Latest News: Forums Technical kicker/vang question and black band on boom.

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  • #4430
    Davdor7038
    Member

    Hello, everyone. I currently have a 4:1 kicker which I hope to upgrade at some stage in the future.

    Currently, with about 150kg on the shrouds, the mast prebends and I end up with the mast about 10-12mm behind the deck. Does that sound about right?
    If I give a good old tug on the kicker, the mast can be made to contact the deck which is obviously increasing the mast bend somewhat.
    My question is; Is this the max mast-bend which could or should be achieved. If I upgrade to a 12:1 or 16:1 system, will the mast continue to bend above the deck as more kicker is applied and the boom is pushed forward? What would be considered an excessive amount of mast bend using an upgraded kicker.

    Also, how difficult should it be to get the leech cringle on the mainsail all the way back to the black band on the boom. There are no actual friction problems sliding the foot along the boom. My mainsail is an old sail and, applying a fair amount of pressure with what I think is a 3:1 system, the cringle ends up about 25-50mm from the black band, depending on my strength on the day. I don’t really to pull any harder.

    Finally, is the purpose of the boom black band to give an indication of best leech cringle position for general sailing? Thanks in advance for any replies, David Doran.

    #10785
    bigal
    Member

    Suggest you down load the tuning guide from the P&B web-site and start from there – it doesn’t sound as though you have any chocks in front of the mast !

    #10787
    Colin Parkstone
    Participant

    Boltropes shrink Dave and so you may not be able to pull a foot, or luff come to that to the band. On a new sail you would find that the tail of the bolt rope extends out of the sail some 50 to 75mm so as to give the owner a chance to free the sail from the shrinking boltrope at a later date. This will extend the useful life of the sail.
    The bands on the spars are to indicate the max size of the sail on the rig, not to say were the sail should be pulled too.
    If your sails were made undersize or smaller than the max you would not be able to ever get the edge of the sail to that band.
    It is important to look at the sail shape and set, not to think of the maximum size I can get!!
    The uprated kicker will help you with the action of pulling the kicker on and so, Yes you will bend the mast forward more because for the same amount of pull from you it will put more preasure on the kicker. Just also make sure you are not binding the pin in the tabernacle.
    I would say that 8:1 is a good amount to use, anymore your have so much more rope to pull and buy!!!

    #10790
    Swiebertje
    Participant

    Note that we use 8:1 on the out-haul not so much for its pulling power but rather to get a more precise adjustment. Every inch of pull translates in 0.125 inch of leach movement allowing very fine adjustments.

    Officially we are not allowed to have our sails over the black bands but nobody is checking. If you have well made sails the black band can be seen as a maximum indicator. Your sail should not be set passed it. But in the end, as Colin said, it is about sail shape not about the position of the sail on the mast or boom. It is better to look at the sail as a whole rather then at the black bands.

    BTW, my sail maker (P&B) used bungee cord as bolt rope. It does not suffer from shrinkage and if it is put under some tension, it pulls the sail automatically forward when the out-haul is released. For this reason it is not stitched to the sail at the goose neck, only near the leech cringle. A figure eight knot held in place by the sail pin at the goose neck puts the tension on. This and a bit of Teflon spray makes my foot follow my adjustments immediately without having to bash or pull the foot. (Did I just say Teflon spray? Must have been an old candle stump!).

    #10795
    Davdor7038
    Member

    Many thanks for the replies, Gentlemen. Things are clearer now on both questions I asked. Just to clarify one point. When I tighten the kicker and the mast bends forward and contacts the deck, will any additional tightening of the kicker then cause the mast to further bend above the deck? Or is hitting the deck, the stop which prevents any further bending? Just so I’m clearer on what will be happening. I’m the only Wayfarer in the “Village/Boat Club”, you see!!! Regards Dave Doran.

    #10796
    Swiebertje
    Participant

    Yes, when the mast hits the back of the fore deck, and the mast foot is against the pin, you have reached maximum bend. Further mast bend would need other adjustments such as, for example, mast rake. There are limits to what we can do, defined by the position and diameter of the pivot holes in mast and tabernacle. Racers need to have the pin in to ensure they all have the same play in trimming the mast. And that is the only function of the pivot holes and mast pin. (You could step the mast without a pin).

    Note that we also use wooden chocks in the gap in front of the mast to limit mast bending in light winds. One or more T-shaped chocks allow a decent amount of luff tension on the Genoa without flattening the main. Genoa luff tension is needed for good pointing. Make some chocks from an old nylon cutting board or ply wood (varnish). Drill a little hole for a thin rope that ties them the mast. This is to prevent them from jumping over the side when not in use. The T shape prevents the chocks from slipping below deck when in use.

    #10800
    Davdor7038
    Member

    Thanks for that. I hope to upgrade later in the year. Regards Davdor

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