Spindle shaped submarine hull

DELFTship forum General Questions Spindle shaped submarine hull

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    • #38821
      AvatarJaroslav Petřina

      Hello guys, I m attempting to model a hull like the “Sword” from Jules Verne “Facing the flag”.

      I have two gripes with my model

      a) I cannot click on the control point on one end and make it “corner point” to make it sharp. I dont know what is the reason

      b) all calculations are incorrect – specifically the lenght of the model extracted etc. Should be 12 meters long.

      Can somebody more knowledgeable take a look and point me in correct direction?
      Many thanks

    • #38829

      Hi Hawk!

      I’m answering your questions without having a glance at your model (DelftShip software is not installed on the computer I’m using right now).

      a) The only only explanation I imagine is that you just ticked the “corner point” box. But if the point is still aligned with the surface it belongs to, it won’t protude (however the software will consider it as a corner). You have to position it away from the surface by changing its coordinates.
      I suggest you draw a square of edges around each of the points (the width of the “cone”s bases), move the whole model backward so that the coordinates origin point (0,0,0) will be right in the middle of the model, then you select all these points (the “cones”s peaks) and slightly change their SCALE (say 1.1 for a first attempt). This will make your submarine look like a hedgehog.
      One finished, don’t forget to move the whole model back to its original position.

      b) The model length is the one you choose, you’re the one who chose the points coordinates. Click on the bow and stern ending points and compare their coordinates. THIS will be your model’s length.
      You probably mistook the waterline’s length (length of the model along the water surface only, theorically the periscope) with the whole model’s length (from bow to stern).
      Maybe, too, you’re using imperial units (foot and inch) meanwhile you think you’re using metric units (or vice-versa). In that eventuality, the error ratio would be then roughly 1/3 (or 3/1).

      I’m glad to know someone else read this novel: Verne is one of my favourite authors and I collect his novels. “Facing the flag” is much less known than “20,000 leagues under the sea” and captain’s Nemo Nautilus. you’ll find mention of electric powered vessels in “Mathias Sandorf” (if I don’t mistake). Verne also wrote “The prepoller island“… the story of an artificial island, already in 1895!

    • #38830
      AvatarJaroslav Petřina

      Many thanks, I shall check what you suggest.

      Yes, torpedo boats “Electricas” in Matthias Sandorf. He sure was my favorite writer when I was kid.

      If you do not know it, there is splendid czech trick movie from 1960´ based on “Facing the flag” called “Invntion of destruction” by Karel Zeman.

      Look for ” Vynález zkázy” on youtube. Nobody else in my opinion came as close to Verne picture of world like Zeman.

    • #38834

      I checked for my method: it works pretty fine!

      I drew a “vernian” submarine with aggressive rostrum and saw-like crest (kinda little Nautilus);
      I drew the “horns” base and diagonals on the upper bow, and I set them as sharp edges (however they were still flat on the hull);
      I moved the model half its length forward;
      I selected the “horns”s peaks and changed their scale to 1.15;
      I moved the model half its legth backward.

      Ready to ram other ships!

      Check for the screenshots and…admire the work! B)

      Thanks for the movies suggestions! 😉
      I already watched a movie by Karel Zeman a few of years ago: “Ukradená vzducholod” (The Stolen Airship), and the children liked it.

    • #38835
      AvatarJaroslav Petřina

      “The stolen airship” is his opus magnum, or so I do think. “Vynález zkázy” is few years before that, acting is tad bit wooden, but it still superb, very Verne film.

      That is one purdy submarine, though, the rams aside it looks more like a russian akula to me, that anything else 😀


    • #38837
      AvatarJaroslav Petřina

      It wont do, I m not as good, or dont understand correctly what you are saying.

      After some pointless playing with the model I didnt got any further.

      Could you take a look at the model, please?

    • #38838

      I’ll have a glance at your ZIPfile (I hope this will tell me when you get confused). Meanwhile I’m going to try to explain the method again, with more details:

      I quickly drew the hull… by creating a sphere and changing its length scale. Then I added a few ornaments.
      Note, the sphere (submarine hull) was drawn with its center at coordinates (0,0,0). This location is very important for the last operation (SCALE).

      Then I chose a few of polygons on the hull and drew (in flat on the hull) the “horns” base and edges (diamond like). See picture 1 of my second message.
      You can just draw a polygons’ diagonals, too.
      A possible problem is you may have tried to draw directly the second diagonal just after the first one… but DS can’t draw crossed lines across a polygon (thinks in terms of polygones: which would be these polyons defined by two crossed lines without intersection point?). So you have to draw the second diagonal in two steps: from a corner to the intersection point, then to the intersection point to the other corner).

      Then I set the base and diagonals segments as sharp edges. If you skip the step, the final result will look more vegetal than mechanical.

      Then I selected the diagonals intersection points (the future peaks) and asked DS to change these points coordinates’ SCALE, ratio: 1.15 (the higher the ratio, the longer the “horns”). Thus these point coordinates are multiplied by this ratio and the points are moved away from the origin point (0,0,0) , so from the hull’s bow.
      I applied the 1.15 ratio to each direction. You can direct the “horns” more to a direction by using a higher ratio on the convenient direction.
      Of course, you can type the new coordinates by hand, but this would take more time and would be a less glamorous method. B)

      If you still don’t understand the method, select a polygon on your hull and play with the SCALE command. I’ll quickly understand its utility.

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