Some first attempts....

Discussion in 'Boat Design' started by henrikb, Nov 17, 2003.

  1. henrikb
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    henrikb Senior Member

    Trying to learn Rhino, this is my first creation that reminds of a boat, an 11m light displ racer/cruiser.
    Comments please!

    When determination correct position for Center of bouyancy, should I use designed WL or sailing WL?


    Best regards!

    Henrik
     

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  2. henrikb
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    henrikb Senior Member

    More pics...
     

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  3. henrikb
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    henrikb Senior Member

    The complete rhinofile....
    Bring the comments please, good and bad!! :eek:

    /Henrik
     

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  4. BrettM
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    BrettM Senior Member

    OK,
    Had a quick look and it looks quite unfair. Use the rebuild option to reduce toe number of control points to something like 5 x 5 and change the degree up to perhaps 4. Do this and you will smooth out the wrinkles by keeping the surface simpler. Use the zebra and envioronment mapping to check it.
    Brett
     
  5. ClarkT
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    ClarkT Senior Member

    nice start

    Nice Job of making the bow work, but I try to avoid that sort of work around b/c it always seems to make NC routers hiccup (go to Analyze:Surface:Zebra and look at the bow carefully.

    As BrettM mentioned, reduce your control points to 3-5 in U direction of the surface and 6-10 in V.

    Once you have the surface basically correct, add a column or two of control points near the bow, and tweak those so you have that nice bullnose you faked with the extra surface. Trim the overhanging edges of the surface against the centerline...it is not necessaray to end your surface at the centerline.
     
  6. henrikb
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    henrikb Senior Member

    Thanks for your comments!!
    Is there any way of tweaking the control point using the keyboard arrows or something similar (steps in mm)?
    So Clark, what you mean is that the stem surface shuld be incorporated in the hull surface?
    I work with the control curves used in the surface sweep rather than the surface controlpoints, should I work directly on the surface instead of the control curves?

    /Henrik
     
  7. ClarkT
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    ClarkT Senior Member

    The control curves are a good place to start, but when you get into fine tuning the hydrostatics, you are going to want to use the control points.

    Set up your 'nudge' under Options:Modeling Aids so they reference the CPlane. I find this helps with dealing with the control points a lot.
     
  8. henrikb
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    henrikb Senior Member

    Faired the hull using the control points and zebra/environment as suggested, worked really fine once I had the controlpoints sorted out... The hull came up quite fair at the end, but it looked like a barge ;) Anyway it was a good lesson in fairing surfaces!
    One more question for you: How do I add row or column of control points?
    Thank you for your help!

    At the drawing board:
    /Henrik
     
  9. ErikG
    Joined: Feb 2002
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    ErikG Senior Member

    Nej (means no) Henrik, I think you might need new glasses. That thing in front of you is not a drawing board it's a computer screen! :)

    Personally I haven't gone through the trouble of creating it "by hand" in Rhino, I use a separate program for doing the hull shape. Maybe that's one of the reasons that I'm still struggling with Rhino itself.


    ErikG

    ------------------------------------
    There's never enough time...

    I'm still waiting for school material about the course at the institute...
     
  10. ClarkT
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    ClarkT Senior Member

    Edit:ControlPoints:InsertKnot

    Try also using the Analyse:Surface:CurvatureAnalysis to get really...really fair. It is intresting to watch the Curvature Analysis change as you move control points. Very instructional as to how the NURBS work 'real world'.
     
  11. henrikb
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    henrikb Senior Member

    Tanks again Clark!
    Faired the hull using curvature analysis, now it came out really fair! Will post result when I get back from work....
    One difficulty seem to be to get the joint between the two halves fair as the surfaces are not merged.
    Now I will start fine tuning the Cp, Dpl, etc.

    /Henrik
     
  12. henrikb
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    henrikb Senior Member

    Quite a good lesson in fairing surfaces....
    Opinions on the hullshape please?

    /Henrik
     

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  13. henrikb
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    henrikb Senior Member

    The Zebra version...
     

  14. henrikb
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    henrikb Senior Member

    Zebra...
     

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