Newly purchased submarine, need a bit of help

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Michael440
    Lieutenant, Junior Grade
    • Mar 2021
    • 37

    Newly purchased submarine, need a bit of help

    Hi. I just purchased a sub in which the dive valve was broken, there are two replacement valves. However I have never seen this type before. Am I correct in thinking that the valve lever is connected too a solenoid. If so what is the best way to do this, there is not much room inside the hull, or is there a better method of getting water in and out of the dive tanks. Thanks, Click image for larger version

Name:	F6A4B27A-D576-4FD8-9F86-F76EE9946A3E.jpeg
Views:	377
Size:	31.3 KB
ID:	148632Click image for larger version

Name:	EC318AC3-F571-4E78-B097-0036C7C33F33.jpeg
Views:	342
Size:	22.2 KB
ID:	148633
    Attached Files
  • Subculture
    Admiral
    • Feb 2009
    • 2119

    #2
    Not enough to go on in those pics. However i spot what looks like an adapted tyre inflator compressor. As you've stated you're UK based in a separate post, I would wager this is an old Darnell submarine with a compressed air system. Need better higher resolution pics and photos of the whole boat.

    Comment

    • Michael440
      Lieutenant, Junior Grade
      • Mar 2021
      • 37

      #3
      It is a Darnell submarine, will post more pics later today, thanks for interest

      Comment

      • Subculture
        Admiral
        • Feb 2009
        • 2119

        #4
        If this is your first model submarine, you're going about it the hard way IMO.

        Comment

        • Michael440
          Lieutenant, Junior Grade
          • Mar 2021
          • 37

          #5
          Click image for larger version

Name:	011DDEC7-AEAD-499A-B732-26115B211502.jpeg
Views:	175
Size:	81.9 KB
ID:	148642Click image for larger version

Name:	7D8A77FA-AF22-4EAA-AF25-6AADA17FD8A3.jpeg
Views:	171
Size:	93.5 KB
ID:	148643Click image for larger version

Name:	44A5DA56-A33F-4142-8158-E61EB1BA076B.jpeg
Views:	174
Size:	89.7 KB
ID:	148644Click image for larger version

Name:	F6BC97E9-3B3D-495A-A762-846CAED11A49.jpeg
Views:	162
Size:	104.4 KB
ID:	148645Click image for larger version

Name:	EBE8FB11-A85F-4CD2-B115-411E0DCF89A2.jpeg
Views:	148
Size:	92.5 KB
ID:	148646Click image for larger version

Name:	B8E55DFA-4B15-4297-9F8C-64296C29658B.jpeg
Views:	143
Size:	100.5 KB
ID:	148647Click image for larger version

Name:	94B5B90C-7B89-46A1-A1F1-2D02EFAEA96F.jpeg
Views:	167
Size:	100.3 KB
ID:	148648

          Comment

          • Michael440
            Lieutenant, Junior Grade
            • Mar 2021
            • 37

            #6
            More pictures. Hope these are ok.

            Comment

            • Subculture
              Admiral
              • Feb 2009
              • 2119

              #7
              Something gone wrong there- nothing showing up at this end.

              Comment

              • Michael440
                Lieutenant, Junior Grade
                • Mar 2021
                • 37

                #8
                Click image for larger version

Name:	11098EBB-3CE6-4C61-A1B9-4CFC4826E942.jpeg
Views:	215
Size:	75.3 KB
ID:	148655
                Click image for larger version

Name:	B0085A36-B33A-49E1-AEF4-5B324C3099F1.jpeg
Views:	220
Size:	73.1 KB
ID:	148656Click image for larger version

Name:	FA4A2F13-3621-4BF7-AD60-3A6C6D9A6EF0.jpeg
Views:	225
Size:	93.6 KB
ID:	148657Click image for larger version

Name:	4356D21B-837E-441B-BB7C-56B240FD7C1F.jpeg
Views:	215
Size:	89.7 KB
ID:	148658Click image for larger version

Name:	98F788B3-E836-44D4-819F-3BF5E3562210.jpeg
Views:	211
Size:	92.5 KB
ID:	148659
                Attached Files

                Comment

                • Michael440
                  Lieutenant, Junior Grade
                  • Mar 2021
                  • 37

                  #9
                  Hope you can view pics now, they show up on my iPad as on site.

                  Comment

                  • Subculture
                    Admiral
                    • Feb 2009
                    • 2119

                    #10
                    Modified Darnell system. Air is sucked out of the central tank by the compressor and stored in the two red painted cans also mounted inside the ballast tank. To surface a servo controlled valve or solenoid operated valve would be operated releasing the compressed air back into the tank, and up you come- hopefully.

                    Some modified this system further by replacing the air pump with a water pump, this is a bit more controllable.

                    Looks like everything in the boat is pretty old school, but should be serviceable with a good check over, Futaba servos seem to last forever if not abused. Wiring needs some tidying, and the rtv hatch seals may need renewal.

                    An alternative is to convert it all to a removable cylindrical based dive unit. Ron Perrott recently placed a module on the market that is purposely designed for the bigger Darnell subs.

                    Comment

                    • Michael440
                      Lieutenant, Junior Grade
                      • Mar 2021
                      • 37

                      #11
                      Thanks Subculture for reply. My other sub uses a water pump, I have never seen an air pump before. I don’t think I will bother purchasing a WTC cylinder for it, if it works, it works. Is there anywhere that shows a calculator for working out the size of dive tank needed for size of model. Replacing the air pump for a small water pump is easy enough, however working out if the current dive tanks will be ok for the job needs a bit of working out.

                      Comment

                      • Subculture
                        Admiral
                        • Feb 2009
                        • 2119

                        #12
                        That's fine if you accept the limitations of this type of enclosure and are prepared to put in the work on any refurbishment.

                        Kavan make a nice pump ideal for this size of boat, they're not cheap, but you get a decent flow rate and good quality components. Buy cheap, buy twice as the saying goes.

                        Calculating the size of the tank is difficult and is likely to have a large 'fudge' factor with most subs but especially a wavy shaped composite hull like this. The simplest and most accurate way is to use the empirical method detailed many times already.

                        Build your boat to the extent that everything is done except the ballast tank itself. Put it in your test
                        tank and you'll almost certainly discover that it's light. Add whatever weight is necessary wherever
                        necessary to get it to JUST submerge - not sink like a rock - and sit as level as possible. Something
                        like just enough weight to have it float with just the top of the conning tower out of the water and
                        then add just enough to get it to completely submerge. At that point, a couple of quarters would
                        probably suffice.
                        Now add square or rectangular polystyrene foam blocks under the hull until the boat sits at its
                        proper waterline. Since it's a round bottomed boat, you'll have to start by building a cradle (use
                        foam) so the foam blocks won't just roll out from under. Make that cradle and the foam blocks you
                        put under it approximately 4" - 6" long. When the boat is at its proper waterline, determine the
                        cubic volume of all the foam (including the cradle) by multiplying length X width X thickness.
                        Then convert that to the volume of a cylinder (3.14 X radius squared X length).
                        Another benefit to this method is that by sliding the foam fore and aft, you can determine the
                        EXACT location for the tank.
                        Yes, when all is said and done, you'll have to remove weight equal to the weight of the ballast tank
                        itself but that's a small price to pay. Plan ahead when you're adding the weight to begin with - don't
                        make it all permanent. Skip Asay



                        I'm guessing this is either an S, T or U class from the limited shots of the hull. However you already have the tank in situ, so I'd just run with that.

                        Comment

                        • Michael440
                          Lieutenant, Junior Grade
                          • Mar 2021
                          • 37

                          #13
                          I am at this time making a cylinder WTC for another sub I have. Servo positions 3D printed, with this sub I am still playing around with dive tank size. And a few other problems. The wife being one of them with her endless DIY projects

                          Comment

                          • Subculture
                            Admiral
                            • Feb 2009
                            • 2119

                            #14
                            Generally to get a scale waterline, those boats need around a ballast tank of around 1 litre in volume, which is fairly substantial. A Kavan pump flows 1.8l per minute at 12 volts, so expect a diving time of about 34 seconds or thereabouts- quite slow, but acceptable.

                            Compressed air is really good at moving lots of ballast quickly, and it uses the least amount of power, but it's not an easy system to control with any finesse. Water pumps and piston tanks are better in that regard. Course if you want to get fancy, you can use compressed air for the majority of the ballast, and use a small piston tank or water pump based system for the final 1% of trim. Such a system gives you a lot of benefits, the one drawback is extra equipment/complexity.

                            Comment

                            • Michael440
                              Lieutenant, Junior Grade
                              • Mar 2021
                              • 37

                              #15
                              Hi Sub, I like simple, I have ordered a Kavan pump. And will ply around with the sub in the bath to see how it goes. My Surcouf is a very large monster, and for that I am making a cylinder WTC, but it all takes time.

                              Comment

                              Working...