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Jack Sparrow View Drop Down
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Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Topic: Landyachting
    Posted: 21 Apr 12 at 6:43pm
True. But I think both of those yacht designs have moveable cockpit shells.
R&J and I think Gosslings in the UK.
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aus230 View Drop Down
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Post Options Post Options   Quote aus230 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Apr 12 at 2:51pm
I thought that the Plumes and the air tracks would have the mast post in a designed position as they are production yachts?
What sail is the best performer at this time. The only sail maker that I can find in your part of the world is R@J.
Cheers
aus230
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Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 12 at 12:46pm
thanks for that very helpful!

Originally posted by aus230


... what distance is the center of the mast post back to the center of the back axles.(Plum for example) Cheersaus230


I would say that it varies depending on the center of balance of the yacht, the center of effort of the sail and the center of lateral resistance of the yacht. My personal view is that the center of lateral resistance is a nightmare to calculate. But is close enough to the center of balance to make no odds. So my answer to your question would be that the mast post position depends on the the design of the yacht, sail and the weight of the pilot. IMO which isn't worth a dime!

Edited by Jack Sparrow - 20 Apr 12 at 12:48pm
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Post Options Post Options   Quote aus230 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 12 at 10:53am
May be usful info .(from NZ Sandpaper mag)


Planing class 5 Battens:
Although the object of your aerofoil is a
maximum camber at around 40%,
because of the mast and mast pocket the
battens need to be shaped slightly differently.
I recommend that the shortest top
batten should have it's maximum camber
at 22% back and the longest at 35% with
the rest arranged logically in between.
Some people prefer 25% for all battens
and the fact that both methods give good
results shows that what is most important
is that you have a uniform shape over the
whole length of the sail. Mixing stiff and
soft battens with the max. camber at vary
-ing amounts is the worst of all worlds.
There need be no magic skill to planing
class 5 battens so long as you are
methodical and prepared to take quite a
long time about it.


Cheers
AUS230
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Jack Sparrow View Drop Down
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Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 12 at 10:09am
Yes R&J sail. I'm not sure if the sail was designed for the mast. But they are both similar in age! The boom is free floating at the goose neck. I've always been unsure about that. it sounds like its something to try. Because as you relieve the pressure on the sheet the boom does move forward and roll around the mast. Having a rollock would help keep the boom from doing this and help keep the bottom of the soft luff pocket from collapsing forward. Good idea.

There is no downhaul. Only a few yachts seem to run a downhaul system from what I've seen. This is normally part of the sheeting system, so as you sheet in you apply more downhaul.

The current battens are fibreglass with a slight taper. They are the white ridged style of batten. In section they look like a cross.
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aus230 View Drop Down
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Post Options Post Options   Quote aus230 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 12 at 1:22am
Gday Jack.
I looks like you use a R@J sail like I use on aus230. I have never had the problem, Is your mast a yorker designed as that is what R@J designed my sail around. We also use a rowlock on the front of the boom maybe that is why mine holds it shape in light winds. Have the battens been tapered?

Q: As I have designed and built my own yachts from trial and error. The one thing that I have not been able to get a clear answer on is what distance is the center of the mast post back to the center of the back axles.(Plum for example)
Cheers
aus230


Edited by aus230 - 20 Apr 12 at 4:06am
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ham4sand View Drop Down
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Post Options Post Options   Quote ham4sand Quote  Post ReplyReply Direct Link To This Post Posted: 19 Apr 12 at 11:18pm
more downhaul if its like a windsurf rig?
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Jack Sparrow View Drop Down
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Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Posted: 19 Apr 12 at 8:42pm
Hi AUS230,

how ya do'in? I think we have chatted on seabreeze before. Good to see you have found this place!

Q: I have bad batten poke on my class 5 sail when I'm easing the sheet in the really light stuff. And I find my yacht is very binary when sailing in these conditions. It's either is going fast or isn't going at all. This seems to depend on if I have enough speed to generate enough apparent to sheet in to the point where my battens stop poking out the front. As you ease the sheet you end up with the luff pocket rolling forward and a really nasty 90˚ shape made by the sail / battens.

Any advice on this? Much much softer battens?
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Post Options Post Options   Quote aus230 Quote  Post ReplyReply Direct Link To This Post Posted: 19 Apr 12 at 3:18pm



Hi I just found this forum. I sail class5 and mini yachts in Australia. I also use a great forum in Australia  http://www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/ I hope that we can share information on building and sailing yachts.
Cheers
aus230

Edited by aus230 - 20 Apr 12 at 2:44am
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Jack Sparrow View Drop Down
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Post Options Post Options   Quote Jack Sparrow Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 12 at 2:39pm
http://vimeo.com/easyridevideos/mondial2012

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Forum embed code for VIMEO anyone?
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