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Re: A Cat Championship in Panama City [Re: Jake] #279194
05/27/15 07:14 PM
05/27/15 07:14 PM
Joined: Sep 2002
Posts: 3,223
Roanoke Island ,N.C.
Team_Cat_Fever Offline
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Originally Posted by Jake
man, just spent some time in that thread on Sailing Anarchy...you guys did start quite a storm. It's all in the wording. Nice that it appears to be resolved and I think you guys are headed down a good path. Contrary to some of the talk, it would be much more affordable to retrofit a standard "ocean hugging" boat with bottom-up installed foils to get it airborne than to go through the contortions of modifying the hull to accept some really oddly shaped daggerboard only to find out another oddly shaped daggerboard works better (and now it won't fit). A fore-aft top adjustment doesn't have to be buried in the trunk either and could just be bolted to the top of the deck.

Personally, after seeing the result of the phantom in the surf during the Florida 300, I'm waiting for someone to build a hull where the dagger board trunk opens through the side of the hull so the foil can be fully raised and permit sliding onto the beach. There are a lot of considerations there but I'm sure it can be done....heck, build the structure on the side of the hull like an old-school leeboard and unpin the entire structure when approaching the beach.


You still can't go beyond max beam, and if you put the box on the inside you would lose a large amount of righting moment. This move has opened things up for innovation ,but it definitely doesn't mean it will be easier or even better, but the opportunity is there. It will be interesting to see the journey.


"I said, now, I said ,pay attention boy!"

The cure for anything is salt water - sweat, tears, or the sea
Isak Dinesen
If a man is to be obsessed by something.... I suppose a boat is as good as anything... perhaps a bit better than most.
E. B. White
-- Have You Seen This? --
Re: A Cat Championship in Panama City [Re: Team_Cat_Fever] #279198
05/27/15 08:18 PM
05/27/15 08:18 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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Originally Posted by Team_Cat_Fever
Originally Posted by Jake
man, just spent some time in that thread on Sailing Anarchy...you guys did start quite a storm. It's all in the wording. Nice that it appears to be resolved and I think you guys are headed down a good path. Contrary to some of the talk, it would be much more affordable to retrofit a standard "ocean hugging" boat with bottom-up installed foils to get it airborne than to go through the contortions of modifying the hull to accept some really oddly shaped daggerboard only to find out another oddly shaped daggerboard works better (and now it won't fit). A fore-aft top adjustment doesn't have to be buried in the trunk either and could just be bolted to the top of the deck.

Personally, after seeing the result of the phantom in the surf during the Florida 300, I'm waiting for someone to build a hull where the dagger board trunk opens through the side of the hull so the foil can be fully raised and permit sliding onto the beach. There are a lot of considerations there but I'm sure it can be done....heck, build the structure on the side of the hull like an old-school leeboard and unpin the entire structure when approaching the beach.


You still can't go beyond max beam, and if you put the box on the inside you would lose a large amount of righting moment. This move has opened things up for innovation ,but it definitely doesn't mean it will be easier or even better, but the opportunity is there. It will be interesting to see the journey.


How much does righting moment matter? (I really don't know)...the Moths seem to get along ok with very little of it. Talking with JC about the CF20 Foiler, once they get up to speed with it and start dealing with really high apparent wind angles, they lose so much of the typical side force on the sail plan that they struggle to keep the windward hull flying. It often results in the windward hull dropping down to the water. That action can result in a wave hitting the people on the trapeze which is, reportedly, pretty darn dramatic at 30 knots!


Jake Kohl
Re: A Cat Championship in Panama City [Re: David Ingram] #279208
05/28/15 06:11 AM
05/28/15 06:11 AM
Joined: Apr 2005
Posts: 473
Panama City, Florida
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I know it is forbidden in the AC, but could you just keep both boards down the whole time to minimize the "tea bagging"? Too much drag???


Rob V. Nacra 5.2 Panama City
Re: A Cat Championship in Panama City [Re: David Ingram] #279209
05/28/15 06:59 AM
05/28/15 06:59 AM
Joined: Aug 2011
Posts: 774
Greenville SC
bacho Offline
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Not that I am against the idea, but I would like to see some builds or proposals on how it will be any cheaper to use foils inserted from the bottom.

I saw a price on the exploder "kit" for foils. Seems like it was about $3k.

Re: A Cat Championship in Panama City [Re: bacho] #279212
05/28/15 07:29 AM
05/28/15 07:29 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
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Originally Posted by bacho
Not that I am against the idea, but I would like to see some builds or proposals on how it will be any cheaper to use foils inserted from the bottom.

I saw a price on the exploder "kit" for foils. Seems like it was about $3k.


Which is funny how cheap we are, yet we demand the latest gizmos.

$3k is close to the entry fee for some leaner regattas...


Jay

Re: A Cat Championship in Panama City [Re: bacho] #279213
05/28/15 07:49 AM
05/28/15 07:49 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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Originally Posted by bacho
Not that I am against the idea, but I would like to see some builds or proposals on how it will be any cheaper to use foils inserted from the bottom.

I saw a price on the exploder "kit" for foils. Seems like it was about $3k.


A lot of guys have sawed out their daggerboard trunks to replace them with curved, or wide open, trunks or even moved the location of the trunks for different types of boards. We had a few guys here do that to get to C-boards but their modifications would have to be re-done to get to any revision of the current foiling boards. When a new board style is developed, it may require a completely different trunk configuration to accommodate the rule that required that the board be inserted from the top.

With an option to insert the board from the bottom of the boat, it means you could conceptually take even a boyer MKIII and configure it with a foiling board without cutting the hull. Any fore-aft adjustment needed for the foil could be done with a mechanism that was bolted/laminated to the top of the existing deck and inserts inside the existing trunks could allow proper operation (although one might argue the value of investing that much into an older A-cat). You could also wildly change board styles without having to go in and modify the hull.

What we're probably going to see early on is the V-style boards like used in the America's Cup...and those really don't have any way to go in from the top into a typical trunk configuration.


Jake Kohl
Re: A Cat Championship in Panama City [Re: Jake] #279218
05/28/15 08:41 AM
05/28/15 08:41 AM
Joined: Jun 2003
Posts: 712
mikekrantz Offline
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I made a set of sliders for my C-boards and glued them to the top of the trunks. It allows me to go from neutral to +5 degrees of cant. One line pulls them both back at the same time and the bungee pulls them forward when I release the cleat.

Works really well running downwind to keep the bows up, and neutral cant upwind reduces the drag.

My next step is to build longer C-boards, and increase the size of the rudder winglets to stabilize the increased lift generated by the C-boards.

[Linked Image]

Re: A Cat Championship in Panama City [Re: mikekrantz] #279219
05/28/15 08:46 AM
05/28/15 08:46 AM
Joined: Jun 2003
Posts: 712
mikekrantz Offline
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Here's a link to a video showing how stable my boat is with the boards set at maximum cant.

https://www.facebook.com/chuck.allen.562/videos/10205915743912691/

Re: A Cat Championship in Panama City [Re: Jake] #279222
05/28/15 09:10 AM
05/28/15 09:10 AM
Joined: Sep 2002
Posts: 3,223
Roanoke Island ,N.C.
Team_Cat_Fever Offline
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Originally Posted by Jake
Originally Posted by Team_Cat_Fever
Originally Posted by Jake
man, just spent some time in that thread on Sailing Anarchy...you guys did start quite a storm. It's all in the wording. Nice that it appears to be resolved and I think you guys are headed down a good path. Contrary to some of the talk, it would be much more affordable to retrofit a standard "ocean hugging" boat with bottom-up installed foils to get it airborne than to go through the contortions of modifying the hull to accept some really oddly shaped daggerboard only to find out another oddly shaped daggerboard works better (and now it won't fit). A fore-aft top adjustment doesn't have to be buried in the trunk either and could just be bolted to the top of the deck.

Personally, after seeing the result of the phantom in the surf during the Florida 300, I'm waiting for someone to build a hull where the dagger board trunk opens through the side of the hull so the foil can be fully raised and permit sliding onto the beach. There are a lot of considerations there but I'm sure it can be done....heck, build the structure on the side of the hull like an old-school leeboard and unpin the entire structure when approaching the beach.


You still can't go beyond max beam, and if you put the box on the inside you would lose a large amount of righting moment. This move has opened things up for innovation ,but it definitely doesn't mean it will be easier or even better, but the opportunity is there. It will be interesting to see the journey.


How much does righting moment matter? (I really don't know)...the Moths seem to get along ok with very little of it. Talking with JC about the CF20 Foiler, once they get up to speed with it and start dealing with really high apparent wind angles, they lose so much of the typical side force on the sail plan that they struggle to keep the windward hull flying. It often results in the windward hull dropping down to the water. That action can result in a wave hitting the people on the trapeze which is, reportedly, pretty darn dramatic at 30 knots!


Righting moment is what gets you foiling in the first place(pops you up). The end game is foiling at minimum class limits, so yeah it's important at least in the direction I've been studying.Not to say some other innovation won't negate that altogether, like a center Moth foil, but active controls are still illegal.


"I said, now, I said ,pay attention boy!"

The cure for anything is salt water - sweat, tears, or the sea
Isak Dinesen
If a man is to be obsessed by something.... I suppose a boat is as good as anything... perhaps a bit better than most.
E. B. White
Re: A Cat Championship in Panama City [Re: Team_Cat_Fever] #279226
05/28/15 09:30 AM
05/28/15 09:30 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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Jake  Offline
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Originally Posted by Team_Cat_Fever


Righting moment is what gets you foiling in the first place(pops you up). The end game is foiling at minimum class limits, so yeah it's important at least in the direction I've been studying.Not to say some other innovation won't negate that altogether, like a center Moth foil, but active controls are still illegal.


You would still have the same righting moment in sea-hugger / displacement mode to initially get up to speed and would have the righting moment reduce as the boat comes up on foils if the foils were inset. Heck, it might be an advantage in some situations. It does seem, however, that the current method of foiling on the a-cats requires the trapeze action downwind...but that need might change as the speeds and apparent wind increase as the foils get better. I'm just tossing out ideas. Regardless, it will be interesting to watch how it develops.



Jake Kohl
Re: A Cat Championship in Panama City [Re: David Ingram] #279245
05/28/15 02:58 PM
05/28/15 02:58 PM
Joined: Sep 2002
Posts: 3,223
Roanoke Island ,N.C.
Team_Cat_Fever Offline
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No you wouldn't have the same in floater mode, the foils would be inboard(can't go outboard because of max beam rule) of your hulls, instead of through them, unless I'm misunderstanding your concept.This puts them 8-10" inboard (each hull)of where they generally are now, making a decrease of 16-20" of righting moment.


"I said, now, I said ,pay attention boy!"

The cure for anything is salt water - sweat, tears, or the sea
Isak Dinesen
If a man is to be obsessed by something.... I suppose a boat is as good as anything... perhaps a bit better than most.
E. B. White
Re: A Cat Championship in Panama City [Re: Team_Cat_Fever] #279249
05/28/15 03:25 PM
05/28/15 03:25 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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I'm looking at the righting moment based on where the platform rotates as it starts to heal. While the hulls are in the water, that rotation would mostly take place at the leeward hull where it contacts the water. The board (depth) at that point has an affect on how easily the boat rotates related to leeway/traction in the water. Most of that righting moment in a floating mode would be calculated at where the hull contacts the water and not the board...BUT, I'm sure there are some other complex dynamics related to heal that that an inward board placement would negatively affect. For instance, you would lose board depth in the water as the boat heals if it were placed inboard from the hull.


Jake Kohl
Re: A Cat Championship in Panama City [Re: Team_Cat_Fever] #279251
05/28/15 03:37 PM
05/28/15 03:37 PM
Joined: Jan 2005
Posts: 6,048
Sebring, Florida.
Timbo Offline
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Sebring, Florida.
Originally Posted by Team_Cat_Fever
No you wouldn't have the same in floater mode, the foils would be inboard(can't go outboard because of max beam rule) of your hulls, instead of through them, unless I'm misunderstanding your concept.This puts them 8-10" inboard (each hull)of where they generally are now, making a decrease of 16-20" of righting moment.


Perhaps the A cat Foiling Rules need to change too. Make it easier to control, via the wand system, make the foils easier/cheaper to build and install, and they will get more boats foiling, faster, safer, cheaper. What's not to like? I mean, if you are going to toss the non-foiling rules, and go with foiling, why not do it right? The Moth guys figured it out a long time ago with the wand system.

Go look at that S9 video Mike posted in the other thread. Do that with the A cats and presto, full foiling class that could also be converted to non-foiling, or allow all the (old, obsolete) A cats to install that type of foil system and be competitive again.


Blade F16
#777
Re: A Cat Championship in Panama City [Re: David Ingram] #279264
05/29/15 12:14 AM
05/29/15 12:14 AM
Joined: May 2015
Posts: 5
A
Abraham Offline
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I'm looking at the righting moment based on where the platform rotates as it starts to heal.

Re: A Cat Championship in Panama City [Re: Timbo] #279269
05/29/15 05:29 AM
05/29/15 05:29 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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Originally Posted by Timbo
Originally Posted by Team_Cat_Fever
No you wouldn't have the same in floater mode, the foils would be inboard(can't go outboard because of max beam rule) of your hulls, instead of through them, unless I'm misunderstanding your concept.This puts them 8-10" inboard (each hull)of where they generally are now, making a decrease of 16-20" of righting moment.


Perhaps the A cat Foiling Rules need to change too. Make it easier to control, via the wand system, make the foils easier/cheaper to build and install, and they will get more boats foiling, faster, safer, cheaper. What's not to like? I mean, if you are going to toss the non-foiling rules, and go with foiling, why not do it right? The Moth guys figured it out a long time ago with the wand system.

Go look at that S9 video Mike posted in the other thread. Do that with the A cats and presto, full foiling class that could also be converted to non-foiling, or allow all the (old, obsolete) A cats to install that type of foil system and be competitive again.


I get the feeling that wands are getting to be a little old-school. There is a lot of complication with the linkage mechanisms and getting the action right takes some effort (unless someone has worked all that out for you ahead of time). I'm guessing the self regulating foils are going to be the future. Back when foiling first started on power boats the foils were self regulating and we've seen that theme through everything from Hydroptere, the recent America's Cup, and even Dave Carlson's creative beach cat adaptations in the 80's. Here's a picture of Alexander Graham Bell's record setting hydro foiler built in 1919. It held the foiler speed record at 60 knots until the 1960s. Even it has a foil system that reduces the amount of foil and the resulting lift as it gets faster and higher out of the water.

[Linked Image]

The trick with a self regulating foil is to do it efficiently. Looking at that picture, you could understand how draggy all of those ladder foils can be. Hydroptere improved on the theme with a single tapered, inward canted, foil. As the boat lifts higher out of the water, it has less foil in the water and that water born foil has a shorter chord for less wetted surface area. The America's Cup testing determined that the V-shaped foil offered a stability advantage with the two somewhat opposed lifting surfaces in the "V" working against each other. That V foil is also self regulating and starts reducing lift gradually as that V pierces the surface.


Jake Kohl
Re: A Cat Championship in Panama City [Re: David Ingram] #279270
05/29/15 07:07 AM
05/29/15 07:07 AM
Joined: Jun 2003
Posts: 712
mikekrantz Offline
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Here is how stable foiling can be. This is Bruce Mahoney on his DNA foiling between races at the NA's last week.

https://youtu.be/m9Jhjr1cl98


Re: A Cat Championship in Panama City [Re: Abraham] #279273
05/29/15 08:18 AM
05/29/15 08:18 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
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Originally Posted by Abraham
I'm looking at the righting moment based on where the platform rotates as it starts to heal.


I'd bet you are, spammer.


Jay

Re: A Cat Championship in Panama City [Re: waterbug_wpb] #279274
05/29/15 08:22 AM
05/29/15 08:22 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
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Naples, FL
I think I like the max beam rule, since a crowded start line with everyone's T-foils underwater might make for additional damage when they all get tangled up...

The moth foils don't extend beyond the beam of the hull, do they? I'd suspect they certainly don't extend beyond the racks...?


Jay

Re: A Cat Championship in Panama City [Re: David Ingram] #279277
05/29/15 09:51 AM
05/29/15 09:51 AM
Joined: Nov 2011
Posts: 554
Boston, Ma
J
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Boston, Ma
They extend well beyond the beam of the hull, but not the racks.


USF18 Eastern Area Rep
Nacra Infusion USA 753
Re: A Cat Championship in Panama City [Re: Jeff.Dusek] #279279
05/29/15 10:24 AM
05/29/15 10:24 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
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so there isn't often foil-tangling going on at busy starts, since the racks would probably collide first?

Not that collisions should be a regular event, but I've got some scratches down the sides of my hulls. I call them "starting badges of courage"

edit: If I get enough of those "badges", I figure I will be the "Keep away from that F'n guy" boat smile

Last edited by waterbug_wpb; 05/29/15 10:27 AM.

Jay

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