Mini 12 or scale down America cup

Discussion in 'Wooden Boat Building and Restoration' started by bilco, Jan 27, 2005.

  1. Tactic
    Joined: Oct 2004
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    Tactic Junior Member

    another take on it..

    I got to thinking about other possible variations.
    I simplified the hull construction to a basic falt bottom stitch and glue type.
    Lightened the overall displacment..lighter hull/lighter keel.
    So smaller rig to drive her equals less money spent.
    This one is 200kg complete with 100kg skipper.
    hull and retractable keel 100kg also.
    Smallish sailplan with square top main sail.
    4.7m overall length,750mm beam.
    Dinghy/canoe/ or small keelboat?
    steer with your feet mini 12 style...no hiking.
    This little thing should be pretty quick for its size and money spent.
    Cheers
    tactic
     

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  2. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

  3. Doug Lord

    Doug Lord Guest

    Tactic

    Tactic, there is something vaguely familiar about that sail plan; I like it!
    I like the original idea you and I had incorporating a canting keel in a "mini 12" type boat but this last iteration is interesting in its simplicity.
     
  4. Tactic
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    Tactic Junior Member

    Thought you might like the sailplan Doug!
    This boat has a good chance of becoming reality..only 4 sheets of ply!
    Thanks Raggi Thor..your backman 21 is nice also!
     
  5. Tactic
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    Tactic Junior Member

    Design has evolved to this..though I kinda like the utter simplicity of the flat bootom.
    Cheers
    Tactic
     

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  6. ricardoribeiro
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    ricardoribeiro Junior member

  7. Daniel Charles
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    Daniel Charles Junior Member

    We built in the 80s two scaled-down J-Class, Ranger and Endeavour II. The problem with scale if that if you divise the length by 8, sail area diminish by 64 and stability by 512, which is quite a big stability deficit! On the other hand, the CG is much lower & ballast ratio much better. What we did was to have the length scaled down by 8, but the beam and depth by 6.5. They were respectable crafts, about 17' LOA, 10' LWL and 140 sq ft. Hulls weighted some 150lbs, and was transported on top of a car. Ballast was lead shot, in bags. It was huge fun, and rather technical. Think of tacking with a main, a quadrilateral jib (two sheets each side!), a staysail and backstays, while steering with the feet! DSPL with a single crew lying down was some1100 lbs. In light air, they went like a bat out of hell. The fun bit was thay they really behaved like true J, as I'd the opportunity to chack when sailing the real thing.
    Easiest way to built was shaping foam then plastifying it (the mini Ranger was built that way).
    It was a fantastic experience.
     
  8. aixam
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    aixam Junior Member

    Do you have any pictures off them? Anny drawings? Planing to bild sometning in that style but should be sized for 2 perssons.
     
  9. Daniel Charles
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    Daniel Charles Junior Member

    Here are some pix.
    What is fun with that sort of boat is the complexity. If you want to make things simple, take a normal boat!
    So, for a two person version, I advise either a schooner or Reliance.
     

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  10. aixam
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    aixam Junior Member

    Thank you for the picktures. It realy lockted nice. How was the salis preformance? Some advise you could give howe not to do? What I like whit it are the stile and more esely to bild and take care of in a normal garage.
     
  11. Daniel Charles
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    Daniel Charles Junior Member

    As I said in my previous post, the scaling difference is critical. It's an interesting design problem, not as simple as it looks. It does require some skills. Remember: scaling down a plan, keeping everything to the same scale WILL NOT DO.
    Construction was quick, making a sort of full size model in foam (like a half-model with surfboard materials), glassfiberizing with epoxy resin, then carving out the foam enough to leave the space for the crew and using dissolvant in the keel to gain as much volume as possible. deck was light ply. Sails are not inexpensive, mind. In light air, this boat was a flyer -13 sq mtr for 450 kg incl crew, with very little wetted area, wow. After light air, it becomes very speed limited because it's a very heavy displacement. But it's one of the funniest boats I've sailed on (and I've sailed a few 100s). definitely worth while. By the way, this boats still exists twenty years later...
     

  12. aixam
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    aixam Junior Member

    Then it´s only tray to find a original drawing and start to woork from there.
    Im like the idea of a easy tranportebale bouth in nice style, but also alow me to take my wife whit me.
     
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