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F16 and Curved Boards

Posted By: Mappy

F16 and Curved Boards - 05/17/11 01:15 PM

Taking a bit of interest in the F16 class with the struggles of getting good crew. I see the F16 class rules do not allow curved boards. With the lighter weight, shorter length of this class potentially the curved boards could improve the performance and handling of the F16. Is there any chance this rule could be changed in the future?
Posted By: Kris Hathaway

Re: F16 and Curved Boards - 05/17/11 01:59 PM

Yes. F16 is a semi-development class but not a strict box rule. Consequently, our rules are tighter to limit an arms race and the potential for immediate obsolescence of the existing fleet, similar to the principals behind the class that you currently sail in. The F16 class has a standing 5 year rules review schedule and the ability to amend outside of the cycle if certain conditions exist. Next scheduled review is 2012. There are two nice opportunities listed on CatSailor, Viper in MD and Falcon in FL. There is also a New England AHPC dealer that can help expedited the process and the Falcon dealer has an affordable service to run boats up the East Coast on a routine basis.

One of the distinguishing features about the F16 class is its flexibility relative to crew. Eric Witte (NE AHPC) is also working hard to expand the F16 presence in New England. If successful, I see a lot of competition shared between the Chesapeake Bay and NE fleets. BTW, the majority of the Chesapeake Bay boats race 1-up most of the time.


Good Luck!!
Posted By: Matt M

Re: F16 and Curved Boards - 05/17/11 02:10 PM

Originally Posted by Mappy
Taking a bit of interest in the F16 class with the struggles of getting good crew. I see the F16 class rules do not allow curved boards. With the lighter weight, shorter length of this class potentially the curved boards could improve the performance and handling of the F16. Is there any chance this rule could be changed in the future?


I suppose anything is possible, but it is not very likely, especially in the near future.

I see you have been reading the internet hype on curved foils. As a true performance enhancer there is still considerable debate. Even with the hard core believers the supposed advantages are heavily dependent on the conditions.

One thing for certain, curved foils require a higher level of sailing skill to make them work to any advantage as balance and hull trim are not just important but critical. When not run properly they are a definite disadvantage. The negative effects of not running them properly are magnified given shorter hull lengths.

Adding curved foils would add further separation between the skilled and the not skilled drivers and make the boat more difficult to run to its potential. Not something I feel is of any advantage to the boat or the class.
Posted By: Junior

Re: F16 and Curved Boards - 05/17/11 08:01 PM

I concur with Matt's comments. If you want the boat to lift given current rules, maximizing the 6 degree cant inboard will help...
V/r,
Posted By: PTP

Re: F16 and Curved Boards - 05/17/11 10:58 PM

I want curved foils and curved rudders with an adjustable t foil on all the foils. then I want a wing sail with a true kite (ala kite sailing). In addition, I want tubes in the bows that eject little nanobots that attack Interlux Perfection paint (inside joke). Maybe some stern tubes that send out carpet fibers to attach to the hulls of any boat that might be behind me.Then our class will be great
Posted By: Karl_Brogger

Re: F16 and Curved Boards - 05/18/11 01:21 AM

I like PTP's style.
Posted By: taipanfc

Re: F16 and Curved Boards - 05/18/11 06:05 AM

Buy a moth if you want to have your boat fly. The cost of doing these curved foils on a cat is expensive and requires a lot more tooling. Takes the class away from the home-builder aspect. Curved foils have to lift 110kg plus 140kg crew weight (just putting in a number for the sake of a number). That is a lot more load on a foil and moves the class from amateur to professional builders only. For example, a moth hull costs 5k but the foils cost 6k+ and it only has to lift 30kg plus 75kg.

Originally Posted by Mappy
Taking a bit of interest in the F16 class with the struggles of getting good crew. I see the F16 class rules do not allow curved boards. With the lighter weight, shorter length of this class potentially the curved boards could improve the performance and handling of the F16. Is there any chance this rule could be changed in the future?


Posted By: Stewart

Re: F16 and Curved Boards - 05/19/11 04:02 PM

agreed
Posted By: Wouter

Re: F16 and Curved Boards - 05/19/11 04:49 PM


indeed.
Posted By: scooby_simon

Re: F16 and Curved Boards - 05/24/11 11:35 PM

Curved fouls would need us to increase beam to keep similar righting moments.

I cannot see a vote going thru in 2012 for curved fouls....
Posted By: waynemarlow

Re: F16 and Curved Boards - 05/25/11 09:15 AM

Originally Posted by scooby_simon
Curved fouls would need us to increase beam to keep similar righting moments.

I cannot see a vote going thru in 2012 for curved fouls....


Scooby you are either being disingenuous or you are missing the whole point of curved boards, curved boards give a lifting vector which reduces water line length which in turn reduces " stiction " of the hulls which in turn means faster speeds which in turn means less righting moment needed, well that is the theory.

Downside is the boat needs much more tuning and understanding of what is going on by the skipper and much more careful positioning of the crew to get those faster speeds. In the right hands they are good, in us mere mortals as much as I would condone them, they are probably not as fast due to the complexity.

But to have a " sexy " image to the boat buyers and "tinkerers" amongst us, we are going to have to allow them if we want to purport to being a semi development class, they are here and here to stay I'm afraid.
Posted By: scooby_simon

Re: F16 and Curved Boards - 05/27/11 04:48 PM

Originally Posted by waynemarlow
Originally Posted by scooby_simon
Curved fouls would need us to increase beam to keep similar righting moments.

I cannot see a vote going thru in 2012 for curved fouls....


Scooby you are either being disingenuous or you are missing the whole point of curved boards, curved boards give a lifting vector which reduces water line length which in turn reduces " stiction " of the hulls which in turn means faster speeds which in turn means less righting moment needed, well that is the theory.

Downside is the boat needs much more tuning and understanding of what is going on by the skipper and much more careful positioning of the crew to get those faster speeds. In the right hands they are good, in us mere mortals as much as I would condone them, they are probably not as fast due to the complexity.

But to have a " sexy " image to the boat buyers and "tinkerers" amongst us, we are going to have to allow them if we want to purport to being a semi development class, they are here and here to stay I'm afraid.


Not being disingenuous at all;

With a plate that is vertical (in plane) of the hull; the leeward hull (roughly) pivots around a point at the bottom of the hull.

The boat will now be heeling / moving about a point down the plate (not at the leeward hull); as the hull is lifting; thus the pivot point moves inboard a foot or so (depending on the plate profile) and thus a wider boat is required for the same sail plan.

Spent a while discussing with Tornado_Alive as I was wondering why the F20 was so wide; it’s because the curved boards reduce the effective beam of the boat.
Posted By: ACE11

Re: F16 and Curved Boards - 05/28/11 09:23 AM

Originally Posted by scooby_simon
Originally Posted by waynemarlow
Originally Posted by scooby_simon
Curved fouls would need us to increase beam to keep similar righting moments.

I cannot see a vote going thru in 2012 for curved fouls....


Scooby you are either being disingenuous or you are missing the whole point of curved boards, curved boards give a lifting vector which reduces water line length which in turn reduces " stiction " of the hulls which in turn means faster speeds which in turn means less righting moment needed, well that is the theory.

Downside is the boat needs much more tuning and understanding of what is going on by the skipper and much more careful positioning of the crew to get those faster speeds. In the right hands they are good, in us mere mortals as much as I would condone them, they are probably not as fast due to the complexity.

But to have a " sexy " image to the boat buyers and "tinkerers" amongst us, we are going to have to allow them if we want to purport to being a semi development class, they are here and here to stay I'm afraid.


Not being disingenuous at all;

With a plate that is vertical (in plane) of the hull; the leeward hull (roughly) pivots around a point at the bottom of the hull.

The boat will now be heeling / moving about a point down the plate (not at the leeward hull); as the hull is lifting; thus the pivot point moves inboard a foot or so (depending on the plate profile) and thus a wider boat is required for the same sail plan.

Spent a while discussing with Tornado_Alive as I was wondering why the F20 was so wide; it’s because the curved boards reduce the effective beam of the boat.


The earlier heeling with a curved board is an advantage as the hull can be popped in lighter breeze and get going with one or two on the wire earlier. Lifting the cuved board abit as the breeze gets up then reverts the heeling moment to the standard straight board amount. Best of both worlds. That's what is happenning with the A's anyway.
Posted By: waynemarlow

Re: F16 and Curved Boards - 05/28/11 11:04 AM

Originally Posted by scooby_simon

With a plate that is vertical (in plane) of the hull; the leeward hull (roughly) pivots around a point at the bottom of the hull.

The boat will now be heeling / moving about a point down the plate (not at the leeward hull); as the hull is lifting; thus the pivot point moves inboard a foot or so (depending on the plate profile) and thus a wider boat is required for the same sail plan.

Spent a while discussing with Tornado_Alive as I was wondering why the F20 was so wide; it’s because the curved boards reduce the effective beam of the boat.


Totally agree with what you are saying about normal vertical boards but with curved boards its a lot more complex. As soon as the boat starts moving through the water, and thats what we try to do ( some more successfully than others ) all sorts of other " vectors " start happening.

Its very new technology with a long long way to go before we fully understand the benefits and repercussions of various assymetrical or symmetrical curved boards but we need to be thinking ahead a little perhaps and think along the lines of at least fitting the newer styles of adjustable daggerboard cases where we can fit curved or straight boards.

See you at the 3 Piers for a beer to discuss.
Posted By: Karl_Brogger

Re: F16 and Curved Boards - 05/28/11 03:58 PM

As scared as sailors are of new technology it blows me away we have spinnakers, and more so that we aren't launching them from a bag on the tramp.

I'm all for it. The earlier it is voted in the better. Nobody will build one for quite a while I'd bet anyway. AHPC won't be doing it anytime soon, Falcon Marine won't be doing it anytime soon, etc. Maybe NACRA?

3000 years of sailing and we're still pushing the ball forward, how cool is that?
Posted By: samc99us

Re: F16 and Curved Boards - 05/29/11 09:25 PM

I agree that they should be allowed, even if they are more difficult to extract performance from (aka, rewards those that spend the most time on the water). The cost of retrofitting them to existing boats is an issue but best I can tell curved foils only cost slightly more than the newest high aspect ratio boards in the F18 class. This makes sense since the proper tooling costs are very similar and the only change is in the amount of material needed in the curved foil (more) so the price reflects the material difference and possibly the slight increase in labor needed. I don't see why this would be any different in the F16 class. If there are concerns over performance, stick with trunks like those used on the Bimare V1R that can accept curved and straight boards.
Posted By: macca

Re: F16 and Curved Boards - 05/30/11 06:48 AM

tooling cost for curved boards are considerably higher than for straight ones.


And you can debate the pro's and Cons for ever, but the only ones I see arguing that the curved boards are not a definite performance gain are those that have not even sailed a relative boat with curved boards... I suggest you all go and try them before passing judgement on the performance gains and the ease of use.
Posted By: Hans_Ned_111

Re: F16 and Curved Boards - 05/30/11 07:30 AM

Originally Posted by macca
tooling cost for curved boards are considerably higher than for straight ones.


And you can debate the pro's and Cons for ever, but the only ones I see arguing that the curved boards are not a definite performance gain are those that have not even sailed a relative boat with curved boards... I suggest you all go and try them before passing judgement on the performance gains and the ease of use.


I did stop reading this forum for a long time but i was called to have a look at the curved board section so i did read it.I am not always agreeing with Andrew but he is right on this one. The curved boards are another dimension and very difficult to get the maximum out of them. Besides the costs of production , it is very difficult sailing them in a good way, it needs a lot of practice to get the benefit of it otherwise it is always loosing. I have found out already unfortantly.

Hans
Posted By: waynemarlow

Re: F16 and Curved Boards - 05/30/11 10:31 AM

Originally Posted by macca
tooling cost for curved boards are considerably higher than for straight ones.


And you can debate the pro's and Cons for ever, but the only ones I see arguing that the curved boards are not a definite performance gain are those that have not even sailed a relative boat with curved boards... I suggest you all go and try them before passing judgement on the performance gains and the ease of use.


Macca, Hans I think is agreeing that you think curved boards are more difficult to sail consistantly well and I'm not sure that is what you are intimating, would you like to clarify a little.

I would suspect also that you are more familiar with the heavier and wider format of the F20 which will be easier to get the best from than the lighter F16's would be. How much time have you spent on an A with curved boards, which would be the closest to our class ?

Honest world wide experiance question which you probably are far more able to answer here as I have yet to sail on a boat with curved boards ( mine are canted at the class 6 degrees ), would you vote to adopt curved boards for the F16 class and the reasons why please.

Tooling costs are almost irrelavent, spread over the lifetime of the moulds of say 300 boats, then it is a few dollars more per boat.
Posted By: scooby_simon

Re: F16 and Curved Boards - 05/30/11 12:17 PM

Originally Posted by macca
tooling cost for curved boards are considerably higher than for straight ones.


And you can debate the pro's and Cons for ever, but the only ones I see arguing that the curved boards are not a definite performance gain are those that have not even sailed a relative boat with curved boards... I suggest you all go and try them before passing judgement on the performance gains and the ease of use.


I'm with you on both points; I see them as an advantage.
Posted By: macca

Re: F16 and Curved Boards - 05/30/11 03:18 PM

Ahh, Hans thinks he is agreeing with me but infact...

I believe that the curved boards will be easy to get an increase in performance with for even your average sailor.

On the a class you are constantly trying to reduce drag, downwind you dont have the option of doubling your sail area and as such you need to sail the boat very differently.

The F16 will be markedly quicker and easier to sail downwind with curved boards, dont gat caught up with all the discussion on shorter WL making it harder to sail with, the curved boards are never at an AOA that is having a negative effect of performance, unless you really screw up, but even then they are helping with your recovery from a nosedive etc.

The downsides are this:-

Added tooling costs
added production costs
you have to raise the windward board each tack/gybe to get best performance
there is a slight loss of righting moment, but the reduction in drag is compensation for this in the overall picture.

As to wayne's comment that the tooling cost is irrelevant... depends on the barrier to entry point, if the tooling is going to cost 15k (more than the hull tools) then its a big issue to factor in to the build costs. and I dont see anyone with F16 numbers in the 300's Hell even the Viper numbers are inflated and they are claiming 160 after 4 years production... makes the ROI seem pretty bad for a board tool. every now and then someone claims that their sisters uncle's neighbour can make a curved board tool for 20 bucks... but in reality its just an expensive thing to make a production quality tool for these things,

Posted By: Seeker

Re: F16 and Curved Boards - 05/30/11 03:52 PM

With all the variations of A cat curved boards being experimented with are there any "existing" A cat curved boards that could be fitted for use in an F16 effectively? $20 for tooling?...no but the $15,000.00 estimate is just as absurd on the other end of the scale. A CNC machine doen't care if its a curved board or a straight one.

Things get so ridiculously overstated on these forums...speeds, weights, costs...very rarely are things kept in the world of reality...and they think fishermen overestimate...obviously they never met a cat sailor.
Posted By: Stewart

Re: F16 and Curved Boards - 05/30/11 03:52 PM

If you allow curved planks why not allow foils?

Still think this is all moot...

Posted By: macca

Re: F16 and Curved Boards - 05/30/11 04:14 PM

Originally Posted by Seeker
With all the variations of A cat curved boards being experimented with are there any "existing" A cat curved boards that could be fitted for use in an F16 effectively? $20 for tooling?...no but the $15,000.00 estimate is just as absurd on the other end of the scale. A CNC machine doen't care if its a curved board or a straight one.

Things get so ridiculously overstated on these forums...speeds, weights, costs...very rarely are things kept in the world of reality...and they think fishermen overestimate...obviously they never met a cat sailor.


Try actually building the tools for a production run of curved foils, then after you have successfully built foils that are of the correct shape, twist and bend all the while not breaking in the kind of use that they need to withstand and then you can tell us all how much it really costs.

I bet you end up a lot closer to my estimate that you thought...
Posted By: pgp

Re: F16 and Curved Boards - 05/30/11 04:41 PM

Sounds like a very nice cottage industry for a skilled craftsman.
Posted By: samc99us

Re: F16 and Curved Boards - 05/30/11 05:01 PM

Clearly Macca is including R&D costs in his $15,000 budget, which I can see as being reasonable.

However, my estimate puts mold costs at <$5000, and it doesn't matter really if its curved or straight, twisted etc., just means you need to find a 5 axis CNC vs. a 3 axis CNC. How many out there have designed something and then built it? Namely how many have designed and built molds? I have and its not a trivial process. You need an aero engineer that knows what he is doing for the foil design, you need a solidworks or other CAD package guru to model the foil properly, and you need a mold guru to aide the CAD guy in tooling design. Then you need a structures expert to design a layup schedule that won't explode under sailing loads, which are hard to predict making his job difficult. Where you spend the money is important, you can reduce the production costs with good design work but often it is easier and safer with composites to build the piece, load test it and make changes to the layup from there. Of course this all has to be repeated to some extent if the foils are asymmetrical.

Posted By: waynemarlow

Re: F16 and Curved Boards - 05/30/11 06:41 PM

Originally Posted by samc99us
Clearly Macca is including R&D costs in his $15,000 budget, which I can see as being reasonable.


So take the real world example of the Viper, $ 15000 / 160 boats = 94 bucks a boat for development and moulds to have the latest all singing and dancing board design intergrated into the latest design and to be one step ahead of your competitiors, seems a no brainer to me.

Nacra with their design knowledge should be first out of the start blocks. Bimare are already in a position to give an option with their design of case, DNA with their skills and design should be looking to expand their production in a Uni only boat, it is going to happen guys and sooner than what we think.
Posted By: Karl_Brogger

Re: F16 and Curved Boards - 05/30/11 09:17 PM

People who are worried about their boats being suddenly obsolete, it will be eventually anyway. Curved boards or not.
Posted By: taipanfc

Re: F16 and Curved Boards - 05/31/11 01:23 AM

Firstly the curved board takes a lot more load. Due to its shape it is trying to pick the boat and its passengers up out of the water. The only production boats successfully picking a boat out of the water and keeping it above are the moths. McConaghy's in China can build the hulls very quickly, but lead times in delivery are delayed due to the time and engineering to make the foils. To get the required strength they put 500kg of weight on the foil when curing to help increase density and strength in the carbon. The finished foils are relatively light and you can put the ends between 2 benches and jump in the middle with minimal deflection. This is the level of tooling and manufacturing required to make curved boards work. The early foilers like Bladeriders would have the foils flex under the loads and this is effectively like having your leech flap upwind so would lose speed and power. The Mach2 under the method described just power forward in the gusts and reach incredible speeds. (33.8 knots peak is the latest top speed for a Mach2) Hence my comment in that it moves the class out of the homebuilder. Would certainly be a performance boost however to the boat.
Posted By: samc99us

Re: F16 and Curved Boards - 05/31/11 01:36 AM

I don't think this moves the boat out of reach for the homebuilder. Here's my reasoning:

1) I'm an engineer and can design a working curved foil solution if I feel like dropping the money to make it happen. I'd likely blow up a lot of boards and the performance may be sub par but it can be done.
2) I can just as easily buy a set of curved foils from a major manufacturer and fit them to my boat. Once again this may be sub par as board location and trim are critical. Granted several people in the A-Cat's are doing this with success.

As far as manufacturer support, I think it will happen. Enough big players have experience with the technology that the costs should remain reasonable and even if R&D is pegged at $30K and production of the boat is say 100, $300 per boat is still pretty reasonable for the chance to literally fly around the course.
Posted By: Seeker

Re: F16 and Curved Boards - 05/31/11 02:54 PM

People change boat designs and models in this class at an expense of a lot more than $300.00...one thing you can always count on is that things are constantly changing...every boat starts becoming obsolete the minute the design is finalized...

Things keep moving forward....doesn't matter how much you drag your feet....go with the flow or get left behind....affectionately called the "dead boat society" in the catamaran world. Look back and see just about everything we enjoy in the way of high performance sailing was attacked when it came on the scene. Wood hated fiberglass> Single skin construction hated Core construction> Cored Fiberglass construction hated Kevlar & Carbon > and the folly goes on….and on…and on…and on
Posted By: sail7seas

Re: F16 and Curved Boards - 07/20/11 03:57 PM

Quote from SA: http://forums.sailinganarchy.com/index.php?showtopic=105814&st=50

>Then we set the kite and left the boards fully down and Adam jumped on the wire, you feel instantly that the boat is lifting on the foils. Its very easy to get the whole boat out! We did this a few times and couldn't stop laughing! It's seriously the most fun you will ever have on a beach cat. For sure the full boards down option is not the fastest in the conditions we had (25kts by this stage) but it's a crazy amount of fun and very addictive..
Anyhow, sanity prevailed and we lifted the boards 30cm and tried again: This is the quickest I have ever been on a beach cat downwind. Pete was only just keeping up in the coach boat at full throttle. The slightly higher board setting still gives lift and the boat is semi foiling the whole time. You can feel that the steering becomes super sensitive and your speed increases as you keep the boat in the groove. It was around this time that I said to
Adam: "this is the future of catsailing" It's a whole new dimension to the sport, The added speed and feeling the boat gives you is something I want to do again and again. I would have stayed out all day if it was possible!<
Posted By: FRENZIED

Re: F16 and Curved Boards - 07/30/11 05:20 PM

I want straight boards. Don't wanna mess with hydrofoiling curved boards. Don't want to pay for the extra hoo-hah either. Simpler is better, IMHO.
Posted By: Karl_Brogger

Re: F16 and Curved Boards - 07/31/11 02:44 AM

Who is frenzied? Is this Select Sail?
Posted By: FRENZIED

Re: F16 and Curved Boards - 07/31/11 03:01 PM

Originally Posted by Karl_Brogger
Who is frenzied?
Just some random human who likes to sail cats, and is recovering from college debt, and has no boat.

"FRENZIED" is in reference to the web-comic @ FRENZIEDminds.com
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