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
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    ====
    Thanks. It is the same main hull L/B as the Weta(on the waterline) and similar to a 20 footer I designed and built in 1971. The main hull is designed to plane -as it does on the Weta and did on my earlier boat.
     

    Attached Files:

  2. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    Resined the inside balsa and cut most of the excess balsa away. Except for the first 5 bulkheads and the transom you can see the deck camber:

    click on image:
     

    Attached Files:

  3. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    Here is the boat almost ready for the deck. Still have to install the vertical carbon tubes for the crossarms and the mast compression tube. The original design for the "new" front deck didn't meet my expectations so I have to figure that out aesthetically as well.


    PS-thanks "nice"!

    click on image-
     

    Attached Files:

    1 person likes this.
  4. rapscallion
    Joined: Oct 2006
    Posts: 500
    Likes: 13, Points: 0, Legacy Rep: 132
    Location: Wisconsin

    rapscallion Senior Member

    WOW! Beautiful Doug! Remember the "man in the arena" quote next time somebody wants to give you grief for having crazy ideas....

    It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.
     
    1 person likes this.
  5. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    Thanks, Raps!
     
  6. Gary Baigent
    Joined: Jul 2005
    Posts: 2,851
    Likes: 60, Points: 0, Legacy Rep: 509
    Location: auckland nz

    Gary Baigent Senior Member

    Wow, rapscallion, powerful quotation, thought it was aimed at me for a second, struggling manfully, very occasional success ... but Doug, Doug, doesn't need that flowery encouragement - bet you right now tears are streaming down his face in rightful recognition and joy ... and pooling in his quick setting glue, maybe he's reading the messages in the congealed blobs like a spiritualist staring at tea leaves. Anyway, nice thoughts ... but we want to see the full sized version sailing, not this model making stuff. It does look good though. Cheers.
     
  7. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    ===============
    You are too kind-thank you. Wait till you see the.....
     
  8. P Flados
    Joined: Oct 2010
    Posts: 600
    Likes: 32, Points: 28, Legacy Rep: 390
    Location: N Carolina

    P Flados Senior Member

    Gary,

    Full sized has some advantages, but mid sized models are not just toys. Working out real solutions as you try to achieve specific goals is frequently best done in the shop. If a model is 1/5 of the work, you can get 5 tries in for the same effort. On the same hand, if you only have enough effort available for one or two models, this is still better than enough effort to get half (or less) done full sized.

    Doug has set very high goals for his project. If he follows through and pushes the effort to completion, he may demonstrate real value in one or more of his ideas. If so, I am confident he will share the results in sufficient detail for others to try some aspect in their projects.

    I for one would be less optimistic about raw performance when trying to factor in things like comfort, usability, upset recovery etc. However, I am pretty sure that most of us take Doug's projections of performance with more than a grain of salt.

    Doug,

    Just pound away and do your best to make it work the way you think it can. Some of the basic physics may not work out quite as you hope, but you will only be convinced when you see for yourself. The journey and the learning have the potential to provide plenty of reward for the effort.
     
  9. Gary Baigent
    Joined: Jul 2005
    Posts: 2,851
    Likes: 60, Points: 0, Legacy Rep: 509
    Location: auckland nz

    Gary Baigent Senior Member

    Quite right P Flados, they are not toys and the model will teach you a lot, and Doug is a model maker and has dozens of things to resolve with this radical boat. One of the leading NZ designers Bill Couldrey, (actually he was more than a yacht designer, really an artist), “The trouble is you can experiment with small models but to get proper reliable data you need full size models - and they are expensive.”
     
  10. rapscallion
    Joined: Oct 2006
    Posts: 500
    Likes: 13, Points: 0, Legacy Rep: 132
    Location: Wisconsin

    rapscallion Senior Member

    Yes... Expensive... and the crazier the dream, the bigger the risk the full size model will have little value when completed... The 2.4mr was a model for america's cup boats for testing out sail plans.... Models can work as test beds as long as the scale of the model allows the reynolds numbers to scale properly... right?

    I think the model is damn impressive... and I for one can't wait to see it on the water... perhaps a model isn't enough to earn props from you guys... but is enough for me.

    Even if the model doesn't meet all the design expectations I bet it will be fast...
     
  11. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    High Performance Self-Righting Trimaran: The Test Model

    Thanks guys-but, ah, how 'bout saving some of the good stuff for the next round?
    Major tests:
    --Static self righting-boat placed nose down in water with the appropriate weights where they should be,
    -
    --MPX Theory(Flight Control System)-Done with radio control: the two main foils on the center hull are designed to lift the boat off very early-in relatively light air and then ,as the boat goes faster they unload 100%. The FCS will control the sailing angle of the boat using an adjustable altitude control system(wand). Most small tri's cannot fly the main hull until the wind is over 15-this should fly the main hull in 5-7 knots of wind with substantially more beam than "normal" allowing increased RM as the wind increases. Small tri's with this much beam and weight would have a hard time flying at any wind pressure w/o pitchpoling/ being overpowered. The FCS remedies that with early takeoff, pitch control, sailing angle control and foil unloading as speed increases. Outboard curved lifting foil in ama works with system to aid pointing ability, early takeoff and max speed.
    -
    --Dynamic self-righting-Done with radio control: testing the "self-rightability" of the boat in various sailing configurations.
    -
    --See earlier test list.....
     
  12. P Flados
    Joined: Oct 2010
    Posts: 600
    Likes: 32, Points: 28, Legacy Rep: 390
    Location: N Carolina

    P Flados Senior Member

    For performance (multiple of wind speed), scale testing is probably not all that good. Scaling can be different for foils, hulls and sails.

    For most of the other stuff, the model results could be more interesting. Scaling up may still present problems, but the risk of a full sized flop for a given feature is much lower after a good result from a model test.

    Then again, getting it finished and running honest tests are required for any of this to matter. Doug, please focus on the build (not on the random comments).
     
  13. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    =============================
    Thanks, Mr. Flados-I will. However, just a word: I'm not testing speed with this model-just function, foil positions, foil area, rig position, weight positions, "self-rightability" and function of the MPX system etc. I had the great fortune to spend a summer with Dr. Sam Bradfield who used one of my rc tri platforms to do similar testing for his SKAT foiler. Learned a lot about what can -and cannot be reliably tested this way. It's going to be fun and very interesting....
    Thanks for your comments.

    Pictures,L to R : 1) Flyer cubed-large spinnaker equipped rc tri, 2) Two Flyer tri's sitting on the dock at FIT in Melbourne ,FL. To get an idea of their size look closely at the upper left corner-the man in the blue jacket is Dr. Sam Bradfield-hydrofoil pioneer, 3) The white tri on foils after having been modified by Dr. Sam and his team to test the 40' Skat altitude control system, foil positions, area etc.
     

    Attached Files:

  14. sigurd
    Joined: Jun 2004
    Posts: 784
    Likes: 6, Points: 0, Legacy Rep: 65
    Location: norway

    sigurd Pompuous Pangolin

    That is nice hull! can you turn it upside down and take a few more pics please?
     

  15. Doug Lord
    Joined: May 2009
    Posts: 13,757
    Likes: 114, Points: 73, Legacy Rep: 1362
    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    ------------------
    Thanks, Sigurd. There are additional pictures on pages 4 & 5 in case you haven't seen them.
     

    Attached Files:

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.