New 3" SubDriver Under Development

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  • He Who Shall Not Be Named
    Moderator

    • Aug 2008
    • 12765

    New 3" SubDriver Under Development

    Mark Green is re-working his SubTech 1/60 scale ALBACORE into a phase-4 configured boat, the one with the two counter-rotating propellers. In support of the overhaul Mark asked for some spare parts for his old, old two-motor version of the WTC-3.

    Several years ago I discontinued production of our 3" diameter SubDriver's. But, now seeing utility to the bigger, thicker Lexan cylinder for this and other kits out there, I started in on an upgrade -- completely new end and internal bulkheads; these items incorporating features and lessons learned over the years.

    Below are some shots and text describing the design and master work that goes into one of our SubDriver's:

    RenShape discs (blanks) are turned from RenShape pattern-making plastic (a very dense foam product) to the specifications indicated in the shop drawings. The seating face of these bulkhead masters is about .030" bigger in diameter than the inside diameter of the average 3" cylinder -- this to account for tool and part shrinkage. When done right the actual cast resin part will be a tight fit within the cylinder.

    Note that the green screw foundations glued atop the blanks were cut from one of our current line of SD internal bulkheads -- I sacrificed two 3.5" internal bulkheads for these parts. So too was lifted the blow-valve and ballast servo seal foundation assemblies. Why re-invent the wheel when you don't have to? These resin parts later glued to the faces of the forward and after ballast bulkhead masters with CA adhesive.

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    Two motor bulkhead masters -- each comprising two pieces, the motor bulkhead itself and the motor retaining plate that bolts to it -- are being worked up. One, a single-motor unit, the other a two-motor unit. Both featuring a 3:1 reduction gear housed within the body of the bulkhead itself.

    Use of the dial-indicator, depth micrometer, surface gauge, lathe, and milling machine insured symmetry and holding of reasonably tight tolerance between drawings and masters.
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    Fillets between screw foundations and blank discs were achieved with Evercoat filler laid in with a dapping tool. Later the work was cleaned up with knife, files, and sanding tools. All tool marks were filled with Nitro-Stan air-dry touch-up putty cut to a watery consistency with lacquer thinner then applied to the work with a brush. The dried Nitro-Stan was wet sanded with foam backed sanding sticks making the master ready for a check-coat of primer.

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    Note the various sanding and cutting tools. Food for thought, guys.

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    Attached Files
    Who is John Galt?
  • ManOwaR
    Lieutenant Commander
    • Jul 2009
    • 217

    #2
    Where'd you get those red spring loaded belt sanders? I'm in love with those!

    Joel
    https://www.facebook.com/HMKcreations

    Comment

    • He Who Shall Not Be Named
      Moderator

      • Aug 2008
      • 12765

      #3
      Damn, Joel, wish I knew the source of manufacture -- those two in the shot where at the hobby-shop but with no tag indicating source or model number. Sorry. I'll looke 'em over when I get into the shop today, will look for any info that might be stamped on the body.

      David,
      Who is John Galt?

      Comment

      • greenman407
        Admiral
        • Feb 2009
        • 7530

        #4
        I would pay real money to come and work(observe) with you for a day. Does Ellie provide lunch?
        IT TAKES GREAT INTELLIGENCE TO FAKE SUCH STUPIDITY!

        Comment

        • He Who Shall Not Be Named
          Moderator

          • Aug 2008
          • 12765

          #5
          Originally posted by greenman407
          I would pay real money to come and work(observe) with you for a day. Does Ellie provide lunch?
          Ellie's the Gate-Keeper in these here parts. Sweet talk her if you wish to get anywhere near the Shop.

          You like fish-heads and rice?

          David,
          Who is John Galt?

          Comment

          • ADDINGTON
            Lieutenant
            • Sep 2008
            • 80

            #6
            Gentlemen,
            I believe those red sanding sticks are made by Excel.
            -Kerry

            Comment

            • trout
              Admiral

              • Jul 2011
              • 3595

              #7
              Yes, Excel Hobby and Blade I believe.
              see if this is the same: http://www.excelhobbyblades.com/product_info.php?cPath=75&products_id=592&osCsid=be01d3be24439e541c0e8e33e2b37b97

              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
                • 12765

                #8
                Good catch, guy's. Thanks.

                David,
                Who is John Galt?

                Comment

                • greenman407
                  Admiral
                  • Feb 2009
                  • 7530

                  #9
                  Dave, is there anyway, in this new design, as a posible variant, to shoehorn two 540 motors side by side to give more thrust availability than two 400s or 380s? I ask this because the Seaview(Rick Teskey version) could use more get up and go.
                  IT TAKES GREAT INTELLIGENCE TO FAKE SUCH STUPIDITY!

                  Comment

                  • Subculture
                    Admiral

                    • Feb 2009
                    • 2210

                    #10
                    Don't think you'll get twin 500's in a 3" diameter cylinder when allowing for the cylinder wall thickness.

                    If you need more poke a couple of options spring to mind- 480 size motors or go brushless. The latter option is pretty attractive nowadays with cheap reversible controllers readily available, and a very wide choice motors.

                    Comment

                    • greenman407
                      Admiral
                      • Feb 2009
                      • 7530

                      #11
                      Ive got brushless motors in a speed boat for all out running but I didnt think that they would be good for slow speed torque and puttering along.
                      IT TAKES GREAT INTELLIGENCE TO FAKE SUCH STUPIDITY!

                      Comment

                      • Subculture
                        Admiral

                        • Feb 2009
                        • 2210

                        #12
                        The very low speed running characteristics of sensorless brushless motors are a little inferior to good quality multi-pole brushed motors. However unless you want to creep along at very slow speeds, it's unlikely to be an issue.

                        Torque wise, brushless motors have far more grunt than a brushed motor.

                        If you take a look at Hobbyking, you can pick-up a pair of low KV brushless outrunners and reversible speed controllers for under $40 e.g.

                        Hobbyking - the world's No1 Online Hobby Store. We stock a huge selection of RC products from Planes right through to Drones and all accessories. Visit Us Today.


                        Hobbyking - the world's No1 Online Hobby Store. We stock a huge selection of RC products from Planes right through to Drones and all accessories. Visit Us Today.

                        Comment

                        • greenman407
                          Admiral
                          • Feb 2009
                          • 7530

                          #13
                          Thanks Subculture. Your helping me out with a possible future project.
                          IT TAKES GREAT INTELLIGENCE TO FAKE SUCH STUPIDITY!

                          Comment

                          • He Who Shall Not Be Named
                            Moderator

                            • Aug 2008
                            • 12765

                            #14
                            Good stuff, gent's. Food for thought.

                            David
                            Who is John Galt?

                            Comment

                            • tsenecal
                              Lieutenant
                              • Dec 2009
                              • 63

                              #15
                              My hope would be for D & E / Caswell to sell a version sans motor/esc/electronics, allowing those of us that are brushless & lipo bigots to build it using premium components and not the "Junk Drawer" EMF spewing ancient technology devices normally found in these types of "built for the masses" WTCs. :biggrin:

                              Comment

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