Luff Tube catching on boom clamp

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.

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?

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

Sail & block are practically touching...Maybe it's the boom ( loft) although I don't have this problem with any other sail.

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.

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.

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.