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Phils Rig School continued...

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G.R.F. View Drop Down
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    Posted: 28 Nov 09 at 5:29pm
Yes I think you're both right, nothing I'd like more than to develop stuff in
a modern restricted class, it could have happened in the Alto, hence why
I was so excited by it, new class in it's infancy with some already fairly
radical ideas (from my limited perspective).

Who was it that suggested the box OD idea? Someone here, and
mentioned it again recently. Sort of a single handed cherub, but with
what can we say some more 'not going to embarrass me in my hard core
world of kiters, snowboarders etc' name.
Oh what you doing these days Graeme? Shifts awkwardly from one foot
to the other, looks at the ground and mutters in a whisper 'er sailing a
cherub'.
Sorry even my skin isn't thick enough to stand the abuse I'd get some
several minutes later when they'd stopped laughing. More seriously, 12 ft
is too short, it doesn't agree with English Channel wave length never has
not in any craft, the bottom's littered with broken 12ft speedboats.

No some 'Open class where the top end of the sail size is set and the
length and maybe width of the box are limited would be highly
interesting.
Would it not also provide a platform for the Bloodaxes and Aardvarks of
this world and if the prime rule is that the craft remain easy to sail by
some limitation that rules out the trickier elements then it would be more
commercial and thus greater demand might re kindle the local cottage
Industry.


This bit for Chris..
Er what's with the racism jokes? last time i looked you convicts were the
same 'race' as us. That's the 2nd time this week the 'R' word has been
used inappropriately, we're touchy about it over here these days, you've
only got to disagree with anything to do with another country and you get
accused of being racists, we've even had the Eytie sympathisers at it
needlessly.
As to the Laser beating a modern Raceboard, you must be doing it very
wrong is all i can say, or your still using 7.5 sqmtr rigs.
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aardvark_issues View Drop Down
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Post Options Post Options   Quote aardvark_issues Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 5:04pm
Please no...
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rs405 View Drop Down
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Post Options Post Options   Quote rs405 Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 4:34pm
GRF should get a Moth! Its seems he wants a sitting diwn windsurfer and
thats about as close as you are going to get! Also a development class.
420, 470, 405, laser 4000
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 2:23pm

I think you're right there Skiffbob.  I've got tapered foam battens, an over-rotating wing mast, a hull that is on its 100th design iteration (or thereabouts), sails from a world renowned sailmaker (designed by a World champ/Olympic medallist, and made in Germany) and total freedom of choice when it comes to controls, innovations and developments. And all for less than the price of a RS200.

Maybe the RS100 should form the foundation of a development class?

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Post Options Post Options   Quote Skiffybob Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 1:53pm

Grumph, you keep going-on about rocket tensioners that are sewn-in as if it's something that the entire dinghy sailing industry does, and it's not. Just because you had this experience with a single loft it doesn't mean that it's commonplace.

We have rocket tensioners in our mains, and have used them for about 12 years. We also use tapered foam and carbon battens (we started using tapered foam battens over 20 yeas ago).

I think that we are all aware that the One Design classes are not at the cutting edge, but that's because they don't need to be, and the are more driven by delivering the reliable, low maintenance boat at the correct price, and as TT says, to some extent it doesn't matter how good or crap things like battens are, so long as eveyone has the same.

The more I read your posts, the more I'm of the opinion that you should be in a development class. You NEVER hear people in development classes complaining about these things, because if they think there is a better solution, they just get-on and do it. If it works others adopt it, and if it doesn't it goes into room 101.

I guess your problem is that your options are really limited to Cherub, 12fter, or IC, none of which I suspect will appeal to you. So I guess you'll just have to accept that whatever class will sail will be a compromise.

12ft Skiff - Gordon Keeble and the Furry Fly-by
AC - GBR271 - Whoosh
B49 - Island Alchemy
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 12:47pm
I've been doing a bit of Raceboarding again recently, and a lot of racing against Raceboards on the One Design. There's no evidence that your Raceboards are faster than the ones down here (or vice versa). With recent wins in Formula Worlds and runner-up in the RSX worlds, there's not much doubt that we have a pretty good high standard in boards (as do you). At the last OD nationals we have three current Olympians (from two countries) and two former Olympians and they averaged about 6th place, so we're not sailing too slowly.

So, racism and ancient jokes apart, there is simply no reason to believe that what we see from Raceboard performance is any less accurate than what you see. And what I see is that on confined waterways in light to moderate winds, a Laser can whip a Raceboard upwind because of its ability to tack faster and point higher when underpowered. And this is from the vantage point of being a successful sailor of boards and Lasers, in a club with 47 registered Lasers and about 35 registered boards. We often get 40+ of the two classes sharing a course, includng sailors who have been on the podium at titles from states to nationals, worlds, World Cup and Olympics. 

Of course, in other conditions (perhaps like those at your club) a board is miles quicker and the world's best Laser sailors are legs behind; even a Windsurfer One Design will pace the world Flying Dutchman champ upwind in a 20 knot breeze and a slop. But the point remains that in light shifty upwind stuff, a Raceboard is in trouble from what I can see from a very good viewpoint.

And yes, of course a windsurfer rig can alter camber on the fly. But a good boat rig can also alter camber on the fly, and it can alter twist without altering camber or with altering camber, because there are more controls and more independent controls that allow you to alter one thing without altering the other.

A board rig does what it does well, and a boat rig does what it does well, That's no great drama.

Sorry, but try winning a Laser title and board titles and then you may have a better basis of comparison about the performance of the two classes. And try playing with a Flying Dutchman rig, or a yacht or skiff rig with someone who knows what they are doing, and you'll surely be impressed.

Boat sailors are not morons, nor are boardsailers. Both are under a lot of pressure to develop.


Edited by Chris 249
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G.R.F. View Drop Down
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Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 12:06pm
Originally posted by Chris 249


In many ways they are less controllable than boat rigs; you can't adjust
draft, twist etc on the fly as well. You often have to buy a new mast to rig
to a new sail, rather than just tightening a wire or two.If board rigs were
so much better, then the most advanced racing board rigs would have
developed a big edge over comparable boats. They haven't. In many
conditions, even something like a Laser will slaughter a board, even a
Raceboard.


I worry about you sometimes Chris.. Er you're not locked up in some
correctional facility by any chance are you? Got sent down in the early
eighties and just using the correctional facility's computer, posting from
memory of the way it was..

Laser? Beat a Raceboard?

A laser couldn't beat the team fifteen kids on their techno's.

And you can't adjust the camber? (not that the camber inducer wasn't
designed specifically to lock the camber in, along with sliding carbon
tubes on draft lock battens, tensioned by 'rocket tensionisers' I notice
dingy sailmakers are now using, but have no idea why, so they just sew
them in such a way they can't be adjusted the way they are intended to.

Er I've got some news for you, nice surprise for when you get out.

You can do all those things and on the fly - miracle eh?

Edited by G.R.F.
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Chris 249 View Drop Down
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 28 Nov 09 at 11:30am
I think Grumpf's projected rig would be way too heavy and have way too much windage to work. Not only that, but there's no real reason to standardize masts in dinghies, as they are aimed at vastly different groups and there is vastly more variation in righting moments and sail area than in boards.

The smallest regularly-used board rigs are about 4m; the largest are 12.5. In contrast, there are tens of thousands of dinghies with 3.5-4m sails, many with 30m2 of sail, and some with 60+m2 of sail. So board rigs handle a variation of about 300%, boat rigs work over a variation of about 1700%.

The lightest boardsailers are about the same weight as the lightest windsurfers, but lots of dinghies carry three crew, so the weight range is about 3 times what a board has to handle. And righting moment in a board varies from about 160 ft/lb to mebbe 800, whereas righting moment in a boat varies from about 320 ft/lb to over 2000 ft/lb.

So in almost all areas, boat rigs have three or more times the variation of board rigs. It seems to follow logically that you cannot throw them all into the same basket.

Let's add in practicality....you can pick up and carry a board rig and chuck it in the water. You don't pick up and carry a boat rig in the same way. If you change some things, you can harm a class. When 12 Foot Skiffs developed sailplans that had to be rigged with the boat on their side, the class became extinct at three clubs where the rigging space was too restricted. Good idea?

The sailboat rig is a great thing. MArk Drela, a famous professor of aerodynamics from MIT whose plane and foiler designs hold world records, has told glider design groups that they should envy boat rigs, because the ability of a boat rig to adjust camber, angle of incidence etc is vastly superior to any aircraft wing ever designed. When an acknowledged guru of aerodynamics speaks, reasonable people listen.

Board rigs can also be great, but they have issues. In many ways they are less controllable than boat rigs; you can't adjust draft, twist etc on the fly as well. You often have to buy a new mast to rig to a new sail, rather than just tightening a wire or two.

If board rigs were so much better, then the most advanced racing board rigs would have developed a big edge over comparable boats. They haven't. In many conditions, even something like a Laser will slaughter a board, even a Raceboard.That's not the sign of a vastly superior design.

PS - variable-height mast collars were used in Aussie 14s, 1988 period. So was a "structural" mast and a non-structural fairing (1930s, 1970s) Neither are used any longer.


Edited by Chris 249
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Post Options Post Options   Quote GraemeB Quote  Post ReplyReply Direct Link To This Post Posted: 27 Nov 09 at 4:11pm
I think all in one bag says it all......
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Post Options Post Options   Quote getafix Quote  Post ReplyReply Direct Link To This Post Posted: 27 Nov 09 at 3:52pm
It's different from just moving the boom up and down the mast because it would allow the top of the mast to go higher / lower thus increasing or decreasing the projected area of the sail but compensating for that extra projected area by flattening the luff curve when you increase the projected area.....

I'm guessing (as I'm no spar designer) that side forces would have to be resisted via the design of the 'collar' or overlap between sections, in much the same way as the current carbon/composite two piece masts are.

I'm just missing the windglider reference....


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