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

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

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

    Doug Lord Flight Ready

    MPX Test Model

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    Thanks. You're right.
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    SRT / MPX Test Model

    I just spoke to Matt(Falcon Marine) to set a tentative date for Phase I of painting which will be spraying the boat with Duratec. Phase II will be the final coat,unless the painter thinks he can spray either Duratec or a special primer they have to fill 80 grit scratches-which is doubtfull. So I'll have to wet sand after the first Duratec coat. That should take about two days.
    I'm hoping to be able to take the thing to Matt Thursday or Friday of this week -at the latest next Tues. or Wednes.. And maybe have it back painted by the end of next week-I said maybe.....
    In the whole saga of building this thing I have almost never been held up by not being able to sand on our porch. Somehow the wind was always from a direction that didn't blow dust thru the screen toward the neighbors porch. Never had a complaint and it always worked out. But today it's 15-20 out of the north and stops me dead!
    So I'm doing the final drawing of the mainfoil adjustment device and wand holder, and the daggerboard, rudder ,mainfoil and rudder foil layout.
    The daggerboard has a tube running full length with a pushrod inside that connects to the flap on the bottom and to the wand shaft on top. The wand shaft uses a bellcrank to make the conection and the bellcrank is also attached to a spring that holds the wand against the waters surface.
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    So stay tuned -going to start moving fast ,I think.
     

    Attached Files:

  3. DennisRB
    Joined: Sep 2004
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    Location: Brisbane

    DennisRB Senior Member

    Looking good. Hey can you please give a short design brief again? This thread is long at it appears the goals have changed from the beginning. Its not going to self right anymore is it?
     
  4. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    SRT / MPX Test Model

    Thanks, heres a sort of summary post. The self-righting will be tested down the line. The high dihedral and "curved pieces" are part of that system as well as being good allround. But the foil system has taken precedence in testing because the potential gains are so great. If you have questions don't hesitate to ask:

     
  5. Gary Baigent
    Joined: Jul 2005
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    Location: auckland nz

    Gary Baigent Senior Member

    Doug, I like your dihedral design (well, it's very similar to my own stuff, so I have to say that) and understand that the cowlings aft of the floats and connecting the beams, are there for spreading loads and cutting weight but, on my light and wide boats, sometimes tacking in a seaway and higher winds, can be a tricky manoeuvre; you have to time everything perfectly, meaning helm, releasing main, coaxing that wide/light platform through the eye of the wind and onto the new board - and sometimes you get stopped head to wind and sail in reverse. You quickly reverse the helm, hold the wing mast up to weather until the boat is pointing correctly for the new tack, drop mast spanner, sheet in, up helm and away. Sort of three point turning. Now your floats are mounted forward (to halt nosing down) and there is nothing much aft of centre and if you are caught aback, there is not much to stop you rocking backwards, only the main hull, which, with your light design, will be reversing at a rate of knots. Could be tricky situation.
    What I'm saying is I think it would be better to shift your small floats aft, so they're more central and not biased forward. Your foils will stop nose down problems anyway.
    But you'll find out if there is a problem soon enough and maybe in Florida's lighter winds, getting caught reversing at high speed will not occur. Cheers.
     
  6. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ===========
    Thanks Gary! The reason for the curved pieces and forward position of the ama hulls is to help to facillitate self-righting-the curved pieces are there primarily for buoyancy-they have about as much as the ama hull does. Same with the dihedral which needed to be high because of the curved pieces.
    The primary testing is for the new foil system now and later on I'll see if the self-righting concept can work.
    After initial testing ,if weight is ok, I think I may add fairings to the cross beams-but that's down the line.
    I'll keep in mind what you've said........
     
  7. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    MPX Test Model oops

    Trouble with the sails: Scott(Sails by Morgan) e-mailed me today apologizing for not having the sails ready-I told him I was behind as well -no worries. However, it turns out that the Sandy Goodall(sail designer who did the main design) patterns were done on software that is incompatible with Scotts sail cutter so the main may have to be done all over again. Scott has used Goodall for a lot of projects including for the sails on my 16' full size monofoiler so it's kinda hard to figure how things got this screwed up. I guess Sandy changed his software and didn't tell Scott? At any rate, no sails for a while. Luckily I'm about two weeks behind(or so) so I imagine it will all work out.....
     
  8. basil
    Joined: Apr 2005
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    Location: aUSTRALIA

    basil Senior Member

    What!!!! this is not about self righting? We've waited months - read thousands of mainly unnecessary words (some 300 posts) and ongoing excuses for the delay and now you say this all about foils - Come on Mr Lord when are we going to see your self righting trimaran???

    Bas
     
  9. CutOnce

    CutOnce Previous Member

    Basil, give Doug a break. Anyone who has taken on a project like this knows the path is longer than expected, it takes you places you never planned and it costs more than you ever imagined.

    Besides, the problem here is a simple typo, not quiet de-prioritization of the major feature advertised and promoted. And it isn't even a misspelled typo - it sounds exactly the same.

    The thread should be labelled "High Performance Self-Writing Trimaran: The Test Model" and when you take that into consideration the project is already an amazing success. I don't know about your expectations, but there certainly has been a shipload of high performance trimaran writing produced ahead of schedule.

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    CutOnce
     
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  10. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    MPX /SRT Test Model

    ======================
    Gee Basil, thanks for you interest, but apparently you missed the part where I said that the foil testing is now the number one priority, but the self-righting will be tested down the line.
    As you probably know from following the thread so closely no changes to the boat were made to allow foil testing to become the first priority. The boat-I'm sure you've seen the pictures of the first float test of the fully assembled hulls-is the exact design required to test the self-righting concept-all I have to do is add lead to the daggerboard.
    Thanks for your interest!
     
  11. cavalier mk2
    Joined: Mar 2010
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    Location: Pacific NW North America

    cavalier mk2 Senior Member


    That is a catty thing to say! The title says trimaran and Doug is certainly trying!
     
  12. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    MPX Test Model

    Finished the 80 grit sanding of the curved pieces and aft end of the amas as well as the aft end(gantry mount) of the main hull and the crosstubes.
    The crosstubes and the verticals presented a nightmare to sand down the superfill because of the difficulty in getting to them by hand. Thursday night I had a brainstorm to use sanding belts(from a belt sander) so I got 3" and 1" belts yesterday.
    Boy, did they work well-was able to knock them all out in an hour-it would have take 3 hours by hand.
    Just some small touch up fills and the boat is ready for Matt to spray with primer or Duratec and then the whole thing has to be 200ed and 320ed which won't take long at all.
    PS- will try to add the mounts for the wand holder tonight and tomorrow....
     
  13. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    MPX/SRT Test Model

    Going to Matt tomorrow or Wednesday. Decided to go ahead and install the plates for mounting the wand holder. Used little 8/32 bondable fasteners sold by Dragon plate(see left picture below). In the right picture the edges of the plates holding the fasteners have just been coated with Super Fil, very lightweight filler from Aircraft Spruce, and there is a piece of peel ply holding the stuff in place on the thick side. The plates are coverd with masking tape and when the tape is removed will be high gloss "natural" carbon fiber. Should look pretty good-we'll see.

    Pictures-Left,an array of the bonded fasteners from Dragon-epoxied in place, Right, the instalation on the main hull.
    click-
     

    Attached Files:

  14. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    MPX-Test Model

    I went to get the paint this morning-"Dupont Marine Series". Matt of Falcon suggested this instead of IMRON because he has aff the stuff that goes with it at the shop. So, I had the number of the "Bright Red" used on some 2013 Chevys but the guy said they couldn't mix that with the Marine Series-just too new. So he picked out another red that, under intense light, was very similar. Oops, they could only mix that color in the Aviation Series!! So to save money I decided to stick with the Marine Series and use their "Journey Red" which is ok-not spectacular.
    Heres something that really is spectacular: one quart of this paint cost me $250-that's DOLLAHS! Unbelieveable. One quart of white would have cost $60-the guy said the red is the hardest to produce. OK, I guess....
     

  15. CutOnce

    CutOnce Previous Member

    Red is not only hard to produce, it is a serious pain in the nether regions to get a quality finish from. It is a semi transparent jewel toned paint, requiring lots of coats to cover faults in the surface underneath. For best results, a even dark grey toned primer will allow red to work best. If there is any variance in the primer coats, it may show through four of five coats of red.

    I once painted a boat red. I'll never do it again. It takes two to three times the weight of paint to equal the finish from other colours. And $250 a quart? Sounds like military pricing to me. Imron I'll avoid due to the toxic off-gassing and need for positive pressure breathing gear. Two part epoxy automotive on good marine high build primer is now my choice for a dry sailed boat. Then again it looks like I'm in a different budget world if you paid $250 / quart.

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    CutOnce
     
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