Luff Tube catching on boom clamp

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sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
14 Dec 2011 12:59pm
I have a problem with my 5.8m KA Kult.The luff tube gets caught up on the boom clamp and restricts it flipping. It comes free but only after a puff of wind,if its not quite strong enough it stays hungup.
I suspect its because I'm short and have to have the boom right at the bottom of the cutout.I move it up prob 2" from the bottom of the cutout ( as high as I can ) by using less extension but I cant go any higher up the cutout (by dropping the extension length ) as then I can't get enough downhaul.
If I lengthen the extension to get enough downhaul the boom needs to be right at the base of the cutout .
Anyone else had this problem and if so any suggestions? I suppose I can get the boom cutout lengthened like I did on my 5m but I don't think that helps the sail set as well.
I wanted to take a photo yesterday but didn't have my camera on me.
sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
16 Dec 2011 8:40am
geez I'm replying to my own topic.. I guess no one else has had this problem?
FormulaNova
FormulaNova
WA
15100 posts
WA, 15100 posts
16 Dec 2011 5:58am
Are you arms too short to reach the boom if its higher, or are your harness lines too short?

If its the later, maybe try longer harness lines?

sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
16 Dec 2011 11:59am
FormulaNova said...

Are you arms too short to reach the boom if its higher, or are your harness lines too short?

If its the later, maybe try longer harness lines?




If I raised it any more the boom would be at nose to eye height which I thought would be a bit too high for easy /comfortable sailing? Lines are adjustable and long enough so I can hook in & out easily when non planing c 26 - 27"?
Relapse
Relapse
VIC
620 posts
VIC, 620 posts
16 Dec 2011 12:35pm
I have a smilar problem with my S1s, they need a bit of a pump to get round. Its probably because I am not using a severne mast, they don't appear to be constant curve where as mine is

It makes getting the clamp round fiddliy as well.

There is a mast comparison chart on seabreeze somewhere, could be worth a look.

Derek
albentley
albentley
NSW
297 posts
NSW, 297 posts
16 Dec 2011 12:54pm
I have the same problem on my S1 but its not the mast, its because I am using a North boom which has some bits for the sleeve to catch on

If you are having the problem with the Kult there must be something wrong as I believe this has a SDM diameter tube (S1 is for RDM only although I have once seen a girl prove otherwise...)

How close are you getting the pulley block on your sail to the extension? I see some pepople sailing around with 3-5 cms difference sometimes - you should be able to rig the sail with both blocks almost touching....

Al
sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
17 Dec 2011 1:08pm
albentley said...

I have the same problem on my S1 but its not the mast, its because I am using a North boom which has some bits for the sleeve to catch on

If you are having the problem with the Kult there must be something wrong as I believe this has a SDM diameter tube (S1 is for RDM only although I have once seen a girl prove otherwise...)

How close are you getting the pulley block on your sail to the extension? I see some pepople sailing around with 3-5 cms difference sometimes - you should be able to rig the sail with both blocks almost touching....

Al

Sail & block are practically touching...Maybe it's the boom ( loft) although I don't have this problem with any other sail.
Sailhack
Sailhack
VIC
5000 posts
VIC, 5000 posts
17 Dec 2011 3:08pm
My 6.4 Kult was doing the same (465ish luff), I checked the specs and it recommended a 430/21 and also a 460/25. I was using the 460/25 & it wasn't rigging right, so tried my 430/21 RDM - rotates heaps better now!
sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
17 Dec 2011 5:33pm
Sailhack said...

My 6.4 Kult was doing the same (465ish luff), I checked the specs and it recommended a 430/21 and also a 460/25. I was using the 460/25 & it wasn't rigging right, so tried my 430/21 RDM - rotates heaps better now!


Thanks. I'll check which mast next time I get it out although I'd assume a 5.8m would need a 430 ? which is what I'm rigging it on.Just checked the 2010 specs ( mine is earlier..?) & 430 /21..Maybe it needs a softer mast although I'm sure my Sailworks 55% lipstick fits the specs.
sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
21 Dec 2011 9:02am
Went out yesterday and didn't rig enough downhaul but the luff wasn't a problem as the boom was closer to the middle of the cutout and maybe the luff wasn't as tight..pain going upwind particularly to starboard - it felt heavy and harness lines felt all over the place.I fiddled with them but then decided it must have been lack of downhaul..no panels floppy..I need to mark on the extension..and pay more attention.
I assume not enough downhaul would cause the feeling I had? Not go upwind, back hand heavy? uncomfortable?
terminal
terminal
1421 posts
1421 posts
21 Dec 2011 8:20pm
sboardcrazy said...

Went out yesterday and didn't rig enough downhaul but the luff wasn't a problem as the boom was closer to the middle of the cutout and maybe the luff wasn't as tight..pain going upwind particularly to starboard - it felt heavy and harness lines felt all over the place.I fiddled with them but then decided it must have been lack of downhaul..no panels floppy..I need to mark on the extension..and pay more attention.
I assume not enough downhaul would cause the feeling I had? Not go upwind, back hand heavy? uncomfortable?


Now you've got me confused.
The boom had been at the bottom of the cutout and was catching, and if you raised it just enough to clear from catching it would be at mouth/nose height.
Now you have reduced the downhaul, which would move the cutout up and make the problem worse?
And you have moved the boom way up the cutout? Why?

It may well be that the sail's cutout just isnt low enough to suit someone short. A friend of mine finds that he is too tall for the cutout on Naish sails and had the same problem as you but at the top of the cutout.

It sounds like cutout height is something you need to take into account when choosing sails in future.

It may be worth your while to get the luff opening lowered, but first just check if you can get comfortable with it as it is.

Are you sure the bottom batten isn't contributing to the luff catching, as you said if there is enough wind, it rotates? Sometimes the mast end of the bottom batten will have difficulty passing the mast.

I would advise putting the boom on and clamp it at the bottom of the opening and dont attach the outhaul.
Then downhaul the sail to within 2 cm of the bottom of its limit.
Then move the boom down to just above the bottom of the cutout and clamp it. Then pull on the outhaul.
If you cant get the sail looking right with the sail block within 2 cm of the extension pulleys, then undo everything and adjust the extension length and start over again.

I usually will have the pulleys of the sail block and extension block within 1 cm of each other after rigging.

From what you have said, under downhauling the sail will only make the boom height problem worse. The sail would also feel more cumbersome and heavier.

sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
22 Dec 2011 10:44am
terminal said...

sboardcrazy said...

Went out yesterday and didn't rig enough downhaul but the luff wasn't a problem as the boom was closer to the middle of the cutout and maybe the luff wasn't as tight..pain going upwind particularly to starboard - it felt heavy and harness lines felt all over the place.I fiddled with them but then decided it must have been lack of downhaul..no panels floppy..I need to mark on the extension..and pay more attention.
I assume not enough downhaul would cause the feeling I had? Not go upwind, back hand heavy? uncomfortable?


Now you've got me confused.
The boom had been at the bottom of the cutout and was catching, and if you raised it just enough to clear from catching it would be at mouth/nose height.
Now you have reduced the downhaul, which would move the cutout up and make the problem worse?
And you have moved the boom way up the cutout? Why?

It may well be that the sail's cutout just isnt low enough to suit someone short. A friend of mine finds that he is too tall for the cutout on Naish sails and had the same problem as you but at the top of the cutout.

It sounds like cutout height is something you need to take into account when choosing sails in future.

It may be worth your while to get the luff opening lowered, but first just check if you can get comfortable with it as it is.

Are you sure the bottom batten isn't contributing to the luff catching, as you said if there is enough wind, it rotates? Sometimes the mast end of the bottom batten will have difficulty passing the mast.

I would advise putting the boom on and clamp it at the bottom of the opening and dont attach the outhaul.
Then downhaul the sail to within 2 cm of the bottom of its limit.
Then move the boom down to just above the bottom of the cutout and clamp it. Then pull on the outhaul.
If you cant get the sail looking right with the sail block within 2 cm of the extension pulleys, then undo everything and adjust the extension length and start over again.

I usually will have the pulleys of the sail block and extension block within 1 cm of each other after rigging.

From what you have said, under downhauling the sail will only make the boom height problem worse. The sail would also feel more cumbersome and heavier.



Sorry..I meant I didn't put the extension at the usual height..I've got a new one and haven't marked it or paid attention to settings..So the extension wasn't set as high as usual which meant the boom was higher up the cutout which meant it didn't get caught on the luff but the downhaul wasn't enough and sail felt lousy.
I've been talking in the KA forum ( been great) and I think I will have the sailmaker lower the cutout as then Ill be able to have the boom at the right height but still be able to use enough extension height to downhaul the sail correctly.
Re batten - Ill note it when I use the sail next but I think it still catches & I have to give it a big pull..?? You've got me wondering now although as the problem goes away when I move the boom higher up the cutout I suspect the cutout height is the problem.
mr love
mr love
VIC
2421 posts
VIC, 2421 posts
22 Dec 2011 12:11pm
Hi Sue, As I mentioned on the KA forum, thankyou for highlighting the issue you are having with the height of the boom cutout. Even though your sail is an older model it is still a great reminder for us to have a complete review of the cutout heights across the range before we lock into our 2013 designs. We do need to get a sense check and make sure we do not have too much bias towards medium to taller sailors.
We have both youth and women sailors on the team, so I will certainly be talking to them about boom heights. Although this has not been brought up as an issue by any of them at this point, we need to have the discussion on our internal team forum, so thankyou for raising the subject.
flipper4444
flipper4444
VIC
1214 posts
VIC, 1214 posts
22 Dec 2011 12:48pm
haha
sboardcrazy
sboardcrazy
NSW
8333 posts
NSW, 8333 posts
22 Dec 2011 1:44pm
mr love said...

Hi Sue, As I mentioned on the KA forum, thankyou for highlighting the issue you are having with the height of the boom cutout. Even though your sail is an older model it is still a great reminder for us to have a complete review of the cutout heights across the range before we lock into our 2013 designs. We do need to get a sense check and make sure we do not have too much bias towards medium to taller sailors.
We have both youth and women sailors on the team, so I will certainly be talking to them about boom heights. Although this has not been brought up as an issue by any of them at this point, we need to have the discussion on our internal team forum, so thankyou for raising the subject.



I was going to mention you had taken the idea on board.Thanks for the help.
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