils, you just tip the whole thing to windward or leeward and let the wing do all the work. When tipped the wing exerts a side lift as the sine of the tip angle. Yaw forces exerted by foil masts are, I believe, quite small.

Why then are course racing boards built wide if not to provide leverage over the foil

Why was there issues with aluminium mast's bending in the early days if no side load exists

and why are high modulus carbon masts better than aluminium if not for stiffness

It doesnt make sense to do all that if side loading is minuscule

You can flex a formula fin by hand but not a foil mast. Yet looking at video you can see foil masts bending along their length.

So I'd say the side loads are far higher on the foil.

I think I've bent aluminum masts in ways I couldnt even with a car. Sideways loads are phenomenal.

Remember the hysterics about numbers in the foil race classes?

www.facebook.com/mmenagen/videos/10158154533233604/

The loads of the fin box and foils are much larger that we have previously had to worry about.
Old FW boards fin boxes can manage the loads, but only if the head fits perfectly, which unfortunately is a bit random.
If there is any play at all, the fin box will collapse within hour of using a 95+ cm Vertical.

That said, we have used old FW boards for years with zero issues...

From what I can tell, all the dedicated Foil boards fin boxes are working perfectly...

Hi Everyone and hope you are all coping with the virus situation...

The foil boxes are a huge challenge partly because the design and construction of the cobra built boards use a box that isn't strong enough to support the load on the leading edge of the box. We have broken every box from several brands because the boxes are potted with a brittle resin that breaks out and then the foil point loads the very front and breaks the box. It goes against the Tuttle design and counter intuitive form an engineering perspective to support the foil at the top instead of the front face. This is also a challenge since there is seemingly no way to make this perfect with contact and mechanical support on two surfaces. However, once we started putting in 3d printed shims at the top of the base all the issues went away and the foils are much more locked in the board. This also gives the ability to change the rake bit which is super great. If anyone wants the 3d model for the shims let me know and I make them available via a printing service.
--cr