Rhino 5 - material thickness

Discussion in 'Software' started by rwatson, Jul 6, 2013.

  1. rwatson
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    rwatson Senior Member

    TANSL - you have a very rude and overbearing manner, and it is you that are not understanding.

    I have cut several projects by CNC, and even if I hadnt, your arrogant approach would be just 'noise' to my learning.

    Please go and make noise somewhere else than this thread.
     
  2. rwatson
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    rwatson Senior Member

    Thanks for that hint BN. Many of the terms you use are still foreign to me, but they give me clues as to what I should be looking for.

    If you can recommend any online resources or illustrations, please feel free to post some links.

    Thanks again.
     
  3. TANSL
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    TANSL Senior Member

    rwatson, yes, I have a rough and direct way to express myself. I'm sorry, I can not change (which is not a justification). Without taking this to a personal level, it would be wrong nor is it my intention, I do want to explain that if someone asks for help in this forum, he must make clear what he knows and what he does not know about the subject, for others, if they want help, they can make effective work.
    Cheers.
     
  4. bhnautika
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    bhnautika Senior Member

    Rwatson I could do some example rhino files if you wish, or you could post a generic file of where you want to start then work through them.
     
  5. rwatson
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    rwatson Senior Member

    That's very generous of you BH. It might be a bit premature to share full files at this stage, but I think some hints as to technique and work flow might come in handy.

    One of the big decisions I have to make is whether to invest in the marine addons for Rhino. In the meantime, I have been creating test hulls in Freeship/Delftship, and exporting them.

    I can export dxf files, in either 3d mesh, or 2d or 3d Polylines from freeship.

    I am keen to establish which format will be easiest to work with, adding features, modelling interiors, adding frames etc.

    The '3d mesh' has the obvious advantage of being able to be rendered and viewed, and the multiple curves created in Rhino from the 3d Polylines means a lot of work splitting them.

    If you able to advise on the most productive starting approach, and any preferred techniques , that would be most helpful at the moment.
     

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  6. rwatson
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    rwatson Senior Member

    Ps - after some research, your suggestions make a bit more sense.

    I have just watched a Youtube demo creating sections in a 'surface'

    Is this the sort of thing you mean ?

     
  7. DCockey
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    DCockey Senior Member

    The method shown in the video in rwatson's post above can be used for cutting a section through an object. But there are simpler methods to obtain the curve(s) showing the shape of a surface at selected location(s). For a single location use Section. For multiple locations with equal spacing use Contour. For multiple locations at irregular spacing using multiple applications of Section. Another approach is to create a set of cutting planes at the desired locations and then use Intersect to determine/calculate the curves of when the planes intersect the surface.
     
    Last edited: Jul 8, 2013
  8. DCockey
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    DCockey Senior Member

  9. rwatson
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    rwatson Senior Member

    Great David. many thanks for both those posts. I will get into the techniques over the next week or so. Thanks again
     
  10. bhnautika
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    bhnautika Senior Member

    The shell command would get you sort of what you want(after a number of steps to get you to a solid) but not all the information you may require to build Here is what I did using some of the software you have mentioned . I created a hull in freeship (2.6) then using the highest precision exported out using Iges , then imported into Rhino. Then using the off set surface command (.019m sorry the original file was in metres). As the surface normals (the arrows) were pointing out I flipped them to face in and changed the surface colour. Base line add as well.
    Another method for getting a line on a surface (theirs always another!) is the project on to surface command which is history enable so the original line can be adjusted and the line on the surface will up dated (useful for stringers)
     

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  11. rwatson
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    rwatson Senior Member

    Hi BK

    Just as advice for future generations, that advice should be " If you use your Rhino hull surfaces as the displacement line"

    But I appreciate the technique advice.

    One of the things that I will need to perfect is to put the frames on a separate layer to the displacement lines, for ease of display options.


    The technique of plotting displacement lines, followed by mould lines is the most common technique in non commercial boat design these days. Think of all the big fibreglass yacht firms, the plywood kit manufacturers and aluminium plate boats of all sizes. Even large commercial ships will often do a displacement line model for 3.5 D milling machines to create
    a) Tank test models
    b) Display models.

    Some forms of building can save money by not bothering to do displacement line drawings, ( steel commercial for example )



    " Basic Ship Theory, Volume 1, Fourth Edition, Rawson & Tupper 1994 p9

    The Shape, lines, offsets and dimensions of primary interest to the theory of naval architecture are those which are wetted by the sea and are called displacement lines, ordinates, offsets, etc. Unless otherwise stated, this book refers normally to displacement dimensions. Those which are of interest to the shipbuilder are the lines of the frames which differ from the displacement lines by the thickness of hull plating or more, according to how the ship is built. These are called moulded dimensions. "

    http://www.boatdesign.net/forums/bo...d-outside-displacment-where-design-47573.html
     
  12. bhnautika
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    bhnautika Senior Member

    Rwatson to get sections /contours I added some temporary surfaces (first model) for trimming the inside surfaces, for this I used “curve from object> object intersection” selected the new and interior surfaces. This will give you a line at the intersection of the surfaces, which you can then use to trim them (I usually extend these lines past the edges as it makes trimming easier also hide the outside surfaces, 2nd model). Once I’ve trimmed the edges I create a centre line surface and a base line surface then using the “curve from objects>contour” select all the surfaces and in profile view select the start point and the end, type in the spacing (.8), enter. Then after selecting the section you want go to ”Dimension> make 2d drawing” (3rd model).
     

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  13. rwatson
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    rwatson Senior Member

    Thats fantastic BK. That sample file gives me a concise series of steps to get the sections out of the hull shape.

    Thank you very much for that. I shall enjoy practicing with that file over the next week.
     
  14. bhnautika
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    bhnautika Senior Member

    Rwatson if you put in contours on each side of the centreline of the frame for your siding width, you end up with frame outline plus bevels lines .A word of warning rhino sometimes doesn’t like lines in 3d space that a too close together (eg front and back section lines of frames) in the “make 2d “ command and will leave some out, to over come this do one lot at a time then overlay them.
    Also if you select the section lines that are on the surface you are going to unroll they will go with rolled out surface.
     

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  15. MikeJohns
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    MikeJohns Senior Member

    You work to the inside of the plating/planking You are working outside in which is where you are coming unstuck, we all work inside out;)
     
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