Nikko Seawolf - blast from the past

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  • tifosi12
    Commander
    • Jul 2020
    • 345

    Nikko Seawolf - blast from the past

    When I was a kid I had one of those Nikko Seawolf subs. Loved it back then and so I recently bought a good one on eBay. Just tested it in the tank and surprisingly all functions work as advertised. In fact the dynamic diving works better than on my other built subs: The thing goes instantly down or up and deeper than its much more expensive brethren.

    Never quite understood why Nikko claims it to be 1/250 scale: There are two seats in the front that are more like 1/50. So I decided to paint the cabin up accordingly and 3d printed a couple of crew members. Also got rid of the stupid Seawolf theme etc. I intend to change that into a Bond villain look. :)

    For the little money these things cost, they are a relative bargain and easy enough to operate/maintain (fingers crossed). And this one even fits into a suitcase so I could take it to an event by airplane.

    Click image for larger version

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  • tifosi12
    Commander
    • Jul 2020
    • 345

    #2
    Inspired by so much success in the first tank trial I went ahead and ordered another Nikko Sea Wolf from ebay. Made sure the rubber membrane is in pristine condition and the electronics work. With that I should be able to keep this unique sub going for many more years. Unreal if you think that these things are at the very least 20 years old, possibly 40 years and they still function like new. Well, at least the ones that have been nicely preserved.

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    • tifosi12
      Commander
      • Jul 2020
      • 345

      #3
      Finally had a chance to take the boat out to the local fountain. Behaved even better than in the tank: Instant reaction to all directions, dives on a dime, surfaces nicely, not jerky while submerged. Even took her so low that the entire antenna was submerged at which point the downward motor stops and the boat starts slowly surfacing thanks to its slightly positive buoyancy. And after the dive, the interiors remained bone dry, the 40 year old rubber seal is still holding nicely.
      Click image for larger version

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      • SubDude
        Captain
        • Dec 2019
        • 803

        #4
        Pretty cool!

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        • tifosi12
          Commander
          • Jul 2020
          • 345

          #5
          Here is a brief video:

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          • redboat219
            Admiral
            • Dec 2008
            • 2730

            #6
            Too bad I missed one being sold online locally for only $10.
            Make it simple, make strong, make it work!

            Comment

            • tifosi12
              Commander
              • Jul 2020
              • 345

              #7
              Originally posted by redboat219
              Too bad I missed one being sold online locally for only $10.
              There are several of them on ebay but a good one that has seen little if any action runs for about $ 200. Still dirt cheap compared to the regular building costs of a RC sub.

              Key thing is the rubber membrane; it needs to be in perfect condition.

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              • redboat219
                Admiral
                • Dec 2008
                • 2730

                #8
                Originally posted by tifosi12

                Key thing is the rubber membrane; it needs to be in perfect condition.
                The seller noted the sub was still fully operational but the seal wasn't good anymore.

                Make it simple, make strong, make it work!

                Comment

                • tifosi12
                  Commander
                  • Jul 2020
                  • 345

                  #9
                  Originally posted by redboat219

                  The seller noted the sub was still fully operational but the seal wasn't good anymore.
                  It's possible that the sub is indeed working and that the seal deteriorated over time but in that period the sub wasn't used. Still I'd be super cautious once we are looking at a broken seal. There is a video on Youtube on how to fully disassemble a Nikko submarine. It's doable but I wouldn't know where to begin if a motor or the electronics had a problem.

                  And: you won't find a seal as a replacement by itself. If you find one, it is normally attached to a fully functional sub. :)

                  Comment

                  • tifosi12
                    Commander
                    • Jul 2020
                    • 345

                    #10
                    Since we're talking so much about the perfect seal, here is what mine looks like:
                    Click image for larger version

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                    • redboat219
                      Admiral
                      • Dec 2008
                      • 2730

                      #11
                      There's a thread at RCG where the owner replaced the old seal with some silicon baking sheet and a lid from a food container. https://www.rcgroups.com/forums/show...-Submarine-mod
                      Make it simple, make strong, make it work!

                      Comment

                      • redboat219
                        Admiral
                        • Dec 2008
                        • 2730

                        #12
                        I'm curious as to why hasn't anybody tried doing their own hobby grade RC sub based on the working principles of the Nikko sub. That vertical thrusther is simplicity itself. No ballast mechanism to fiddle and adjust. Just push the switch and down she goes. Stop and let bouyancy do the rest. David already showed how to make a gimballed prop for pitch control, it's just a matter of turning it 90° for yaw control. Or you could just go with a normal fixed prop and servo operated rudder.
                        Make it simple, make strong, make it work!

                        Comment

                        • tifosi12
                          Commander
                          • Jul 2020
                          • 345

                          #13
                          Originally posted by redboat219
                          I'm curious as to why hasn't anybody tried doing their own hobby grade RC sub based on the working principles of the Nikko sub. That vertical thrusther is simplicity itself. No ballast mechanism to fiddle and adjust. Just push the switch and down she goes. Stop and let bouyancy do the rest. David already showed how to make a gimballed prop for pitch control, it's just a matter of turning it 90° for yaw control. Or you could just go with a normal fixed prop and servo operated rudder.
                          It is simple and immensely effective. Goes down and up fast but not too fast, just right.

                          I suspect the reason it isn't popular because it looks odd and out of place. So it wouldn't work for any scale model of an existing boat. But it would be a good solution for a fantasy boat and/or a research boat, the ones that have all kinds of weird appendages. In my case I'll "dress" it as a Bond villain's boat pretending the vertical thruster is the connector to the underwater station of Spectre. :)

                          BTW: Nikko also did a nice job with the buoyancy: You add as many horizontal rings as needed to get the ride height correct and then in a second under the bow container you add little weights to get the forward vs rear balance right. Again, super simple and effective.

                          Somebody should reverse engineer this boat and 3d print it twice as big. :)

                          Comment

                          • He Who Shall Not Be Named
                            Moderator
                            • Aug 2008
                            • 12241

                            #14
                            Originally posted by redboat219
                            I'm curious as to why hasn't anybody tried doing their own hobby grade RC sub based on the working principles of the Nikko sub. That vertical thrusther is simplicity itself. No ballast mechanism to fiddle and adjust. Just push the switch and down she goes. Stop and let bouyancy do the rest. David already showed how to make a gimballed prop for pitch control, it's just a matter of turning it 90° for yaw control. Or you could just go with a normal fixed prop and servo operated rudder.
                            Because it ain't scale.

                            David
                            Who is John Galt?

                            Comment

                            • tifosi12
                              Commander
                              • Jul 2020
                              • 345

                              #15
                              Originally posted by redboat219
                              There's a thread at RCG where the owner replaced the old seal with some silicon baking sheet and a lid from a food container. https://www.rcgroups.com/forums/show...-Submarine-mod
                              Whoa! That's a great thread and what an undertaking OldNeet did changing the electronics and servo. Wow! And figured out how to replace the seal, not bad. I have to find some Chef Boyardee stuff as a backup. :)

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