Non pneumatic cannons?

Discussion in 'Weapons & Pneumatics' started by modelshipsahoy, Aug 10, 2018.

  1. modelshipsahoy

    modelshipsahoy Vendor

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    Everything We see in the rules refers to pneumatic cannons.

    We have an idea for a compact mechanical cannon. Prohibited?

    Could be a game changer for small ships.

    Tim & Dori
    Modelshipsahoy.com
     
  2. buttsakauf

    buttsakauf Well-Known Member

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    I’ve never seen one small enough or powerful enough in anything other than single shot form factor effectively implemented. If you have a good idea, pursue it. I would run the theory past experienced persons who could illuminate any potential issues.
     
  3. modelshipsahoy

    modelshipsahoy Vendor

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    I’ve built this system for another application and it works great. Not really willing to give out the details of it, but something very simple and effective. Can generate muzzle velocity galore. Is there a limit on muzzle velocity? I’ve only seen rule state limits on co2 pressure.
     
  4. SteveT44

    SteveT44 Well-Known Member

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    Our cannons are shooting between 260 to 300fps on average. If your mechanical system can do that in as compact a package at several rounds a second, then it would be something.
     
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  5. modelshipsahoy

    modelshipsahoy Vendor

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    But is there a limit? I’m thinking 500 ft/sec ish should be attainable, but could be dialed down with smaller less powerful components. Would want to build as powerful as allowed by rule and space available.

    Also note: I’ve no experience in combat. I’m just a mad scientist with a smoking hot lab assistant keeping me motivated.
     
  6. SteveT44

    SteveT44 Well-Known Member

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    In IRC, there is no FPS limits specified. Current safety measures are implemented by max PSI and barrel lengths. If you wanted to introduce a viable mechanical system, I'd imagine an FPS limit would have to be introduced. A good rule of thumb for safety testing is would you want to put your hand in front of the barrel and fire it?
     
  7. modelshipsahoy

    modelshipsahoy Vendor

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    That’s the craziest “Safety” test I’ve ever heard of! Lots of good velocity meters out there.

    Not thinking it’s worth it to develop something that could be disallowed.

    Already so many have their nickers in a bunch that I built ships others make?!?
    Air cannons are already being done by others.... Going to catch flak for using/selling tanks and popitt valves????

    It’s so hard to be a Mad Scientist these days!
     
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  8. SteveT44

    SteveT44 Well-Known Member

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    The rules date to the 70's and velocity meters back then were definitely not a Kmart item.

    And Dude, you need to lighten up a bit. No one said, no you can't do that. All I said was there are no current FPS limits and that if you were to bring a non-pneumatic system to the pond, limits would probably be contemplated and introduced. The hobby is not adverse to new tech, but it has to be safe tech. And if your so adverse to putting your hand in front of your cannon, how about your fellow battlers 9 year old daughter that may be pond side?

    If you want to sell tanks, go for it, but I doubt you'll be able to undercut current providers pricing on that.
     
  9. modelshipsahoy

    modelshipsahoy Vendor

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    I’ve been trying to lighten up for years... I used to be 395#. Down to 275 and still working at it.

    BB’s are notoriously fast decelerators, being spheres. The reynolds numbers are really bad with a delta V something in the negative 25 ft/sec squared range.

    So, muzzle velocity of sticking your hand point blank range in front of the gun is significantly more dangerous vs low slung guns skipping them off the water at one of my 6 kids even 50 ft away in my humble opinion.

    Again I’ve no combat experience.
     
  10. Kotori87

    Kotori87 Well-Known Member

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    Safety is one aspect of the hobby that is very important. Most battles take place within 20 feet of shore, and shots skipping off decks lose much less energy than shots skipping off water. The average broadside engagement range is better measured in inches than feet. I've also been on the receiving end of misfires during bench testing, at point-blank range. So yes, a point-blank shot to the hand is a perfectly reasonable safety standard. That said, while the IRCWCC currently lacks an effective safety test for its cannons, most other formats do not. Big Gun clubs use a penetration test, prohibiting cannons from shooting through 2" of blue or pink insulation styrofoam, commonly available at local hardware stores. This results in muzzle velocities of about 220 fps for .177" bbs, down to 15o fps for the 0.25" ball bearings. I believe some other clubs use chronographs to check muzzle velocity, although I am less familiar with their rules.

    I am somewhat of a tinkerer myself, having tried every method of building cannons from CNC machining to laser cutting to 3d printing, from massive multi-barrel CO2 and HPA powered battleship cannons to single-shot spring-powered torpedoes. I am always open to new ideas, and I am eager to help people improve their designs. So build your cannon, and test it.
     
  11. modelshipsahoy

    modelshipsahoy Vendor

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    Thank you for that. Would never want to see anyone hurt. I just needed a target velocity to design the system specifically for. The cannon I made previously fired at 314 ft/sec measures by a ballistic meter. Wish I still had it, but was very small and should be no problem to make again from my old and faded memory
     
  12. WillCover

    WillCover -->> C T D <<--

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    Tim a good person to talk to on one to one would be Mark Roe. He is our local engineering /expert, and is relatively close to you in Clarkson. He also has the club FPS measure thingy:rolleyes: we will be in Saranac tomorrow.
     
  13. modelshipsahoy

    modelshipsahoy Vendor

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    Thanks Will! No way I can make Saranac tomorrow. Overnight Sailboat race tonight (right by your house) and kids coming back home tomorrow from 10 days up north with Oma and Opa.

    All I really need is the legal top FPS in a number. Rules are all written around pneumatics. I hate pneumatics. Bulky; Heavy; expensive.

    I used to be an Engineer at General Dynamics. My lil pea shooter was made 25 years ago for a buddy who mounted it in a tank. Was bad a$$. He drove around shredding cardboard boxes like a recycling factory.
     
    Last edited: Aug 10, 2018
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  14. SteveT44

    SteveT44 Well-Known Member

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    In my first post I gave you a range of 260 to 300FPS as a benchmark. If IRC was to implement a max FPS limit to accommodate non-pneumatic cannons, it's safe to assume it would be in this range.
     
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  15. WillCover

    WillCover -->> C T D <<--

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    GREAT! someone else to make me look stupider...:laugh:
     
    Last edited: Jun 28, 2019
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  16. modelshipsahoy

    modelshipsahoy Vendor

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    I got better.
     
  17. SteveT44

    SteveT44 Well-Known Member

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    So I'm assuming your cannon will be some variant of a centrifugal gun which tended towards full auto operation.. To be IRC legal, it will have to replicate semiautomatic function. For one trigger pull, only one shot down the barrel. If your design is similar to below, you will need some impressive motors and power handling to get to the RPM's to support 300FPS in a compact package. Looking forward to see what you come up with.

    upload_2018-8-10_15-16-52.png
     
  18. modelshipsahoy

    modelshipsahoy Vendor

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    I don’t make assumptions.
     
  19. modelshipsahoy

    modelshipsahoy Vendor

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    Again with assumptions. And a 1929 Popular Mechanics article?!?!? You crack me up!!!!
     
  20. NickMyers

    NickMyers Admin RCWC Staff

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