the bottom of my jib is constantly flapping... how can i fix this? also what are the tracks that can move the jib blocks fore and aft for? when would i want the blocks further forward and when would I want them further back? thank you in advance for your help.
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edited by: Ecker786, Jun 22, 2009 - 11:36 PM<!-- end editby -->
-- Bud
Hobie Cat 18
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Posted: 22.06.2009, 22:13
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if the bottom of your jib is flapping but the back of the jib is not it sounds like your jib blocks are pulling too vertically on the jib tack
ie if you can move the jib blocks back there will be a more horizontal vector in their pull and the jib bottom should tighten up
you generally work this out by having 2 sets of telltales on your jib
a high set and a low set
if the low sets breaks from streaming before the high set the bottom is too loose and you need to move the jib blocks back to balance the tensions
if the high set breaks from streaming before the low set you need to move the blocks further forward
not sure on the hobie18 but many hobie's have a 4 position plate at the jib tack where you attach the jib sheet
experiment on different positions to see if that helps balance the sail
-- 1982 nacra 5.2
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Posted: 23.06.2009, 02:12
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Also.... with the blocks not attached to your jib clew (tack) pull down and aft... you should be able to feel/see the position where there is equal pull from the foot and leach. this is close to where you want your jib sheet/block to be.
The fore / aft adjusters are also a good way to depower in heavy air. by moving them back (past where there is equal pull on the foot/leach) you can open the top of the jib and spill air off (depower) in heavy air. the opposite (forward in light air) only works a little as you will lose shape in light air and lose efficacy.
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Posted: 23.06.2009, 05:53
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I thought you would bite at that one Andrew. I couldn't help it. The pilot in me just wanted out.
Sails are not unlike an air foil or wing. The theory applies to air flow as well. You know the Lo pressure Hi pressure issue. Sail tension changes this property as the sail shape changes. Don't want to get all technical. Keep it simple.
Like I was saying trial and error will work this out.
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Posted: 23.06.2009, 06:36
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ummmm... i think i have seen this post before! :)
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Posted: 24.06.2009, 06:09
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Ok sounds good ill experiment and see if i can figure it out. Thanks guys.
