FreeCAD + Gene-Hull for 3D Hull Generator

Discussion in 'Software' started by Yves Pfister, Feb 8, 2022.

  1. Yves Pfister
    Joined: Jan 2022
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    Location: Switzerland

    Yves Pfister Junior Member

    Hello,
    I did a POC to automatically generate hull shapes with freecad using Gene-Hull data.
    This is the alpha version (only one type of keel and rudder).
    The design is fully parametric (with Spreadsheet Workbench) and can generate all hull types calculated by Gene-Hull.
    Here are 3 examples (same drawing, but with different datas):
    • V1 (reference modern classic sailboat).
    • T10 (T10, inspired by Tofinou 10 / Joubert-Nivelt).
    • Classic 6m JI (inspired by this metric class with a classic approach).
    There is still work to do (macro for automatic import, etc...)
    If people are interested, I share the file.

     
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  2. pafurijaz
    Joined: Dec 2016
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    Location: Jamestown, Saint Helena

    pafurijaz Senior Member

    Very interesting this approach, yesterday I saw these images in the gallery, congratulations on your results.
    
I'm very interested in this method
     
  3. Dolfiman
    Joined: Aug 2017
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    Location: France

    Dolfiman Senior Member

    Great this connection of Gene-Hull with FreeCAD, two complementary tools which together could be powerful enough to develop a sailboat complete design :
    -in addition to the hull geometry itself, Gene-Hull brings the hydrostatics, the stability study (GZ curve, RM, STIX) and the speed prediction (VPP).
    - with FreeCAD : the architecture of the structure, deck, internal accomodation, rig, ...
    Many thanks for these developments.
     
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  4. Skyak
    Joined: Jul 2012
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    Skyak Senior Member

    I am also interested. I love Gene-Hull for early rounds of the design spiral, but want to get to fully parametric for production refinements and standard file formats.
     
  5. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    A very interesting addition to the suite of Freecad utilities.Thanks for the work you have done.
     
  6. Yves Pfister
    Joined: Jan 2022
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    Location: Switzerland

    Yves Pfister Junior Member

    For those who want to test or continue the development, here are the files:
    • The Freecad file.
    • The GeneHull file (with a new "FreeCad" tab for unit conversion).
    Here is the link to download because I can't upload freeCAD files :

    GrosFichiers https://www.grosfichiers.com/2GTLMyzV3hF

    Make your comments and suggestions. :)
     
  7. Dolfiman
    Joined: Aug 2017
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    Location: France

    Dolfiman Senior Member

    About the Freecad sheet added in Gene-Hull file, I understand that mostly it is a conversion of offsets data unit from cm to mm + some changes of signs here and there. But I have two questions :
    ** The values in column A / lines 13 to 35 : seem to be copy/special paste data, but from where ? and what are their roles ?
    ** The values in cells I2, J2, I3, J 3 : I have not seen where they are used ?

    Once these points clarified, I can prepare other Gene-Hull versions (Dinghy, Catamaran, Canoë) with such FreeCAD sheet added. Later on, once the engineering studies done with FreeCAD , one can imagine to retro input the corresponding masses and repartition in the Gene-Hull file /mass spreadsheet , in order to update the stability study.

    Again, it is a great initiative, merci Yves.
     
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  8. Yves Pfister
    Joined: Jan 2022
    Posts: 5
    Likes: 5, Points: 3
    Location: Switzerland

    Yves Pfister Junior Member

    I cleaned up the FreeCAD file by deleting the useless values:
    • In italics: the name of the FreeCAD spreadsheets.
    • yellow cells: the data are used for the drawing.

    Not yet implemented:
    • Hard chine.
    • Keel-bulb inverted T.
    • Fin keel without bulb.
    • Rudder with skeg.
     

    Attached Files:

    Skyak likes this.

  9. Dolfiman
    Joined: Aug 2017
    Posts: 1,523
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    Location: France

    Dolfiman Senior Member

    Ok, got it. I propose you the hard chine exercise with this file attached, using the U1 model. I don't know how you proceed exactly but these comments if they can be helpful :
    - the hard chine line actually plays the same frontier role as the sheer line for a hull without hard chine : so you have a "lower" hull from the keel line to the hard chine line, in the file/FreeCAD sheet/sections from line 35 to line 14.
    - and from the hard chine line to the sheer line, it is like you have another surface, here very simple because just vertical, in the file from line 14 to line 13 : at each section, the y are the same, just the z are different.
    - the two surfaces share the same offsets data, the line 14.

    In the Dinghy case that I am also preparing for you, the upper side of the chine will be more complicated, a real curved surface with its own offsets using 12 lines of data instead of 2, but the principle is the same.
     

    Attached Files:

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