Just an Idea!

Discussion in 'Sailboats' started by WerpKerp, Mar 10, 2018.

  1. WerpKerp
    Joined: Mar 2018
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    WerpKerp Junior Member

    I have friend who has an old Nacra 5.8 hull lying around in his shop. Yeah, just one hull, not the complete boat, but the hull is in great condition and has a tiller and rudder and everything. We were wondering if we could strap a pair of wings to the side of the hull, and buy a Moth sail and put it in the middle. Now if the hull is too long we can slice the middle off and rejoin it, and we were wondering if we could put some Moth foils under it and a T-foil rudder on it. Would it sail? (We aren't trying to build a Moth, just we want something to do with that hull.). Thanks guys!
     
    Last edited: Mar 10, 2018
  2. OzFred
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    OzFred Senior Member

    I've heard of something similar a few years ago, using a Tornado hull I think. Reportedly it was diabolically difficult to sail.

    A Moth gets away with a very skinny hull because the rig is quite light. The hull is 10kg or less, the entire boat, ready to sail, is about 35kg or lower. Before carbon rigs, skinny Moths had aluminium rigs and were nigh on impossible to sail to the extent that the class nearly disappeared. Even carbon rig boats are not easy for someone starting out. I know of at least 4 reasonably good sailors who just couldn't get to grips with one, they just couldn't get on and stay upright.

    So if you just want a serious challenge and a bit of fun, go right ahead but you'll need to spend quite a bit of money for foils and rig for a boat that you might not be able to sail.
     
  3. Dolfiman
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    Dolfiman Senior Member

    Historical precedent : Eric Tabarly in 1975 used a Tornado hull, two small amas and two foils + a T shaped rudder to test full flying capabilities and issues. What becomed later (in 1979) the Paul Ricard with which he broke the Charlie Barr North Atlantic record (in 1980). May be now you can do better with lighter materials and more knowledge on foils and control.
    See from 29:15 to 30:00 in this video :
     
  4. Rumars
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    Rumars Senior Member

    The simple thing to do woud be to transform it into an outrigger sailing canoe.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    Rumars on the right track, but if you want foiling checkout the F101 foiling tri. Some who have sailed both say the F101 is much easier to learn to sail than the Moth.
    No need to cut down the Nacra-just whip up some very small amas......






    F101 foiling trimaran.jpg

    F101 2-8-17.jpg
     
  6. gggGuest
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    gggGuest ...

  7. WerpKerp
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    WerpKerp Junior Member

    Yes, my idea was to make into a F101 style trimaran, but instead of having the foils on the central hull, having two L-boards on the amas and then having a T-wing on the central hull.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    ======
    Would you sail it like the SuperFoiler-with the windward foil retracted? I imagine that by "L" foil you're referring to the type of foil invented by TNZ in AC34 that has automatic altitude control?(called "uptip" foils by their inventors)
    The most stable foil configuration for a tri is one with a lifting foil(+wand on a small boat) on the daggerboard and a rudder T foil both on the main hull and an uptip foil on each ama-one in the water at a time.
    Good Luck!
    Uptip foil:
    MPX ama + ama = cat --foil comparison 011.JPG

    This basic foil configuration is being used on Maserati, Gitana 17 and Bank Populaire except instead of a wand controlling the daggerboard foil , it is done manually:
    MPX assembled 2 008.JPG
     
  9. WerpKerp
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    WerpKerp Junior Member

    What if I strapped some mini-DSS foils to the side of the hull to compensate for the narrowness? Would that work? (If I couldn't get it to foil)
     
  10. OzFred
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    OzFred Senior Member

    I doubt it, you still need speed through the water for the foil to do anything useful. F-101 style floats that act as training wheels (suitable dihedral so not in the water when the boat is sailed flat) would be "better" from a cost and stability–when–required perspective. If you're going for L boards, you're back to a catamaran… it seems to me that for a small multihull, the central hull is redundant.

    And for small catamarans (say < 7m) Z boards seem to be simple and easy to sail, talk to an A Class sailor.

    But really, if you just want to get foiling in something that's reasonably easy to sail with relatively easy to make foils, consider V foils on a cross beam. Checkout Broomstick.
     
    dsigned likes this.
  11. Dolfiman
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    Dolfiman Senior Member

    Is there a theory or a rule of the thumb about the optimal V angle of such foils ?, the one of Broomstick foils seems small (just a feeling ...).
     
  12. Doug Lord
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    Doug Lord Flight Ready

    Last edited: Mar 12, 2018
  13. Doug Lord
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    Doug Lord Flight Ready

    =============================
    If by "L" foils you're referring to auto-stable versions of uptip foils then a trimaran is one of the best applications of those foils-particularly when designed with enough crossarm dihedral so that the windward ama foil is clear of the water when foiling. Uptip foil applications other than this require that the windward foil is retracted with every maneuver.
    Further , a trimaran using a wand controlled lifting foil on the daggerboard in combination with auto-stable versions of uptip ama foils(one used at a time) allows an oversquare platform that has more power to carry sail than any beach cat with much greater stability.
     
  14. WerpKerp
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    WerpKerp Junior Member

    Okay, here's the design that I think will be final, which I call the "Poor Man's Superfoiler". The central hull will the Nacra, with two wing tramps starting roughly 3/8 of the way from the stern, swept back at 12 degrees, and with two relatively large amas on the tips. As for foils, the ama foils will be Uptips, with a T-wing rudder and a foil on the daggerboard. I will rig it with a Contender rig or a 420 rig with no jib. Thoughts?
     

  15. BlueBell
    Joined: May 2017
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    BlueBell Ahhhhh...

    Great, now just lose the mast and attach a kite to the centre of your forward crossbar and you're away!
     
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