Working on an End Cap using magnets

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  • trout
    Admiral
    • Jul 2011
    • 3545

    Working on an End Cap using magnets

    Prototype for an end cap that does not need openings for pushrods or shaft for prop. Using magnets the push rod and propellor shaft can move or spin without ...


    Wouldn't it be nice if we did not have to worry about seals? No cup seals, no bellows, and no o-rings?
    So I prototyped this and will be testing soon. (this is Nick's fault! just say'n - LOL)
    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.
  • He Who Shall Not Be Named
    Moderator
    • Aug 2008
    • 12253

    #2
    Originally posted by trout
    https://www.youtube.com/watch?v=DRDKM5qlv9I

    Wouldn't it be nice if we did not have to worry about seals? No cup seals, no bellows, and no o-rings?
    So I prototyped this and will be testing soon. (this is Nick's fault! just say'n - LOL)
    Examples of magnetically coupled linkages: Mast lifting systen - The Sub-drivers Forum (rc-sub.com)

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    Who is John Galt?

    Comment

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

      #3
      Nice Tom,

      Question, how high is the friction of the coupler to the propellorshaft, the sliding action is a clever move, did you measure the amount of pull?

      Manfred.
      I went underground

      Comment

      • trout
        Admiral
        • Jul 2011
        • 3545

        #4
        David, some of my thinking was from this. I certainly am building on your shoulders. Thank you! I may change the design of the pushrods for a more compact version. Using something similar to what you have used in the 1" tube. I can put the magnet horizontally and make a square tube that it slides in. I would rather have the tube going inwards rather than outwards for protection. Many ideas......First, I want to test this current design to get it to work. How will the nipples hold up with the spinning prop drive running on it? There is some interference of magnets between pushrod and drive. So, I just need to play.
        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

        • Monahan Steam Models
          Captain
          • Apr 2020
          • 755

          #5
          Nice work Tom!

          Regarding the friction at the shaft connection. I always envisioned using a ball bearing type thrust bearing sandwiched between the bulkhead and the magnetic shaft coupler. The video that was floating around a while back of the submarine using a Tupperware container and lego components used a adhesive sided slippery film on the face where the magnetic part contacted the bulkhead. If the resin nipples don’t hold up to wear, maybe replace them with one made of metal like brass or stainless steel.

          Anyways, keep up the great work. Happy to see you having fun playing around with your magnetic design again. Still not my fault!!! LOL

          Nick

          Comment

          • RCSubGuy
            Welcome to my underwater realm!
            • Aug 2009
            • 1768

            #6
            I played with this years ago, but ended up shelving the idea. Primarily, I couldn't get a solid binding of linkage output to linkage that didn't jump a bit during actuation. Having full, precise, proportional control is pretty important.

            It's a good thought, for sure.

            Comment

            • trout
              Admiral
              • Jul 2011
              • 3545

              #7
              Bob, me too, but applying “Home Improvement” mentality to this, the internal shaft connector and external shaft connector do not slip…….so far. I will keep you posted.
              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

              • rwtdiver
                Vice Admiral
                • Feb 2019
                • 1768

                #8
                Tom & Bob,

                Where is your go to source for this type magnets?

                Thanks,

                Rob
                "Firemen can stand the heat"

                Comment

                • Ken_NJ
                  Captain
                  • Sep 2014
                  • 744

                  #9
                  I get mine from K&J Magnetics. Always good to have many sources and they have a large variety to chose from. I usually order a variety of sizes at one time.

                  K&J Magnetics - Incredibly strong neodymium magnets at affordable prices. Large variety of stock rare earth magnets available.

                  Comment

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

                    #10
                    Gaussboys Super Magnets - Neodymium Magnets and Rare Earth Magnets

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                    Who is John Galt?

                    Comment

                    • trout
                      Admiral
                      • Jul 2011
                      • 3545

                      #11
                      David, the klic-ons where did you source the threaded pieces with 1/16 on the other end?
                      I got my magnets same as Ken, K&J magnets.
                      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

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

                        #12
                        Originally posted by trout
                        David, the klic-ons where did you source the threaded pieces with 1/16 on the other end?
                        I got my magnets same as Ken, K&J magnets.
                        Du-Bro. Part No. #111
                        Who is John Galt?

                        Comment

                        • trout
                          Admiral
                          • Jul 2011
                          • 3545

                          #13
                          Originally posted by He Who Shall Not Be Named

                          Du-Bro. Part No. #111
                          Thank you!
                          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

                          • trout
                            Admiral
                            • Jul 2011
                            • 3545

                            #14
                            Here is a video I should have posted a long time ago, but here was the test in the tub:


                            Now I needed to re-trim the sub. Added a small weight and placed it between its current location and the sail. Slowly moved it back (because the aft was light) until it leveled out and sank gently.
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                            Moved the piston control (knob to the right) to just past 3/4s and got the sub to get a neutral or as close as possible neutral buoyancy.
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                            Let the sub settle down to make sure the trim was good.
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                            Brought the sub to the surface to check trim and It came out good.

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                            Now get that weight affixed to the inside bottom of the hull and fix servo travel. Then get out to the river and film (David says no photos or film it did not happen).
                            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

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