How to create lines drawings from a model?

Discussion in 'Boat Design' started by Omeron, Jun 4, 2007.

  1. Omeron
    Joined: Feb 2007
    Posts: 163
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    Location: Istanbul

    Omeron Senior Member

    I am an amateur, trying to design a 38ft sailboat.
    Instead of starting with drawing lines, i wanted to create a scale model.
    The first step for me was freehand drawings, to get an idea of the
    finished boat, which i did.
    Second step was to create a solid scale model (1/14) which is nearing
    completion.
    Now i have in my hands a solid block of the boat which is roughly 2.5 ft
    in total length. Deck and superstructures not yet done or decided.
    My problem now is how to retrieve the lines from the model to get to the
    actual lines drawings.
    I tried to mark and measure a total of 30 points on the hull in x,y,z, and
    tried to feed them into freeship 2.6 program.
    The resulting boat is close in appearance but not the one i have.
    Because unless the points measured are an edge,defining the boundary
    such as sheerline or keel,all other points become a control point and
    produce a different curve. They do not become an actual point
    on the surface of the hull,as measured.
    I think it is almost impossible to play around with those control points
    so that the curve goes through the measured point.
    So i am stuck here.
    Is there a way to accurately retrieve lines from a model, with or without
    using software such as freeship?
     
  2. nero
    Joined: Aug 2003
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    Location: Marseille, France / Illinois, US

    nero Senior Member

    The more measure points you take the closer to the hull you will come. In TouchCad, you can add a series of points into a ruler (line). Then you command TouchCad to reduce the number of control points. The result is excellent!

    Not sure if freeship has this ability.
     
  3. lazeyjack

    lazeyjack Guest

    what I would do is drag the point around, then hide the net, then measure the hull you can see the measures as you move mouse onto the lines, as the top of screen
    Hello Nero how are you, you home or home?
     
  4. Guillermo
    Joined: Mar 2005
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    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Yes, the old way:

    "In the years before Naval Architecture had evolved, boat and ship design was developed through model construction. A master builder would fashion a hull form to the requirements of the client. The model would then be cut vertically down the center, leaving two halves.One half would be cut along the horizontal planes, known as waterlines, at evenly spaced distances. The other half would then be cut vertically at evenly spaced distances, known as "stations".

    These pieces would be laid out and traced in outline on wood or parchment. The dimensions were then expanded to reflect the true size of the vessel, in what is known as the table offsets. This table was used to put the vessel lines down on the lofting floor, from which the construction forms for the centerline structure and framing systems were made. After the process was completed the "waterline" pieces of the model were reassembled and that half was mounted on a wooden backing plate, and often put in the master builder's office to show off the boats that the yard had built."

    You can find some books on the technique by googling around for 'half models lofting' or similar.

    Cheers.
     
  5. lazeyjack

    lazeyjack Guest

    I still do that guillo, put the lines down on the floor, especially if I have never worked with the CAD man before:)) you still need to draw the stem, the sheer in plan(if you are going to form a big caprail) and you still need to draw the body plan, mast step etc, most buiders do a half model of the boats they build, just to hang on the wall, looks great
     
  6. nero
    Joined: Aug 2003
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    Location: Marseille, France / Illinois, US

    nero Senior Member

    Down side of doing it the old way is your model is lost.

    Perhaps, now that he has a good idea of the hull shape he wants, he could create a model with some software? The advantage is he could know displacement. Also, the offsets coming out of the program ( if done correctly) will be fair. Yes, I know that lofting will solve this also.

    Lazyjack, I am still in Illinois. Getting ready to glass the outside of the first hull. Will dry lay the glass day after tomorrow and wet it out the next day. Looking for volunteers if you want to fly in for the week. (smile)
     
    1 person likes this.
  7. lazeyjack

    lazeyjack Guest

    that'ud be neato, but me flying NZ to stick an engine in a newbuild
    best way to make a half model, on cad, make a waterline every 10mm, then put a 10mm a 4 sized piece of ply in your hp desk printer, and so on::p
     
  8. lazeyjack

    lazeyjack Guest

    thanks to the coward who posted this
    An Arrogant **** aren't you. feedback from this thread:))
     
  9. Omeron
    Joined: Feb 2007
    Posts: 163
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Istanbul

    Omeron Senior Member

    lazeyjack, whats wrong with you man?
    This is the second time you are doing this to me.
    We are probably living in different ends of the world.
    And i dont take my computer to bed with me.
    Go back to the maltese falcon thread and read my last post.

    Sorry to all others. And thank you for your comments.
    Ofcourse i do not want to loose the model by cutting it up.
    I shall think about how to get it done and give it another try
    by using freeship.
     
  10. lazeyjack

    lazeyjack Guest

    what the hell are you talking about?
     
  11. lazeyjack

    lazeyjack Guest

    all i said was someone who read thsi gave me bad feedback, not you!! I love turkey and turkish people
     
  12. Omeron
    Joined: Feb 2007
    Posts: 163
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Istanbul

    Omeron Senior Member

    Well, thats ok then.
    I didnt understand what you were referring to, but since
    i posted the original thread, i thought you were calling my name.
    sorry for the misunderstanding.
     
  13. lazeyjack

    lazeyjack Guest

    i will be back in ist August be nice to meet
     
  14. Omeron
    Joined: Feb 2007
    Posts: 163
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Istanbul

    Omeron Senior Member

    lazeyjack, i am trying to understand your 10mm waterlines suggestion.
    what i did before was, six stations between stem and transom, and five
    lines vertically.
    top line being the sheer, and the bottom was the keel. additional three
    lines equally spaced in between,giving me a matrix of 30 measured stations.
    How is that any different to creating waterlines 10mm apart?
    Well probably i would end up with many more points, but wouldnt the same problem prevail? ie the curves still not going through the stations.
    What would happen if you treat all points as an edge? as if the hull has multiple chines, and then try to smooth them out? Would that be possible do you think?
     

  15. Omeron
    Joined: Feb 2007
    Posts: 163
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    Location: Istanbul

    Omeron Senior Member

    With pleasure. Pls let me know when in Ist.
     
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