Announcement

Collapse

Forum rules and expectations

Hello, and welcome to the forums at the Nautilus Drydocks, formerly Sub-driver.com!

We welcome anyone with a passion for submarines and a desire to learn and share knowledge about this fascinating hobby. Use of these forums indicates your intention to abide by our code of conduct:


1. No spam. All automated messages, advertisements, and links to competitor websites will be deleted immediately.

2. Please post in relevant sub-forums only. Messages posted in the wrong topic area will be removed and placed in the correct sub-forum by moderators.

3. Respect other users. No flaming or abusing fellow forum members. Users who continue to post inflammatory, abusive comments will be deleted from the forum after or without a warning.

4. No threats or harassment of other users will be tolerated. Any instance of threatening or harassing behavior is grounds for deletion from the forums.

5. No profanity or pornography is allowed. Posts containing adult material will be deleted.

6. No re-posting of copyrighted materials or other illegal content is allowed. Any posts containing illegal content or copyrighted materials will be deleted.
See more
See less

Little Something I've been working on...

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Hey all, thanks for the kind words!
    The Ballast tank is of the piston variety, similar to those used by Engel. A piston, attached with a threaded rod (PTFE coated one in my case, runs easy though the lead nut), moves in and out to displace the water. The motor is run through a gear reduction, pictured below, to increase torque. There are limit switches (see the one mounted in the photo already posted) that stop current flow to the motor when the extremes of the tank are hit. Since the limit switches do not have the current capacity to run the motor when operating at peak without burning out, I modified some relay units and wired up the limit switch output to those (indicated in the photo below).
    The lead nut/spur gear assembly pictured above is inserted into that bearing in the bulkhead next to it (its a press fit). this allows the lead nut to spin freely, while the gear can ride up against the large bronze thrust washer when spinning so it doesn't get caught up or lock up.
    I've also included a video of an initial test run of the motor assembly, which shows pretty well the motion.







    Edit - can't post the video from work. I'll upload it when I get home.

    -Derek

    Comment


    • #17
      And here's that video:


      Edit: accidentally posted multiple times, my bad. should be fixed now.
      Last edited by TechnoD11; 06-18-2019, 11:33 AM.

      Comment


      • #18
        Very good description. Do you have a picture of the lead nut in its gear housing. Also what shape is the lead screw where it attaches to the piston.
        Thanks, Scott T

        Comment


        • #19
          here's a photo of the end of the piston:

          And here is the lead nut/spur gear assembly pressed into the inner race of the bearing:



          -Derek

          Comment


          • #20
            Originally posted by TechnoD11 View Post

            -Derek
            Hi Derek, nice work sir.

            As you work with a piston tank I assume it will be a static diver.
            Is the 3 holed alu plate intended to accomodate magnets to trigger reed sensors?
            Just curious.

            Grtz,
            Bart

            Practical wisdom is only to be learned in the school of experience.
            "Samuel Smiles"
            http://scale-submarine.com/index.html

            Comment


            • #21
              Originally posted by bwi 971 View Post

              Is the 3 holed alu plate intended to accomodate magnets to trigger reed sensors?
              The three holes are for .25" OD bearings for the gear reduction that drives the lead nut for the ballast. Take a look at the video posted above.

              -Derek

              Comment


              • #22
                Mounted the windings of the slip ring commutator yesterday. Getting these wound tight was a massive pain, but I verified full 360 degree electrical contact. This will enable the tether wire to spool in and out without getting tangled, as metal contacts will run against this commutator for data transmission.


                -Derek

                Comment


                • #23
                  And after some hours in the shop this past weekend, the slip ring and spool assembly is done! Here's a video showing it working (sorry for the focus in some bits):


                  And some stills:




                  As always, more to come. Getting very close to sea trials...

                  -Derek

                  Comment


                  • #24
                    Nice work, the machining is impeccable! -so this is is going to have a tethered ASDS from the main sub that actually houses the radio gear, keeping the radios close to the surface and the main sub could go 30ft deeper from the ASDS ,technically as a tethered ROV- ...(cool smile emoji)
                    Last edited by Bob Gato; 07-01-2019, 02:23 PM.

                    Comment


                    • #25
                      Originally posted by Bob Gato View Post
                      Nice work, the machining is impeccable! -so this is is going to have a tethered ASDS from the main sub that actually houses the radio gear, keeping the radios close to the surface and the main sub could go 30ft deeper from the ASDS ,technically as a tethered ROV- ...(cool smile emoji)
                      Yup! And if everything works correctly (so far, so good...) I'll have a live video feed from the sail. Here's hoping!

                      Comment


                      • #26
                        Got the Front bulkhead all wired up with its connectors this past weekend:

                        The front bulkhead slides onto the threaded rods, and in the process mates with the other end of the connector which passes through the controls for the headlights, electromagnet, servo (and analog feedback), and an additional PWM for future expansion. Also carries regulated 5V and ground.
                        Speaking of power, also officially mounted the battery and power switch. This was difficult!

                        Access to the power switch is through the side of the poly carbonate tube - I've got two small, tapped holes right over the on/off positions. A button head bolt threads into the tapped hole with an o ring to seal and is removed to allow a pin to enter and toggle the switch.

                        Comment


                        • #27
                          The Camera Works!!

                          In the bottom right, you'll see the sail which has the camera mounted in it. The TV in the background is displaying the footage live from the camera (you can see the multimeter quite clearly). The video feed is run through the front bulkhead, through the shielded conduit, through the tether, to the wireless transmitter, which then sends it to the wireless receiver hooked up to the TV. I had some serious concerns about signal attenuation but everything looks fantastic!

                          Comment


                          • #28
                            The Core is done!

                            To slide the tube over, a little bit of silicon/PTFE grease will be needed. Made this cheesy duct tape-wrapping applicator:

                            ...And after being greased:

                            Should still be on track for sea trials end of this week/or next week...
                            God I hope this thing works!

                            Comment


                            • #29
                              This is great work! I can't wait to see her in the water!

                              Comment


                              • #30
                                Bathtub Trials were a success!

                                Now to add the diagnostics access holes, sail, and electromagnet. Then mount the mini sub, then time for some real sea trials!

                                Comment

                                Working...
                                X