Small trimarans under 20'

Discussion in 'Multihulls' started by Doug Lord, Jun 24, 2012.

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

    =======
    Thanks, Cholsson. The Fire Arrow is 5'+ LOA X 7' wide. I think that discussing the system used on Fire Arrow first and on larger boats later is a subject of interest for trimarans 20' and under where the advantages are as great or greater than on larger boats. Waynemarlow suggested: " it's still only proven at model size and that whole concept belongs in that model thread until proven at full size." He said that back in 2015 and was probably right then. However, things have changed with the system having been 100% proven beyond a shadow of doubt on multiple fullsize trimarans.
    Anyone considering the design of a small performance trimaran would do well to consider whats been learned with the Fire Arrow Foil System-from the Test Model to Maserati and Gitana 17 and the other Ultims over the last few years.
     
    Last edited: Apr 24, 2019
  2. Gary Baigent
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    Gary Baigent Senior Member

    You have rabbited on for near two decades, about your fixated slightly enlarged toys (with their infantile grandiose names) ... but have you produced even a realistic 6 metre size? - zero, nothing, zilch. Not even a tangible failed effort. Which would be to you a credit. Instead the nauseating postings of fantasy continue.
     
    Last edited: Apr 23, 2019
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  3. Doug Lord
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    Doug Lord Flight Ready

    exact scale model of the 19.5' X 22' Fire Arrow:
    MPX_Fire Arrow-3D SAILING-7-24-14 009 (4) - Copy - Copy.JPG

    Two decades?! You're way wrong Gary-as usual-started Fire Arrow design and development 2010. I've designed , built and tested a revolutionary trimaran foil system where the mainfoil can generate downforce that is now used by Maserati, Gitana 17, Macif jr and Macif 100 as well as by Banque Pop. I've completed the design of WOLF, a 15 foot trimaran using the Fire Arrow Foil System with automatic , instantaneous, downforce and Two Stage Amas. God willing and the creek don't rise I'll get WOLF built. Your inability to understand and even discuss the foil system is unfortunate....

    MPX Fire Arrow.jpg
     
    Last edited: Apr 23, 2019
  4. Dolfiman
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    Dolfiman Senior Member

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  5. Cholsson
    Joined: Aug 2015
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    Cholsson Junior Member

    Tested out my reef today for the first time, that North Sails put in. Reduced the main sail A LOT, to maybe 6 m2, from 13.9 m2.
    Still, the boat was doing pretty ok?
    Then wind speed was maybe 10-14 knots. Some times less.
    Think I can use the reef more. Much easier to tack.



    In the end, I did a BottleCapChallange attempt, but the first once totally failed
     
  6. upchurchmr
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    upchurchmr Senior Member

    Cholsson,

    Looks nice. The speed looks great with that amount of sail reduction.
    I don't remember, can you fly the main hull with full sail?
    This is a tremendous improvement verses your first attempts.

    Why do you think it tacks better with less main?
     
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  7. Cholsson
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    Cholsson Junior Member

    Thanks! I cant really fly the main hull. It was not designed to do. Maybe thats the way to go anyway. Everyone tells me to get more volume in the amas. Could be a project for the winter.
    It tacks ok if I release the sails in the correct moment. It was easier with a tiny main.

    If the wind is ok I will compete in a round the island race on Saturday :)
     
  8. Doug Lord
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    Doug Lord Flight Ready

    Instead of more volume in the amas why not go with (at least) uptip ama foils that can work well w/o adjustment? Have you considered a lifting foil on the daggerboard(assuming you have one?). You've done great work-always a pleasure to see your excellent videos!
     
  9. Vantage475T
    Joined: Aug 2016
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    Vantage475T Vantage475T

    With reduced main sail the centre of effort could be moving forward?
    I found that significant enough on my kaymaran (over 21ft long and very narrow) so I made leeboard position movable depending on the sail set up being used.
     
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  10. revintage
    Joined: Nov 2016
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    revintage Senior Member

    Hey Christoffer,
    Way to go, seems more realaxed and speedier now. Have suspected you where somewhat(or a lot;)) overrigged earler. The main might not have been very effective due to too much twist in abscence of a traveller and car, as I mentioned earlier. Probably the new jib is more effective and works better with a smaller main. But what about balance, as you have moved CoE quite a bit forward?
     
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  11. Cholsson
    Joined: Aug 2015
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    Cholsson Junior Member

    Yes Vantage475T, think you are right. The jib (if I release it a bit during tacking) seems helping more when the main was smaller.

    Doug Lord, thanks for kind words about the my videos. Try doing my best and adding some post-production things to make it more enjoyably.
    About foils.., lifting the boat, uptipfoils and more..., like Jack says, its things a man can do, and thing a man can't do. (with carbon & mechanics)
    I can only build small things in my small 20x20feet garage. I have very limited time with two small kids, and I don't have a multi-million investor in my project. I had Just a few thousand.
    Several multihulls that can foil, also getting calculation help from either Boing or NASA or both, and built by pros.
    In Sweden, we one have Marstroms, that design and builds fast multihulls like the M32-catamaran. Not even they can make anything fly :)
    (Except FrankenFoil-projects in Sweden, that may produce something flying soon @revingtage)

    What maybe possible could be done that is "related" to foiling, is to buy a used Nacra17 with C-boards or foiling boards and switch my two ama's to that.
    But... very very few used Nacra17 in my regoin, and,.. will be expensive... and will it even work or help??? Will the allround performance be better?

    I have two more "newer" A-cat hulls, that maybe could be rebuilt and give my boat ama's more volume and make it less submarine when I push it.
    Anyways, focus right now is sailing and be on the water! :) Trying to create some more videos I can analyze during winter.

    Thanks for comments anyway, and I'm trying to improve my boat and videos bit by bit :)

    Chris
     
  12. Eric Lundy
    Joined: May 2017
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    Location: Vermont

    Eric Lundy Junior Member

    I am also enjoying your videos. I think a lifting foil may give your current ama's enough extra boost at speed to provide better performance when driving hard without the need of physically enlarging the AMA . Like you mentioned the M32 t can be set up with lifting foils without the added complication of "flying" foils to keep the lee ama from burying. In your current setup it would still be a lot of work to get a foil onto the Ama, but it would be way less fiddly than trying to fly. I think there is a lot of design space in the lifting category other than C boards. I enjoy the idea of a creative way of increasing the righting moment at higher speeds.
    cheers,
    -eric
     
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  13. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    Foils require cubic $ - meaning lots of $.
    Bigger amas are relatively cheap. And not technically difficult.

    Perhaps you could then afford a mainsheet track for easier control of the main.
     
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