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  1. #8
    Junior Member
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    Jun 2015
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    The point 7 sails need a lot of downhaul. The loose leach between the second and third batten from the top has to to go 20 cm near the luff pocket. Maybe You need more downhaul? What mast are You using?

    I have two ack sails, one from 2013 one from 2014 (had two from 2011 before). Cam rotation was not an issue with all of them. I am rigging them with a noname constant curve mast and a gaastra hard top mast.

    best regards

    Alex

  2. #9
    Member Benji82's Avatar
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    Jul 2011
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    Littlehampton
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    86
    My sails are 3g 2013. I'm using point-7 80% masts.
    After reading the Windsurf magazine review I decided to buy the 460 mast to go with the 7.2 as they found this to perform better. Looking at the unifibre mast selector some time later I discovered that the 430 is a hardtop mast and 460 a constant curve.
    I do have the same problem with the 8.5 and 490 which is the correct combination

  3. #10
    Senior Member
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    Nov 2009
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    3,876
    I don't know if the P7 cams are the same type as North but I had one north Ram sail with cam rotation problems and had to modify the cams a little to resolve it. Firstly the batten tension needs to set correctly regardless what that does for the rotation....so in terms of the cam battens for North RAM, they are tightened until all wrinkles are gone then about 2 more turns ( ie set quite hard). I then ( as you did) reduced the size of the 3 cams because cam tension even without any spacers was too hard. I also found that the throat of the cam where it slides over the end of the batten pocket was too narrow...or you could say the stitching and reinforcement at the end of the batten pocket was too thick. Due to this I was able to get good rotation on one tack but not on the other because the cam was jamming on the batten pocket end. I opened up the throat of the cams a little..........everything then worked fine. I set my cam tension so that I could rotate each cam with 2 hands (rigged on the ground)....I found that to be sufficient to ensue full stability but not so much that it took a enormous tug on the new tack to get them to rotate. In many respects the fuller the belly of the sail the less absolute cam tension is needed to keep a steady luff profile. If the luff profile is shallow it requires more cam tension to ensure it maintains that shallow profile. All of these adjustments are very fine....a few mm. Hope that helps.

  4. #11
    Member Benji82's Avatar
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    Jul 2011
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    Littlehampton
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    I had to take 10mm off each of the lower two cams before they would rotate. This seems quite excessive. Now I have quite big wrinkles running down the luff below the boom on the leeward side of the sail.
    I might buy some gaastra cams from 4boards and start again.
    I would prefer to get mine working better than have to buy a new set of sails.

  5. #12
    Senior Member Sailrepair's Avatar
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    Feb 2010
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    Helensburgh
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    1,676
    10mm is a lot. 4mm is the most adjustment I have ever seen necessary.

    Some sails require a few cm of outhaul to get them to rotate while others rotate fin with no or even negative outhaul.

  6. #13
    Member Benji82's Avatar
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    Jul 2011
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    Littlehampton
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    New cams ordered. Will have a play tomorrow night. Fingers crossed.

  7. #14
    Senior Member
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    Nov 2009
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    If you are starting from scratch with new cams, follow my post above. The batten tension and cam pressure are separate things although if you under tension a cam batten you do reduce cam pressure at the expense of wrinkling the sail. So first step is to set the batten tension...as above..usually to the point of removing wrinkles going up and down into panels from the batten pocket.....plus a little bit more ( because the batten pockets invariably stretch a little).

    Push the cams onto the batten pocket ends and make sure each cam is able to move back and forward from the centre position equally. Rig the sail. With sail still on the ground and the cams fully rotated, try each cam in turn and see if you can derotate the cam using both hands. In my book if you are unable to do that, the cam pressure is too high. Assuming you have not used any spacers, your only option is to reduce the overall length of the cam. I did that by running a pencil line around the batten end of the cam and then using a file and sandpaper to rub the cam down until the pencil line disappeared all around ( probably 2 or 3 mm). Repeat as necessary. If the cam has insufficient pressure try a thin spacer ..again about 2 or 3 mm. Repeat until right.

    Most 3 cam sails set with a lot of downhaul and very little if any outhaul. On North sails the recommended way to rig is to apply about 80% of total downhaul.....then maximum outhaul.........then push the cams on.......then apply the rest of the downhaul.........release outhaul as necessary to neutral or mayeb 1cm positive. That rigging method has a number of virtues. It enable the cams to be engaged ( and disengaged following the reverse procedure) without any danger of breaking battens or wearing holes in the luff. It also enables you to see exactly what is happening to the cam profile as you rig it.

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