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X1 - Venture - Argo Test Sails |
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Medway Maniac
Really should get out more Joined: 13 May 05 Location: United Kingdom Online Status: Offline Posts: 2788 |
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Topic: X1 - Venture - Argo Test Sails Posted: 27 Mar 12 at 12:31pm |
It's the little finger that wears on my gloves, so yes, little finger closest to the boom. On Minisails - or indeed any other singlehander with a traveller wherein the lower mainsheet block(s) float from side to side, you can of course have the problem that when you try to pull yourself into the boat in a lull, all that happens is the boom comes towards you! No such problem with a lower block(s) fixed on the centreline on a bridle. Off-the-boom sheet loads are lower because the final fall pulls usefully sideways rather than down - you don't waste so much effort doing what the kicker should be doing. But as to why square top (and indeed other large roach mainsails) are easier to sheet compared to triangular sails of the same area, I think may be because the chord (width) if the sail is generally shorter, putting the centre of pressure closer to the mast. When switching from Laser 2 to L3k, I noticed that gybing was easier for what I presume is the same reason - the centre of pressure isn't moving so far (plus - so far a gybing benefits are concerned, the boom is correspondingly shorter). That said, I'm not entirely convinced that square or large roach mains really do give do more thrust for your heeling moment as current fashion dictates. More thrust in upriver conditions, sure, where all the breeze is aloft, but you pay a heeling moment penalty in open waters. A better lift/drag ratio, maybe - this is where everyone gets off on the aircraft theory - but not necessarily lift/heeling moment. Aircraft are much less worried about the moment generated by the load - heeling moment so crucial to us, is merely bending moment at the wing root to them, and is balanced by the other wing! The really crucial thing for wing efficiency, aspect ratio aside, is the profile. Planform (e.g. square top or triangular for us) is very much secondary, and it seems to me that it is much easier to cut a well-shaped sail profile on a triangular rig; with all those battens supporting the big high roach, it is hard to reliably build in a good shape over the full range of conditions. Look how quick 505's and Fireballs are to windward, despite having far less righting moment than current skiffs (my Fireball used to regularly beat the local 800's to the windward mark in a F.5). Must be down to rig efficiency - sheer power it ain't.
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G.R.F.
Really should get out more Joined: 10 Aug 08 Location: United Kingdom Online Status: Offline Posts: 4028 |
Post Options Quote Reply Posted: 27 Mar 12 at 12:41pm |
Is there an off the boom cleat and jammer that is preferred. I like the system, want to switch the V twin to off boom sheeting but will still need to cleat downwind when playing the kite, what cleat set up should I opt for?
Edited by G.R.F. - 27 Mar 12 at 12:42pm |
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Medway Maniac
Really should get out more Joined: 13 May 05 Location: United Kingdom Online Status: Offline Posts: 2788 |
Post Options Quote Reply Posted: 27 Mar 12 at 1:30pm |
Messrs Hollands and Thompson (D&D to you) of your very own club seem to be world experts in this field. You need to talk to them
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Rupert
Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956 |
Post Options Quote Reply Posted: 27 Mar 12 at 1:50pm |
Give I use mainsheet tension rather than kicker in light winds, so it is possible to keep leech tension correct in the lulls, how would I get round this with off the boom sheeting? Do you just have to play the kicker all the time?
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Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
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Medway Maniac
Really should get out more Joined: 13 May 05 Location: United Kingdom Online Status: Offline Posts: 2788 |
Post Options Quote Reply Posted: 27 Mar 12 at 2:04pm |
No, in the light stuff you can let the kicker off - you still have the blocks on the bridle to pull down on the boom, after all. But I do tend to play the kicker a lot upwind as soon as the crew is on the gunwale and beyond. No problem: it's easy to trap the (lightly loaded) sheet in your tiller hand to free the other for kicker and other adjustments.
Obviously, a decent ratchet block on the boom is crucial to all this - perhaps why off-the boom didn't take off in the 60's. Snipes used potentially head-gouging Holt jammers up on the boom, but they do have very high booms.
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G.R.F.
Really should get out more Joined: 10 Aug 08 Location: United Kingdom Online Status: Offline Posts: 4028 |
Post Options Quote Reply Posted: 27 Mar 12 at 2:19pm |
They are in hibernation, haven't seen either of them since Xmas and they are divorced which may also be a contributory factor. What would you suggest?
Edited by G.R.F. - 27 Mar 12 at 2:20pm |
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x1testpilot
Posting king Joined: 11 Feb 11 Location: Ealing Online Status: Offline Posts: 175 |
Post Options Quote Reply Posted: 27 Mar 12 at 3:03pm |
I do use the kicker quite a bit - particularly when wind aloft is different to lower down and I like to alter the twist. We have also been converted to really playing the cunningham upwind. This is ultimately easy for the helm as he/she does much less. The crew keeps adjusting for power. really works. MD |
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ChrisI
Posting king Joined: 09 Aug 10 Location: United Kingdom Online Status: Offline Posts: 143 |
Post Options Quote Reply Posted: 27 Mar 12 at 4:01pm |
Yes, we use a Harken 57 Ratchamatic as last block on the boom (plus a high tech mechanism for preventing boom to go out too far - knot in mainsheet) which takes some of the load of course. But this doesn't help to completely cleat off...
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Medway Maniac
Really should get out more Joined: 13 May 05 Location: United Kingdom Online Status: Offline Posts: 2788 |
Post Options Quote Reply Posted: 27 Mar 12 at 4:10pm |
No idea really - I've never given it much thought, except to appreciate that it ain't easy to find a set up that doesn't gouge your head and is operable throughout the range of the boom's swing, where the angle of sheet to boom changes significantly. You might find this thread interesting - similar probs to yours: But we're now way off-topic.
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x1testpilot
Posting king Joined: 11 Feb 11 Location: Ealing Online Status: Offline Posts: 175 |
Post Options Quote Reply Posted: 27 Mar 12 at 5:55pm |
I can't see much reason for a main-sheet cleat, I've certainly continuously sailed 9 hours without one. Perhaps single-handed it might be handy to occasionally cleat it off, or as one gentleman suggested it might be handy while helming and teaching to take to moment to help/demonstrate something to the trainees.
Perhaps some kind of open Vee or a hook and cleat could be installed on the deck for very occasional use? Perhaps two cleats a bit like the original lasers had (remember those nasty plastic laser cleats?). |
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