My Folding Catamaran

Discussion in 'Multihulls' started by billgow, Feb 17, 2012.

  1. billgow
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    billgow Junior Member

    Sorry, I missed your reply at the end here.

    What is the square cube rule?

    Thanks!
     
  2. spidennis
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    spidennis Chief Sawdust Sweeper

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  3. Richard Woods
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    Richard Woods Woods Designs

    If two boats are scale models of each other then area goes up by the square of the length, volume (or weight) by the cube

    So something that works in a small size (like putting up a beach cat mast by yourself) won't on a bigger boat. People don't change size when their boat does

    That's why big boats look more elegant than small ones, their freeboard is proportionately lower

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  4. Fanie
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    Fanie Fanie

    The rule that says the hulls must be designed to fit in a certain size container. Of course you can put one hull per container as well.
    LOL, all imported boats with the funny 90 deg 'feature' is a givaway ;)

    It's the same thing as the 'garage boat'. They are designed ti fit in someone's garage instead of fitting on the water properly, usually 5m500 as in ski-boats.
     
  5. billgow
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    billgow Junior Member

    That looks a lot like the folding mechanism on the Dragonfly Tris. These were an inspiration to me. My beams are many times more substantial than those on the Dragonfly. The forward beam not only has to open and close, it has to support the mast and it also has to deflect oncoming waves. To do all this, I proportioned it as follows;

    [​IMG]

    I'm guessing this is enough mass for an engineer to design something that would probably support the whole boat, let alone just the mid section.

    The rear beam isn't quite as robust but probably the equal of anything on the Dragonfly.
     
  6. billgow
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    billgow Junior Member

    Got it.

    Thanks!

    If nothing else, I'm getting an education... ;)
     
  7. billgow
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    billgow Junior Member

    Do you mean "90 deg feature" as in the hull shapes that are 90 degrees on the sides? Just about all fishing boats are like that, even the great big ones like the Vikings, Cabos and Hatteras'.
     
  8. spidennis
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    spidennis Chief Sawdust Sweeper

    I wish I had more info on the Dragonfly system. Yeah, I think the biggest problem is supporting the weight of the single stick sailing rig, and that's partly the reason I'm using a biplane rig. When I fold mine I'll stand over on one of the hulls just to take the weight off the center deck. Of course we're talking about two completely different sized boats.

    You know that suggestion to use Kurt Huges help for this sounds pretty good. He's already gone thru years of all of this and I'm sure he's got some more ideas "if he were ever to do this again". Bernd is another I'd talk to. Can't hurt to have input from those that already did this vs those just thinking about it. Richard Woods has his folder but that is a different concept, but i'm sure he's thought about other folding systems though from what I'm hearing he's as stumped as the rest of us for your sized folder.
     
  9. spidennis
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    spidennis Chief Sawdust Sweeper

    I don't know just what boat this is but it's a folder for sure. I just had these pics stuffed in a folder with my other related pics ......
     

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  10. basil
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    basil Senior Member

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  11. Blacky
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    Blacky Junior Member

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  12. Blacky
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    Blacky Junior Member

    why dont you take this design:
    it has the folding mechanism you want, instead of a plate in the middle a further hull you can put your feet in ;-)

    but maybe its not exotic enough for you, it wouldnt be the only example of this boat on the whole planet,
    and it wouldnt be your genial design but the design of the grandmaster brown :-(

    [​IMG]

    [​IMG]

    [​IMG]
     
  13. spidennis
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    spidennis Chief Sawdust Sweeper

    From what I read, the sea clipper had some beam flex. I wish there were close up pics of the folding system.
     
  14. billgow
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    billgow Junior Member

    That's pretty clever. I translated the page from Italian to English with bablefish. I'd be interested to see how long that thing lasts! ;)
     

  15. billgow
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    billgow Junior Member

    Bablefish is getting a workout today, French to English. Too bad they don't have any decent images of the folding mechanism on that page. I'd love to see how it works.
     
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