Possible rig for Scarab 18

Discussion in 'Multihulls' started by buzzman, Sep 2, 2012.

  1. buzzman
    Joined: May 2011
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    buzzman Senior Member

    Ah, I see...your 17fter has a Hobie 16 mast.....that is different to what I was getting at which was if the 17 had a 'standard' mono mast, then that would not be a good choice for a tri, due to the extra beam as you say.

    Multi to mono ought to be ok, as the rig needs to be stronger on the multi than for a similar length mono, as I understand it.

    But interesting that the Hobie rig went straight on.....piece of luck, that! :)
     
  2. buzzman
    Joined: May 2011
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    buzzman Senior Member

    Masthead quadrant?

    I've been researching the Scarab for a while, and I came across the build blog of an S22 by a Canadian guy, Olivier, whihc I'm sure a few people have seen:
    http://www.voile.org/trimaran/

    In the sailing posts near the top Olivier demonstrates his pivoting prodder.

    I'm sure I read something somewhere on here about the desirability of being able to move the tack fixing point of the jib, but I can't remember why that was considered a good thing....

    But it struck me that even with Oliviers set up (or similar movable prodders) that the head of the jib or headsail will still be fixed the the hounds or masthead (depending on rig), and it occurred to me that if being able to move the tack is important, wouldn't the idea of being able to move the head also be important for changing the shape of the luff and it's relationship to the 'slot' and the mainsail..??

    So I scribbled down and idea for a *masthead quadrant* that might enable this, if people think it would work....

    Left to right is 'normal', pivoting prodder, pivoting prodder plus quadrant, close-up of quadrant....

    Remember, I'm an idiot, so be gentle if this has been tried before and failed :)
     

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  3. redreuben
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    redreuben redreuben

    Issues I see are windage, weight and complexity where you don't want it, aloft. But the biggie would have to be uneven tension, the forestay to the side is going to twist the mast wether a rotating mast or not.
     
  4. buzzman
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    buzzman Senior Member

    What if the quadrant was at the hounds, rather than masthead, and had diamond shrouds to masthead and opposite, to counter bending forces..?
     
  5. redreuben
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    redreuben redreuben

    Wouldn't matter the force applied is off centre so its going to try and wrack the mast around and any sort of running back arrangement will foul the main.
    Guess you could have a running forestay on the other side but then you have just doubled the windage !
    Too complex for a marginal benefit. imho
     
  6. buzzman
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    buzzman Senior Member

    Yeah, figured that would be the answer...but had to ask... :)
     

  7. ThomD
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    ThomD Senior Member

    The other side of that is that if on a boat like my Hughes the beam is 18.5 feet, then the rigging angles are far more favourable, and the mast is not so badly loaded. Also they sail the hell out of the Hobies, often it is not the static stuff but the dynamic stuff, like jumping off a wave, and generally running at higher speeds crashing the boat and all that.
     
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