Akula 1/144 Scratch built

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  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12347

    You're encapsulating bushings into the resin parts. Slick! Overkill .... but slick. Resin makes fine bushings on its own. Excellent tool design on display here. Get some Alumilite polyurethane casting resin. Minutes, not days.

    M
    Who is John Galt?

    Comment

    • bwi 971
      Captain
      • Jan 2015
      • 906

      I know it went over the top with the bushings......but after college when I went sailing I was lucky to be re-educated on board by old school engineers (good behavior and good manners went down the drain also) ...they are the reason that it became my natural behavior to try to make things sailorproof (never succeeded though, I learned we can only attempt to make things sailorproof).

      Additionally the root bushings in the diving planes and rudders are protruding and act as a center pin for positioning the planes and rudders on the hull, that is the intention will see if it turns out ok.

      I will go shopping for Alumilite polyurethane casting resin or some kind of substitute THKS!

      Grtz,
      Bart
      Practical wisdom is only to be learned in the school of experience.
      "Samuel Smiles"

      Comment

      • bwi 971
        Captain
        • Jan 2015
        • 906

        David I'm using epoxy now.....found a polyurethane resin in the same shop 3-4 min curing time.....I feel like a donkey.

        Grtz,
        Bart


        Practical wisdom is only to be learned in the school of experience.
        "Samuel Smiles"

        Comment

        • He Who Shall Not Be Named
          Moderator
          • Aug 2008
          • 12347

          Originally posted by bwi 971
          David I'm using epoxy now.....found a polyurethane resin in the same shop 3-4 min curing time.....I feel like a donkey.

          Grtz,
          Bart

          Not at all, Bart. When I first started out with casting you would not imagine the bizarreo-bull**** crap I first used! Live and learn. Lov'n your work -- very good stuff, sir.

          M

          Who is John Galt?

          Comment

          • trout
            Admiral
            • Jul 2011
            • 3547

            I certainly am taking it in. It is appropriate timing for me as I plan on doing some part casting this summer. So, casting with bearing in is a nice touch. I must have missed the part of what you used to cast with that takes 72 hours to cure (certainly a great work time to vacuum and pressure cast!).
            Peace,
            Tom
            If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

            Comment

            • bwi 971
              Captain
              • Jan 2015
              • 906

              Originally posted by trout
              I certainly am taking it in. It is appropriate timing for me as I plan on doing some part casting this summer. So, casting with bearing in is a nice touch. I must have missed the part of what you used to cast with that takes 72 hours to cure (certainly a great work time to vacuum and pressure cast!).
              Peace,
              Tom

              the curing time came in handy now .....for the moment I'm captain slow.......but futurewise I will use the 3-4 minutes one LOL.
              Grtz,
              Bart
              Practical wisdom is only to be learned in the school of experience.
              "Samuel Smiles"

              Comment

              • bwi 971
                Captain
                • Jan 2015
                • 906

                Almost run out things to do (and can do) while waiting for the epoxy to hard out.

                Made the saddles for the SD. The saddles are made of 9mm styrene sheet (3 pieces of 3mm glued/melted together).
                I will provide some hooks in the saddles to keep the SD pushed in the saddles with rubber bands, yep that's why they are 9mm wide, need some flesh to screw the hooks in.

                They are both provided with a recess, to prevent the longitudinal movement of the SD, and when the SD is placed in the sub it will always sit in the same position.

                As my SD is hanging, the saddles are partly above the water in surfaced condition. So I needed to keep the weight of the saddles as low as possible. The lift capacity of the SD is limited, I previous calculated I have some spare but I need to keep things light above the waterline. That’s why I drilled some holes in it, 25 gr (0.88 oz) together, not bad at all.

                To let prevent air pockets when diving I provided some channels on the edges of the saddles. One suggestion drill the holes before you cut out the desired shape of the saddles else you will not be able to drill those holes i.w.o. the edges.

                And YES I thought about it before I made the cut, seems I’m not so donkey after all.

                Grtz,
                Bart
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                Practical wisdom is only to be learned in the school of experience.
                "Samuel Smiles"

                Comment

                • trout
                  Admiral
                  • Jul 2011
                  • 3547

                  No pictures in the last post.....waaaaahhhhh. Me want pictures.
                  If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

                  Comment

                  • bwi 971
                    Captain
                    • Jan 2015
                    • 906

                    I need to have a new computer......I think this one is reaching crush depth, It is even slower than me.

                    But to keep peace with "she that must be obeyed" I think it is better I will start from scratch, work from the bios onward, reinstalling windows, and hope for the best......and score some points......I think I'm in the negative for the moment........I just was informed by "she that must be obeyed" that I must change "think" into "definitively".

                    I will post them again Tom.

                    Grtz,
                    Bart
                    Practical wisdom is only to be learned in the school of experience.
                    "Samuel Smiles"

                    Comment

                    • trout
                      Admiral
                      • Jul 2011
                      • 3547

                      Before you do all that, blame the website. It is possible it is in the uploading there is an issue. I have also run into if I take too long to post, the very same thing will happen as what happened to the posting you made. You could edit your post, replace the photo or re-upload the image. Try just a few at a time and save. Go back and edit to add more and so on.
                      If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

                      Comment

                      • bwi 971
                        Captain
                        • Jan 2015
                        • 906

                        The sail still has to be scribed.

                        The mobility of my arm is FINALY improving, scribing is not yet on the menu. But I managed to get some stencil prep, I can do small stuff but I must do it in small steps, more breaks than work. But there are 24hr in a day and most of them I’m awake.

                        The method making GRP laid up stencils and marking all the stuff on them does not suit me. I’m not good at it, a man have to know his limitations, and needs a lot of practice.

                        So I developed my own way that suits me well but is more time consuming (says the man who uses epoxy as a cast resin, which takes 7 days to hard out). I make flat stencils and bent them around the model. But there is a catch.

                        First I made a copy of the drawing. The sail in top and side view. Both were cut out.

                        As the sail model is 3D and the drawings are orthographic views you have deviations when you bent the paper cutouts around the sail of your model.
                        Never the less I do it because I want to know where the deviations are and what I have to do to correct them.

                        Here the GRP made laid-up stencil of the sail I made previous but didn’t use came in handy. I used it to squeeze the paper cutouts nice and tight to the sail.

                        As an example the sonar dome on the aft part of the sail it is drawn as a straight lateral line in the top view, but when you bent it around the sail it deforms into a curve, and you don’t want that. So the solution is you have to draw a curved lateral line on your flat stencil. So it becomes a straight line once you bent it around your model.
                        You will also have misalignment's between the different paper cutouts that also has to be addressed.

                        Based on the paper cutouts I have drawn everything on a paper sheet making adaptions on the way. (corrections from foto’s, curves, positions).
                        I glued the paper on a 0.5mm styreen sheet to make a test stencil, cut, milled, filed, punched all openings into it.

                        Need to do some minor adaptions, as indicated on one of the pictures below, I have also indicated the aft sonar line/curve I mentioned above.

                        Next up will be the side stencils of the sail.

                        Grtz,
                        Bart

                        Paper cutouts
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                        Sceeze tool
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                        Test stencil
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                        Stencil cut into different parts/layers
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                        Used the stencils to see the result, noted along the way I need to make some adaptions for positioning the different stencil layers, hatch need to be allocated in a different stencil layer.
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                        Here are example of adaptions to be made and the curved line
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                        Practical wisdom is only to be learned in the school of experience.
                        "Samuel Smiles"

                        Comment

                        • bwi 971
                          Captain
                          • Jan 2015
                          • 906

                          Today after 6 days of curing I could open the pressure pot and see the result.

                          I was very happy everything worked out very well.....It's all in the prep gents.
                          The overkill bushings were encapsulated perfectly and the vacuum casted tiny pieces are incredible, no air bubble what so ever.

                          Lets not forget that I could not have accomplished this result without the help/guidance/instructions of HWSNBN, THANK YOU DAVID (I think this is worth a big step up the buttshark ladder?).

                          Grtz,
                          Bart

                          Opening the pressure pot Click image for larger version

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                          All stuff removed from the toolings Click image for larger version

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                          The result Click image for larger version

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                          Some details Click image for larger version

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                          These pictures were taken in macro focus. Click image for larger version

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                          Practical wisdom is only to be learned in the school of experience.
                          "Samuel Smiles"

                          Comment

                          • He Who Shall Not Be Named
                            Moderator
                            • Aug 2008
                            • 12347

                            Well done ... well done, sir! (just passing on what others taught me).

                            M
                            Who is John Galt?

                            Comment

                            • bwi 971
                              Captain
                              • Jan 2015
                              • 906

                              Thks David.

                              Just to let you guy's know that the towed array pot (lost wax method) also worked, weight before melting the wax 20g (0,7oz), weight empty 7g (0,25oz).
                              Pictures will follow soon, need to clear the living room from sub parts before I get into trouble.

                              Grtz,
                              Bart

                              Practical wisdom is only to be learned in the school of experience.
                              "Samuel Smiles"

                              Comment

                              • HardRock
                                Vice Admiral
                                • Mar 2013
                                • 1609

                                Well done Mate. You're doing fine job. Hope you are back to full speed soon.

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