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Blobby View Drop Down
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Post Options Post Options   Quote Blobby Quote  Post ReplyReply Direct Link To This Post Topic: CHERUB
    Posted: 22 Aug 05 at 1:51am

Originally posted by Jack Sparrow

Originally posted by Blobby

...and my CHerub is the quickest
Cherub thats never been built...


But will you be able to keep it upright

probably not - but atleast the water is warm over here...

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Granite View Drop Down
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Post Options Post Options   Quote Granite Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 1:05pm

Lifting foils with no trim tabs or angle adjustment are asking for trouble if you ask me. OK for going up wind at a steady pace, then you turn around pop the kite the speed doubles giving much more lift you hit a wave and

bang goes your carefuly set angle of attack!

If you had up and down wind settings for the foils it might be enough but auto control is the way forward.

PS no lifting foils when this was taken



Edited by Granite
If it doesn't break it's too heavy; if it does it wasn't built right
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andy_cherub View Drop Down
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Post Options Post Options   Quote andy_cherub Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 4:53pm
This is why we love our cherubs!!!
-12ft skiff, Team 'CST Composites'
-Many thanks goes out to all of my sponsors.
Ignore my user name, my views are of a 12ft skiff
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Ginger_69 View Drop Down
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Post Options Post Options   Quote Ginger_69 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 5:45pm
hey strawberry i did some reading and thinking about foiling and when you put the lifting foils on there is an increase in form and parasitic drag from the foils themselves plus when you put an angle of attack on the foils and use them to generate lift there is some induced drag which depends on the efficieny of the foils and the ammount of lift generated. Which is not good

The gain is because you reduce the displacement of the hull thus reducing the wavemaking drag and potentialy a decrease in form drag as the weted surface area will decrease slightly. All this helps to promote early planing.

When the boat is planing the part of the weight of the hull  will be taken on the lifting foils reducing the effective weight on the hull. The lifting foils use both the upper and lower surfaces rather than just the lower as with a planing hull giving efficiency improvements. Further efficiency improvements come from the higher aspect ratio of the fols compared to a planing hull which is short and fat.

Obviously lifting the hull totaly out of the water would result in lower drag again biut this introduces serious control issues if you are standing on the side dangling from a bit of wire.

Chew valley lake s c
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I14 1209
lightning-168
Whaam (cherub)
Atum bom (cherub)old crew (the 1 in the youtube vids)
Will be arup skiff crew aka marmite
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andy_cherub View Drop Down
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Post Options Post Options   Quote andy_cherub Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 5:58pm

Well said dude!

-12ft skiff, Team 'CST Composites'
-Many thanks goes out to all of my sponsors.
Ignore my user name, my views are of a 12ft skiff
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Ginger_69 View Drop Down
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Post Options Post Options   Quote Ginger_69 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 6:28pm
thanks im quite proud of that if i do say so my self
Chew valley lake s c
Topper(RED)-29412
I14 1209
lightning-168
Whaam (cherub)
Atum bom (cherub)old crew (the 1 in the youtube vids)
Will be arup skiff crew aka marmite
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Strawberry View Drop Down
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Post Options Post Options   Quote Strawberry Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 7:31pm

Originally posted by Ginger_69

ye because lifting the boat and not flying the boat would create less drag and potentialy be faster.  

Exactly, well said. Therefore lifting the entire hull out the water would create less drag everytime!

Cherub 2649 "Dangerous Strawberry
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Ginger_69 View Drop Down
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Post Options Post Options   Quote Ginger_69 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 8:35pm

thank you

Chew valley lake s c
Topper(RED)-29412
I14 1209
lightning-168
Whaam (cherub)
Atum bom (cherub)old crew (the 1 in the youtube vids)
Will be arup skiff crew aka marmite
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Chris Noble View Drop Down
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Post Options Post Options   Quote Chris Noble Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 9:38pm
its easy to see why hydro foils are faster by far, when the boat is foiling there is hardly any wetted surface to ceate the drag in the first place!!! And Phil well done with your result at the Cumbrae's, it was great to watch your boat on the water, good weekend, made all the better by Dave's dancing display on Sat. night.
Competitive Boat Insurance From Noble Marine

FOR SALE:

I14 2 Masts 2 poles 3 Booms, Foils Kites/Mains/Jibs too many to list.
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Black no sugar View Drop Down
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Post Options Post Options   Quote Black no sugar Quote  Post ReplyReply Direct Link To This Post Posted: 22 Aug 05 at 10:18pm

Originally posted by Chris Noble, who refers to one part of someone's anatomy in his signature - no, please, on one else tries to outdo him,

Come Fly International Moth Airlines
http://www.int-moth.org.uk

The Arse! 
 Out of curiosity, what's the second link in your sig, Chris? I've tried to view the picture (no comments please....) but it says "Sorry, but you do not have access to this picture."

Is it just a wind-up on your part, trying to see how many gullible girls (and maybe a few blokes too, ) want to check you RS out?

Or is it a comment on one of the photographers who provide regular pictures to fotoboat?? (j/k)

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