FreeShip...will I be able to

Discussion in 'Software' started by Ed-H, Feb 6, 2013.

  1. Ed-H
    Joined: Mar 2010
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    Location: Montana

    Ed-H Junior Member

    I'd like to design a small boat using freeship. Can anyone tell me if after I complete it on FS, would I be able to print out cross sectional "slices" of the hull? They need not be printed out life size, but if I were able to print them out at all, I can scale them up to life size. Thanks in advance....

  2. lewisboats
    Joined: Oct 2002
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    Location: Iowa

    lewisboats Obsessed Member

    There are two or three ways to do that in FS. First is to put stations at at the "slices" and print the offset table. This will give you points to plot full sized that you then connect with a straight edge or a batten (depending on the design). Second, you can create individual panels for each of the areas that fit into the model, then you can export them as a DXF from the "develop plates" section or you can again export the offsets and plot them from there manually. The third method I am not familiar with which is to do something with intersecting planes and will result in the same as option number two. Before you do any of that you will have to decide whether the skin you see in the model is the inside of the skin or the outside of the skin. Thickness is not taken into account in the software except when determining weight for the CG. The skin you see is infinitely thin... it has no thickness. When doing transverse panels you will have to either subtract your skin thickness from the final result if you choose to have the visible surface as the exterior surface, or you will have to view the surface as the inside one and then your model will actually be larger by twice the thickness of your chosen material.

    Of course... the software is only a tool to draw shapes... whether that shape will be viable as a safe and usable boat is determined by the knowledge of design that resides between your ears... or not. A decade ago I was in your shoes... now my library of design and building runs to around 100 books, and around 15 hulls built. Most have been usable...some more than others. Before you start to "design"... start to read. Do a search of the forum for "boat design books" and "how to design a boat" for a decent list of books... primers if you will. You will also need to know about materials and their strengths, weaknesses and suitability for what you are planning. Methods of construction are also integral...determining and depending on the materials chosen and the suitability of the design to the chosen materials. You must also learn that a boat is a series of compromises that only "tend" to favor it's ultimate purpose. Heavy is slow but light is expensive, High speed results in low speed inefficiency, low speed efficiency pretty much kills the chance of high speed. Multi-hulls don't follow all of the same rules that mono-hulls do... at least initially. Each feature of your design has an up and a down side and you have to choose carefully to balance that out with your requirements to arrive at a shape that you can live with. Same with materials. And build method. And powering. And.....
  3. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    Ed; take notice of what Steve has written. He has been there, done that. FS or any other program merely outputs whatever input instructions you give it. The program can not design a good boat on its own.

    The usual way to scale up the sections is not to scale them up directly but to translate the shapes into a table of offsets. Many of the computer programs are capable of doing that for you.

  4. Ed-H
    Joined: Mar 2010
    Posts: 18
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    Location: Montana

    Ed-H Junior Member

    Thanks guys for the information. My main problem is, back when I got my engineering degree, only one guy in the class had a calculator.....calcs. were done via slide rule!!! My biggest problem is less in the design parameters and more in the software. I'll probably just go back to what and how I know to do things.......probably get it built long before I could learn the CAD stuff!!

    Thanks again,

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