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USS Jimmy Carter SSN 23 1/96

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  • Navy2000
    replied
    The angle keeper is installed I will give these ideas a try and see how it goes from there.

    Thanks

    Duane

    Leave a comment:


  • He Who Shall Not Be Named
    replied
    As Steve asks, is the angle-keeper installed? If so the stern plane servo 'chatter' during motor run is an artifact of vibration, not motor 'noise'. Not a problem as this vibration is damped out to a significant degree when the model is in the water. Take the angle-keeper out of the loop and test with the motor running -- no stern plane servo chatter.

    Leave a comment:


  • SubDude
    replied
    Do you have a pitch control in it?

    Leave a comment:


  • Navy2000
    replied
    I finally have all of the control surfaces working now in the Jimmy Carter. I have noticed that If I have a little throttle that the stern planes start to twitch some. The motor has the proper diodes or what ever they are called for the electronic noise. The stern planes servo is the only one doing the dance the others remain calm. Can it be just the servo has some issues and should I replace it?

    Duane

    Leave a comment:


  • He Who Shall Not Be Named
    replied
    Originally posted by Navy2000 View Post
    Thanks Dave

    Duane
    Anytime, pal. You're boat's looking good.

    David

    Leave a comment:


  • Navy2000
    replied
    Thanks Dave

    Duane

    Leave a comment:


  • trout
    replied
    David shows the simple solution to magnets pulling apart.
    I did a 3D printed version that did the same thing.

    Leave a comment:


  • He Who Shall Not Be Named
    replied
    From 1/16" brass rod bend a U-shaped retainer that you slip over the ends of the resin magnet foundations. This will keep the control surface pushrod from dropping away if the magnets are pulled away to a degree where the magnetic attraction is lost.

    Click image for larger version

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    David

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  • Navy2000
    replied
    Ok here is a little bit more of this build.

    After a few days of working at it I was able to get the stern planes in and aligned with each other.





    When the stern planes are at full rise the two magnets are separated by 1/32" but they do come back together when the servo moves back. Should I have any concerns for this or is it ok? They stay close together by the attraction of the magnets like they are still trying to get back together.



    Duane

    Leave a comment:


  • jphatton
    replied
    Originally posted by DrSchmidt View Post
    In addition there is a follow on publication by Joubert, going into further detail on submarine design optimisation. Here is the link to the PDF;

    http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf

    The concept of the SSK presented in the paper became the basis of a standard hydrodynamic models (the BB2) of a modern conventional submarine for studies in the open literature. There are number of publications from CDF, wind tunnel and test tank models studies. The MARIN institute in the Netherlands made a 3.8m long model for free running tank tests.

    Leave a comment:


  • He Who Shall Not Be Named
    replied
    Originally posted by DrSchmidt View Post
    That second document is most enlightening, Doctor. Thank you so much for sharing that. I now have a weeks worth of night reading to do. Froud, Rynolds -- familiar names/terms in this game. Wish I had the math skills to better understand their findings.

    David

    Leave a comment:


  • DrSchmidt
    replied
    That's why I ask...

    https://www.researchgate.net/publica...Mini_Submarine

    Also a good read:
    https://apps.dtic.mil/sti/pdfs/ADA428039.pdf
    Last edited by DrSchmidt; 05-13-2022, 08:59 AM.

    Leave a comment:


  • He Who Shall Not Be Named
    replied
    Originally posted by wlambing View Post
    Lately, we've taken to inserting large modules well aft of the sail, which makes it look like the sail is way off. The sail was there first! Then, the modules were designed and inserted. The Block V Virginia Class are going to look that way, too. Kind of like "Baby" boomers!
    Three things at work here: 1. Now that we've dropped periscope tubes running through the hull, sail location is no longer driven by where they stick the control room. 2. The forward sail might be out of the 'water slam' that occurs during high speed, high turn rate maneuvers (snap-roll) as the water sheds from the boundry layer and goes crazy turbulent, and 3. The sail so far forward of the c.g. de-stabilizes the boat about the yaw axis which may increase the turn rate.

    These observations and hypothesis are my own and not derived from any readings I can remember. I very well could be full of **** on the matter.

    David

    Leave a comment:


  • wlambing
    replied
    Lately, we've taken to inserting large modules well aft of the sail, which makes it look like the sail is way off. The sail was there first! Then, the modules were designed and inserted. The Block V Virginia Class are going to look that way, too. Kind of like "Baby" boomers!

    Leave a comment:


  • DrSchmidt
    replied
    What is it with us submarines having their sails so far off center to the bow? I once read a paper that said that this is bad with respect to the drag coefficient....

    Leave a comment:

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