Scaleships Akula II

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Subculture
    Admiral
    • Feb 2009
    • 2121

    What do you mean you lack the skill to hollow it out, no skill in that. Just long winded and tedious work.

    the reason you need to hollow it out, is that it will serious throw your centre of buoyancy out of whack.

    Comment

    • He Who Shall Not Be Named
      Moderator
      • Aug 2008
      • 12320

      Originally posted by Subculture
      What do you mean you lack the skill to hollow it out, no skill in that. Just long winded and tedious work.

      the reason you need to hollow it out, is that it will serious throw your centre of buoyancy out of whack.
      Jeezus H. Christ on a crutch!!! .... what is it with you complexity worshipers anyway!!!!!

      Do as I say. At the very least, do what Andy says.

      Don't make me come over there!

      M
      Who is John Galt?

      Comment

      • HardRock
        Vice Admiral
        • Mar 2013
        • 1609

        Originally posted by He Who Shall Not Be Named
        Jeezus H. Christ on a crutch!!! .... what is it with you complexity worshipers anyway!!!!!

        Do as I say. At the very least, do what Andy says.

        Don't make me come over there!

        M
        Yes Sir. Right away Sir. Three bags full Sir!

        Comment

        • Peter W
          Captain
          • May 2011
          • 509

          Ok, took a grip again and have done the hollowing out thing.

          Click image for larger version

Name:	Akula b 999999999996.jpg
Views:	1
Size:	86.9 KB
ID:	93028
          The planned cut
          Click image for larger version

Name:	Akula b 999999999997.jpg
Views:	1
Size:	83.1 KB
ID:	93030
          The cut, new xacto extra fine blade required now it is well and truly blunt now.
          Click image for larger version

Name:	Akula b 999999999998.jpg
Views:	1
Size:	19.1 KB
ID:	93029
          Started the material removal with this 22mm (3/4") scotia 1/4" drive router cutter
          Click image for larger version

Name:	Akula b 999999999999.jpg
Views:	1
Size:	84.0 KB
ID:	93031
          The result
          Click image for larger version

Name:	Akula b 9999999999991.jpg
Views:	1
Size:	83.5 KB
ID:	93032
          After using a variety of drill bits, a mini drum sander and a few diamond burr bits I have done it. Now do I have it free flooding or sealed ? Free flooding does mean lots of unsightly holes. I have managed to get the weight down from 52 grams ( 1.8342 oz) to 29 grams ( 1.0229 oz ) and loss of 44%.


          Peter

          Comment

          • He Who Shall Not Be Named
            Moderator
            • Aug 2008
            • 12320

            If you butten it up, you have not reduced the displacement of the thing one bit, and the exercise was for naught. It's gotta flood when submerged.

            Put your drain-flood hole under the rudder where it won't be seen, and put one 1/8" diameter vent hole at the extreme high point on the egg. Done.

            Good work, pal.

            M
            Who is John Galt?

            Comment

            • HardRock
              Vice Admiral
              • Mar 2013
              • 1609

              Hey Pete,

              I feel your pain. Not that I'm afraid of hard work etc etc, BUT, I'm planning to break out the 3D printer and run up a new hollow egg. Meanwhile, I have been venting. Wondering if you made use of the indented edges of the vent holes as a mounting flange for the brass inserts or cut the whole thing out to get a completely flush fit with the hull. I've done both and the latter seems to require less work. Thoughts?Click image for larger version

Name:	P1000653.jpg
Views:	2
Size:	89.3 KB
ID:	93036

              Comment

              • Subculture
                Admiral
                • Feb 2009
                • 2121

                You'd be better off using old school methods. 3D printers are good for some things, but producing low displacement thin wall components isn't one of them from what I've observed.

                If you want a really low displacement piece, pull a two part tool off the original solid item you have, and lay up a super lightweight epoxy glass laminate. This will be very strong but should only displace a few grams at the most.

                Comment

                • Peter W
                  Captain
                  • May 2011
                  • 509

                  Scott, I think I went for the harder 3rd option. I cut the holes smaller than the vent and then used a diamond burr to rebate the hull. I , rightly or wrongly, felt this would give more strength to the bond between brass and CA.
                  Click image for larger version

Name:	Akula b 99991.jpg
Views:	1
Size:	102.7 KB
ID:	93037
                  Slow and steady work but good results IMHO. The tricky bits using this method are the rear access hatch part no. 10 ( that one was heart in mouth stuff because of the aggressive nature of the tool I used) and the front and rear round things part no. 5. Any minor over runs with the burrs just got filled with Red Acryl Filler ( my favourite product recommended to me of 2014)

                  Click image for larger version

Name:	Akula b 9999992.jpg
Views:	2
Size:	87.8 KB
ID:	93038



                  Andy, does my effort on the pod pass muster then ?

                  Peter

                  Comment

                  • HardRock
                    Vice Admiral
                    • Mar 2013
                    • 1609

                    Originally posted by Subculture
                    You'd be better off using old school methods. 3D printers are good for some things, but producing low displacement thin wall components isn't one of them from what I've observed.

                    If you want a really low displacement piece, pull a two part tool off the original solid item you have, and lay up a super lightweight epoxy glass laminate. This will be very strong but should only displace a few grams at the most.
                    Sounds like a better plan. Have to bone up on mould making.

                    Comment

                    • HardRock
                      Vice Admiral
                      • Mar 2013
                      • 1609

                      Originally posted by Peter W
                      Scott, I think I went for the harder 3rd option. I cut the holes smaller than the vent and then used a diamond burr to rebate the hull. I , rightly or wrongly, felt this would give more strength to the bond between brass and CA.
                      [ATTACH=CONFIG]29433[/ATTACH]


                      Slow and steady work but good results IMHO. The tricky bits using this method are the rear access hatch part no. 10 ( that one was heart in mouth stuff because of the aggressive nature of the tool I used) and the front and rear round things part no. 5. Any minor over runs with the burrs just got filled with Red Acryl Filler ( my favourite product recommended to me of 2014)

                      [ATTACH=CONFIG]29434[/ATTACH]



                      Andy, does my effort on the pod pass muster then ?

                      Peter
                      The third option! It must have been a bugger getting the gratings flush with the deck. At this stage I might have to leave the gratings for a time whilst I bone up on pulling a mould of the towed array "egg".

                      Comment

                      • Peter W
                        Captain
                        • May 2011
                        • 509

                        Scott, on reflection it wasn't too differcult doing the brass this way just time consuming and it has worked a treat. This hobby will throw up different ways of doing things. I do have to CA them from the back yet using baking soda to cure the glue as directed by Mr. M.

                        I have to also say that scooping out the pod wasn't as hard as I had feared. As we communicate now I am starting to plan and do the vents to make it free flooding.

                        Peter

                        Comment

                        • Subculture
                          Admiral
                          • Feb 2009
                          • 2121

                          The hollowing out looks fine. You would need to keep a bit of thickness in the pod, as the plastic is unreinforced, so I think you've gone as far as you can.

                          33 grams probably doesn't sound much, but right at the end of the boat , it seriously throws things out of whack. Also it's almost 7% of the boats ballast tank displacement, assuming you use a 500ml tank. That probably sounds a bit more impressive.

                          Comment

                          • HardRock
                            Vice Admiral
                            • Mar 2013
                            • 1609

                            Click image for larger version

Name:	P1000654.jpg
Views:	2
Size:	109.8 KB
ID:	93101Click image for larger version

Name:	P1000657.jpg
Views:	2
Size:	87.7 KB
ID:	93102Click image for larger version

Name:	P1000655.jpg
Views:	2
Size:	92.7 KB
ID:	93103
                            Akula holes! I see what you mean peter about the scribed lines on the sail not matching up with the plans. I'm glad that I read that on your post before going ahead like a maniac.

                            Comment

                            • Peter W
                              Captain
                              • May 2011
                              • 509

                              Starting to seriously think about an SD for the Akula now. For those of you in the know I assume that the 3.5" SAS is the way to go with the single motor bulkhead kit?

                              I also have very daft question to ask, but how does the vent valve work exactly?

                              Peter

                              Comment

                              • He Who Shall Not Be Named
                                Moderator
                                • Aug 2008
                                • 12320

                                Originally posted by Peter W
                                Starting to seriously think about an SD for the Akula now. For those of you in the know I assume that the 3.5" SAS is the way to go with the single motor bulkhead kit?

                                I also have very daft question to ask, but how does the vent valve work exactly?

                                Peter
                                Click image for larger version

Name:	DSCF3395.jpg
Views:	3
Size:	88.2 KB
ID:	93207 This beast demands the 3.5" SAS type SD: http://www.sub-driver.com/sub-driver...ub-driver.html As this thing is already assembled all you need is outfit it with the devices, drop it in the hull, and go make the lake safe for Communism.

                                It's got about 30 ounces of floodable volume in the ballast tank. More than enough to float that thin-walled AKULA of yours (now that you've hollowed out that god-awful egg atop the rudder!). Give me your wallet, walk away, and no one gets hurt.

                                From those of us in the know.

                                M
                                Who is John Galt?

                                Comment

                                Working...