A Type XXIII in Ireland

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  • Bob Gato
    Captain
    • Feb 2019
    • 826

    #46
    No worries about charging batteries in a sealed container?-maybe vent the chamber when charging..

    Comment

    • The Boattrainman
      Commander
      • Mar 2016
      • 443

      #47
      Hi Bob,

      No real issue, we charge NIMHs in closed enclosures all the time (inside a Transmitter), but will open the WTC every now and then for maintenance.

      Might be different with LIPOs.

      Just got a pain in my butt having to strip the WTC down on my other subs to get at the balance plug on the LIPO for correct charging.

      Rob
      Last edited by The Boattrainman; 06-01-2019, 06:37 AM.
      ''We're after men, and I wish to God I was with them........!''

      Comment

      • He Who Shall Not Be Named
        Moderator
        • Aug 2008
        • 12253

        #48
        Originally posted by The Boattrainman
        Hi Bob,

        No real issue, we charge NIMHs in closed enclosures all the time (inside a Transmitter), but will open the WTC every now and then for maintenance.

        Might be different with LIPOs.

        Just got a pain in my butt having to strip the WTC down on my other subs to get at the balance plug on the LIPO for correct charging.

        Rob
        About charging the specific cells of a lithium-polymer battery: Not necessary on a model submarine -- you can get away with gang-charging all cells through the main wires coming off the power connector. We're not racing boats or high performance airplane drivers here; a less than ideal, maximum battery charge is a waste of effort. 80% capacity is good enough for us. I've been charging my r/c sub batteries this way for over a decade with no issues as to performance or noticeable damage to these batteries.

        KISS!

        David
        Who is John Galt?

        Comment

        • The Boattrainman
          Commander
          • Mar 2016
          • 443

          #49
          Good point David, and noted.

          Just a bit nervous of boosting LIPOs while inside the sub, especially after one of my 5000mahs went on fire.

          Rob
          ''We're after men, and I wish to God I was with them........!''

          Comment

          • He Who Shall Not Be Named
            Moderator
            • Aug 2008
            • 12253

            #50
            Originally posted by The Boattrainman
            Good point David, and noted.

            Just a bit nervous of boosting LIPOs while inside the sub, especially after one of my 5000mahs went on fire.

            Rob
            When I was young, good-looking and stupid the first submarine I qualified aboard was a diesel-electric. So, battery charging -- the does and don't, and the evils of off-gassing during high charge/discharge rates -- has been ingrained in me.

            So, on my toy submarines I always open up the battery compartment during the charge. ALWAYS!



            Of the many, many Lithium-polymers I have been using the worst thing that ever happened was the occasional 'puffer' (not 'fluffer', you a-holes!), and even those continue to be used, even though their original capacity is long gone. The only Lithium-polymer fire I've had was the one I threw down onto the side-walk in front of my house. Never going to do that again!

            David
            Last edited by He Who Shall Not Be Named; 06-01-2019, 10:04 AM.
            Who is John Galt?

            Comment

            • The Boattrainman
              Commander
              • Mar 2016
              • 443

              #51
              Mrs. Boattrainman was a bit pi**ed when her upstairs carpet got fried, have promised to be a good lad while my work space is in the house.

              Anyway, here is the shot of the snort arrangement, the instructions state it should be mounted high in the tower.....

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              ...............a small plastic mount topped by a magnet and another on the base of the snort.......

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              .................the fitting is pulled out the back of the second slot, again no bolts or screws..............

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              ..............a final shot through the door that holds the rescue raft, the foam for the scope raising will be in front of it.


              Now I can finalise the wiring from the nav lights, will take this through the front of the tower......

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              .............and down through the upper hull.......

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              ...........I can fix the tower permanently in place now.


              However, test tub trials have come up with an issue.

              This is the first sub I've made that won't sit at the waterline without foam under the waterline, I think the large heavy sail on a small sub body is the issue.

              So how does one get the balance right, just keep adding lead in the keel, then more foam around the waterline. And there's precious little room around the edge between the hull and the WTC.

              The Boattrainman
              ''We're after men, and I wish to God I was with them........!''

              Comment

              • The Boattrainman
                Commander
                • Mar 2016
                • 443

                #52
                I just spotted Bob's build on U-Tube, he seems to use loads of ballast and foam!
                ''We're after men, and I wish to God I was with them........!''

                Comment

                • MFR1964
                  Detail Nut of the First Order
                  • Sep 2010
                  • 1290

                  #53
                  Rob,

                  Yes, she has a weight issue with that high tower, first thing i did was adding enough lead to counteract the weight of the tower, then started to play with the foam.
                  Chopped up the foam to get it all around the SD, you have the advantage of your waterline cut, i had to tinker with my beloved radial cut.
                  It will take some time to get her right, i ended up with a tad more lead to keep her upright with the tower, mine has more stuff inside, if i recall right it was about 450 gram of lead, you can use much less, i would try 100 gram more as the weight of your tower.

                  Manfred.
                  I went underground

                  Comment

                  • Subculture
                    Admiral
                    • Feb 2009
                    • 2119

                    #54
                    With a figure of eight hull design, you should have enough depth to whack the batteries underneath the wtc. Also has the advantage of centralising the weight around the boats c.g.

                    Comment

                    • The Boattrainman
                      Commander
                      • Mar 2016
                      • 443

                      #55
                      Thanks guys.

                      Can't put the batteries under the WTC, they are in the forward part in a custom made tray.

                      So I've gone with whacking a load of foam around the waterline, 26 thin pieces between the internal ribs, I can remove pieces if it's too much.

                      Plus I cut up a 450g metal bar into six pieces, is that a coincidence the pump tank hols around 450ml? May not need them all.

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                      I also balanced the WTC itself first, by adding a 150g lead block under the servos (just enough space), the block offsets the weight of the batteries at the other end. The WTC now sits level in the water, I found it easier in the past not to be fighting the boat and the WTC when ballasting.

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                      Rob
                      ''We're after men, and I wish to God I was with them........!''

                      Comment

                      • The Boattrainman
                        Commander
                        • Mar 2016
                        • 443

                        #56
                        So that wasn't any fun.

                        This little sucker needed so much foam, I had to remove my carefully cut small pieces and whack in loads of solid pieces.....

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                        ...........including a huge block in the nose, it's just press fit so I can get at the front dive planes linkage.

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                        I managed to get some down into the rear as well.

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                        But at least it floats on the waterline with around 200 mg of metal in the keel.

                        Just waiting for the battery packs to test the dive function.

                        ''We're after men, and I wish to God I was with them........!''

                        Comment

                        • The Boattrainman
                          Commander
                          • Mar 2016
                          • 443

                          #57
                          The light connectors are 12V Planet automotive items.....

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                          .......I cannot praise these highly enough, they are cheap and very robust, but I've found a drop of epoxy around the wire inlets and plenty of silicone grease on the yellow banjo ensures waterproofing.
                          ''We're after men, and I wish to God I was with them........!''

                          Comment

                          • The Boattrainman
                            Commander
                            • Mar 2016
                            • 443

                            #58
                            I dislike messy interiors, spagetti wiring and lumps of ballast all over the place.

                            After endless tricking around with metal weights, the result is this.....

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                            ........four metal strips fitted into styrene keepers, just a press fit no glue, I got really lucky it's balanced with no offset ballast needed.

                            Now having seen how little weight buggers up the submerged trim on small subs, I added this adjustable bar, it's overall weight is used to keep the boat at the waterline on the surface, but when the submerged trim is just about right using flotation foam, I have about an inch of travel fore and aft to get the sub balanced.


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                            The submerged trim is up next.

                            ''We're after men, and I wish to God I was with them........!''

                            Comment

                            • The Boattrainman
                              Commander
                              • Mar 2016
                              • 443

                              #59
                              The aerial rigging is as per my Type VIIIC, good quality black rigging cord from scale ships.

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                              The insulators are small walnut blocks sanded to a lozenge shape, with shrink wrap tubing. As per a photo I've seen two near the tower, and three near the deck.

                              I've gotten quite good at making these, pity I won't be making any more WW2 subs for a while!

                              The Boattrainman
                              ''We're after men, and I wish to God I was with them........!''

                              Comment

                              • The Boattrainman
                                Commander
                                • Mar 2016
                                • 443

                                #60
                                To my great surprise this little sub is finished the build phase.

                                The last item was the life raft door which I made functional so I could get at the collars holding the flotation foam on the periscope.

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                                The rigging isn't attached as is streteched from the ceiling on weights for four weeks so that it won't sag on the madel.

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                                So off to the paint shop!

                                The Boattrainman
                                Last edited by The Boattrainman; 06-15-2019, 03:29 PM.
                                ''We're after men, and I wish to God I was with them........!''

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