Intriguing "problem" with FREEship

Discussion in 'Software' started by AstroTux, Jul 20, 2006.

  1. AstroTux
    Joined: Jul 2006
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    Location: United Kingdom

    AstroTux Junior Member

    Hi,

    I've started to design a hull in FREEship and encountered a rather interesting problem. I altered some of the points at the stern of the hull, to make the sides of the hull at the top more vertical. tWhen I went to run the Design Hydrostatic calculations on it, it returned that the hull was not submerged!! This slightly defies the laws of physics IMHO. Why is this? User error or bug? Interestingly, some of the figures that move dynamically as you move points around disappear when this happens, too. It seems it doesn't like have the rear of the hull as level. The file is available on request.

    Screenshots attached.

    [​IMG]

    [​IMG]

    Best regards,
    Robin.
     
  2. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Check where your waterline is relative to those points, and make sure there's no opening between stern and centreline (ie, all points on centreline have y=0). If a leak point drops below the waterline, it's impossible to compute hydrostatics data.
     
  3. lazeyjack

    lazeyjack Guest

    I encountered same Prob, Marsh
    mind you I ALWAYS have problems
    latest is trying delete control points in Rhino, highlight, press delete, nothing happens
    You know I could have built a boat whilst I fiddle with CAD
     
  4. AstroTux
    Joined: Jul 2006
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    AstroTux Junior Member

    Hi,

    (I'm sure I already replied to this thread a minute ago???)

    Thanks for mentioning about checking the points relative to the waterline! :) If you look at the stern of the hull (closest to you in the perspective view) you can see that the open end of the hull is below the water line. How do I close this off??

    Best regards,
    Robin.
     
  5. Windvang
    Joined: Jan 2006
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    Location: Rotterdam,The Netherlands

    Windvang Yacht Designer

    See
    http://boatdesign.net/forums/showthread.php?t=12769
     
  6. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Make a transom. To do so: Ctrl + click on the aft edge of the hull. Edge > Extrude. Extrude it either vertically or transversely, then set the coordinates of the new points to where you want them. Often if I want a flat transom, I will collapse all its interior edges and points, so that it's not curved.
     
  7. marshmat
    Joined: Apr 2005
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    marshmat Senior Member

    So could I.... but for me at least, fiddling with CAD is free, while building a bigger boat would cost thousands. And the university keeps taking my thousands. Grr. Ah well, can always dream....
    Working on a 12.5m cat of my own right now. 10 t disp, target is 20+ kts with 180 hp. Might actually build something like it in another 10 years, when I have a real job.... :D
     
  8. lazeyjack

    lazeyjack Guest

    well I could give you a REAL job
    I,m thoriughly sick of this, Id pay you to do it, not a lot but?
     
  9. nero
    Joined: Aug 2003
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    Location: Marseille, France / Illinois, US

    nero Senior Member

    Hang in there lazeyjack! It will start making sense soon.
     

  10. lazeyjack

    lazeyjack Guest

    ok mate thanks for farm stuff, sorry have not written will call, get bogged down
     
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