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

    The boat looks very nice! You could start a thread so we could follow along on your progress....
     
  2. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    This is the first picture of 2012 and it is a sort of summary of whats been done so far-not including the extensive design work on the foil system etc.. Lots to be done and hopefully more time to do it this year.
    Happy New Year!

    click on image:
     

    Attached Files:

  3. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    Will see Sharon tomorrow about making mating halves for the stryo curved foil molds. (See post 174) Unfortunately, she had tossed the inserts that came out of the originals.....
    Starting to do some minor filling on the bow and sterns of the amas and main hull with cabosil/epoxy.
    Also found a "bondo" tailored specifically for epoxy substrates that works like regular bondo: quick mix -quick set-easy sand-$30 a quart-made by Adtech. It's been suggested by one "expert" that I just use regular bondo since this is a model so I'm calling the Dynalite company tomorrow just to see what they say.
    Should be getting the 5.9oz carbon cloth by the end of the week or first part of next week.
     
  4. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    Revised and updated ama+curved piece buoyancy:
    1) All up model weight incl ballast=16.688lb (fullsize 750lb)
    -
    2) Ama buoyancy(model)= 6.27lb. (fullsize=281lb.)
    -
    3) Curved piece buoyancy(model)= 6.9lb (fullsize= 310lb)
    -
    4) Ama+ curved piece buoyancy as percentage of total buoyancy: 79%


    Picture: both curved pieces and both amas next to main hull:

    click on image-
     

    Attached Files:

  5. AsterixDeGaul
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    AsterixDeGaul Junior Member

    How much does the model weigh at this point and how long is it ? How about the weight of th emain hull alone ?
    What is the scale ? (I'm too lazy to go back and look :p )
     
  6. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    ==================
    Me too... Target for the mainhull is about 3.8lb and it is less than that now.Weights post-carbonating are posted earlier as are the specifications several times-everything is on target for a 16.688lb all up weight including ballast. Length is 60.75", scale is 1'= 3.375".

    ======================
    The following may be changed at any time before,during or after testing:
     
  7. AsterixDeGaul
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    AsterixDeGaul Junior Member

    So roughly 146 pounds (real life) for the main hull and 642 pounds all up(inc ballast)

    It's amazing how fast these models gain weight :(
     
  8. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    ======================
    No. See above.
    Knock on wood, but so far this model has come in under its target weight-no weight gain at all.
     
  9. AsterixDeGaul
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    AsterixDeGaul Junior Member

    Sorry Doug, I went back and am having a good look at the numbers now. I am trying to compare with my project is all ... love your work
     
  10. AsterixDeGaul
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    AsterixDeGaul Junior Member

    I'm cubing your 1' : 3.375" to get my numbers for real life weight.

    ie: 3.375^3 * 3.8pounds(main hull of model) = 146.0847656 pounds for the main hull.

    Please explain how you calculated to real life weight.



    Just to compare with my model, I am looking at a scale of 1' : 1.9" (12:1.9 or )and the model is 6.5 pounds right now @53.5". (28 foot cat (roughly)) so i used (12/1.9)^3 * 6.5 to give me 1637.556495 pounds for a 28 foot cat(without crew). OK, I see now where I went wrong with your numbers ...hahahaha

    your main hull calculated my way would be (12/3.375)^3 * 3.8 --> 170.8071331 pounds
     
  11. Corley
    Joined: Oct 2009
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    Location: Melbourne, Australia

    Corley epoxy coated

    Just out of interest what laminate are you using on your models hulls Doug?
     
  12. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    ======
    Thanks! This thing has some built in hedges in case there is weight gain:
    1) the "crew" is way too heavy for just the RC stuff so to be accurate ballast will have to be carried(or a large battery) if the thing stays on target. Otherwise there is room to go heavier w/o changing the all up target.
    2) One of the most important aspects of this test model is the foil system so if we wind up too heavy we can reduce ballast and/or increase the daggerboard length. And for foil testing specifically to evaluate the MPX system the boat will be sailed w/o ballast.
    3) My biggest problem on a one off project like this is weight gain during finishing. I'm really particular about how the thing looks and want an excellent finish-not just good. Depending on how it goes the "excellent" finish may be completed after testing. If I wasn't working a "normal" Real Life job the best way to have built this boat would have been to build a plug and mold-then I could have guaranteed an excellent finish and in-budget weight. This way is very tough....
     
  13. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    -------------
    One layer of 5.7oz carbon @ 45/45. If I was building in a mold I'd use two 5.7's on the main hull/deck and one with 1.5oz kevlar for the amas.
    I think I posted the layups for the foils a few pages back.
     
  14. troy2000
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    troy2000 Senior Member

    Looking good.... Happy New Year.
     

  15. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ====
    Thanks, Troy! Hope you have a great year as well....
     
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