MPX-11 Very Small High Power Trimaran

Discussion in 'Multihulls' started by Doug Lord, Jul 13, 2010.

  1. Doug Lord
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    Doug Lord Flight Ready

    MPX-12---daggerboard/foil

    ===================================
    A whole lot of problems are solved with this system but the increased total wetted area is a big problem. I'm looking again at the concept of tilting* the foil itself. The foil would be mounted in a "bulb", as described before, and it would pivot about 20 degrees in order to allow some improvement in windward work. This would eliminate the canting board and the need for a gybing board-IF it can be done reliably and robustly.

    * first incarnation of this idea in post 25 but movement 10 instead of 20 degrees and used along with gybing board.
     
  2. Munter
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    Munter Amateur

    I forgot the golden rule of posting in Doug's threads. Make sure you use quotes because Doug has an unfortunate habit of going back and editing past posts without acknowledging it in some kind of attempt to revise history to cast him in a better light.

    Back on topic - it is one thing to claim "simple, automatic" systems but completely another thing to actually create them. Your claims aren't backed by any demonstrated ability to deliver such a complex vessel and I don't see any other similarly sized vessels with the same degree of complexity. Its all just claims and hot air.
     
    Last edited: Oct 27, 2010
  3. Gary Baigent
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    Gary Baigent Senior Member

    Munter, we should learn ... that any simple, empirically arrived at knowledge encompassed in a suggestion to Doug - ends up with an enraged lecture along with yet another page of red type.
     
  4. Doug Lord
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    Doug Lord Flight Ready

    ===========
    Like your comments on "negative lift"?? Funny.
    Gee, Gary, I even agreed with your comment on the twin boards.....
     
  5. CutOnce

    CutOnce Previous Member

    For unfathomable (to me) reasons, Mr. Lord appears to be a highly valued contributor to this site. Somehow to the publisher/website owner there must be value in his presence even accepting his intentional provocations and obvious enjoyment of conflict. Surprising too is his lack of interest or visible effort in actually building his designs.

    I'm trying the "Ignore" function on this site.

    --
    CutOnce
     
  6. Doug Lord
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    Doug Lord Flight Ready

    MPX-12-----design

    The MPX-12 design is not complete but is getting close. The two major areas needing to be resolved are the board problem-I won't accept the hydrofoil working poorly upwind. That will be solved.
    And I want to continue to evaluate the rig-including the feasibility of a wing prototype.
    A couple of minor areas also need to be looked at.
    -----------------------
    As stated several times before: no prototype for this boat will be built at least until the first Trapwing proto is sailing. I really think the MPX-12 proto and the technology it represents offers tremendous potential for spectacular performance exceeding that of any 12' trimaran I've seen yet. The technology-particularly the planing amas and the foil system that controls the amas running angle and the boats sailing angle automatically are not to be found on any other trimaran ,period. Should this boat meet expectations during testing it will be a major improvement in small trimaran design. This is shown in the comparative statistics as the boat is evaluated with widely understood ratio's figured for Moths, C Class Cats, A class Cats. The results compared to the Moth are astonishing and if the boat is built within the parameters used to make those comparisons performance should be outstanding-most especially considering how much easier a single crew will find this boat to sail.
    -----
    The "Fun Factor" with this boat, should it perform as expected, will be a jump as significant as the sailing technology: crew movement and the physical requirements for the crew are far less than any comparable high performance sailboat 12' long. Crew comfort will be second to none and is a MAJOR design consideration with the MPX-12 proto. No more high speed torture chambers-this thing will be easy to sail, very fast, very stable and easy to transport.
    I'm really excited about the potential and there is a high likelihood that a proto will be built once the Trapwing proto is sailing.
    But the design must be finished and I will continue to chronicle the questions I still have and the solutions I come up with.
    --
    I don't mind comments at all-I like constructive criticism-it is invaluable- but anyone that expects me to automatically agree with any criticism is living in a fantasy world. But if I don't agree I will explain in detail why not. Those, whose modus operandi is uninformed,speculative personal attack, can expect no response at all. If you criticise or make a suggestion and it is obvious you have not even read the material you may not get a response.
    --
    I've put a lot of effort ,time and research into this concept and have learned a lot and will learn a lot more before I'm thru. The work and research I've done all my life-especially the numerous boats I've designed,built and experimented with give me the confidence in the potential of this exciting boat.
     
  7. cardsinplay
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    cardsinplay da Vinci Group

    So, when is the Trapwing supposed to be completed? A date, progress photos, anything at all beyond the long lists we have already seen?

    "The work and research I've done all my life-especially the numerous boats I've designed, built and experimented with give me the confidence in the potential of this exciting boat."

    When you say this, I get the feeling that you are unsure of yourself and hesitant to actually build this boat, or the Trapwing. You seem to be the only person raving about the trimaran and it's future. Nobody has stated that they want one.

    If you can show that the Trapwing is being built and has a due date, maybe that would change the minds of the people who follow the thread and put some credibility into the lone voice presentation?
     
  8. Munter
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    Munter Amateur

    hah - it seems I've been censored! I'd be interested to know what is was that made the post unacceptable to the moderator. Can feedback be provided?
     
  9. Doug Lord
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    Doug Lord Flight Ready

    MPX-12------wavepiercing planing amas: an update on the thinking behind them-p1 of 2

    The amas on this boat are designed to plane but most importantly: not with a full load from zero speed like most other planing hulls. These hulls(one at a time) only begin to carry a load at about 10 knots boat speed and gradually take the whole load as the speed increases further.
    Their running trim angle is controlled by the two main foils as is roll angle which is maintained by a surface sensor(wand) on the main foil.
    One critical design consideration is that small planing hulls will not work well if the planing surface has too low an aspect ratio-in other words is too long and narrow. The planing surface of these hulls from 10 knots boat speed on up is about 1 to 1(or better) which is fairly high and similar to the aspect ratio on many small planing hulls like windsurfers at this speed and above.
    If the prototype is built much experimentation will be done to optimize the aspect ratio and planing area-which will be simple to change.
    Because the design of the planing ama's relies on the control of the running trim angle by the foils on the main hull the design of the ama includes a "wave piercing" shape that morphs into the proper planing shape and should help in waves-especially short steep waves.
    --
    As mentioned earlier, these amas will also allow very small t-foils to be experimented with as a form of "foil assist" to aid the planing ama's in certain conditions. These foils will be fully retractable and have an adjustable angle of incidence -but no altitude control system(wand).

    click on image and then again on resulting image:
     

    Attached Files:

    Last edited: Oct 31, 2010
  10. Doug Lord
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    Doug Lord Flight Ready

    MPX 12-wave piercing amas- p2 of 2

    If the prototype is built the ama planing surface will be subject to much experimentation. One of the things that will be tried is to make the planing area slightly concave which some sailboard designers say increases lift and improves control. As well as testing concepts to improve the aspect ratio of the surface. Since the ama is so small it may be able to be tested on a frame attached to a small powerboat as well as be sailed on one side of the MPX-12 only to be compared directly to the performance of a "base" design on the other side.
    Since this planing hull is controlled differently and works differently than most planing hulls I think there could be big gains with this kind of relatively simple testing.
     
  11. cardsinplay
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    cardsinplay da Vinci Group


    Time to get real. IF the prototype is built, the whole thing will be subject to experimentation.
     
  12. Doug Lord
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    Doug Lord Flight Ready

    Mpx-12----

    =====================
    The MPX-12 will be equipped with sliding bench seats that are extremely easy to move. It appears possible that these seats can be used to allow the tilt from tack to tack of the main foil as the crew changes sides. Use of the seats for this purpose would not restrict their maximum movement(2') and would tilt the foil in the first few inches of movement. Still working on this but it looks more and more feasible to move the foil in this manner and to use a 20 degree tilting main foil on a retractable daggerboard to solve the negative effects of a "normal" t-foil when used on a trimaran main hull sailing at an angle of heel.
    Since the angle of heel is fixed at 10 degrees, the 20 degree pivoting foil would unload the daggerboard and improve windward performance fairly significantly.
    Making headway on the final design issues....
     
  13. CutOnce

    CutOnce Previous Member

    Mr. Lord:

    How do you plan on "locking out" your sliding bench(es) when the boat heels? Seems like just when you want a stable seat to "hike" for righting moment, the seat will be trying to roll you two feet towards the center. This will also mess up your canting/gybing T-foil/bench entanglement/autocanting control scheme. Add a gust and three foot wave and it could be 45 degrees in a heartbeat. Practically limiting heel to ONLY 10 degrees will require an ironclad "no waves & gust-free" arrangement with your chosen deity. There are constantly variable uphill and downhill inclines with your benches that seems to be studiously ignored.

    If you do put in a manual "lock-out" mechanism to keep the bench from rolling about, the driver of this boat is going to be one busy darned beaver. Perhaps you could incorporate the Trapwing joystick controls with the benches? Use a Trapwing instead of the benches and have the operator sit on the Trapwing?

    The whole thing seems to get more and more interesting - although I'm sure you've thought of everything. It will be nice to see the real world model demonstrate how you solve all the complexity.

    --
    CutOnce
     
  14. Doug Lord
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    Doug Lord Flight Ready

    ======================
    Yes I have tried to, thank you. But as this is an ongoing design and ,maybe, testing program- we'll experiment with a lot of different solutions. Your remarks regarding the 10 degree angle of heel shows that you have not read the material, or, perhaps, don't understand it. The angle of heel is controlled fairly precisely by the wand based altitude control system which is proven on numerous boats. Contrary to your wildly uniformed assertion: this boat is not as complex as a whole number of 12' high performance boats-on the contrary the systems are designed to be mostly automatic with much reduced physical requirements for the crew( and a MUCH higher comfort level) compared to any high performance boat in this size range.

    Your silly remarks about the Trapwing are duly noted. Please don't participate in this thread if you intend to make further uniformed, ignorant comments along those lines.
     

  15. cardsinplay
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    cardsinplay da Vinci Group

    and you say this with a straight face?
     
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