Crossbow fl

Discussion in 'Sailboats' started by Doug Lord, Jun 21, 2012.

  1. Doug Lord
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    Doug Lord Flight Ready

    Crossbow fl --primer

    Here are a few with white primer-changes the look a bit:

    click-
     

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  2. sharpii2
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    sharpii2 Senior Member

    Beautiful model, Doug.

    If you do as good of a job building the full sized boat, that should be half the battle
     
  3. Doug Lord
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    Doug Lord Flight Ready

    Thanks!
     
  4. Doug Lord
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    Doug Lord Flight Ready

    I've learned a lot during my time participating on this forum and I need some help deciding this question: click on the image below and see the illustration of a possible spray and/or rolling water guard-does the boat need it? The "spray/buoyancy" rails are quite large and should reduce spray and rolling water a lot BUT I can visualize water rolling down the lee or windward deck and pouring into the cockpit at the juncture of the curved front deck and side tanks. On the windward deck the water could at least be moved aft so it doesn't pour in on the poor crew. What do you think? Any comments or suggestions would be gratefully received.......

    click-
     

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  5. sharpii2
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    sharpii2 Senior Member

    The only problem I see with your splash boards is the out board ends are too low; they taper down to the deck. I would have the out board ends at least half as high as the in board ends, if not full height. Putting a radius on the top out board corners might soften the look. I would make the radius equal to about half the height of the out board end. Remember what splash boards are for. To shove any water, that dares come on board, over the side.

    For this reason it is a bad idea to give them an aft rake. They should be dead upright if not raked forward a bit.

    I have sailed on a number of boats with ineffective splash boards. They were always raked aft (due to molding limitations) and had a lot of out board taper as well (probably for styling reasons).

    It is maddening.

    Splash boards I design are full height at the out board ends. they are designed heavy, as the boat will sit on them when it is stored upside down.

    They are so ugly, I have nick named them 'granny glasses'.
     
  6. Doug Lord
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    Doug Lord Flight Ready

    Thanks sharpii2, I basically agree with you. The only way to have them angled back and still work would be to put a piece of material on the top-I've seen those. I would have them angled forward and probably not molded in if the boat was ever produced. I was also thinking of a short rail-about 2"-3"- just extending aft along the top of the inside edge of the side tank(see pix below) but then figured I might want to put my arm down on the deck?
    Do you think this boat needs them given the very wide "spray rails? My Windmill had 3" spray rails that worked fairly well and these are 6" on a boat with a bit more freeboard....

    click for more detail:
     

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  7. ancient kayaker
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    ancient kayaker aka Terry Haines

    It's not clear to me how the water will behave coming off the splash boards; it seems just as likely it will fire off to the side. Maybe the best thing is built and test the boat and find out, then modify it to fix a problem if one exists, rather than add non-performance related stuff that might become a nuisance later. Just my thought . . perhaps the model can be tank-tested.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    Thats probably a good idea, Terry-thanks. It's going in the water for a 90 degree roll-over test to see if it will right itself using the wing(regardless of ballast position). I'll get a feel for it- maybe-then. If I was to use spray guards they'd be added separately anyway.
     
  9. Doug Lord
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    Doug Lord Flight Ready

    Crossbow fl-Stage One

    The partially completed model was delivered to Matt McDonald of Falcon Marine today along with some drawings and a breakdown of the jobs he needs to get done on the fullsize boat for Stage One, including: (see clarification below)
    1) make test panels of the lay up on one square ft. styro panels to check compatiblity of his resin and laminate weight,
    2) build and/or install:
    a. DSS foil trunks,
    b. Daggerboard trunk,
    c. Spinnaker tube,
    d. chainplates(4) plus forestay attach system,
    e. spinnaker trough.
    f. cockpit drain tubes-one on each side,
    g. 3/8" Okume deck reinforcement in cockpit and on aft deck,
    3) Carbonate hull with two layers of 5.7 oz. carbon fiber,one 0/90, one 45/45 with local reinforcing,
    4) Carbonate deck with similar lamination as hull and reinforce for wing mount and mast compression(eliminating mast compression tube),
    5) limited cosmetics
    6) Install deck(begin Stage Two-outfitting)
    I got to see his new F18 hull-looks great! Should here from him in a week or so.......
    ------

    Clarification: Matt McDonald is the owner of Falcon Marine and builds full size boats including a new F 18 catamaran. The quality of his workmanship is second to none. He will carbonate the fullsize Crossbow as well as do the other jobs on the full size boat listed above. One of the main reasons for building the model was to give Matt a 3D view of the boat built to scale to help him do an accurate "costing" of the jobs listed above(Stage 1). In Stage 2, he will provide a carbon wing mast and assemble all components.
     
    Last edited: Jul 26, 2012
  10. Doug Lord
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    Doug Lord Flight Ready

    Rick Loheed shipped the DSS foils today!
     
  11. ancient kayaker
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    ancient kayaker aka Terry Haines

    Doug: are these foils full-size or model size?
     
  12. Doug Lord
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    Doug Lord Flight Ready

    Full size Terry-see posts 21 and 22.....

    Picture of foils after Rick had carbonized them:
     

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  13. ancient kayaker
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    ancient kayaker aka Terry Haines

    That means you're committed to the full-sized build. Exciting!
     
  14. Doug Lord
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    Doug Lord Flight Ready

    =============
    You bet! But there are problems that can delay the building-but there always are. I'm determined to get this thing in the water and determined to prove the Trapwing and work out DSS on this size boat. Its exciting for sure!

    PS there are other components and toys that go with this project already here-see the first page and thanks for checking in....
     

  15. Doug Lord
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    Doug Lord Flight Ready

    Since the actual hull may be started by Sharon(styro) and Matt(carbonation) before too long , I'm going over every element of the design point by point.
    Check page 1, posts 10 and 11. In post 10 Bill("cutonce") suggests that I sail the boat without the Trapwing to start with but design and build it to be able to take the "wing" at a later time. In post 11 I give the reasons why I wouldn't want to do that.
    However, there is a lot of money pressure right now and I find that IF I were to take Bills suggestion I would save over $2000 over the next couple of months or so. Not only that but Eric has suggested(several times) that I be very carefull about getting into too many new things right off the bat.
    ---
    The idea of the Trapwing is to give the boat a lot of power upwind as well as to help out downwind.
    But the Trapwing will require a lot of testing-which I really want to do-but because of the money pressure it might be better if I waited until the boat gets sorted using just the DSS foils. The boat will probably require taking the 80lb of lead(already here) that will be used in the wing and puttting it in a bulb on the bottom of the daggerboard to assure self righting(needs to be doublechecked). The buoyancy in the Trapwing allows the wing to be used to right the boat from a knockdown-without it the boat will require a keel to be rightable w/o crew movement. The idea here is a "sit-in" sailboat-not a "sit on" boat because of my limitations with moving. And I firmly believe that the Trapwing will be an ideal solution for the boat down the line-increasing performance substantially.
    So IF I decide to scratch the Trapwing for now what are the technical implications for the boat? Here are some TENTATIVE answers:
    1) Upwind sail area will have to be reduced from 120+ sq.ft. to between 75 and 95 sq.ft..
    2) The asy spin will have to be reduced from 120 sq.ft to 90-100 sq.ft..
    3) Weight may be able to be reduced by up to 50 lb with about 57lb in a bulb on the daggerboard.
    4) The wing mast made by Matt McDonald and Falcon Marine from an A Class wing mast mold will be shortened from 18 to 15'. Just so happens that Matt mentioned he might have a 15' foot section now!
    5) The DSS foil will be a major contributor to boat speed off the wind providing over 60% of the RM in this configuration. And while in the Trapwing configuration the DSS foil provides about 14% of the upwind RM, in the new configuration the foil provides 29% of the total upwind RM. Not because the foil does more but because total RM is less without the Trapwing.
    -----
    As pigheaded as I can be about "keep it simple stupid" when confronted with the realty of the current situation, it seems that going with a simpler version to start with makes sense. I hate to lose the performance potential of the boat with the Trapwing, but looking at it realistically(trying hard to, anyway) I will still have the chance to soup the boat up down the line-and this way I can concentrate just on the DSS foils. I might even get to like the idea.
    Comments, welcome......

    pix-without the Trapwing:
    click-
     

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