Old boatplans of Hurley 22 needs to be surfaced in Rhino, will this method work?

Discussion in 'Software' started by Chirpingler, Jan 24, 2015.

  1. Chirpingler
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    Chirpingler Junior Member

    Hello Boat Design, I'm happy you exist.

    I have just put together the 2D curves from the boatplan of Hurley 22 way back from the 60s, and I now want to make a surfaced hull out of them in Rhino, so I can start modify my boat to make it seaworthy for the roaring fourties.

    I cannot surface the hull with the "loft" function, it goes bananas, and I think it is because the curves are not aligned on the same axis.

    Here is a picture of what I think is a good solution:

    [​IMG]

    So I basically want a function that renders my boat in curves in just this axis, from portside to starboard. Then I can use the "loft" function to get a nice surface of the hull shape.

    Do you know if this is possible or do you know another solution?

    Thank you in advance.

    Here is my blog about my project to sail to Argentine with this Hurley 22.

    langfardsloggen.blogspot.se

    Most Sincerly
    Oskar Huledal
     
  2. TANSL
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    TANSL Senior Member

    Well come to the forum.
    The first thing to notice is that your picture is not seen.
    The second is that, although not knowing your boat, is not easy, only with the "soft" command, you are able to get a correct surfaces for your hull.
    The more information you give us, the better we can help.
     
  3. Richard Woods
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    Richard Woods Woods Designs

    I am not sure how Rhino will help you

    I assume you have been to this site

    http://www.hurleyownersassociation.co.uk/index.htm

    lots of information there, including most of the drawings

    You should check your rudder carefully, it is a major weak point. See the December issue of Practical Boat Owner and the story of a H22 sailor who broke his rudder off the Shingles. Fortunately I sailed by a couple of hours later and towed him to safety (at 2am!)

    Richard Woods
     
  4. TANSL
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    TANSL Senior Member

    Apparently Chirpingler wants to improve some conditions of the ship for which he needs to make a 3D model of the hull surfaces. As you surely know, Rhino is a good program for modeling and rendering of surfaces. Hence the question.
     
  5. Richard Woods
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    Richard Woods Woods Designs

    Not sure how having a 3D picture makes it more seaworthy. I would have thought new sails/rigging, roller furling and (as I said) checking the rudder etc would be better

    RW
     
  6. TANSL
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    TANSL Senior Member

    3D picture is useless. What Chirpingler are looking for is a three-dimensional model of the boat to make improvements (not sure which) on it. That is the procedure followed in recent years.
     
  7. DCockey
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    DCockey Senior Member

    I frequently use the Patch command to create boat hull surfaces from sets of lines. It does require some experimentation. I usually create an initial surface using just the edge curves, and then use that surface as the starting surface in Patch.

    How much experience do you have with Rhino?
     
  8. Chirpingler
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    Chirpingler Junior Member

    Thank you. The image should now be showing, sorry for that inconvenience. The 3D model is based on a 2D sketch, so it is not so well understood by Rhino at this stage, therefore, I would like to simplify it so it is surface-able.


    Thank you Richard. It is true, I recently became a member of the association and got permission to download the boat plans from the website that the 3D model is based on.

    A pity my blog is mostly written in swedish, but I will translate my ideas here.
    Sven Yrvind is coaching me through this project. His suggestion about the rudder is to replace it with two new rudders mounted on the transom. So there will be no dependency on the old rudder.

    I am planning major modifications to my Hurley 22 from 1978. It should be seaworthy for very rough conditions.

    I'm posting a sketch in paint over some of the modifications that is planned.

    This includeds:
    watertight bulkheads
    replacing the cockpit with roof and watertight hatch. The middle compartment should be living quaters, dry and warm, the two others storage-wetrooms.

    [​IMG]

    Thats my situation exactly.

    I will try out the patch function. I do not have much experience with Rhino at all. I have modelled in Sketchup and Cinema 4D earlier, but never in this caliber in Rhino. I am unfamiliar with with the behavior of curves, they don't seem to snap to each other and also not effect each other when moving one curve that is aligned to another. New stuff for me. I did the 3D model right when I got the program installed.
     
  9. tdem
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    tdem Senior Member

    I would recommend getting the manual and quick-start guide for Rhino, from the website. Snapping is achieved by turning on a switch in the bottom of the window somewhere. You can select what it should snap to.
     
  10. SukiSolo
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    SukiSolo Senior Member

    Rhino will model it fine, if you can get accurate enough data into it. The most useful curves to create are the Section ones not the Buttock curves. You may also find that you need to treat the hull as a separate surface to the keel, which you can model then join using one of several commands.

    Be prepared for some of the old drawings not to match up from different elevations. They won't be far out but fair surfaces can be distorted by very minor discrepancies in a curve. On the original plug and moulds these would have been faired out by hand.

    One other way to get the hull surface into Rhino is to get it scanned and then import as an IGES surface. However this can also create a different set of problems with way too many control points.

    My own preference would be use the drawings but do not assume they are completely correct. You have the hull, so measure it with large caliper and tape at certain points to verify the geometry. Make these points match to notated dimensioned points on the drawings if possible. Also note you have a 78 boat and the original moulds are much much earlier and may heve been changed or modified.

    I note one review of the 22 critcises the original steering for being influenced by the long keel downwash ie it judders. It also recommended cutting away part of the aft keel form and skeg mounting the rudder, as well as moving the mast aft..... It also considers the vessel suitable for coastal cruising.....

    You also need to spend some time learning Rhino, 2 or 3 days is usually enough to get a good grasp if you have used 3D before. To really get to all the nuances, well weeks and weeks! but it is actually a powerful program that is remarkably capable and easy to learn. BTW even professional CAD modellers say it takes at least 3 months to properly learn another modeller at high end level.
     
  11. TANSL
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    TANSL Senior Member

    I wonder if what we can see in the picture in post # 1 are lines in space or are only projections of these lines on a plane.
    In the first case, while it should improve a bit, could be used water lines to generate one surface, or more, by sweeping between wl.
     
  12. Chirpingler
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    Chirpingler Junior Member

    I think I will rebuild the model in only sections, and try the loft function.
    The lines is in 3D space in Rhino, correct.

    I will try to measure the hull IRL and compare when I get the opportunity.
     
  13. Chirpingler
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    Chirpingler Junior Member

    I have now finished the boat hull in sections hull and up. I am happy with the results, although the hull did not align perfectly with my curves, anyone know why?

    I also want to make the hull as thick as in reality to plan the interior, is there any function you know that can do this?

    [​IMG]

    Best Regards
    Oskar Huledal
     
  14. TANSL
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    TANSL Senior Member

    In most programs, some very good in the calculations, it is very difficult to pass the surfaces exactly where you want. It costs a lot of work and you can never be sure of the degree of accuracy achieved.
    The "OffsetSrf" command enables you to obtain a parallel to the original surface. I do not know if this will be enough for what you want.
    May be you have a "thicken" command or simmilar.
    Also, check if surfaces you got have been drawn from the outside or the inside of the hull. Typically, in most cases, lines in Body Lines plan are drawn through the interior of the hull.
     

  15. Chirpingler
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    Chirpingler Junior Member

    Yes, I will search for something like that.
    Yes thats important, its "outside on the skin" according to the boat plans.
     
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