Announcement

Collapse
No announcement yet.

1/32 French Arethuse

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

  • #16
    Abysmal progress, I know, but progress nonetheless. Rear dive planes were drafted and printed in high strength resin. I actually really like the configuration of the stern. The rudder is directly behind the prop, which will, in theory, offer some great yaw response. The rear planes are really conveniently located where they don't interfere with the prop shaft. They're large and situated well in good proximity to the propeller. I am anticipating good pitch response from this boat as well.

    Next up will be engineering the rudder actuation. There is room for a tiny horn, however I will likely go with something like a pull/pull steel cable on a wheel in order to keep it close and tidy back there.

    Once the stern is finalized (and we're close on that), then it's onto the crazy forward dive planes. I've spent quite a few hours pondering how to engineer the push/push extending front dive planes. The biggest challenge is the narrow bow. When retracted, the planes actually almost touch the inside of the opposite side of the hull. For those unfamiliar, the bow planes are engineered such that there is one on the starboard side to surface, and another on the port side to submerge. Proportional control of surfacing/submerging is handled by pushing out the respective dive plane to different degrees. The advantage to this is that when a level bubble is achieved and desired, there is no drag from forward dive planes. The disadvantage is the crazy linkage needed to make it all happen.

    More soon, though progress will likely be further stalled by preparations for SUBFEST, which is in 2 weeks.
    Attached Files

    Comment


    • #17
      With everything going on in preparation for SUBFEST, I've been pulled in a hundred different directions, but I have had a bit of time to work on Arethuse. The hull is nearly ready to commit to surface finish. These photos show it in her final coat of primer before the last sanding session. From here, she will get some high build primer and I can begin transferring the scribed details to the hull.

      I've also begun work in earnest to get the forward plane linkages sorted. I think I have a strategy that will work. I have it drafted on a napkin and it should (in theory) work well.

      Nothing more on this or any other project until after SUBFEST next week.
      Attached Files

      Comment


      • #18
        Well Done! Enjoy relax at Sub Fest. The SubFest site is the most beautiful set up. Safe Journeys.

        Steve

        Comment


        • #19
          I have a special interest in this topic. I started an Arethuse submarine a few years ago but other projects came up and have been sitting. I come here looking for inspiration, amazing work.

          Comment


          • #20
            Hopefully this project at Nautilus works will resume on schedule now or soon once Bob completes other projects. The sail is tall in proportion to the hull but is correct by the detailed drawings. The sail height is determined by height of the periscopes. the periscope height is determined by the periscope depth needed or deemed necessary for sufficient stealth due to the clarity of the water (then) in the Mediterranean Sea she was designed primarily to operate in. The Skipjack SSN's have proportionally tall sails too. The Model may handle similarly in the water leaning over in turns, but don't expect you will be flying this model like a Skipjack either. Will see.

            The sub barrows many 'American' features. It uses the same propulsion arrangement as te American fleet boats, (diesel engines generate electrical power to a electrical motor which propels the boat on the surface or submerged, just switching to batteries when submerged) a departure from earlier French submarines de clutching before the war. This is more efficient, but primarily was used as the spaces in the small hull afforded no other option, the system affording flexibility in placing the diesels and motor. The Argonaute also used the American ST attack periscope (or a french licensed copy) with its radar head for accurate ranging.

            The Americans about the same time developed a tiny SSK barrier submarine SSK-1 to SSK-3 that was designed as prototypes for mass production should American strategy shifted that way It didn't and and in stead went with the Thresher/Permit concept. The SSK-1 to 3 were dogs compared to the French Arethuse's. Deeper diving, and much faster underwater ( can be considered in concept the first true as designed 'Hunter Killer' mission boats. I love their look and think these subs in a model need more recognition. But Cramped! Even a special version (shorted torpedoes had to be designed for these 4 boats. But from what I can glean they were successful very boats in design & operationally.

            Steve
            Last edited by Albacore 569; 01-31-2023, 03:15 PM.

            Comment


            • #21
              We are getting close to being able to resume work on this boat. Hoping within the next few weeks and we can get on it in earnest.

              Comment


              • #22
                I wish I could say the same. Mine is far from finished:

                Submarino de patrulha FrancÍs de 543 toneladas em seco, mais pequeno que os submarinos da classe Daphne que equipam a marinha Portuguesa e ...

                Comment


                • #23
                  Beautiful, exacting work, sir. Magnificent.

                  David
                  Who is John Galt?

                  Comment


                  • #24
                    Click image for larger version

Name:	wu0GlJy.jpg
Views:	142
Size:	87.6 KB
ID:	170362


                    Front to back Ariane, Argonaute, Arethuse, Amazone. The entire Arethuse class hunter killer Sous Marins.

                    Steve

                    Comment


                    • #25
                      Back at it in earnest.

                      The cylinder driving this boat will be a brand new OTW 3.5" unit with 12" ballast tank. It will be outfitted with pitch control and depth-keeping as well as a remote on/off switch. Jason is 80% done the installation of these electronics and should be done that today if things go well.

                      Click image for larger version

Name:	20230404_064919.jpg
Views:	113
Size:	77.5 KB
ID:	170453

                      The forward planes are proving to be problematic, though I plan more work today to try and work out the mechanism. At this point, the hardware for the sliding planes are installed and working perfectly. Both upper and lower planes extend and retract along their rails perfectly smoothly. All that remains now is to work out how to actually make them move.

                      Click image for larger version

Name:	20230403_143547.jpg
Views:	132
Size:	110.2 KB
ID:	170448Click image for larger version

Name:	20230403_143557.jpg
Views:	135
Size:	109.9 KB
ID:	170449Click image for larger version

Name:	20230403_143738.jpg
Views:	137
Size:	108.5 KB
ID:	170451

                      The challenge to this is that, when retracted, the planes are tight against the inside of the hull, and when extended, nearly fully pushed outside the hull. I have, maybe, 1/8" of real estate to work with, particularly on the lower dive plane, which sits in a much narrower part of the hull.
                      Attached Files

                      Comment


                      • #26
                        Wow! I didn't realize there was such a distance "gap" between the 2 planes. Is there similar for the Type 209 German? Perhaps there's some part of that mechanism that can be adapted, of course assuming someone's done the 209 with properly operating bow planes!?

                        Comment


                        • #27
                          Thank you Bob for the Photo progress images. After the bow planes are done and operating well, Hopefully the hull will be sanded and crisped up with sharper crisp smooth surface lines. The hull sections definitely looks robust as you described.

                          The German planes are similar in function and location, but different in engineering execution. Elegant thing is when either plane isnt actuated, the hull should be clean of control empennages in the bow.. To rise (depth not angle) , you extend the starboard upper plane and a fixed curved foil emerges varying the degree of rise by the amount of surface area becomes exposed or reduced. The opposite for the lower port plane. exposing the lower plane only to descend.

                          The German design seems similar in function (but to me) much simpler. Again two fixed curved triangular foils opposite sides, on a vertical axis swinging in or out. one on a fixed up angle varying the surface area, and a down angle one on opposite side.

                          you tube actuation of rc model 209 bow planes.
                          https://www.youtube.com/watch?v=MEdp0qNVidg

                          On both the French and German designs of the same period. the area of the bow planes themselves are small. But they are on both sub designs on the end of long moment arms dynamically for pitch function, so small is acceptable. Will see....how they work in the water on the model.
                          Last edited by Albacore 569; 04-05-2023, 02:44 AM.

                          Comment


                          • #28
                            I'd look at a scotch yoke mechanism, perhaps with two servos mixed in transmitter, although it could use a single servo. https://en.wikipedia.org/wiki/Scotch_yoke
                            Time to DIVE IN! https://www.facebook.com/groups/133360626703083/

                            Comment


                            • #29
                              Originally posted by Albacore 569 View Post
                              Hopefully the hull will be sanded and crisped up with sharper crisp smooth surface lines.
                              And that... is why I don't like sending in-progress photos of builds to customers. Of course the hull will be post-process and finish-sanded. Methinks I detect a hint of passive aggressive commentary regarding the hull. Then again.. maybe I just haven't had enough morning coffee yet. If the former, please let me work. If the latter, well then I apologize. Fresh coffee is in my cup as we speak.

                              The German design seems similar in function (but to me) much simpler. Again two fixed curved triangular foils opposite sides, on a vertical axis swinging in or out. one on a fixed up angle varying the surface area, and a down angle one on opposite side.
                              Absolutely not applicable to this design. The 209 swivels out, the Arethuse slides. Completely different methodology and with infinitely more challenging movement.

                              Originally posted by Subculture
                              I'd look at a scotch yoke mechanism, perhaps with two servos mixed in transmitter, although it could use a single servo
                              Perhaps more applicable, just not feasible. I literally have about 1/8" of surface area on the plane to work with. Retracted, it butts tight against the hull. When extended, only about 1/8" of the forward edge is accessible.

                              I have zeroed in on a strategy that involves a pair of servos with an arm, one per plane. The planes are pulled inward by a high-strength elastic cable. The servo pushes to get them to extend. I'll have pics later today and we'll see if the solution is feasible. I have a backup if it doesn't work out.



                              Comment


                              • #30
                                It isnt passiv/agressive. Faith in you. Its your emails spam blockers. i am always not recieving emails. I only know this because of we started sendng tet messages instead. I don't like in public either. I agree with Merriman on the earlier Scale ship yard thread. I agree. I'll try & send text messages if I have any questions. but can't being blind. i apologize too. Just been waiting15 years. Letting you work and leavng you alone. thank you for everything.

                                I agree with you Bob , The bow planes of the 209 and the Arethuse use completely different methodolgy. if I was the French designers in the early 1950's I would have used the 209 methodology.
                                Last edited by Albacore 569; 04-05-2023, 11:05 AM.

                                Comment

                                Working...
                                X