Rotating Big Gun Cannons

Discussion in 'Weapons & Pneumatics' started by BigGunJeff, May 1, 2018.

  1. nmmichris

    nmmichris Member

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    I need to find that file for the qev so I can experiment with designs. How do you disarm the ship? Valve on tank side to relieve pressure as to not trigger the valve..
     
  2. BigGunJeff

    BigGunJeff Well-Known Member

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    Yeah, The design is supposed to be as similar to the Indiana cannon as possible as most ship builders are used to that design. Especially laying out the accumulators. Responses to your questions:

    1. The 3D printed barrels are pretty un-tested. You can replace these with standard bent ones without issue. The only constrain is that the barrels are 0.8" on Center.

    2. This could be an issue. I have the same basic design on my Alabama, and it works well when full of Ammo... Not enough experience to know if it's an issue. If it is, I could add a conical ramp so that the ammo runs down to the holes.

    3. If you look at the cross section picture, there is a hole through the riser near the bottom. This gets a 1/8" pin that passes through riser to stop ammo from dropping down. The pin is also sandwiched between the two halves of the magazine and keeps the riser in place. I haven't notices any double shots so far.
     
  3. BigGunJeff

    BigGunJeff Well-Known Member

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    Not yet
     
  4. BigGunJeff

    BigGunJeff Well-Known Member

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    A couple of approaches to safe the guns.

    1. You can add a second air line to the accumulator to vent.it.without firing

    2. If you drop the supply pressure to the guns slowly it will equalize in 30 seconds or so without firing.
     
  5. thegeek

    thegeek Well-Known Member

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    No gun pins?
     
  6. BigGunJeff

    BigGunJeff Well-Known Member

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    I haven't seen them used in practice in the WWCC.

    Some older boats have barrels drilled for them, but I never see them used.

    We pretty much rely on disabling the gas with a deck mounted switch that vents the accumulators.
     
  7. nmmichris

    nmmichris Member

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    I've seen the pin holes on some big gun ships. Not a bad idea I think but just not common practice i guess
     
  8. buttsakauf

    buttsakauf Well-Known Member

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    Big guns cannons tend to remain with their accumulators uncharged until they hit the water. There is no pond side tweaking so however you are set is it. You drop the boat, flick the switch, and go shooting
     
  9. thegeek

    thegeek Well-Known Member

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    Flick the switch? Nah , somehow not good enough, IMO.
    Been doing this hobby since 83 and gun pins have been a safety standard in IRCWCC forever. And yes I know not required for NAMBA insurance.
    Rob Wood our NAMBA rep might want to chime in about now, or not.
     
  10. buttsakauf

    buttsakauf Well-Known Member

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    Fast gunners tend to arm/charge the ship on the bench and walk it down to the lake then un-pin it. Big gun tend to walk it down to the lake then arm/charge the ship once it is on the water or about to be. I’m not debating the merits of pinning barrels. Just saying it has been done differently and I’ve never witnessed it be a problem. Respective safety features are:

    Fastgun= bottle removed and pins
    Big gun= bottle removed and a switch that vents the system (check valves trap charged air in various parts)

    Read all this as:
    fast gun bottle hooked up= guns hot> pins in
    Big gun bottle hooked up= guns cold > safe until armed

    both are effective at preventing projectiles from leaving the barrel unintentionally. You have a greater depth of experience in fast gun by far and I have broader experience in both (with various groups from coast to coast). There’s more than one way to skin a cat and most people have preferences. Me and Rob have talked about this stuff before. It’s all fine NAMBA wise. When it comes to safety there is always room for improvement though. We have spent quite a bit of time together over here in CA with SD Argonauts and WWCC events.
     
    Last edited: Dec 17, 2019
  11. nmmichris

    nmmichris Member

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    @BigGunJeff did you find a 3d rendering of that valve your using? Or did you create that file? I like to render the cannon config I have before I even flip a switch to see if it will even work lol. Thanks
     
    Last edited: Dec 18, 2019
  12. BigGunJeff

    BigGunJeff Well-Known Member

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    I Created the file for the 1/2 of the valve that I use. I can share what I have with you, but it's not the as-bought valve.
     
  13. nmmichris

    nmmichris Member

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    ah ok. sharing is appreciated. modifying the file for the DL I found is being difficult for some reason.
     
  14. BigGunJeff

    BigGunJeff Well-Known Member

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    PM'ing you for details...
     
  15. OverThinker

    OverThinker Member

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    Hey Jeff how much would you charge for a double barrel set up? I have a Bismarck that I desperately want to make headway on... and where are you out of?
     
  16. Sven’s

    Sven’s New Member

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    Hey Jeff, I’m new to the site but interested in buying a single gun rotating system. Would you be willing to sell me one? Thanks!
     
  17. BigGunJeff

    BigGunJeff Well-Known Member

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    I'm going to make a quad version for a friend, and will try to make a twin barrel version as well.

    I can make these, but sometimes it takes some time to get it all sorted out. PM me if you want to start a conversation on getting some of these
     
    Nibbles1 likes this.
  18. Spencer Koontz

    Spencer Koontz New Member

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    Hi,
    I am new to the hobby, and a doing a scratch build of the French cruiser Émile Bertin. Rite now I have the hull mostly completed, but I still need guns.

    I was wondering, could you post the files to make this? I have seen a lot of your stuff and am impressed!

    Thanks a million,
    -S
     
  19. Garrett

    Garrett Member

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    can you please share it with me too.
    thanks
    -G
     
  20. Garrett

    Garrett Member

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    could you please share the can files so I can make one of these.
    thanks
    -G