High Performance MPX Foil/Self-righting Trimaran-The Test Model

Discussion in 'Multihulls' started by Doug Lord, Dec 28, 2010.

  1. Doug Lord
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    Doug Lord Flight Ready

    Fire Arrow Foiling System Testing and Development

    ============================

    Powerful quote by Raps then and now. He wrote this on page 6 just after seeing the main hull take shape. It was encouraging back then-2011-and is encouraging now!! Thanks, Raps! A gift that keeps on giving.......and I need the courage it speaks of.
     
  2. Doug Lord
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    Doug Lord Flight Ready

    Fire Arrow Advantages scaled up to 19.5' LOA

    I'm trying to come up with a relatively short but complete description of the advantages inherent in the full size version of the Fire Arrow design. This is another improved version:
    ================================
    The full size version of the Fire Arrow at 19.5' would have a beam of 22'. It would fold to be trailered.
    This beam would be impossible without the foil system described below:
    --
    Probably the most significant feature of the Fire Arrow is that it uses two completely independent altitude control systems for the first time on any trimaran:
    1) UptiP ama foils(also a first for any size trimaran*) that control the height of the ama above the water,
    *used on this boat way before they were used on any other tri.
    2) Wand controlled mainfoil on the daggerboard-controls main hull height above the water which, in turn, sets the angle of heel for the whole boat.The mainfoil also allows the main hull to fly in very light air.(5mph)
    But its the interrelationship between the main and rudder T-foil with the ama foil that makes the system so significant. The rudder T-foil is a trailing foil and "follows" the main foil. Altitude and angle of heel for the whole boat are set by adjusting the wand length. The angle of heel can be set between 10 degrees and 17 degrees. The boat is extremely stable in pitch because of the bi-foil arrangement on the main hull-the daggerboard foil and rudder foil always work together to control pitch when the boat is foiling. But they also control the ride angle and pitch of the ama foil which can't pitch on its own-in other words the ama foil can't all of a sudden "go negative" and cause a pitch pole.
    --
    3) A major advantage of the wand controlled mainfoil is the ability of the wand to cause the foil to create downforce which can add significantly to the righting moment of the boat. It is an automatic response to the boat heeling even a slight amount: the wand will cause the flap to go up as much as is necessary to restore the main hull to its designed flight altitude. That can add a large amount of righting moment to the boat.(40-60% of boat weight or a bit more)
    The use of foil downforce has been well proven on the Trifoiler ,Rave, Skat and Osprey. And the drag caused by doing this is not as much a disadvantage as the extra RM is an advantage.
    --
    4) Two Stage ama(see pix below) : the ama hull is attached to a "curved piece" that adds to the ama buoyancy in knockdown conditions. This "two-stage" design allows for a small planing hull with relatively low drag during incidental contact with the water but provides tremendous buoyancy during a knockdown-enough; combined with the high dihedral crossarm structure, to prevent a capsize in most conditions.
    --
    5) Oversquare platform: the boat is 1.22 times as wide as it is long. A "normal" tri with that much beam would need at least 15mph of wind to be able to fly the main hull. But because of the wand controlled main foil, this boat will fly the main hull in as little as 5 mph of wind which opens up the effective wind range for the foiling system-way beyond most multihull foilers.
    --
    6) Light Air Foiling: from a marketing perspective selling a foiler that only starts to foil in 10-15mph of wind is a mistake but that has been true of many multihull foilers. More and more boats are targeting starting to foil in lighter winds: The Whisper foiling cat and Quant 23 are examples of foilers whose designer/builder has made the commitment to start flying in light air. The Fire Arrow test model was designed to begin to foil in a 5mph wind 5 years ago and reached that design goal on July 24, 2014. The full size version will take off in about the same wind speed.

    =====================
    Hopefully, I'll be able to get the help I need to build a 19.5' version of the Test Model which would be a very cool trimaran and would illustrate well why this system is such an advance in small trimaran design.
    In the meantime, I'm planning on getting more video with the reefed rig and shorter mainfoil and rudder foil.


    [​IMG]
     
    Last edited: Apr 22, 2016
  3. NoEyeDeer
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    NoEyeDeer Senior Member

    How are you latest two posts consistent with your current first goal?

     
  4. Doug Lord
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    Doug Lord Flight Ready

    Fire Arrow Foiling System Testing and Development

    Seems obvious to me and probably should to you too. Description of the boat and the system in the first of the last two posts is self-explanatory.
    My last post is simply an exploration of the potential of the Fire Arrow foil system on a larger boat. Seems to have great potential. All part of the continuing development of the
    system.
     
  5. NoEyeDeer
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    NoEyeDeer Senior Member

    Ok, but how is any of that contributing to "first, more sailing with the Test Model..."? Where "first" means "before doing anything else".
     
  6. Doug Lord
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    Doug Lord Flight Ready

    Fire Arrow Foiling System Testing and Development

    If you had read the thread you'd know the answer-I can't sail now. "First" meant the first thing to be done before building a fullsize version.

    When possible:

    1) more testing and video of the Test Model,

    2) build full size prototype.
     
  7. brian eiland
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    brian eiland Senior Member

    I sent you a private message asking about you sail material(s), (what they are made of). Did you get it?
    Brian
     
  8. PerthMini40man
    Joined: Jan 2014
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    Location: Australia

    PerthMini40man Senior Member

    sail cloth

    Hello Brian - Yes I got it and have replied, and have sent you two links to sail cloth suppliers

    Rgds
     
  9. Doug Lord
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    Doug Lord Flight Ready

    Condo Seawall/steps

    Got the word a few minutes ago that the seawall will be started this Monday, April 25th. The last I heard is that it would take about two months. When done there will be steps going from the grass to the water which may make it easy to launch my boats right here-we'll see:

    Looking north from our dock-the seewall next door was done by the same company doing ours--

    [​IMG]


    Looking south--

    [​IMG]
     
  10. hoytedow
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    Location: The Land of Lost Content

    hoytedow Fly on the Wall - Miss ddt yet?

    We just finished our seawall. I wish we had spent the extra 5 grand for a boat ramp.
     

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  11. Doug Lord
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    Doug Lord Flight Ready

    I hope the steps work out here. I'm not looking forward to the noise level for a couple months.....
     
  12. brian eiland
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    brian eiland Senior Member

    Sail Material

    Thanks for that info you sent. Doug has also sent me some info. I just have to find the time to go forward with a little 'model testing' on my own when I finish up multiple home projects

    I had thought that the sail material I saw in that other posting of yours appeared to be much stiffer in nature that ordinary sail cloth...particularly the jib in this photo of yours....
     

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  13. Doug Lord
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    Doug Lord Flight Ready

    Seawall/steps

    ----------------------------
    No seawall builders so far......
     
  14. PerthMini40man
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    PerthMini40man Senior Member

    The jib and mainsail on the tri closest to the camera are made from 75 micron mylar

    Rgds
     

  15. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Sail Material

    Brian , here is more on RC sail material:

    http://bbjsails.com/bulk-materials/

    http://www.ec12.info/Sail Material.htm

    https://www.siriussails.com/materials.html

    Scott Morgan, Sails by Morgan(in Cocoa) has made all my sails for around 20 years. He made production RC sails for me in the late 90's including spinnakers. You might check with him to see if he has any triSpy mylar left or any suggestions. My next set of sails will be experimental cuben fiber(haven't talked to Scott about this yet) but it has drawbacks including wrinkling easy and cost but it is very light weight.
    His phone is: 321-633-4275
     
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