Humble design critique request

Discussion in 'Powerboats' started by lumberjack_jeff, Oct 4, 2011.

  1. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    The cockpit sole looks too high. Difficult to get a self bailing cockpit on a 15 footer and not upset stability.

    I have a really hard time looking at a lines drawing for a boat that will be made of plywood and determining if it is build able.


    Making a crude half hull model then bending thin sheet metal panels around the form identifies shapes that are possible to achieve with plysheets.

    Personally I would put more shape in your skiff. I prefer canoe shaped skiffs, with beam max located where the helmsman ...the most mass on the boat...will sit and fine ends. .
     
  2. lumberjack_jeff
    Joined: Oct 2010
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    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    Although I'd considered it (and rejected the idea for cost and practical reasons) there is no cockpit sole on this boat. What looks like a raised sole in the lines view is actually part of bulkhead #1.
    The seating surfaces are about 11 1/2" above the deepest part of the hull. I think I need to raise those a few inches.
    I ordinarily build a 1/4 scale model as proof of concept, (especially to test the construction jig) but that's problematic on boats with 9mm panels because I can't find a source for 3/32 ply, so I basically redesign using 12mm and 18mm and cut it on the cnc machine at 25% size using door skins and 3/16" underlayment.
    Attached is the profile view with hydrostatic characteristics and the perspective view with developability highlighting turned on as well as a linesplan with the extraneous interior lines hidden.
    The tension on the bottom panel bow may be a little sketchy, but I still think I can do it.
     

    Attached Files:

  3. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Gee, your skiff looks ok. As a personal preference I prefer long thin skiffs. On any small skiff its not possible to move a crew outboard without flipping over. To move inside a small skiff you must shift crew weight fore and aft along the centre line. Hence a long thin boat has the maximum usable people space. Again, its only personal preference and a preference for both Somali pirates and oceanic skiff fishermen .
     

    Attached Files:

  4. lumberjack_jeff
    Joined: Oct 2010
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    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    I appreciate what you're saying, and don't necessarily disagree. What I'm hearing from the regional salesmen of small fishing boats is somewhat contrary to my personal preferences.

    We think there are some good biz dev reasons to focus on this part of the market right now.
     
  5. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Sure. I agree. You never build a boat for yourself, You always build to market demands. Its logical if you wish to stay solvent. Building boats is a brutal way to make a buck
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    If there is any intent to venture into open waters, you don't want a skinny, fine-bowed 14 footer. The only boat of that size I would take offshore would be beamy and full-bowed, you might have to suffer a little spray, but staying upright is of prime importance.
     

  7. Easy Rider
    Joined: Oct 2009
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    Location: NW Washington State USA

    Easy Rider Senior Member

    I think one stats upright mostly w seamanship.

    Not w beamy boats.

    Fat boats are dogs.
     
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