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

today's work

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


  • We go back in time to the initial 1.25-inch diameter Swann standard quality video camera-transmitter watertight enclosures. The upper one, with the long foil-shaped antenna fairing is the type strapped to the hull of a model submarine. A shot of how that is used posted in an earlier segment.

    The lower enclosure is the type designed to be housed within the sail of a model submarine. The tools used to cast the polyurethane parts seen here are still available to me and present options applicable to the current work, such as the 1.25-inch diameter watertight enclosures housing the 'modern', High-Definition (HD) quality equipment now in development.



    This new enclosure varies only in that the forward removable bulkhead -- which mounts the camera and lens -- had to be contoured sharply to get the lens to fall along the plane of the 1/35 Type-23's deck-gear access door, which projects slightly ahead of the sails leading edge.

    I've nearly completed the masters of the Type-23 enclosure forward bulkhead as well as a new, more robust, antenna fairlead.

    That fairlead, mounted atop the enclosures cylinder, routs the transmitters coaxial cable through a watertight gland and up into the hollow periscope cylinder where it terminates at the top as an antenna within a hollow, plastic (and RF transparent) periscope head. The 5.8gHz signal will not punch through water, hence the need to mount the antenna where it sticks up into the air as the model travels about at, 'periscope depth'.

    With the FPV system installed aboard the Type-23 the only variance from scale will be the missing deck gear access door and the lens of the systems enclosure peeking out from where the deck-gear access door used to be.

    The old enclosure was too blunt at the front to get the lens far enough forward in the sail. However, the new forward bulkhead -- seen here as an in-the-ruff master with its much sharper tapper -- will.



    The forward bulkhead was manufactured by turning a dense piece of RenShape on the lathe. Here I'm cutting the blank out from a scrape piece of RenShape board. RenShape is the ideal medium for almost all the masters I produce these days. Expensive, but worth every penny!



    First cut was to establish the outside maximum diameter of the bulkhead, equal to the 1.25-inch diameter of the enclosures Lexan cylinder.



    Here I've already cut the inside and outside tappers, as well as the recessed radial flange that slips within the forward end of the cylinder. I have yet to cut the O-ring groove that will make the watertight seal between the eventual cast resin forward bulkhead part and cylinder.



    I found that the two pancaked printed circuit boards (PCB) that attached to the lens and sensor, being of square profile, became a big-time interference fit only half-way into the forward bulkhead.



    So, I moved the work over to the milling machine which had my rotary table bolted to its bed, centered the work on the rotary table and proceeded to cut four equally spaced grooves within the bulkhead. These grooves permitting complete, uninterrupted passage of the camera-transmitter all the way forward. The objective was to get the cameras lens even with the forward end of the bulkhead master.



    The front end of the bulkhead needed a little putty and sanding work (damned thing kicked out of the chuck during an earlier turning set-up and got a few scares as a result). I've temporarily installed the camera-transmitter to affirm that the camera lens sits even with the forward end of the bulkhead.

    After fixing the damage the master was coated with CA, sanded, puttied where required, spot-sanded, primed and readied for use as a master to give form to a RTV rubber production tool.



    Looking into the seated camera-transmitter within the forward bulkhead. Note the milled out longitudinal channels that gave clearance to the PCB's corners.



    The completed forward bulkhead and antenna fairlead masters and some of the layout tools used to transfer two-dimensional graphics to the three-dimensional work. Layout is everything! Measure twice and you'll only have to cut once. The ideal I all too often fail to attain.

    They used to teach this stuff in shop-class.

    What? What's that you say!... they don't teach shop in school anymore?!!! No wonder so many under-forty types today can't even figure out how to stick two pieces of wood together!

    To be fair, the government education system of today has taught our kids all about 'fairness'; how many sexes there are (we're up to 15 as of his writing); that all white people are stinkers; and what used to be shop-class is now, how to write code.

    Yikes!

    Yeah. Our future is secure with this lot.




    Resident Luddite

    Comment


    • I still worried about the limber holes. Exit, stage right……
      Of the 40,000 men who served on German submarines, 30,000 never returned.”

      Comment


      • Originally posted by Das Boot View Post
        I still worried about the limber holes. Exit, stage right……
        He takes a swift kick to the hornets nest as he scurries off…. LOL
        Last edited by Monahan Steam Models; 01-24-2022, 10:24 PM.

        Comment


        • My hearing isn’t as good as it used to be but I could’ve sworn I just heard David say, while sitting on my back porch in California say **** you ********!

          Comment


          • Originally posted by Monahan Steam Models View Post
            My hearing isn’t as good as it used to be but I could’ve sworn I just heard David say, while sitting on my back porch in California say **** you ********!
            We shall never speak of this again!

            Resident Luddite

            Comment


            • Originally posted by He Who Shall Not Be Named View Post

              We shall never speak of this again!
              Don’t be so dramatic. The camera pod work looks amazing by the way. Nice clean work. Don’t worry about the limber holes…. Worry more about the incoming torpedoes at the next meet. Hahahaha

              Comment


              • Damn. We'll have to do something about that.
                Resident Luddite

                Comment


                • They’re coming to take you away ha ha hee hee ho ho to the funny farm where life is beautiful all the time….. Click image for larger version

Name:	F52DA5F5-2B33-478F-9C84-B022135ABAC2.jpeg
Views:	182
Size:	64.4 KB
ID:	158444
                  Of the 40,000 men who served on German submarines, 30,000 never returned.”

                  Comment


                  • Originally posted by Das Boot View Post
                    They’re coming to take you away ha ha hee hee ho ho to the funny farm where life is beautiful all the time….. Click image for larger version

Name:	F52DA5F5-2B33-478F-9C84-B022135ABAC2.jpeg
Views:	182
Size:	64.4 KB
ID:	158444
                    https://youtu.be/_xRCbdFrSSc
                    Resident Luddite

                    Comment



                    • I'm side-stepping away from the Type-23 model submarine kit assembly to address the work taken to produce and outfit the FPV on-board camera enclosure.

                      Here's the completed unit. To the right is the camera lens even with the forward end of the forward bulkhead that contains the entire camera-transmitter unit. Atop the cylinder is the coaxial cable fairlead that also serves as the watertight gland between the coax and the enclosures interior. To the extreme left is the after-access bulkhead with an equalization valve set into its center (used to dump the slight over-pressure that occurs whenever one of the bulkheads is pushed into the cylinder.

                      The fairlead and forward and after bulkheads are cast from polyurethane resin using rubber tools to give these items their shape.



                      Tool making starts by securing the masters within containments that hold the liquid rubber till it changes state to a solid. For the forward bulkhead that containment is nothing more than a short length of 2-inch diameter Lexan. This is a one-pour tool, which will be sliced into a two-part tool later, after the rubber hardens and is slid out of its cylindrical containment.

                      The coax fairlead is a two-pour tool which requires masking half of that master in clay, then pouring the first half of the tool. Its containment will be a wrap of masking tape around the moldboard itself. Note the dimpling of the clay to produces keys that will ensure proper registrations when the eventual two halves of this tool are assembled for use.



                      Once the tool making rubber had been catalyzed -- a process which also folds into the mix a lot of air-bubbles that if left in the mix would spoil the tool. So, before pouring the rubber, it is subjected to a hard vacuum which enlarges the entrapped air-bubbles, which become super-buoyant, rise to the surface, burst and are sucked out through the pump. Effectively de-airing the mix.



                      After a few minutes of vacuum the rubber is taken out of the machine and dumped into the containments.





                      The antenna fairlead tool incorporates a 1/8-inch diameter brass rod that serves as a core which will render a bore through the eventual cast resin part. Additionally, that core suspends two O-rings that will provide the watertight seal between coaxial cable and fairlead body.



                      Before assembling a tool, it is first coated with a silicon oil spray and then given a dusting of talc. The oil serves as a part-release agent. The talc helps wick the introduced resin into all portions of the tools cavity, helping to insure a complete fill.

                      The 3/8-inch diameter brass rod core of the forward bulkhead tool produces the bore that will pass the camera-transmitters lens.



                      Alumilite RC-3 'tan' polyurethane resin is mixed and poured into the tools sprue holes. This resin, at room temperature, has a pot-life of about 90-seconds. Time enough to mix, pour, and get the work into a pressure pot and under pressure. De-mold time is as short as 15-minutes! Good production stuff. I swear by it.



                      A common spray-gun pressure pot is used as the vessel to contain and put under pressure the resin filled tools. It's while under pressure that the resin stays till it changes state from liquid to solid. About two-atmospheres is maintained. The pressure forces any bubbles in the mix to crush back into solution, resulting in void-free castings.



                      Removing cast resin parts from their respective tools. Note the vent and sprue channel extensions atop this forward bulkhead cast resin part -- artifacts of the casting process and are snipped off and the nubs block sanded smooth. Removal of its core leaves the bore for the camera lens.

                      Removal of the antenna fairlead core leave a bore to pass the coaxial cable. However, removal of the core leaves the two O-rings, mostly encapsulated within the resin piece, to affect the seal between coax and the fairlead body.



                      The main elements of the 1.25-inch diameter camera-transmitter enclosure. All that is needed to power this bad-boy up is to connect the battery to the camera and you're on the air!



                      It fits!





                      Resident Luddite

                      Comment


                      • Hiw about a test video of the camera's POV .
                        Last edited by redboat219; 01-26-2022, 02:30 AM.
                        Make it simple, make strong, make it work!

                        Comment


                        • Originally posted by redboat219 View Post
                          Hiw about a test video.
                          In time............
                          Resident Luddite

                          Comment


                          • Very nice work and it fits like a glove!

                            Couple quick questions. What effects have you seen with these camera enclosures on the ballasting and stability of the model? Are you going with a snort system or S.A.S? And finally, are you planning on using a ghz or MHz radio in this build? Asking because of the model only having the single periscope where normally you can hide the antenna or snort intake.

                            Looking good Pal!

                            Nick

                            Comment


                            • Originally posted by Monahan Steam Models View Post
                              Very nice work and it fits like a glove!

                              Couple quick questions. What effects have you seen with these camera enclosures on the ballasting and stability of the model? Are you going with a snort system or S.A.S? And finally, are you planning on using a ghz or MHz radio in this build? Asking because of the model only having the single periscope where normally you can hide the antenna or snort intake.

                              Looking good Pal!

                              Nick
                              Overall submerged trim is as before because the enclosure (which is well above waterline in surfaced trim) weights as much as the water it displaces. However, the extra weight of the system does make the models surfaced freeboard a bit lower than scale. The added topside weight also contributes to a slight de-stabilization of the boat about the roll axis. But I always go over-kill with the amount of fixed ballast weight I stick in the models lower hull.

                              SAS. Only because I built this SD over ten years ago. As this camera mule will spend most of its time at PD I could have gone with current fad of 2.4gHz for the r/c system. And that is not a problem with the current FPV camera-transmitters as those operate on the 5.8gHz band.

                              I'm going with 75mHz gear as I plan to dive and work out a means of recording the video on board to a mini-SD card. That way, when the cameras transmitted signal is lost at the ground-station (say, I see a target I want to chase that went deep), I still have a complete camera record which I can pull from the mini-SD card later.

                              The 75mHz antenna will be down in the hull.

                              David
                              Resident Luddite

                              Comment


                              • Runcam split will record to SD.

                                https://shop.runcam.com/runcam-split-hd/
                                Time to DIVE IN! https://www.facebook.com/groups/133360626703083/

                                Comment

                                Working...
                                X