MPX-11 Very Small High Power Trimaran

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

  1. twosheds
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    twosheds New Member

    Gary- I was in no way comparing Doug's designs to Jon Howes, I was stating that he too seemed to me to be getting attacked for out-of-the box thinking on this forum. I never made statement suggesting Doug's designs were "brilliant innovations", simply wished him luck. Like I said in my post before, what's it to you? If you don't like it, don't read it, it is a free country.

    Munter - you are right, that was kind of a sweeping statement I made, "pockets of resistance" would have been a better way to put it. If you can see glaring mistakes in a design, then it would be beneficial to the designer if they got pointed out. If he chooses to ignore them, then so be it. He will find out for himself at the prototype stage, or maybe find out it was not even a mistake after all. Also, what would a project be without setting goals? Sure maybe they are too optimistic, but better that than not having a direction to work towards.
     
  2. Gary Baigent
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    Gary Baigent Senior Member

    Eraind44, I've altered one of my old sketches and downsized the design to 14x14 feet - this is Little Flash Harry, serious competition to Doug's Flashingtri. It could be simplified further by getting rid of the foils and having a trampoline carried out to the amas, also you could run a semi circular mainsheet track out there too; then you would use your weight to keep the boat upright.
     

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  3. Doug Lord
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    Doug Lord Flight Ready

    MPX-12 Rig(s)

    As mentioned previously one of the rigs to be tested will the one below-it has been used full size on the 16' foiler and on several models and appears to have advantages over a traditional rig.
    Another rig that is being considered is a solid wing with molded skins.
    Steve Clark has experimented with this and I've done some preliminary work that shows a wing weight right on the edge of viability. More work to do and possibly a model test with a molded wing on an RC cat. A molded wing offers many potential benefits including being able to be effectively sealed, enough buoyancy to prevent turtling(same with the "soft" rig above), and the ability to design in a method of reducing "sail" area. A molded wing could conceivably
    be much easier to adapt to production if that is considered. Fairly easy transport is an important consideration as well.
    The first rig will be the soft rig shown below and when and if suitable wing design can be done it will be tested.
    The rig below has these advantages:
    -- square top masthead jib with adjustable upper and lower outhaual. Jib set up allows whole rig to twist not just the main and jib individually.
    --easy to reduce sail
    --masthead buoyancy
    -- main can use a carbon gaff that also allows and adjustable upper outhaul
    -- automatic gust response
    -- forward third of main to come right down to the deck.
    --may use a screecher






    click on image-then again on lower left picture:
     

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  4. Eralnd44
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    Eralnd44 Wanderer

    there i see trappingwing again.

    maybe we have full boat as to humans now. is flashingtri now dead so trappingwing comes again as complete. maybe you make sneaking attack mr. doug.
     
  5. Munter
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    Munter Amateur

    Hi eralnd, what sort of tri do you have in mind? Btw - your pm appears to be dissabled.
    Gary's design appears to use short floats. Are they reliant on foils for stability?

    Where did cav2's post go? Did he decide better not to join in the mud wrestling?
     
  6. Gary Baigent
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    Gary Baigent Senior Member

    Twosheds, by comparing reactions of posters to Doug Lord and Jon Howe, implies to me that you consider the two to be similar, not only in criticism received but also in design ... when in fact there is an enormous difference in the designs; Howe's is creative to the point of being unbelievable, beyond most sailors' wildest dreams of watercraft, but also brilliant, an aircraft/boat which will be a forerunner to future designs - and his real experimentations will be emulated later because fast sailing craft are going to evolve closer and closer to aircraft using wing in ground effect as well as foils and asymmetric wing rigs. But the big difference is Howe is not bombarding us with screeds of crazed figures and tiny models but is getting on to quietly and courageously building the full sized yacht/aircraft .... whereas Doug drives us all bonkers with his frankly silly designs, end of story. But if I've misjudged his unseen brilliance and he actually succeeds in building his dreamland boat, then I'll be one of the first to praise him and admit I was wrong.
    Munter, the foils for Little Flash are important for small floats but if the amas were increased in volume and length, then the foils could be removed (a daggerboard would have to be placed in the main hull to compensate) and a secondary beam/mainsheet track connected aft to the longer floats; you would use your weight well out to windward for stability and carrying the high rig power. That is only a sketch, I would keep the foils and small floats should I build it, (can't see that at the moment) but if steering from the mainhull, the IT rudder could be changed to a conventional one - thinking of non-complication.
     
  7. cavalier mk2
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    cavalier mk2 Senior Member

    I did delete this post last night to avoid the mud wrestling but Doug good sportsman that he is PM'd me with a nice response and sent it to me so I could repost it. Indeed it wasn't meant as a mud ball, there is something to learn from everything and almost every one so lets try to behave like gents while critiqueing each others concepts. So from last night here it is .....

    You may protest me on this one but I think this is where a lot of people are coming from Doug. Numbers only tell part of the story because they are describing a parameter in one point in time yet sailing in the wet stuff involves ever changing fluid and aero dynamics hence the need to get something real out there to verify the design process. Boats don't translate well into reality on a paint by numbers basis and most designers know and embrace this aspect of design development to take their thought process to the next level. Hence the chorus chanting all right already go for it . Asking for feedback is great but without applying anything in the real world it is just theory and theory never did float a boat. People used to carve half models to build from, are there any offsets yet? An empirical approach is not to be despised if it results in a tangible reality that can be improved upon after demonstration in fact. The design process to be a process needs to move past the theory into a prototype stage so it can develop because the numbers only tell part of the story. We all know the interface between the atmosphere and sea is a constantly changing barrier and a craft traversing it have to interact in a ever changing way. Gary builds his ideas and learns on an intuitive level what really works on the water. Everyone can outdesign his or her ability to construct but to share knowledge of reality steps have to be taken into reality. Otherwise it is just an exercise in theory, and a lot of revisions to read which take time better spent sailing. I mean how do you revise something that hasn't gotten wet yet ? Keep innovating Doug but take it to the next level so the effort counts for something . You are certainly doing the homework, I like the idea of testing the floats. I can dig up old AYRS plans for small test tanks if it helps. Obviously a great computer program would be neat but even so they are only a approximation. At 12 feet it would be fun to just make the thing. The design brief is like a story line that my writer friends would then draft out. Without the draft it isn't a story. The shape concept is interesting but I would get more at this stage from a detailed build proposal, figuring out the nuts and bolts really brings things to the next step.
    __________________
     
  8. Doug Lord
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    Doug Lord Flight Ready

    Chris, from my PM this morning:

    The MPX-12 started as a design exercise-to see if it was even feasible. In such a design exercise numbers are critical to the evaluation of the design-without them you have nothing. But some of the numbers go much further: comparing specific ratios to already existing boats. That is not theory-it is cold hard facts assuming the prototype could be built to the parameters of the comparative ratios. This is the only way to evaluate a design-especially a radical one-to try to determine if it looks like it would be worth the time and money to build a prototype. I'm not finished with the design yet but things look very good so far.
    Again, thanks for your thoughts-go ahead and re-post if you'd like to-I appreciate the effort and input.
     
  9. Munter
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    Munter Amateur

    Doug - you keep referring to the importance of numbers but are relying on some particularly suspect figures in your justification. Instead of providing substantiation you merely assert that others can't read. This is a poor response.

    You claim a mass of 155 lbs, previously 120. This boat is nigh on 50% wider than a Weta and nearly as long. Given that you previously used dimensions to scale the mass - on what rational basis can you claim your design with nearly 30% larger footprint will be 25% lighter? Don't forget you have also included a bigger, more complicated rig with resulting higher rigging loads, sliding seats, hydrofoils, masthead floats, cranes, cantilevered planing amas etc. What miracle are you relying on to make all that weigh minus 50 lbs? Your refusal to accept the reality that this boat will be significantly heavier than you claim completely undermines this process of analysis by numbers. If its junk in then its junk out. As Gary puts it - it's just silly. (Perhaps Gary is worth listening to - unlike yourself he has actually designed and built foiling trimarans and could never be characterised as refusing to consider new, out of the box thinking.)

    Cav2's message of "play nice people", was accompanied by a suggestion that you should build and test. Though probably futile, I'd repeat it again. The physical reality you discover during testing will not be swayed by reams of coloured text and breathless self congratulation you have repeated here.
     
  10. Doug Lord
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    Doug Lord Flight Ready

    MPX-12-----change

    Before and after mods to cross arm position:

    (click on image and then click on resulting image for best picture)
     

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  11. Doug Lord
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    Doug Lord Flight Ready

    MPX-12-----angle of heel

    These three pictures show the automatically controlled angle of heel of the boat. The altitude control system maintains this angle fairly precisely with virtually instantaneous response to gusts or even to crew movement. The system controls pitch as well. A unique feature of this foil system is that it UNLOADS as it goes faster and sails in more wind with the max crew weight. Max foil lift occurs in the lightest air the boat can fly the main hull, while the lowest load is at max speed! The same system allows the boat to sail at this angle and at max power regardless of crew weight in the range of 120 to 240 pounds:

    (click on image and then click on resulting image for best picture)
     

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  12. Eralnd44
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    Eralnd44 Wanderer

    mr doug you say auto heel. i see no auto heel more is the talk you say. must to make flashingtri truth boat. maybe that flashigtri have some words to say for self. you make big hot air on boat. boat have no way to make complete.
     
  13. Eralnd44
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    Eralnd44 Wanderer

    mr. doug where is trappingwing you show on day before now. is trappingwing real now. maybe trappingwing is to the hot air also.

    how is flashingtri more important as to trappingwing. i read words you make on trappingwing. you say most important boat for you and is already dead. is ok with you to do that.
     
  14. Doug Lord
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    Doug Lord Flight Ready

    MPX-12(Flash Tri) and Flash Harry : WEIGHT

    Flash Harry is a trimaran designed about 30 years ago to use two surface piercing main foils and a rudder T-foil. It was designed as a foiler but apparently didn't work too well in waves: "...but in decent waves it was prone to crash-and it would leap up again, sprint and crash." Gary Baigent continues: "... so I switched [to] two fixed inverted V foils set permanently below the small floats." Lift off (before crashing) was in 12-14 knots. Anybody experimenting with foils is bound to have some trouble at first. So the boat was converted from a foiler to "foil assist" where the foils assisted with stability.
    But Flash Harry was a truly remarkable boat even though it failed as a foiler in decent waves: it was 19.68' long and 19.68' wide and weighed only 150 lbs including a 30' wingmast rig with 193 sq.ft. of sail area and three(3) sets of foils. That's 5lb less than the projected weight of the MPX-12(Flash Tri) with a much bigger rig and 50% more foils than the MPX!
    ------------------
    Note: in a previous post some mention was made of scaling Flash Harry down to 14'. Directly scaled down it would weigh 54lb(114 w/crew) and have a sail area 97 sq.ft. So obviously some modifications to the hull(and/or its waterline position) and rig would have to be made to make the "scaled down" design viable at 14'.

    http://www.boatdesign.net/forums/mu...rans-new-zealand-attn-gary-baigent-22671.html

    http://smalltrimarans.com/blog/?p=2974
     
    Last edited: Oct 3, 2010

  15. Eralnd44
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    Eralnd44 Wanderer

    and also flashingtri now dead mr. doug.

    flashharry make better for smart truth boat. mr. gary make strong boat over flashingtri dream boat. so to talk more now on flash harry is good.
     
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