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new stuff in the a-class

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#1 Lars Schrøder D13

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Posted 06 January 2013 - 09:29 PM

interesting stuff out of the Netherlands - http://www.dnacat.bl...3-update_5.html - less curve than the mayfly, so that might solve the problems of the mayfly going sideways. How does the sailor control the height of the boat? Hopefully they can do some boards that works straight out of the box, so they don’t repeat the problems with their first generation boards and rudders..

And perhaps we should change the rules within the class, so a 20-25 m2 gennaker is allowed - it would give more power downwind so flying is easier + it could make the design of a rigid wing more simple because its only need to do the job upwind?

all the best

Lars

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#2 juniordave nz

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Posted 06 January 2013 - 11:31 PM

How do they get that little tip on the foil in from above? In the article they talk about the need to be able to do this, but it looks very tight. Be interesting to see it fly.
If you want gennakers, go sail f18's or the like.

I do wonder whether the rule should open up the 750mm measurement though. Maybe make it 500. Still restrictive, but would allow a lot more variation.

#3 AClass USA 230

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Posted 07 January 2013 - 01:27 AM

Wow, can't wait to see more.

#4 AClass USA 230

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Posted 07 January 2013 - 01:34 AM

Do the "tiplets" act like end plates at the end of the foil and reduce induced drag? This would be similar to the "winglets" you see on airplanes and I believe the practical result is that it makes the water "think" the span of the foil is longer. I also cannot figure out how you get the board up and down the trunk with that tip. Cool stuff.

#5 MR.CLEAN

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Posted 07 January 2013 - 01:36 AM

designer? can't seem to find it on the DNA site.

#6 Doug Lord

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Posted 07 January 2013 - 02:27 AM

interesting stuff out of the Netherlands - http://www.dnacat.bl...3-update_5.html - less curve than the mayfly, so that might solve the problems of the mayfly going sideways. How does the sailor control the height of the boat? Hopefully they can do some boards that works straight out of the box, so they don’t repeat the problems with their first generation boards and rudders..

And perhaps we should change the rules within the class, so a 20-25 m2 gennaker is allowed - it would give more power downwind so flying is easier + it could make the design of a rigid wing more simple because its only need to do the job upwind?

all the best

Lars

=======================
Thanks for the info! Are they using rudder T-foils like Landy or rudder "J" foils like the Mayfly?
UPDATE-answered my own question:
"Winglets are available for sale now and can be retrofitted to the old rudders. Winglets are identical to ones Mischa used at The Worlds, which are almost identical to Landy's."

Landy pix:

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#7 Doug Lord

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Posted 07 January 2013 - 02:34 AM

designer? can't seem to find it on the DNA site.

-------------------------
Here ya go ,Clean: http://www.racingcats.com/about/

#8 Börni

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Posted 07 January 2013 - 06:32 PM

See the dna blog http://www.dnacat.blogspot.de for more detailed information on their etnz-style foils testing. Looking at the photos I think that is not exactly the etnz approach since the s-bend in the top of the boards is missing. with the s-bend you can reduce dihedral of the foils sailing upwind (beside to the canting of the complete board). this could reduce the drag upwind, which was the major setup of the test trials by dna. Would be interesting what the experience of the paradox-guys are with the s-bending.

#9 MountainCat

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Posted 08 January 2013 - 05:16 AM

Do the "tiplets" act like end plates at the end of the foil and reduce induced drag? This would be similar to the "winglets" you see on airplanes and I believe the practical result is that it makes the water "think" the span of the foil is longer. I also cannot figure out how you get the board up and down the trunk with that tip. Cool stuff.


The sharp radius of the J-board tips would require an enormously wide board case to fully withdraw the boards from the top. A close reading of the rule shows that the boards only need to "be capable of being fully retractable into the hull."

Rule 8.2 states: Movable and retractable hull appendages shall be inserted from the top
or be capable of being fully retractable into the hull.

From the photos it looks as though there may be a hull recess into which the tips can retract to be flush to the hull bottom. Can anyone confirm that?

If so, the boards will still need to be loaded from the bottom, similar to a moth. That would seem to somewhat defeat the intention of the rules which I believe were written to make the A-cat simple to sail off the beach, unlike the moth. Is that a good thing? :(

#10 PJD

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Posted 08 January 2013 - 01:27 PM

Hi Guys ,

The new J-board with wingtip can be inserted from the top, just like the standard daggerboards.
New cases have such a shape, that in combination with the tapered J-boards it works . The top and bottom slots are exactly the same as on standard boards .
The new sliders have more range, up to 4 degrees in AoA on the boards .

The whole idea is that anticipating on developments in boards, we designed a smart daggerboard case , in which a wide range of board shapes will fit : the standard 1200 mm short radius , the standard 1400 mm wide radius , the J board, but also boards like the 1300 mm radius Nikita boards and even possible S boards , so customers of new boats don't have the risk the have to refit their boat the coming years .

If the J boards -or what ever boards- are giving big advantages,don't worry too much,we plan to supply new daggerboard case kits which can be fitted in existing stanadrd daggerboard-boats reasonable easy .

Our tests with the "TNZ" foils are just for fun and to learn what works and were the bounderies are . The S on the top is missing as remarked , thats'because our "TNZ" foil was based on an existing 1400 mm radius standard daggerboard .
It felt draggy upwind, but we only spend a few hours on the water with 11/12 knts max breeze sofar .
Plenty of room to fine tune it .
As soon we test again, we will report on the blog with pics and video.


As we look at things now , we have good believe in our J boards being the best allround setup.
It is not making a whole lot of difference compared to the already very good standard configuration , but just small steps forward , learning every time a bit more .,.


Stay tuned, good sailing !

#11 samc99us

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Posted 08 January 2013 - 05:13 PM

Fun, thanks for the reports! Any chance you can snap some pictures of loading the J boards into the cases?

#12 Lost in Translation

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Posted 09 January 2013 - 05:46 PM

Thanks for the report. PJD, do you have to change anything on the transoms to support the rudder vertical loads? Are the plastic clips on the DNA sufficient to keep the rudders down still?

#13 dacarls

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Posted 09 January 2013 - 06:13 PM

It will be interesting to see how the ARC winglets sell for do it your selfers. Apparently, rudders fitted with them "go down" into position well. As opposed to 2013 World participant Oliver's which did not. One cannot see rudders in the posted pix, but Oliver's C-shaped wnglets were placed on the bottom of the "rather-long" rudders, requiring more leverage to get them down. Once the boat is moving much at all, there is terrific drag and it is very difficult to overcome this drag.

<- Learned in the A-cat foiling at speed in the adjacent thumbnail. Once these rudders are down, they do not have a problem staying down.

#14 PJD

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Posted 09 January 2013 - 07:05 PM

Thanks for the report. PJD, do you have to change anything on the transoms to support the rudder vertical loads? Are the plastic clips on the DNA sufficient to keep the rudders down still?


The new boats are fitted with a strong SS rudder clip ( Nacra style )

for existing boats with plastic clips , these can be replaced by the stronger ones , or, as a more simple solution ; just add some spacer and pin or ring through the small hole in the rudder pintle to avoid the rudder coming up.

i'll make some pics to show some details soon .

PJ

#15 Bang Zoom

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Posted 10 January 2013 - 11:15 PM

I use a 2/1 on my rudder pull downs and if one is quick can get them down up to 10 knots. My bottom pintle is a ss bolt with a delrin washer and lock nut.
7.4.11 017.jpg

#16 NZL255

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Posted 11 January 2013 - 06:05 AM

I'm interested in putting a set of winglets onto my rudders. One question that I would like to ask - is there a formula for positioning the winglets onto the blade?

#17 juniordave nz

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Posted 11 January 2013 - 06:07 AM

Yeh I thinking about it as well. Hoping it will help keep the rudders in the water downwind. Any one have any details on what they have put on, be interesting as a start point

#18 Indecision

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Posted 11 January 2013 - 08:16 AM

Junior Dave, go and talk to the R Class boys. If they can make a 12 foot skiff foil with two on the wire the A should be a good challenge for them. Might show them the error of their ways.

#19 juniordave nz

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Posted 11 January 2013 - 08:30 AM

They've already worked on a foiling A http://www.trademe.c...n-551342134.htm, no where near class legal though.
Yeh I might have a chat to Dan next time I see him and see what foil sections he's been using.
Question (thoughts), I could put the winglets at the bottom of the rudder and that would mean I get a little end plate effect and would mean that downwind it stays in the water for as long as pos when the nose digs in, but on the other hand will add extra drag when going up wind. So I could put the winglets near the middle of the rudder and that would keep them out of the water up wind (on windward rudder any way).
Have any thoughts on position?

#20 SimonN

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Posted 11 January 2013 - 08:33 AM

The position of the winglets has been an ongoing saga here is Oz as we try to find a "1 position fits all". The bottom line is, there is no such thing!

The first debate is exactly where to put them. First, there is a rule to observe which basically means that they cannot be within 6 inches of the bottom of the boat. The problem with this is that nobody knows what thsi means and the International rules committee are looking at this at the moment. I have seen various potential rulings. The most strict option I have been told about is to take the lowest point on the rocker, draw a line from that parallel with the waterline from there and then measure 6 inches down from that. I personally don't see how that is right, but wiser people than me seem to think it might be!

Having said that, one of the keys is to make sure that the windward winglet is either in all the time, or out all the time. Continual surface piercing would be bad, as it adds a lot of drag. Having spent last weekend observing the point at which rudders pierce the surface, I suspect that we don't want to have the winglets at the highest piont allowed, as that seems to be almost exactly where the rudder comes out of the water going upwind.

Steve Clark proposes that the winglets should be at the bottom of long rudders. This would mean keeping both foils in all the time and while that gives more drag, it could well be offset by the end plate effect achieved. I really like this option, but for most it would mean all new rudders.

Finally, you have the position that Landy, Micha and others seem to have settled on, which is about where they are on the photo above. I ssupect that for most with existing rudders, this would be about right. You can keep the foils in upowind and out downhill.

The next problem is setting the angle of attack of the foils. There is a fair amount of debate about this as well. I believe that it all depends on what you are trying to achieve. If they are being used to dampen pitching and stop nose diving, you probably want them pretty neutral. If you are after some lift from them, well, your guess is as good as anybody's!

The big problem is that people use rudder rake to tune the balance of the boat. This is the real reason why one position doesn't fit all. Even on the DNA's, I know 3 top 10 sailors who use differing degrees of tuck under and only one of them is what DNA suggest. On different designs, you use different amounts of tuck under as well. And even if you seem to be using the same amount as somebody in the same design, make sure both boats have transoms that are square to the waterline and that the rudder fittings are the same. Some makes of rudder fitting have the rudder closer to the boat than others. the final factor is the small differences between where the pivot hole is drilled.

In short, I believe that you have to be very careful copying other boats and if you get a rudder with the foils already on, it is seriously tough to set up unless you can

We struggled with all of this back in the day with lowrider Moths when foils were first fitted to the rudders of them. The way we are looking at to get it right is to float the boat on a bit of totally flat water (calm day) with all the gear (c/b's down) with the helm in the upwind and then get somebody to record the waterline. I believe you want to start with the foils neutral to that waterline.

Hope this all helps. It distills down about a month of discussion and research.

#21 juniordave nz

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Posted 11 January 2013 - 09:29 AM

Cheers, that is helpful. I like the idea of having them at the bottom of the rudder and keeping the flow over them as stable as possible. For my boat anyway, I'm also thinking neutral AoA, which as you say, isn't that easy to achieve.
Have the Nationals in just over a week and it seems like there will be a fair bit of technology on show there, so that's going to be bloody interesting, much more productive than sitting at work for a week.

#22 sailingkid

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Posted 11 January 2013 - 10:07 AM

JuniorDave etc, are you running curved boards or straight ones? I feel it could be beneficial for both curved and straight boats just in that you could theoretically push harder downwind without the noses going under, and reduce pitching upwind, even without having lifting foils.

#23 samc99us

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Posted 11 January 2013 - 03:50 PM

Has anyone looked at the data from the F16 stealth with T-foil blades? I'm wondering why they haven't been more prevalent in the A's before now and why more folks aren't using them in the F16 class? Are the tuning issues Simon discussed a hindrance to the average sailor who ends up getting worse performance with foils than without? Or are earlier designs not as refined as the new t-foils on the DNA and others?

#24 AClass USA 230

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Posted 11 January 2013 - 04:32 PM

Good conversation that is addressing a bunch of questions I have been pondering. I'm hoping to get a set of DNA winglets similar to what Landy and Mischa used at the WC and as a starting point plan to copy their strategy in terms of positioning (interesting in the last LAC that Canaan and Aethon had two different strategies in terms of rudder winglet positioning, each seemed valid). I agree with Simon that if you are looking to use the winglets primarily for pitch stability, a neutral AOA is probably the best starting point and I agree that you need to be happy with your helm balance/rudder positioning before attaching the winglets. Using the winglets for reducing wave making drag or trying to reduce displacement would probably require on the fly adjustment of the rake/AOA for different conditions (like a foiling Moth tiller twist control for its single rudder) and the singlehanded multihull nature of an A-Class makes that a difficult task. The best sailors in the class stress keeping it simple. Glad I have a spare set of blades to experiment with! It's a fun science project.

#25 juniordave nz

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Posted 11 January 2013 - 08:43 PM

Salingkid, I have straight boards. My boat is an old Boyer, so has pretty fine bows but I find she goes quite well down wind if I can keep the bows out

#26 PJD

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Posted 18 January 2013 - 10:52 PM

Today we placed DNA 'edition 2013' at Boot Dusseldorf, Europe's biggest boatshow.
We were invited by VDAC ( German A class Association) and DSV (Deutscher Segler Verbund) to show the boat at the 'Multihullplaza' stand together with an GC 32, Nacra 17 and a F 18, in Hall 15.
The boat is rigged with an Landenberger membrame sail with dna-outline .
The showwill open Tomorrow 19th until sunday 27th.

On the attached pictures you can clearly see the new 'J boards' , and the way they fit in the cases. Also a detail of the new slider to adjust the angle of attack on the foils .

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#27 Lost in Translation

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Posted 19 January 2013 - 03:24 AM

this is great and I'm thankful for the promotion of the A Class. We just had a great week sailing in Islamorada in much more typical conditions than the worlds offered. I still don't see how the boards fit into the cases.

#28 juniordave nz

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Posted 28 January 2013 - 07:33 AM

Some good stuff at the NZ Nationals last week. Winglets on rudders (good weed catchers), the J boards on Mikes boat, a few other curved foils, a few straight ones, old masts, new masts, new ashby string sails and some top end sailors. Photos can be found here http://a-class.org.nz/photos.htm

Posted Image

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#29 Lost in Translation

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Posted 28 January 2013 - 04:18 PM

very cool pics. Thanks. How stiff is Mike Drummond's boat with its H16 style tramp? Looks like you had some really nice breeze.

#30 AClass USA 230

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Posted 28 January 2013 - 07:08 PM

Some good stuff at the NZ Nationals last week. Winglets on rudders (good weed catchers), the J boards on Mikes boat, a few other curved foils, a few straight ones, old masts, new masts, new ashby string sails and some top end sailors. Photos can be found here http://a-class.org.nz/photos.htm







Posted Image


The planform of those winglets in the orientation on the rudder blades look like they are backwards to what I would expect. Are those the winglets DNA supply?

#31 juniordave nz

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Posted 28 January 2013 - 07:21 PM

His platform seemeb plenty stiff and also he has a line to pull to adjust everything. It's very much a test platform. It's pretty cool to look at and theres another one almost finished in Auckland.
We had breeze from 10 through to 23 knots I think. Last day several of us didn't go out and the second day several pulled out due to the wind/chop.
The winglets are homemade, solid carbon milled on cnc machine.
Also there was a lot of trapezing downwind by Murray and Blair, but Murray did pass Blair while sitting in when it really got windy.

#32 juniordave nz

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Posted 04 March 2013 - 07:29 AM

Still no talk about this on here?
Posted Image
http://raphael-censier.jimdo.com/
http://www.catsailin...d-designer.html

Finally pictures of a flying A-Class, and its built and sailing by a teenager. Bloody good work.

#33 Joan Pons Semelis

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Posted 04 March 2013 - 09:12 AM

Impressive !

#34 ita 16

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Posted 04 March 2013 - 12:47 PM

is one year that I look at his photos, works very well, congratulations on the results.

#35 Doug Lord

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Posted 04 March 2013 - 02:51 PM

Still no talk about this on here?

http://raphael-censier.jimdo.com/
http://www.catsailin...d-designer.html

Finally pictures of a flying A-Class, and its built and sailing by a teenager. Bloody good work.

---------------------------
Anybody know the details behind the flying A Cat? who, where, etc

#36 tikipete

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Posted 04 March 2013 - 03:51 PM

http://www.catsailin...d-designer.html

A child prodigy with carbon.

#37 Doug Lord

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Posted 04 March 2013 - 04:33 PM

http://www.catsailin...d-designer.html

A child prodigy with carbon.

------------------------
Thanks tikipete-that is just fantastic-a 19 year old kid designs, builds and flys a legal A Class cat-it's incredible! What a talent that guy has-what a great contribution to sailing, foiling and design....

#38 Waynemarlow

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Posted 04 March 2013 - 05:33 PM

One thing we found by almost all the Stealth F16 owners, was that when the foils are right at the bottom of the rudder as per the best aerodynamic situation ( gliders went T tails 30 years ago ) they are very vunerable to scuffing and such like when beaching and moving around the boat park. Almost everyone at some time has damaged the lower surface in some way.

Now if you just damage a tip its not quite so critical.

#39 FishAintBiting

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Posted 04 March 2013 - 06:24 PM

One thing we found by almost all the Stealth F16 owners, was that when the foils are right at the bottom of the rudder as per the best aerodynamic situation ( gliders went T tails 30 years ago ) they are very vunerable to scuffing and such like when beaching and moving around the boat park. Almost everyone at some time has damaged the lower surface in some way.

Now if you just damage a tip its not quite so critical.


So would you suggest moving the foils up by roughly 50 mm to prevent this?

#40 SimonN

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Posted 05 March 2013 - 05:39 AM

For me, the real story with this kid is that he built the boat himself at such a young age. There seems to be a bit of a trend going on with young people building A's (some with help) and I think that this needs to be encouraged. In fact, these youngsters are setting a real example to others. I think the class should be looking at ways to encourage home build as a way of reducing costs. Maybe the class could fund a mould and develop a set of build instructions. I know that if I could get hold of a mould for a competitive boat, i would certainly build one as i cannot currently afford a new design. I also suspect that it would be possible for people to develop build groups to share the work load, have more than one pair of hands and hopefully, bulk buy. If this lad can do it, so can others!

I should add that i know of people who are building good quality foils that will be available to all, so if people do build their own boats, they don't have to worry about what i think is the hardest part.

#41 juniordave nz

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Posted 05 March 2013 - 07:04 AM

Theres plenty of building still going on in NZ. There are a few decent moulds in Auckland and north. I did look at bringing one of them down to Christchurch, but now there are a few of us looking at building a different design. A few different people building boards as well.
This guy has done a great job. His build quality looks really good and he has some great design in there.

#42 trucdesign

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Posted 05 March 2013 - 09:26 AM



#43 sailingkid

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Posted 05 March 2013 - 10:18 AM

I feel like the worlds most unskilled 19 year old A class sailor, If I tried to build something like that I'd end up with a proa. Very well done.

#44 AClass USA 230

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Posted 05 March 2013 - 12:54 PM

Congrats to this 19 year old for building his own A-Class but the "foiling" I am seeing in the video is similar to what you can do with any current platform with curved daggerboards. Not convinced yet if sustained, fast (you have to be be competitive upwind on a race course) and controlled foiling is feasible or practical with the current class rules.

#45 Doug Lord

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Posted 05 March 2013 - 02:01 PM

Looks like, to me, that if Raphael had very small foils on the rudder he'd have it made for flying. That doesen't necessarily mean it would be faster than a standard A class to do that. But I'd bet the kid will figure it out!

#46 SimonN

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Posted 05 March 2013 - 02:27 PM

Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

#47 Doug Lord

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Posted 05 March 2013 - 02:49 PM

Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

=======================
You ain't seen nothin yet!

#48 Rasputin22

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Posted 05 March 2013 - 03:00 PM

One thing we found by almost all the Stealth F16 owners, was that when the foils are right at the bottom of the rudder as per the best aerodynamic situation ( gliders went T tails 30 years ago ) they are very vunerable to scuffing and such like when beaching and moving around the boat park. Almost everyone at some time has damaged the lower surface in some way.

Now if you just damage a tip its not quite so critical.


Good point Wayne, but the main reason sailplanes went to T-Tails in that the raised position keeps the horizontal stabilizer out of disturbed airflow as the plane nears a stalled condition. Better recovery when a stall does occur. Another consideration in in a way similar to the damages issues you bring up. A T-tail sailplane is less likely to damage the stabilizer in an outlanding such as in a filed or brush. The structural challenges of the T-tail are greater due to tourquing of the tail boom and acrobatic sailplanes such as the Fox MDM-1 have the stabilizer at the bottom of the rudder for that reason. A few sailplanes were built with the horizontal stab at the midpoint of the rudder but the T-tail seems to predominate in modern sailplanes.

#49 SimonN

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Posted 05 March 2013 - 08:21 PM


Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

=======================
You ain't seen nothin yet!

You may be right, but I am not sure you fully appreciate the problems faced, or the amount of effort that some have put into getting an A to foil. The rules are, deliberately, very limiting. It's interesting that some on the technical committee that wrote the rules are now AC designers and and I believe that they haven't changed their view that the rules prevents an A to fully foil in a stable manner for any reasonable distance. If you have been following what the DNA guys have been doing, they have needed to use non class legal foils to get properly foiling. In addition, there have been a couple of pretty expensive failures which has put a lot of people off.

The other thing to consider is that it is my impression that overall, there isn't the support within the class for full foiling A's. I am pretty sure that for many, that would be one development step too far and that if boats did begin to successfully foil, there would be a powerful lobby within the class to get the rules changed. And although it goes against my beliefs of what is right in a development class, I can understand why people think like that.

#50 barney

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Posted 05 March 2013 - 09:24 PM

How would it be possible to foil* on a curved daggerboad? Isn't ventilation gonna be a huge problem?

* even though I found the video of the French guy's A pretty cool, by foiling I mean foiling for some time...

#51 Doug Lord

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Posted 05 March 2013 - 09:46 PM



Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

=======================
You ain't seen nothin yet!

You may be right, but I am not sure you fully appreciate the problems faced, or the amount of effort that some have put into getting an A to foil. The rules are, deliberately, very limiting. It's interesting that some on the technical committee that wrote the rules are now AC designers and and I believe that they haven't changed their view that the rules prevents an A to fully foil in a stable manner for any reasonable distance. If you have been following what the DNA guys have been doing, they have needed to use non class legal foils to get properly foiling. In addition, there have been a couple of pretty expensive failures which has put a lot of people off.

The other thing to consider is that it is my impression that overall, there isn't the support within the class for full foiling A's. I am pretty sure that for many, that would be one development step too far and that if boats did begin to successfully foil, there would be a powerful lobby within the class to get the rules changed. And although it goes against my beliefs of what is right in a development class, I can understand why people think like that.

===========================
You retro guys better start changing the rules now! It isn't going to be much longer. Thats already been done once(unfortunately)-you really think they'll do it again?

#52 SimonN

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Posted 05 March 2013 - 10:25 PM

You retro guys better start changing the rules now! It isn't going to be much longer. Thats already been done once(unfortunately)-you really think they'll do it again?

Doug

It's nothing to do with being retro and everything to do withwhat the majority of the fleet believes the A's stand for. I personally would vote against any rule change that tried to further limit foiling, but I beleive that I am in the minority. Back when the current rules were made, the class gave a very clear signal that they don't want full foiling and I believe that is still the view of the majority. I am sure if A's are made to fly competitively, there would be a vote to alter the rules to prevent it. While I would vote against any rule change, I do share the view that fully foiling A's would kill a very succesful class. It's a very different class and situation from the one the Moths had when foils were developed for them.

I love Doug's total confidence that competitive full foiling is simply a matter of time. I would love to know the technical reasons he believes that, because there is little evidence to date that this will be so.

#53 Lost in Translation

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Posted 05 March 2013 - 11:01 PM

People want simple boats and are no doubt intrigued by the foiling that the AC boats are doing. Look at all of the blog entries and such on foiling, but nothing is proven on the race course. I think the rules have been really good so far and as Simon notes the class is thriving. I would guess if folks can start demonstrating that not too much is involved to get to full foiling on the A that the class would find it interesting. That is just my personal view.

#54 fireball

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Posted 05 March 2013 - 11:08 PM

One of the reasons for the growth in the A class in recent years is the money coming from the AC. It was funny to see all the brand new DNA's that were supplied to AC crew members at the last Australian National titles at Wangi Wangi.

At that stage, A classes were foil assisted, AC 45s were non foiling and the AC 72s were still in development. But, now that AC 72s are full foiling, the reason for buying everyone a practice A class is somewhat diminished.

I think the current A class rules were a mistake. If the foils had been allowed to be bigger then there would have been a sequence of new designs working towards full foiling downwind. Instead, we have a lot of new designs all trying to foil within the constraints of the rule. This seems to be a waste of everybody's time and money because the rule was quite arbitrary in the first place.

In simple terms, designers are wasting their efforts to get around a rule. It's simpler to remove the rule and get on with developing the boats to go faster around the racetrack.

#55 Doug Lord

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Posted 05 March 2013 - 11:34 PM

I remember the old Australian A Class Cat forum. Back when Rohan Veal had an A Cat. From my memory of that forum it seems most who posted were for foiling. Then the forum disapeared into cyber space-for a technical reason I'm mostly sure. I always wanted an A Cat from the time I was racing Windmills, but when I could afford one I was too heavy to be competitive. But I still love the boat.... And I think if the rules are changed again it would be a damn shame.

#56 juniordave nz

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Posted 05 March 2013 - 11:59 PM

If you want to build the fastest boat around a race track, then don't build an A-cat. There are several measures in the rule that stop it from being faster. Why not drop the weight limit as well? Or sail area? Rules are there to maintain a similar playing field so that quality racing can take place while development is carried out.
I think foiling would be great to see, but why not make it work within the rules, the AC teams had to do it that way. It's easy to make what every you want without rules, but then who do you race against.
I wouldn't be against a rule change to increase the ability to foil, but I think it should still be limited in some way.
There are talks going around about some clarifications to the rule, similar to what we were talking about with winglet sizes and where they can be placed on the rudder (wrt to bottom of hull), and is there any need to limit how far aft the rudders can be place (think how the foiling C class had their rudders placed).

#57 SimonN

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Posted 06 March 2013 - 12:28 AM

There is something very important that needs to be understood about the A and which I think is fundemental to its success. It is definately the easiest boat to sail when measured on a performance vs ease of sailing. Yes, they are tippy for a cat but you can stick the vast majority of sailors on an A and they will go out and be able to sail. The A gives you accessable high performance. The moment you take that away, the class will begin to die. For some, trapezing downwind has reduced the accessabilty of the A (don't worry, there won't be a rule change to ban that :D ). The A certainly has the oldest average age of any high performance fleet I have ever seen and this also effects people's views on what they want for the class.

Although I wouldn't vote for rule changes, the reasons why i believe it would be bad for the class revolves around 3 things. first, it would reduce the "accessability" of the class, needing fitter, more agile and higher skilled sailors at the entry level. Second, it would make most of the current fleet obselete. While there are many boats that aren't competitive against the top designs, people are prepared to accept that, as we see from the number of older boats at championships. This is becaus ethe real differences aren't huge. But if foiling proves to be better, you will see what has happened in the Moths - the low riders have died. And unlike the Moths, I don't see a whole army of people waiting to come into a foiling cat. If you want foiling, you get a Moth. Finally, not only will platforms and foils be obselete, but i suspect it will lead to completely changed rigs, to match the higher speeds when foiling but also to promote early foiling. We saw the development of Moth rigs, but there a mast is $1400 while an A mast is more like $4500!

As much as I like foiling, the answer isn't to simply stick foils on everything. I therefore hope that the current A class rules do succeed in preventing competitive full foiling, which based on everything we have seen to date, looks highly likely.

#58 fireball

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Posted 06 March 2013 - 01:15 AM

If you want to build the fastest boat around a race track, then don't build an A-cat. There are several measures in the rule that stop it from being faster. Why not drop the weight limit as well? Or sail area? Rules are there to maintain a similar playing field so that quality racing can take place while development is carried out.
I think foiling would be great to see, but why not make it work within the rules, the AC teams had to do it that way. It's easy to make what every you want without rules, but then who do you race against.
I wouldn't be against a rule change to increase the ability to foil, but I think it should still be limited in some way.
There are talks going around about some clarifications to the rule, similar to what we were talking about with winglet sizes and where they can be placed on the rudder (wrt to bottom of hull), and is there any need to limit how far aft the rudders can be place (think how the foiling C class had their rudders placed).


Actually, the AC 72 rules have worked out much better than many people expected, but this may be more by accident than by design.

It turned out that the size of the foils wasn't heavily restricted. ETNZ figured this out first and the other teams have had to play catch up to get to full foiling.

But the use of control surfaces has been restricted and this has forced the AC teams to develop much simpler foiling approaches which should be a lot easier and cheaper to apply to smaller boats.

IMHO, the A class rules have been too restrictive and nobody has managed to achieve stable flight downwind in a configuration that it also competitive upwind. This hasn't been from lack of trying and it seems that with the current rules and technology then a boat that foils downwind won't be competitive.

So the A class can either stick with foil assist and get left behind in the development stakes. Or they can relax the restriction on foil size and participate in the fantastic technological changes taking place in sailing right now.

#59 Doug Lord

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Posted 06 March 2013 - 01:18 AM

There is something very important that needs to be understood about the A and which I think is fundemental to its success. It is definately the easiest boat to sail when measured on a performance vs ease of sailing. Yes, they are tippy for a cat but you can stick the vast majority of sailors on an A and they will go out and be able to sail. The A gives you accessable high performance. The moment you take that away, the class will begin to die. For some, trapezing downwind has reduced the accessabilty of the A (don't worry, there won't be a rule change to ban that :D/> ). The A certainly has the oldest average age of any high performance fleet I have ever seen and this also effects people's views on what they want for the class.

Although I wouldn't vote for rule changes, the reasons why i believe it would be bad for the class revolves around 3 things. first, it would reduce the "accessability" of the class, needing fitter, more agile and higher skilled sailors at the entry level. Second, it would make most of the current fleet obselete. While there are many boats that aren't competitive against the top designs, people are prepared to accept that, as we see from the number of older boats at championships. This is becaus ethe real differences aren't huge. But if foiling proves to be better, you will see what has happened in the Moths - the low riders have died. And unlike the Moths, I don't see a whole army of people waiting to come into a foiling cat. If you want foiling, you get a Moth. Finally, not only will platforms and foils be obselete, but i suspect it will lead to completely changed rigs, to match the higher speeds when foiling but also to promote early foiling. We saw the development of Moth rigs, but there a mast is $1400 while an A mast is more like $4500!

As much as I like foiling, the answer isn't to simply stick foils on everything. I therefore hope that the current A class rules do succeed in preventing competitive full foiling, which based on everything we have seen to date, looks highly likely.

================================
Just out of curiosity: why would you not vote for rule changes if you really believe "foiling" would be bad for the class?
-----
This is just nonsense! Are you saying there was an "army" waiting to get into the foiling Moth? No way! And if the the A-Class can be made to foil reliably, which is almost certain, then it will be the easiest to sail foiler on the planet. There will be tremendous excitement from inside and outside the class. One more giant step in the revolution that is changing sailing!

#60 juniordave nz

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Posted 06 March 2013 - 01:22 AM

Well said (simon), and I agree. Although I do think full foiling will be possible in some conditions and will be faster, but I think over a balanced regatta (varied conditions), the full foiler would have little or no advantage over a current design.

Also practicalities of adding those appendages in sailing situations with weed. Little winglets make it hard enough to clear weed, big T foils will make it incredible slow to clear weed. While currently all you have to do is heel the boat enough and the weed falls off.

#61 Doug Lord

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Posted 06 March 2013 - 01:28 AM

Well said (simon), and I agree. Although I do think full foiling will be possible in some conditions and will be faster, but I think over a balanced regatta (varied conditions), the full foiler would have little or no advantage over a current design.

Also practicalities of adding those appendages in sailing situations with weed. Little winglets make it hard enough to clear weed, big T foils will make it incredible slow to clear weed. While currently all you have to do is heel the boat enough and the weed falls off.

-----------------------
Nobody is suggesting adding "big T-foils"-where did you get that from??

#62 sailingkid

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Posted 06 March 2013 - 01:31 AM

Id love to see As fully foiling, but id never be able to afford to buy one for a few years, and my current boat wouldnt be stiff enough to make it work. However it would be cool, and I can see it attracting younger sailors into the class that would otherwise but a moth.

#63 dacarls

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Posted 06 March 2013 - 01:32 AM

It is great fun seeing the French kid doing his thing. If you look, it is momentary foiling, with obvious loss of lift and crash at the completion of each "jump" as he calls it. Just like the Marstrom 32 and every other non-rudder-foiled cat with lifting or curved boards: They are thusly not stable.

#64 juniordave nz

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Posted 06 March 2013 - 01:43 AM


Well said (simon), and I agree. Although I do think full foiling will be possible in some conditions and will be faster, but I think over a balanced regatta (varied conditions), the full foiler would have little or no advantage over a current design.

Also practicalities of adding those appendages in sailing situations with weed. Little winglets make it hard enough to clear weed, big T foils will make it incredible slow to clear weed. While currently all you have to do is heel the boat enough and the weed falls off.

-----------------------
Nobody is suggesting adding "big T-foils"-where did you get that from??


His rudders have T's. And big doesn't mean that big. You can go for L's, but you still get the similar problem with weed.

Also foiling has all but killed the R-class. The 12 foot guys have completely shuned the class now even though not all the R's are foiling. I think the foiling R-class is awesome, it was a toss up between sailing them or sailing the A-cat, but it hasn't done the class any good to move to foiling.

I understanding foiling when done well can be a lot faster. But look at how many people still sailing slow boats when there are already faster ones around. Just going faster isn't always what people want.

I like the A, because I can rig it and get it sailing myself with no complecation even though its a bloody big boat for one person. Foiling may not make this aspect harder. But if you look at the R-class and the moths, they need to launch side ways

#65 AClass USA 230

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Posted 06 March 2013 - 05:14 PM




Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

=======================
You ain't seen nothin yet!

You may be right, but I am not sure you fully appreciate the problems faced, or the amount of effort that some have put into getting an A to foil. The rules are, deliberately, very limiting. It's interesting that some on the technical committee that wrote the rules are now AC designers and and I believe that they haven't changed their view that the rules prevents an A to fully foil in a stable manner for any reasonable distance. If you have been following what the DNA guys have been doing, they have needed to use non class legal foils to get properly foiling. In addition, there have been a couple of pretty expensive failures which has put a lot of people off.

The other thing to consider is that it is my impression that overall, there isn't the support within the class for full foiling A's. I am pretty sure that for many, that would be one development step too far and that if boats did begin to successfully foil, there would be a powerful lobby within the class to get the rules changed. And although it goes against my beliefs of what is right in a development class, I can understand why people think like that.

===========================
You retro guys better start changing the rules now! It isn't going to be much longer. Thats already been done once(unfortunately)-you really think they'll do it again?


Douyg,

Your posture as a non-active A-Class sailor throwing darts is showing itself. First, I don't think we will ever reach foiling A-Cats with the current rules because I don't believe curved C-foils can do it. The only way to do it would be with L or T foils similar to the AC72's and the Moths and these foils will not work with the current class rule requirement in that the daggerboard must be inserted and removed from the top of the trunk. The reason the rule is written this way is safety for the singlehanded A-Class sailor in that having to install or remove the daggerboards from the bottom of the boat would be very difficult especially in a windy, crowded launch area (and it would also be dangerous to others). Second, you have to be competitive upwind and downwind. Even the AC guys don't know at this point if a foiling arrangement is going to be competitive in light to medium air upwind sailing. Third, even if you can work out something to get the boat flying, I don't think a singlehanded sailor can control the foiling AND race at the same time. Your points can be valid at times if we were talking about speed trials in a straight line but you have to tack, jibe, slow speed maneuver on a starting line, and go upwind and downwind on an A-Class. If this had a chance of of working. I think the C-Class guys would be well into it as it would be more practical to develop on their boats. The fact that they are not supports the reality I state here.

#66 Doug Lord

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Posted 06 March 2013 - 07:31 PM





Doug

Sorry, but we know that small wings on the rudder do not lead to proper flight. How? Because people are sailing with winged rudders and still getting similar or only very slightly improved results. As AClass USA230 says, this is nothing new.

=======================
You ain't seen nothin yet!

You may be right, but I am not sure you fully appreciate the problems faced, or the amount of effort that some have put into getting an A to foil. The rules are, deliberately, very limiting. It's interesting that some on the technical committee that wrote the rules are now AC designers and and I believe that they haven't changed their view that the rules prevents an A to fully foil in a stable manner for any reasonable distance. If you have been following what the DNA guys have been doing, they have needed to use non class legal foils to get properly foiling. In addition, there have been a couple of pretty expensive failures which has put a lot of people off.

The other thing to consider is that it is my impression that overall, there isn't the support within the class for full foiling A's. I am pretty sure that for many, that would be one development step too far and that if boats did begin to successfully foil, there would be a powerful lobby within the class to get the rules changed. And although it goes against my beliefs of what is right in a development class, I can understand why people think like that.

===========================
You retro guys better start changing the rules now! It isn't going to be much longer. Thats already been done once(unfortunately)-you really think they'll do it again?


Douyg,

Your posture as a non-active A-Class sailor throwing darts is showing itself. First, I don't think we will ever reach foiling A-Cats with the current rules because I don't believe curved C-foils can do it. The only way to do it would be with L or T foils similar to the AC72's and the Moths and these foils will not work with the current class rule requirement in that the daggerboard must be inserted and removed from the top of the trunk. The reason the rule is written this way is safety for the singlehanded A-Class sailor in that having to install or remove the daggerboards from the bottom of the boat would be very difficult especially in a windy, crowded launch area (and it would also be dangerous to others). Second, you have to be competitive upwind and downwind. Even the AC guys don't know at this point if a foiling arrangement is going to be competitive in light to medium air upwind sailing. Third, even if you can work out something to get the boat flying, I don't think a singlehanded sailor can control the foiling AND race at the same time. Your points can be valid at times if we were talking about speed trials in a straight line but you have to tack, jibe, slow speed maneuver on a starting line, and go upwind and downwind on an A-Class. If this had a chance of of working. I think the C-Class guys would be well into it as it would be more practical to develop on their boats. The fact that they are not supports the reality I state here.

------------------------
You're kidding, right? Thats what you think my comments were? How about all the A Class owners working as hard as they can to fly the boat- are they throwing darts ,too?

#67 Doug Lord

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Posted 06 March 2013 - 07:58 PM

This quote is from Martin Fisher who is just one of a number of guys working on a flying A Class cat-his first version didn't work too well in light air:

It was already mentioned in the previous section that the boat is equipped with curved foils and with lifting rudders. We won’t go into details on the foil and rudder design, just a few hints: The radius of the foils is not constant and they are twisted. The size of the foils and the rudders was set such that they provide a stable configuration for pitch and sinkage variations. Such a configuration enables stable flight in stronger winds, without the need for a mechanical surface sensor as used on the Moth. We have filed a patent for this type of configuration.

In addition to Martin, there is Dario Valenza with Paradox, Raphael, the wonder kid, Team DNA and I'm sure a number of other"leaders" in the A Class all working to fly using class legal foils! But flying is not the whole game-flying across the finish line in first place is. A lot of talent thinks flying is a great idea.

Picture below of the Phantom F18 flying using a foil system designed by Martin Fischer. That boat with crew weighs about twice what an A Class cat weighs:

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#68 SimonN

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Posted 06 March 2013 - 09:05 PM

Doug

How can quoting Martin Fischer help your cause. All he has done so far is to design 2 A's that have, to date, proven to be incredibly slow.

But let's get straight to the point. This is like deja vu all over again ;) 3 or 4 years ago, you stalked every single Moth post on the net and pissed off every single Moth sailor by telling us all that we didn't know what we were talking about. Watching you tell 3 seperate World Champions that they didn't understand foiling was, for a while, funny, but bit all ended in tears. One of my favorite reactions to you was the guy who named his boat "See no Doug, Hear no Doug, Speak no Doug" and who had it in big letters on his sail. It provided much laughter when he turned up with that.

Your problem is that you take snippets off the internet and try to build a story to support your own views. What you don't seem to realise is that the A Class community talks to each other more than most. Most people share the ideas and what is going on. Don't you think it is strange that every A Class sailor on here is saying you don't know what you are talking about? Yes, there are lots of people playing around with full foiling, but if you actually knew them, you would find that it isn't so much the quest for a full foiling A but more to understand what is going on when we are in foil assist mode.

So please stop trying to tell the people who are actually doing the development and sailing that they don't know what they are talking about, because this is only going to end one way. If you are that interested, get involved. You don't have to actually sail an A, but you do need to be designing and building the stuff. You might be surprised that there are people around who would sail and/or even get involved with development with you. Who knows. If you actually design something with potential, I might even make it and try it with and against some of the best A sailors in the world. You can't get a better offer than that! Until then, stop trying to teach your grandmother to suck eggs. :)

#69 Doug Lord

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Posted 06 March 2013 - 09:24 PM

Doug

How can quoting Martin Fischer help your cause. All he has done so far is to design 2 A's that have, to date, proven to be incredibly slow.

But let's get straight to the point. This is like deja vu all over again ;) 3 or 4 years ago, you stalked every single Moth post on the net and pissed off every single Moth sailor by telling us all that we didn't know what we were talking about. Watching you tell 3 seperate World Champions that they didn't understand foiling was, for a while, funny, but bit all ended in tears. One of my favorite reactions to you was the guy who named his boat "See no Doug, Hear no Doug, Speak no Doug" and who had it in big letters on his sail. It provided much laughter when he turned up with that.

Your problem is that you take snippets off the internet and try to build a story to support your own views. What you don't seem to realise is that the A Class community talks to each other more than most. Most people share the ideas and what is going on. Don't you think it is strange that every A Class sailor on here is saying you don't know what you are talking about? Yes, there are lots of people playing around with full foiling, but if you actually knew them, you would find that it isn't so much the quest for a full foiling A but more to understand what is going on when we are in foil assist mode.

So please stop trying to tell the people who are actually doing the development and sailing that they don't know what they are talking about, because this is only going to end one way. If you are that interested, get involved. You don't have to actually sail an A, but you do need to be designing and building the stuff. You might be surprised that there are people around who would sail and/or even get involved with development with you. Who knows. If you actually design something with potential, I might even make it and try it with and against some of the best A sailors in the world. You can't get a better offer than that! Until then, stop trying to teach your grandmother to suck eggs. :)

----------------------
I haven't said that or implied that in any way whatsoever. I have an opinion on development within the A Class which I follow very closely. When I'm accused of "throwing darts" or "telling people who are actually doing the development that they don't know what they are talking about" I say thats 100% made up false!!!
--
Simon, you haven't answered my question about why, if you think foiling is bad for the class, you wouldn't vote for a more
restrictive rule? You've said that at least twice-I'm just curious.

#70 Chris O

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Posted 07 March 2013 - 12:32 AM

Guys... why feed the troll?

Every answer to his nonsense only allows him to think he's involved in some meaningful way and all of you fellows already know that he isn't. Hell, he can't even finish (and sail successfully) a model boat of his supposedly great ideas in well over a year now, much less actually build a full-sized anything for an A that can actually work.

Don't engage him. Put the goof on ignore, or you'll simply get more of the same tired shit you see above.

#71 Doug Lord

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Posted 07 March 2013 - 01:15 AM

I have always loved the A Cat Class and the recent developments in catamaran foiling are simply extraordinary. People who are opposed to an A Class foiling have run out of time because as this quote below from Dario Valenza makes clear it is happening now. The question is: is it faster?

From Dario Valenza, an extraordinary innovator and designer of the Paradox-
http://www.carbonicb...logspot.com.au/
excerpt:

March 4, 2013

"Martin's insights and numbers have been vindicated by the behaviour of the new boat. It handles very 'un-spectacularly' which shows the foils are doing their job.
Rather than jumping and crashing, the motion is straight and level, unperturbed by external disturbances. As soon as the skipper starts to see white caps on the water, the technique is to flatten the boat out. The hulls nudge up until they are just clear of the surface and the magic carpet ride begins. Taking a small step forward keeps the foils loaded and the boat tracks straight and true with little regard for chop and wakes. All who have tried it so far have come away very excited saying stable foiling on an A Cat is a sensation unlike any other sailing they have done.
The really remarkable fact is that it all happens automatically. There is none of the 'skirting the death zone' dance familiar to those who have tried to balance on C or J boards."


#72 Doug Lord

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Posted 07 March 2013 - 03:09 AM

You can argue with me if you wish doug. But im reasonably close to the action

-------------------
I don't want to argue with anybody-I want to celebrate this tremendous accomplishment. Why in the world would Dario publish this on his blog on March 4th if it wasn't true?? Please help me to understand.....

#73 Waynemarlow

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Posted 07 March 2013 - 07:01 PM

Because he wants to sell boats.

#74 AUS

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Posted 08 March 2013 - 03:35 PM

Photos or it didn't happen. In the videos the boat isn't flying anymore than the mayfly or my Nikita or DNA for that matter. DP didnt seem to perform to his usual standard when he raced the boat.

#75 AUS

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Posted 08 March 2013 - 03:44 PM

Saying that I wish all of the new projects and new builds all the success. It is great to see continued evolution. The class is amazing and the reason why there is even a debate. When someone indicates a concern for rapid development it is simply the non-selfish opinion of what it best for the class, anyone who knocks them has know idea of what it is like to turn up to an international event with 100 simmilar high performance boats and have awesome racing! We have a great think going right now and there is no reason to spoil it! I don’t see the current rules allowing a boat to fully foil and race competitively, if and when that time comes I am sure the class will do the right thing. I would like to see some more people not worry about the rule just to see what they can come up with.

#76 AClass USA 230

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Posted 08 March 2013 - 04:31 PM

Saying that I wish all of the new projects and new builds all the success. It is great to see continued evolution. The class is amazing and the reason why there is even a debate. When someone indicates a concern for rapid development it is simply the non-selfish opinion of what it best for the class, anyone who knocks them has know idea of what it is like to turn up to an international event with 100 simmilar high performance boats and have awesome racing! We have a great think going right now and there is no reason to spoil it! I don’t see the current rules allowing a boat to fully foil and race competitively, if and when that time comes I am sure the class will do the right thing. I would like to see some more people not worry about the rule just to see what they can come up with.


+1

#77 Doug Lord

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Posted 08 March 2013 - 06:32 PM

Photos or it didn't happen. In the videos the boat isn't flying anymore than the mayfly or my Nikita or DNA for that matter. DP didnt seem to perform to his usual standard when he raced the boat.

===================
After what he said on March 4th, I would bet Dario will have video up before long. But just because it's foiling does not mean it's fast-the last 50 years of foiling catamarans have mostly been slow compared to their non-foiling sisters-Rocker being the most recent major example.
I hope Dario's got it right!

#78 TornadoSail2016

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Posted 08 March 2013 - 09:32 PM

With all the new boats coming out this year, the D3, Arrow 2, DNA MKIII, Paragon and a few one offs it should be an interesting years to watch in the lead up to the Worlds this year. I am sure that I have missed a couple or more new projects so I will apologize now for doing so. Nothing is meant by this. If you are working on a new design let SA know and start a thread about it. I am really curious about all the new foil development going on in the class. Would also like to hear more about the wing that was built last year.

#79 SimonN

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Posted 09 March 2013 - 01:22 AM

Just out of curiosity: why would you not vote for rule changes if you really believe "foiling" would be bad for the class?

Doug

This is a fair question which i missed and think deserves a fair answer.

I have sailed development classes all my life and in every case, each class I have been involved in has had good times and less good.I believe that if you keep changing teh rules of a development class every time something comes along which reduces the appeal, all that happens is that you end up with too many rules and development stagnates and the class eventually dies. In addition, over time, things that might be unappealing now become more appealing. By way of example, i used to sail a development class in the UK call National 12's. As a reaction to a couple of boats a friend of mine built, they brought in rules to stop people building boats witha double bottom. the view as that it would make the boats uncomfortable to sail, more difficult because of the higher centre of gravity and would outclass the rest of the fleet. 10 years later, with new classes coming out with double bottomed boats, the idea was far more acceptable and the rule was changed. The class continues to do well. In general, development classes do best over the long term when development isn't stiffled, even if there are times when they take a short term hit.

So while I believe that banning foiling, if it is proven to be better, would be good for the immediate future of the class, I think it is the wrong thing to do on a long term basis.

#80 k2mav

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Posted 09 March 2013 - 11:21 AM


Photos or it didn't happen. In the videos the boat isn't flying anymore than the mayfly or my Nikita or DNA for that matter. DP didnt seem to perform to his usual standard when he raced the boat.

===================
After what he said on March 4th, I would bet Dario will have video up before long. But just because it's foiling does not mean it's fast-the last 50 years of foiling catamarans have mostly been slow compared to their non-foiling sisters-Rocker being the most recent major example.
I hope Dario's got it right!


Doug, you've been reading , but you need to do it better. The Paradox design is by Martin Fischer, and Dario has put lot of hours and investment on making the project a reality.

You also being "more catholic than the pope" regarding the effectiviness of a flying A, even Fishcer says no flying A has won anything till now. Did a q&a with him las week, will publish on monday.

#81 demon936

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Posted 09 March 2013 - 12:21 PM

Photos or it didn't happen. In the videos the boat isn't flying anymore than the mayfly or my Nikita or DNA for that matter. DP didnt seem to perform to his usual standard when he raced the boat.

In fairness to the paradox mate when i raced it we opted for a very conservative set up. Also i sailed conservative ie clear air starts rather than favoured end and conservative mark roundings etc. I felt as though this boat showed potential and i wish dario all the best and i think an aussie builder is what our class needs here again.



#82 AClass USA 230

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Posted 09 March 2013 - 01:19 PM

What could be missing in this discussion is the distinction between "foiling" and "flying". Any rudder or daggerboard is technically a hydrofoil so we are always foiling when sailing. Take it one step further with canted and curved daggerboards and we now have reduced displacement foiling which in it's best execution is where the performance of the A-Class is peaking currently. We know that uncontrolled leaps and wheelies are possible and it is becoming clear that rudder winglets are a valid solution to gain more control of the boat.

We have yet to see an A-Class "flying" for any sustained period with control like a Moth or an AC72. Probably the biggest obstacle to this is the current class rule which requires that the daggerboards must be inserted and removed from the top of the trunk. As stated earlier in this post this was done to keep the boat simple and safe. The class did not want the scenario of a singlehanded sailor having to lift a hull to remove a daggerboard. This is the main reason you will probably not see an L or T daggerboard on an A-Class which are the types of foils used by the AC72 and the Moth to achieve "flying".

Will flying A-Cats be possible with current rules? Hard to say. Arno with DNA claimed he flew for 20 seconds with their new J boards with winglets this week and I think what Dario is trying to do with the Paradox program is to get hulls skimming but not elevated. I believe elevated, clear of the water "flying" might be achievable but I am not sure a singlehanded sailor can optimize the setup or control while sailing to make it competitive against a platform and foil combination that is employing a simpler approach to optimizing reduced displacement sailing combined with easy and effective pitch stability.

No matter what, the boats have become faster and easier to sail so it's all good.

#83 AUS

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Posted 09 March 2013 - 01:24 PM

Hey Demon,
I meant no disrespect to the Paradox program, just in the videos of it sailing it looks to sail similar to Cairnsie and Martin’s boats while we were practicing before Denmark worlds. A couple of times the boats really did look close to flight. But didn’t end up being fast. A couple of the guys on here are alluding to the boat flying, if so this is a totally different and I look forward to hearing and seeing more. You have raced the boat, what do you think? Will it fly?
A builder in AUS would be a good thing for the class, we are in a similar situation in the US. Buying the boat is one thing but having to pay to ship is the killer. We need a min of 6 boats to make a shipment worthwhile. Unlike AUS the US guys don’t travel much so it is hard to add just a couple of boats to a regatta shipment.
I hear the Paradox is a beautifully made boat, if the current development pathway doesn’t prove to be the way I presume they could adapt the moulds for a more conservative appendage package, moved aft with c of J boards?

#84 Doug Lord

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Posted 09 March 2013 - 02:20 PM

I have always loved the A Cat Class and the recent developments in catamaran foiling are simply extraordinary. People who are opposed to an A Class foiling have run out of time because as this quote below from Dario Valenza makes clear it is happening now. The question is: is it faster?

From Dario Valenza, an extraordinary innovator and designer of the Paradox-
http://www.carbonicb...logspot.com.au/
excerpt:

March 4, 2013

"Martin's insights and numbers have been vindicated by the behaviour of the new boat. It handles very 'un-spectacularly' which shows the foils are doing their job.
Rather than jumping and crashing, the motion is straight and level, unperturbed by external disturbances. As soon as the skipper starts to see white caps on the water, the technique is to flatten the boat out. The hulls nudge up until they are just clear of the surface and the magic carpet ride begins. Taking a small step forward keeps the foils loaded and the boat tracks straight and true with little regard for chop and wakes. All who have tried it so far have come away very excited saying stable foiling on an A Cat is a sensation unlike any other sailing they have done.
The really remarkable fact is that it all happens automatically. There is none of the 'skirting the death zone' dance familiar to those who have tried to balance on C or J boards."

-------------------
I was under the impression that Marin Fischer designed the foils and Dario the boat. I guess I was wrong.
There is no equivalence in Dario's post of March 4th: he specifically states that the boat was foiling("..hulls nudge up until they are just clear of the surface...". If that is true then this design is a breakthru and both Dario and Martin are to be congratulated.
I hope we'll see a video soon that leaves no doubt. But the question about it's speed vs other A's still remains-full foiling does not necessarily mean that this A is faster that other A's. I hope it is and look forward to following the progress of the Paradox design.

#85 Doug Lord

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Posted 11 March 2013 - 02:03 PM

Excellent Martin Fischer interview here: http://www.catsailingnews.com/
Excerpt from the article:

Paradox A
- This year Dario Valenza is launching the Paradox, and you are responsible for its design. Which are the diff on this design/system from your previous versions?
MF: The principal setup is the same as on the MayFly, but this time we added a system to adjust the dihedral angle while sailing. This is important to get a good all-round boat. At low speed a small dihedral angle is advantageous, whereas at high speed a larger dihedral angle is the better solution. On the Paradox we think we got both.

>- Main Diff for L rudders against almost defacto Winglets in production As?
MF: To obtain positive pitch stability a lifting horizontal surface is absolutely necessary. The required size for pitch stability of the horizontal surface at the rudder can be computed from perturbation theory.
The main parameters that go into the equations are the surface of the main foil and its position with respect to the centre of gravity. This type of computation gives you the minimum size for a neutral configuration (pitch stability = zero) and then it is the designers work to add some safety margins to this minimum surface. It seems that I am more conservative in terms of safety margins than the other A-Class designers, since my L-rudders are significantly bigger than the typical winglets - to be seen.

A second point is the intersectional drag. The winglets form a sort of cross (+) with the vertical part of the rudder. This makes for 4 rectangular angles between surfaces and the corresponding intersectional drag. According to our simulations an L-rudder has less drag than a +-rudder for the same horizontal surface.

- The Paradox will be able to fly in high winds?
MF: Yes, I hope so



#86 k2mav

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Posted 11 March 2013 - 02:45 PM

In case their are any doubts about the viability of the Martin Fischer foil system, here is the best video yet-on the F18 Flying Phantom, Fischer foil system with Frank Camas sailing:


But this is not the same 100% system on the other boats. Check how dagger foils are digitalized in the video.

#87 Doug Lord

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Posted 11 March 2013 - 02:48 PM


In case their are any doubts about the viability of the Martin Fischer foil system, here is the best video yet-on the F18 Flying Phantom, Fischer foil system with Frank Camas sailing:


But this is not the same 100% system on the other boats. Check how dagger foils are digitalized in the video.

===========
You're right, of course, but is it because the Fischers F18 is not bound by any rules like the A is? The F18 is not a legal F18, is it?
I see what you mean in the video! Thanks for the info. Interesting that they are flying with the windward foil retracted.
In the article, Fischer says he needs both foils(W&L) down on his A Class system.Very interesting....

#88 k2mav

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Posted 11 March 2013 - 02:56 PM



In case their are any doubts about the viability of the Martin Fischer foil system, here is the best video yet-on the F18 Flying Phantom, Fischer foil system with Frank Camas sailing:


But this is not the same 100% system on the other boats. Check how dagger foils are digitalized in the video.

===========
You're right, of course, but is it because the Fischers F18 is not bound by any rules like the A is? The F18 is not a legal F18, is it?
I see what you mean in the video! Thanks for the info. Interesting that they are flying with the windward foil retracted.


NO, the Flying Phantom is an epoxy light, carbon mast, 3mts wide cat, the only 'F18' stuff are the hull molds from the Phantom F18.

#89 Börni

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Posted 11 March 2013 - 04:36 PM



In case their are any doubts about the viability of the Martin Fischer foil system, here is the best video yet-on the F18 Flying Phantom, Fischer foil system with Frank Camas sailing:


But this is not the same 100% system on the other boats. Check how dagger foils are digitalized in the video.

===========
You're right, of course, but is it because the Fischers F18 is not bound by any rules like the A is? The F18 is not a legal F18, is it?
I see what you mean in the video! Thanks for the info. Interesting that they are flying with the windward foil retracted.
In the article, Fischer says he needs both foils(W&L) down on his A Class system.Very interesting....


If you take a closer look at the windward foil, I think there is a horizontal lifting surface at the end of the boards. So it looks very much like the 1 gen S-L foils config of ETNZ AC72. I think the daggerboard case is also a major rework, probably allowing change of AOA and canting angle? Maybe Cammas is testing foil setups for his C-Class campaign???

#90 Doug Lord

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Posted 11 March 2013 - 07:30 PM




In case their are any doubts about the viability of the Martin Fischer foil system, here is the best video yet-on the F18 Flying Phantom, Fischer foil system with Frank Camas sailing:


But this is not the same 100% system on the other boats. Check how dagger foils are digitalized in the video.

===========
You're right, of course, but is it because the Fischers F18 is not bound by any rules like the A is? The F18 is not a legal F18, is it?
I see what you mean in the video! Thanks for the info. Interesting that they are flying with the windward foil retracted.
In the article, Fischer says he needs both foils(W&L) down on his A Class system.Very interesting....


If you take a closer look at the windward foil, I think there is a horizontal lifting surface at the end of the boards. So it looks very much like the 1 gen S-L foils config of ETNZ AC72. I think the daggerboard case is also a major rework, probably allowing change of AOA and canting angle? Maybe Cammas is testing foil setups for his C-Class campaign???

-----------------------------
I see what you mean-its not horizontal when retracted but because of the nature of the curve it sure would be when down. Wouldn't be legal on a A ,I don't think.

#91 Doug Lord

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Posted 11 March 2013 - 10:49 PM

This is the Phantom 18 designed by Martin Fischer. The foils here are not Martins-they belong to the other designer on the team:
http://www.youtube.c...d&v=taJYT4eAiWE

#92 dacarls

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Posted 13 March 2013 - 12:47 AM

The most we can see is that they fuzzed the "naughty bits". SO do you reckon---these C-foils with the L tip go down into the trunk and form a semi-V Surface-Piercing shape for off the wind work (like original ETNZ-72)?
Pretty smooth sailing overall, especially with a genny up: Apparently they have their rudder Ls at the correct AOI, unlike most curved-foil A-cats I've seen with rudder tabs. This is tricky stuff.

#93 Doug Lord

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Posted 13 March 2013 - 01:07 AM

The most we can see is that they fuzzed the "naughty bits". SO do you reckon---these C-foils with the L tip go down into the trunk and form a semi-V Surface-Piercing shape for off the wind work (like original ETNZ-72)?
Pretty smooth sailing overall, especially with a genny up: Apparently they have their rudder Ls at the correct AOI, unlike most curved-foil A-cats I've seen with rudder tabs. This is tricky stuff.

==================
Dave, I think it's a combination "L" foil and curved foil-with the curved part acting like a surface piercing foil.
Maybe like this sketch going on a tri project of mine. Characteristics change with a bit of retraction:

Attached Files



#94 SimonN

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Posted 13 March 2013 - 02:36 AM

Guys

Its great to see debates about foiling, but this thread is about new stuff in the A Class. Sorry to sound like the thread police, but please can we keep it to that and take other cat foiling stuff elsewhere?

Many thanks :)

#95 coxcreek

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Posted 13 March 2013 - 07:46 AM

In regards to the silly rule requiring the boards/foils be loaded from the top (because of danger and other nonsensical toss) what's to stop some inventive person designing a quick detach (like bolts with internal nuts set in the dagger, then countersunk heads covered/smoothed with quick set epoxy) this for attaching for the L/J whatever sections? Board is loaded top, crew lifts platform a foot or so, attaches lifting section.
Years ago in an AYRS journal, a couple of Australians had T foils on an A sized cat (Bandisnatch?) that folded up parallel with the dagger section; they pushed the folded foils down a wider case, then locked them open. Presumably they had some packer to fill the gaps.
If there is a way, there is a %#@ way.
Also the conservatives are blowing smoke if they believe that foiling flying is not going to come to many classes of boats - notwitstanding the stuck and predictable negativity from ChrisO. Tide has changed and is running in fast.
If the A's DON'T change to the real new stuff, for sure the class will either be superseded ... or die.

#96 Lars Schrøder D13

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Posted 13 March 2013 - 08:20 AM

Classes do die, but if foiling is the future then other classes wil take over and sailing will still be fun.

Just because the a-cat is pretty cool right now for a group of grumpy old men, the class doesnt need to chase every new development. Its a very good job the technical commitee is doing (thumps up to Graeme Harbour, Carla Schiefer, Andrew Landenberger, Thomas Paasch, Mike Drummond, Luc Du Bois, Murray Philpott, Guido Schulte and Bob Hodges) and hopefully they can stay in front of the developments so we can keep (more or less) the boats at the same levelled playground.

For stable foiling downwind a catamaran probably needs more power, so a 16-20 sqm spinnaker and a fixed wing, wider platform and some larger foils is the way to go. So go and make a class like that (I suggest you call it f-cat;-) if some of all you fast thinking peoble thinks the a-cat is too boring.

\Lars

#97 juniordave nz

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Posted 13 March 2013 - 09:03 AM

I don't agree with your suggestion that the technical committee should stay ahead of the developments. It's a development class, thats why so many of us love it. You can go mess around in your garage and go chuck it on your boat and not worry about breaking the rules, because there aren't many and they're easy to understand. But every interpretation stifles this a little. If you want a class with a level playground, go sail F16's or 18's or paper tigers or any other similar one design or tightly restricted classes.

And as for getting a full L foil in from above. Yeh that's possible, I'm sure we can make it work, there is nothing stopping how far inboard your foils can go above the water line, just so long as they don't stick past max width.

#98 Lars Schrøder D13

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Posted 13 March 2013 - 09:23 AM

It’s not a matter of staying ahead of any developments, but avoiding that the class is being changed into something totally different from what it is today - that’s the goal for the technical committee.

So fully foiling could be outside the scope and therefor they find ways to refine the rules, so it’s not possible.

It’s easy to form a new class with way more open rules that makes all the fun possible. Just publish some rules somewhere on the internet and see how many other that joins you. There is already a discussion here -http://forums.sailin...howtopic=144776

\Lars

#99 Doug Lord

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Posted 13 March 2013 - 11:48 AM

It's not a question if an A Class cat can foil or not-according to Dario Valenza his boat is stabley foiling and others have foiled with less stability. The question is can foiling be faster than non foiling under the current rule? Given that many people thought the boat could not foil under the current rule-it may be possible that the foilers can improve enough to be competitive.

#100 Chocko

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Posted 13 March 2013 - 12:12 PM

We at Tinaroo embraced the A cat because
1. they are light and can be easily set up by 1 person
2. simplicity
3. The A class guys of all levels helped us, and still are today
We didn't pick the a class because we all wanted to fly on foils...
Full foiling at our club, be it an anomoly, wouldn't be advantageous because of the generally light conditions.
We do have a foiling moth race at our club on the odd rare occasion.
He does abandon races because he cant get it out of the water and is soo far behind
Point being, Flying A classes don't suit everyone

I do applaud the current technical committee, they are doing the best anyone could ask for.




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