Simple button valve

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  • Glickman
    *Insert Witty Phrase*
    • Sep 2003
    • 2673

    #16
    Originally posted by ojhspyro89
    Yeah i was kinda going towards the point of that you can shoot at very low pressure or High pressure low volume and still be rather fast. Its all bout effeciancy i guess.

    Did u know its impossible to shoot 1200 fps (mach 1) with normal air?
    i disagree



    god help anyone who doesnt know what that is (i swear, even at 9 and 13, my sisters had no idea...)

    Comment

    • trains are bad
      Registered User
      • Oct 2003
      • 1751

      #17
      HAHAHA

      if you make the barrel of you LAW short enough, it comes to a point in the curve where dwell doesn't matter. Even infinite dwell will still not shoot hot. Do this by testing carefully and cutting a bit at a time. This works if you have a single load you will be using like a nerf rocket. This is not very air efficient but is a very simple/cheap/light/handy way to build one with a simple valve. It's just a matter of holding the valve until it clears the barrel and trying to let go soon enough to keep some air.
      TRB's feedback

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      • ojhspyro89
        The bushy man!
        • May 2004
        • 1078

        #18
        Originally posted by trains are bad
        HAHAHA

        if you make the barrel of you LAW short enough, it comes to a point in the curve where dwell doesn't matter. Even infinite dwell will still not shoot hot. Do this by testing carefully and cutting a bit at a time. This works if you have a single load you will be using like a nerf rocket. This is not very air efficient but is a very simple/cheap/light/handy way to build one with a simple valve. It's just a matter of holding the valve until it clears the barrel and trying to let go soon enough to keep some air.

        A problem with that is air effeciancy. After the projectile leaves the barrel the access air in the tank/chamber will be dumping into atomospheric pressure pretty fast which would just be a loss of air. The best way to do it is get a 2 to 1 ratio of chamber to barrel. That is the way to get maximum performance out of a pneumatic cannon. You also might want to go download GGDT. Its a program to simulate and help design pneumatic air cannons. Its a very helpfull program but you need to know alot of random things like dwell of the valve you use. Its a very nice program

        Oh and the Mach 1 thing with normal air is the air isnt fast enough it cant expand fast enough to push out the projectile that fast. Now if you heat it up or use a lighter gas like helium you can acheive speeds of mach 1 and above. Its been done before with compressed air and propane mix. dont try it ull get hurt lol.
        Stock BKO (so far)
        68/3k Carbon Fiber Crossfire tank
        Halo B
        woot! :headbang: :headbang:
        I can tell that my parents hate me. My bath toys are a toaster and
        a radio.

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        • Glickman
          *Insert Witty Phrase*
          • Sep 2003
          • 2673

          #19
          Originally posted by ojhspyro89
          A problem with that is air effeciancy. After the projectile leaves the barrel the access air in the tank/chamber will be dumping into atomospheric pressure pretty fast which would just be a loss of air. The best way to do it is get a 2 to 1 ratio of chamber to barrel. That is the way to get maximum performance out of a pneumatic cannon. You also might want to go download GGDT. Its a program to simulate and help design pneumatic air cannons. Its a very helpfull program but you need to know alot of random things like dwell of the valve you use. Its a very nice program
          anything is better then a 1-shot depletion of a 12 gram , ill look into that though

          Comment

          • JoshK
            Je mange du poulet. mmmmm
            • Mar 2004
            • 2666

            #20
            Could you do that...but have it go into a chamber that has a little gauge on it? Once the gauge goes to a certain pressure you let go of the button, and either open a lever or push another button?

            Also....I don't know much, but how would you make sure there is a tight seal inbetween the part with the whole, and the red part?

            Comment

            • JoshK
              Je mange du poulet. mmmmm
              • Mar 2004
              • 2666

              #21
              Originally posted by Glickman
              i disagree



              god help anyone who doesnt know what that is (i swear, even at 9 and 13, my sisters had no idea...)
              That be bad stuff...

              bad stuff + big boom bomb = tons of s in our future generations...

              Comment

              • doc_Zox
                Team Dead by Dawn
                • Jun 2003
                • 723

                #22
                my internal piston design:


                PVC liability issues caused me to go with an aluminum MKX:

                Comment

                • Glickman
                  *Insert Witty Phrase*
                  • Sep 2003
                  • 2673

                  #23
                  Originally posted by JoshK
                  Could you do that...but have it go into a chamber that has a little gauge on it? Once the gauge goes to a certain pressure you let go of the button, and either open a lever or push another button?

                  Also....I don't know much, but how would you make sure there is a tight seal inbetween the part with the whole, and the red part?
                  i was thinking of that too, and for the second part, o-rings i could show you waht i had in mind, but thats more crappy drawing i would have to do



                  thanks for the blueprints im gonna see if i can simplify that

                  im trying to make a simple single tube design, easy to carry on my side

                  Comment

                  • TheTramp
                    Registered User
                    • Jan 2001
                    • 4019

                    #24
                    doc zoc's launchers are wonderful but far beyond most people's ability (or pocketbook ).

                    Here's something that the average guy could make. Obviously it's not painted in this picture and I hadn't cleaned up the hose and wires yet.

                    "Relax. Don't worry. Have a Home Brew."
                    -Charlie Papazian

                    Feedback: http://www.automags.org/forums/showt...threadid=40134

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