Design Challenge: Trapwing-"on-deck" ballast-12'-22'

Discussion in 'Sailboats' started by Doug Lord, Oct 7, 2009.

  1. bistros

    bistros Previous Member

    I'm sure a model will help dramatically, especially when there are little to no actual formal design tools (CAD,CAE), experience using those tools and formal education in place to provide the same level of support to the process. Traditional shipbuilders used half models long before Solidworks, Prosurf and Rhino etc. appeared. A lot of the old guys got a lot right by eye and by model making.

    Typically, professionals today use sophisticated computerized tools with integrated "rules" and engineering design parameters to help make sure things work as envisioned. Without these tools to help the process, it is far easier to make a scale model and "test" functionality on a smaller scale both in size and expense.

    I'd be willing to bet Doug will be far ahead of the game building a model, as his legal pad drawings are effectively useless in predicting and solving problems. I'd also be willing to bet that Doug has adapted his "design" process around models as they become essential as the only real reference used to build the final product.

    If I were Doug, I'd invest the time necessary to learn and use the current tools of the trade - the one problem with doing things the traditional way he does is that material science and optimization stops being easy, and mistakes and engineering problems are amplified. It isn't hard making something strong, and it isn't hard making something light, but really light and just strong enough isn't easy.

    If the goal is just drawings, computers aren't a huge benefit - but if you embrace the "Computer-Aided Design" component of CAD, the resulting drawings incorporate and reduce the need for a lot of modeling and trial and error design.

  2. Paul B

    Paul B Previous Member

    Models can be useful as proof of concept. To be useful they need to be representative.

    If you have not done proper preliminary design why would you build a model? I don't know any good designers or engineers who would do that.

    You don't need CAD to do preliminary design, kinematics, and engineering.
  3. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Trapwing Prototype

    The following is a detailed look at the characteristics of the new Prototype, as well as the design elements it will encompass and test:
    Trapwing Prototype:
    LOA 17'
    Beam hull-3.25' overall 12'(subject to testing)
    Weight- hull 155lb
    ballast-wing 80-180lb(variable and subject to testing)
    keel 0-80(subject to testing)
    SA-upwind 100-180sq.ft. variable
    downwind 200-360sq.ft. (variable and subject to testing)
    crew-singlehanded-120lb-220lb (variable and equalized under class rules-
    subject to testing)
    crew position for racing on the centerline inside boat, fixed
    athwhartships, variable fore and aft
    1) Sail area to be between 100 and 180 sq.ft
    a-different rigs
    b-different amounts of ballast
    2) Ballast wing to be supported by trapeze wires and unique retention system that allows wing and ballast to slide simultaneously, allows athwhartship pivoting and fore and aft movement.
    a-version one will use two aluminum tubes with sliding external tray- the tubes and tray move simulataneously:
    -attachment system allows wing- with weight centered-to be levered up and then pivoted from a position 90 degrees to the CL to a position parallel to the centerline for transport and stowage.
    -weight can be added or removed in small increments.
    -fore and aft pivot/sliding tube is mounted to the boat slightly offset from the CL to allow room to retract board/keel.
    -aluminum tubes terminate at outboard ends in buoyancy pods-pods will be changeable as determined in testing.
    -sliding ballast tray and structural design of wing to be capable of 180lb max ballast @9' from CL; ballast completely adjustable in the range of 80 to 180lb.
    b-version two is a slightly curved(athwhartship), molded and sealed(with sealable access to ballast tray) wing with an internal sliding ballast tray. This version will be the final version and incorporates all the features of version one with significantly increased sealed buoyancy.
    c-Wing movement by manual or electric means. Minimum electrical movement speed 4' per second. Minimum electrical "stamina" on single battery-12 hours at a rate equivalent to a approximately 60 (full track)tacks per hour.
    3) Crew Position
    a-version one-racing position-allows crew to sit in an extremely comfortable seat that is fixed athwhartship and slides fore and aft adjustably while sailing.
    -extremely wide crew weight range:for racing lower tray attached to seat may contain ballast used to equalize crew weight in the range of 120 to 220 lb.
    -seat may be moved manually or electrically.
    b-version two-center seat is removed and two fixed carbon seats with backrests are "plugged-in" to each side deck.
    4) Rigs to be tested are main and jib, main alone, with and without an asymetrical spinnaker.
    a-asymetrical will be tested as permanently mounted off a bowsprit(a la Weta tri) or retracted into a trough with roller(a la Viper) and a retractable pole.
    b-mast to be sealed with masthead floatation in an endplate configuration. Some buoyancy possible in head of sail.
    5)-Daggerboard/ keel/rudder
    a -boat will be tested with and without a retractable "lifting keel"
    which would essentially be a carbon daggerboard with the minimum ballast required(determined in testing) to right the boat from a pitchpole(where the wing buoyancy may not significantly help).
    b-self-righting from a knockdown or pitchpole is a required design element for any version of the boat used for disabled sailing.

    c-a turbo version of the boat will not use a ballasted keel and may not be suitable for disabled sailing but this will be determined in testing.
    d- the daggerboard may include as standard a lifting hydrofoil designed to provide "foil-assist" to reduce wetted surface and in conjunction with the rudder hydrofoil improve the pitch and planing characterstics of the
    e-a fully flying hydrofoil system will be tested as will a fully flying system that allows the boat to fly downwind only(requiring less upwind SA and less ballast).
    f-rudder will be retractable with a t-foil.
    6)-On the Beach
    a-the boat will be able to be easily beach sailed with a dolly incorporated into the trailer design to make it very simple to go from trailer to water. A "power assist" dolly may be available.
    a- the goal is to develop a high performance planing sailboat that can be safely sailed from a center crew position by disabled or able-bodied sailors. I am hoping to be able to achieve an SCP/total weight of 30% or slightly better though that is just a target and a less powerfull version with numbers and performance more like a Windmill or Tasar may be perfectly acceptable. The use of foil-assist technology will help to achieve the performance goals. Full flying foiling is possible in a selfrighting boat-particularly one with the righting assist this boat has from version two of THE Wing.
    The concept has extraordinary potential and it will be a blast finding out just what she'll do.
  4. Paul B

    Paul B Previous Member

    Another list of numbers.

    Still no technical drawings showing how any of these "unique" systems will actually work.
  5. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    You know Mr. "B", I'm kind of surprised at your apparent aversion to numbers
    in relation to boat design. Must make it kinda hard on you,huh?
  6. Paul B

    Paul B Previous Member

    Lists of numbers is not "boat design".

    Since you claim the hull is one of your existing designs maybe you will post the linesplan you drew for it. I'd bet against that.
  7. Paul B

    Paul B Previous Member

    I guess dropping everything doesn't include the same old, same old posting on this forum.

    Of course among the multiple posts you've made today none have been to show how the complex mechanisms you are suggesting for this project will actually be constructed.

    You have not shown us the linesplan for your existing design you plan to use for this project. We have not seen any technical drawings showing the drive mechanism for the wing that will move in at least 3 axis. We have not heard any cogent idea of how the trap wire will deal with this proposed movement. We have not heard..well, anything about how this whole shebang will actually work.

    I suspect we have not heard or seen these things because you have not dropped everything and actually started drawing the thing.

    If I needed to Drop Everything to get the most important project of my career rolling I would not be posting on internet sites about non-related issues.
  8. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Thanks for your interest, Mr. "B":
    1-2-Generally speaking no lines plan, technical drawings etc. will be published here prior to the completion of prototype testing, if then, depending on patent and other considerations.
    3) well, gosh, you must have missed it! It's been discussed(the original system) in some detail and illustrated in drawings and on the models pictured in earlier posts. Basically, the Wing is mounted to a structural tube that allows the wing and the wing mount to pivot athwartship and slide fore and aft. The original system has been successfully model tested for years with zero failures though improvements and possible improvements were discovered during this testing.
    When the Wing is centered the trapeze wires on the original design support no
    load and the wing is kept level with shock cord tension. The tension, amount of "stretch"(and consequently, the amount of athwartship pivot with wing movement) is fully adjustable and allows the lee trapeze wire to not interfere with the main.
    4) Again, it might help if you re-read the thread. There are no issues that have not been solved in terms of a functioning full size version of this concept. There are a number of areas where improvements may be made as a direct result of prototype testing. This thread discloses in detail a system that has worked for thousands of hours in model testing and exactly how it works. If there are any specific questions I'll be more than glad to answer those I can.

    Attached Files:

  9. Paul B

    Paul B Previous Member

    No one has missed anything.

    You have not solved the issues at all. Sounds like you have not done any drawings or calculations.

    It is no surprise you will not reveal any information. Two years from now you will probably still be talking about how revolutionary this is, but nothing will have come to fruition. Just like the other 10 or so of your "designs" that have never actually been built as you had once breathlessly described their imminent birth.

    Will this mystery guy Mark the boatbuilder be doing the drawings for you this time?
  10. Chris Ostlind

    Chris Ostlind Previous Member

    Well.... it has been one week now. Where are the photos of the model?
  11. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Thanks for your interest-be another week or so-been sidetracked by day to day stuff.
  12. Doug Lord
    Joined: May 2009
    Posts: 16,670
    Likes: 337, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Trapwing Proto One--the model

    Making great progress on the prototype model based on the actual model of the donor boat(see pix). The model work has already resulted in a major design change from the previous rough sketches producing a striking shape and equally well done wing attachment system. The boat will be significantly dryer for the crew as well. Exciting and well worth the effort.
    LOA of the proto is 17.5'..... More coming before long...

    Attached Files:

  13. Paul B

    Paul B Previous Member

    This gets funnier all the time.
  14. Munter
    Joined: Jul 2007
    Posts: 285
    Likes: 11, Points: 18, Legacy Rep: 125
    Location: Australia

    Munter Amateur

    Doug - stop messing with us - is that the Aeroskiff hull?

    Is it really true that the Aeroskiff is getting put back together? Great news!

  15. Timothy
    Joined: Oct 2004
    Posts: 307
    Likes: 15, Points: 18, Legacy Rep: 202
    Location: canada

    Timothy Senior Member

    If you like to laugh here is an idea I was toying with some time ago. It came about as a response to a comment made by T Spear about an idea I had for an underwater transversely moving horizontal foil with bulbs He said I think facetiously , something like why not use buoyancy on one side apposed by weight above the waters surface on the other , a trimaran! Well I came up with this. It is similar to Doug's concept except it has a lifting foil as well. The idea was to simultaneously deploy both the lifting foil and the ballast wing as well as move the ballast as far as possible with a single winch operated with an electric motor powered by a battery contained with in the movable lead ballast charged by either one or the other of two solar panels mounted on the flat side at either end of the sliding wing containing the ballast, or manually by crank, and still contain the whole contraption within the hull when not deployed. I know nothing about foils and have no idea how much lift as apposed to drag the foil would generate and am aware that the apposing lift from the wing would do little or nothing to add to RM but 400 kilos of lead 15 ft from the center line of a 40 ft boat has got to help. Needless to say I abandoned the idea but I had a lot of fun. I don't know if Doug's concept is viable or not but I respect him for examining the possibilities. Sure there are going to be problems and he may not succeed but if he does't so what. It will no doubt lead to another concept and another. I should say that the lifting foil is an outright steal from DSS a company I became aware of through one of Doug's posts.

    Attached Files:

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.