Latest News: Forums Technical Which mucsle box

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  • #4048

    Hi all,

    At present I have a highfield lever on my mast. Not a problem for myself, but the crew are now refusing to go anywhere near it due to trapped and pinched digits.

    Normally this case of mutiny would result in some form of punishment, however I have also noticed that correct rig tension is sometimes difficult to achieve.

    I am therefore asking for more help from the wayfarer experts out there to suggest which muscle box / cascade system works on their W’s. I have seen these fitted both on the mast and by the centreboard case, so a couple of hints as to location would also be gratefully received.

    Happy New Year to all and safe sailing for 2010.

    Laurie W1858

    #8823
    Fantasia
    Member

    A cascade system would probably be the cheapest option, the most effective and give the greatest range for ease of hooking onto the halyard. I have my boat in the shed at home at the moment, I’ll try and take an image and post it here to show my set-up.

    #8825
    Swiebertje
    Participant

    A cascaded purchase has three sheaves (8:1). A muscle box has 8 sheaves (8:1) and consequently much more friction. In fact, adding more sheaves in a muscle box is pointless, the extra purchase is lost on friction. The only thing better in a muscle box is that it is a neat solution. A cascaded purchase tends to become messy once it is unhooked from the halyard.

    Because a cascaded purchase has less friction it is easier to operate. I am using a muscle box but I always have to pull the control line perpendicular with one hand and then quickly pull it with the other hand while releasing the “perpendicular” hand. This is to overcome friction. Just pulling the control line does not put the tension I want on the rig. A friend of mine, who uses a cascaded purchase, only needs one hand to pull maximum tension on his rig.

    And as John already pointed out, a cascade is much cheaper. But if you insist on a muscle box: Harken does not make them anymore but RWO still makes them ( http://www.rwo-marine.com/ ). And if you are looking for quality similar to Harken try Sprenger ( http://www.sprenger.de/ ) (Sprenler is available through UK chandlers).

    #8827
    Fantasia
    Member

    The image shows the halyard hook attached to the mast step with a short length of bungy elastic. This keeps everything in place. Lines need to be strong: dyneema or similar.

    #8831

    Hi
    Our cascade quite similar to the picture but we have it threaded through a piece of 2″ish diameter clear plastic tubing 1′ to 18″ish long, which keeps it all tidy especially when unhooked, but we do have an loop of elastic onto a fixing just near to the bottom of the mast which we hook to for storage

    #8832
    tempest51
    Member

    Interesting photo John,

    Is there a budding artist in your midst that could prepare a line drawing of that cascade setup, as for dummies like me, I still have difficulty in seeing the detail?

    Regards,

    #8833
    W10143
    Member

    Tempest51 wrote:

    Interesting photo John,

    Is there a budding artist in your midst that could prepare a line drawing of that cascade setup, as for dummies like me, I still have difficulty in seeing the detail?

    David Barker draws a good representation of a kicker cascade here:
    http://wayfarer.org.uk/forum/viewtopic.php?t=508&highlight=cascade

    David

    #8834

    Hi everyone,

    Thanks for all your help, which should get me thinking about how to empty my wallet.

    Regards.

    Laurie
    W1858

    #8835
    Fantasia
    Member
    tempest51 wrote:
    Interesting photo John,

    Is there a budding artist in your midst that could prepare a line drawing of that cascade setup, as for dummies like me, I still have difficulty in seeing the detail?

    Sorry, I am not good at drawing electronically and do not have a scanner at home. In the first picture ignore the blue and the pink lines (cunningham and clew outhall); you will see a series of three single Harken s/steel blocks. The first (furthest forward/left) has a strong hook attached to it and this is used to hook onto the end loop of the s/s wire halyard (halyard and mast foot not visible as they are not fitted at the moment). The first shortish length of dyneema is made off to the centreboard case at one end (drilled through + pink plastic ball under), the other end is attached to the second block. Second length of dyneema fixed to the underside of the case top a foot or so furthe back and its other end attached to the third block. The third length of dyneema (black and multicoloured) is fixed way back underneath the thwart to a D ring just visible in the second image, its other end is cleated ont he rear of the centreboard case – see second image. It could also be more simply cleated to the underside of the thwart.

    #8837
    tempest51
    Member

    Thank you John, most helpful.

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