Terry Hollis
Super Anarchist
Hmmm .. still doesn't work .. Try this ..Terry Hollis said:
Kaenon Interviews: A - Class Worlds with Burling, Tuke and Davies
new stuff in the a-class
- Thread starter Lars Schrøder d 13
- Start date
Kaenon Interviews: A - Class Worlds with Burling, Tuke and Davies
Sonofabitch
Member
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Fuck it, I'm going to get me an NS14 and bust Dougy's balls.
eracer
New member
Crashing on a Moth at 25-30 knots is one thing; crashing at near those speeds from the transom of an A-cat while on the trapeze is quite another. For injury, damage, insurance and practical reasons I have come to the conclusion that we (A class) should indeed go "back". We seem to have hit the practical limit of the terminal velocity, especially in rough water conditions. The picture of the completely airborne A-cat seems to confirm that, although that was probably operator error. That is a rodeo, not a boat race. Imo, the better class goal is that we "skim" at 20 knts with reasonable control, with rudders that pop up and down quickly and "appendages" that are easily and fully retractable. I would add that both of those functions are demonstrable within some time limit, while sailing . Surely those goals could be a achieved with minimal word and measurement changes to the current class rules. Can we let things keep going as they are for another year or two? Another year to experience foiling development and it's consequences may make for a better proposal and better reasons for pursuing or not pursuing a proposal. If foiling on the A-class platform prices the class out of the market of non professional and/or non-sponsored sailors then such developments are not good for our "development" class. Designing, building and altering your own a-cat rocket in your own garage is half the fun; we dare not lose that aspect of our class character.
eracer
New member
Submitted by A-cat US-80
BalticBandit
Super Anarchist
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doug if you read earlier, there were efforts do do this but they were not being used. Now Fuck Off
Jim Caldwell
Member
Hasn't anyone else followed the "Stunt S.9 Full Fly" tread?
The answer is already developed.
The answer is already developed.
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BalticBandit
Super Anarchist
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Jim - good to see you here. You will get your questions answered by actual A Class folks if you ask them here instead of Dougy the Pest.
The Stunt S.9 has a couple of problems WRT A class
A) it uses T foils which the A Class cannot use since the T foil extends outside the edge of the hull and thus violates max width rules
b ) it uses a wand system to drive a flap - which ALSO violates A class rules
So the Stunt S.9 - while an interesting boat - doesn't address this
The Stunt S.9 has a couple of problems WRT A class
A) it uses T foils which the A Class cannot use since the T foil extends outside the edge of the hull and thus violates max width rules
b ) it uses a wand system to drive a flap - which ALSO violates A class rules
So the Stunt S.9 - while an interesting boat - doesn't address this
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GybeSet
Super Anarchist
Scott Anderson is on a conventional boat, was Landy too ?
both great results, top of fleet barring the paid guns
both great results, top of fleet barring the paid guns
duncan (the other one)
Super Anarchist
Crazy thoughts on height control:
would venturi-type vents in the foil (say somewhere on the surface, just back from the LE of the main foil) which vented up the strut at ride height provide a passive (in the context of Rule52) height control?
The idea is that with the strut fully immersed, foil acts normally and provides (excessive) lift. As you hit your ride height, the upper opening is exposed to atmosphere and air is sucked down to vent at the surface of the foil.
I'm guessing this would only work if the venting was on the upper (low-pressure) surface, and then I'm not sure if it would reduce lift, or give you a catastrophic increase in lift!
I'm sure this isn't a new idea (or is new, but fundamentally flawed).
would venturi-type vents in the foil (say somewhere on the surface, just back from the LE of the main foil) which vented up the strut at ride height provide a passive (in the context of Rule52) height control?
The idea is that with the strut fully immersed, foil acts normally and provides (excessive) lift. As you hit your ride height, the upper opening is exposed to atmosphere and air is sucked down to vent at the surface of the foil.
I'm guessing this would only work if the venting was on the upper (low-pressure) surface, and then I'm not sure if it would reduce lift, or give you a catastrophic increase in lift!
I'm sure this isn't a new idea (or is new, but fundamentally flawed).
I think you could argue that mast rotation is adjusted by a control line, which is operated by the crew. Similar comments apply to the other examples given: the angle of the J foils is adjusted by a control line, which is operated by the crew.
It's not so clear with wands because they work independently of the crew. I've looked through the ISAF Case Book and couldn't find any mention of wands. It's a simple enough question though and ISAF should be able to rule them in or out. They've been around for long enough.
The A class should sort this out before proposing changes to rule 8.2. Otherwise, we don't know what we're voting for: ETNZ style L boards or T foils with wands.
BalticBandit
Super Anarchist
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I can see RRS 52 being read both ways
Now particularly in light of Rule 42, and its various interpretations, its perfectly ok for your boom to be moved by forces other than just manual power during a gybe or a tack ("natural action of the wind and the water") so it seems to me that a mechanism that dynamically translates wind energy vector (ie forward motion) into some other energy motion in a different axis of freedom is completely within the sense of those rules. After all, the sails translate wind energy TWD X to boat speed in CMG Y... all the flap is doing is making yet another translation, albeit at a much higher speed. And it is doing so at the penalty of increased drag
ita 16
Anarchist
yes, I've seen this air turbulence, on 'S.9, I think this air going to fill an area of the flap where there is standing water, thus reducing the friction drag of water.
I regret a little that no one uses as an example the S .9, it is not a class A but is the boat more similar to A.
regarding the A class, I can say they are doing a lot of experiments with good L, J, C foil, but I do not think that all of these are suitable, it is a path that I have already done and the end p...oint is always and only one "automatic control sistem "then, wand and flaps.
surely we will see the Class A fly better in the coming months, but many problems remain.
currently the class is divided between yes and no fly, the current rules do not satisfy both sides, I believe that the only solution is "divided into 2 classes," an old style, one totally free from rules. I think this is the end point of the class A.
my statements are based on current technology and mechanical systems, but this could change if someone invents new solutions.
regards , Michele Petrucci
The key for the A class is not "should or shouldn't an A foil", but what is the vision is for the class?
Should development be limited? If so, by what mechanism? Singling out foiling (as in you can have any development you like as long as one hull stays in the water) doesn't make any sense. Foiling is just the current hot topic, probably the same arguments were made over other technological developments but "we're a development class" seems to have won the day.
Arguments against foiling:
Should development be limited? If so, by what mechanism? Singling out foiling (as in you can have any development you like as long as one hull stays in the water) doesn't make any sense. Foiling is just the current hot topic, probably the same arguments were made over other technological developments but "we're a development class" seems to have won the day.
Arguments against foiling:
- It's too hard—only because current rules try to ban it by making it hard. The fact that As foil anyway says a lot about how much easier it could be if the rules were at least neutral. It could be really easy if the rules were sympathetic.
- It costs too much—hydrofoils are only a marginal extra expense in the overall cost of the boat, plenty of other advances have also made the boats more expensive (carbon wing masts, carbon hulls, exotic sails)
- It will obsolete the entire fleet—the introduction of carbon fibre hulls obsoleted other materials in addition to increasing cost and making it harder for back yard builders. But they weren't banned or vicariously ruled out.
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ita 16
Anarchist
there is no one solution that satisfies both parties, the class is already divided, is a fact.
so if you want to get ahead you have to understand this and immediately change the rules.
the class is already big and has many members, now, the most important thing is to keep the number of members, then rules that satisfy the members.
the argument technologies, fly, foil, etc. is in the second floor.
so if you want to get ahead you have to understand this and immediately change the rules.
the class is already big and has many members, now, the most important thing is to keep the number of members, then rules that satisfy the members.
the argument technologies, fly, foil, etc. is in the second floor.
Steve Clark
Super Anarchist
Taken at it's face value and interpreted strictly, Rule 52 makes sailboats impossible.
Everything stretches and bends and thus 'adjusts" itself under load.
If the load varies, as in sailing, then the degree of bend and stretch changes independent of the manual effort of the crew.
Any design that takes advantage of the stretch and bend of materials to improve performance is therefore in violation of Rule 52.
Goodbye.
SHC
Everything stretches and bends and thus 'adjusts" itself under load.
If the load varies, as in sailing, then the degree of bend and stretch changes independent of the manual effort of the crew.
Any design that takes advantage of the stretch and bend of materials to improve performance is therefore in violation of Rule 52.
Goodbye.
SHC
BalticBandit
Super Anarchist
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That's kinda where I was going steve with the example of a boom in a gybe. Under the most onerous reading of 52, one would have to manually pull in the boom before starting the gybe lest the wind not act as "external power source to move the boom"
Moths did not invent water powered operation of appendages. Its been around for more than 60 years in wind vane mechanical autopilots used in model yachts before RC and then in short handed trans ocean yacht racing, long before electronic autopilots.
read: http://en.wikipedia.org/wiki/Self-steering_gear
Rewording of RRS52 can not backdate history.
read: http://en.wikipedia.org/wiki/Self-steering_gear
Rewording of RRS52 can not backdate history.
BalticBandit
Super Anarchist
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Agreed. and the old ruling on ooching was that it had to be "the natural action of the wind or the water" and under that wands would be just fine
Definitely not a new idea though I don't know if it has been tried in the last 5-10 on sailing foilers. I think part of the issue would be response times. Bleeding air takes time and, possibly more importantly, washing off any air introduced to the foil area would also take time. IIRC mothies also report feeling drag when there is air on the foils. It would be a nice mechnism to use in some way though.
