How can i make a piston for a 2" piece of pipe

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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666lucky693
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i am going to make a coaxial piston cannon and i need to make a piston can any one give me a easy design for a piston that size and i am wondering if a blow gun will work for the valve in the back
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hi
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yes a blowgun will work for exhaust, but a ball valve would be better.

take a peice of 2'' pipe about 2 or 3 inches long. put some aluminum foil around one of the ends (make sure it is an even cut) and put rubber bands around it to hold the foil on. take some PAM or some other greesy butter like oil and lube it up really well. then take a hot glue gun and about 5 or 6 sticks and mold yourself a piston.

good luck.

edit- you can also take a 1.25'' end cap and wrap it in duct tape.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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666lucky693
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yea but how is the air supposed to get past the glue to get to the chamber
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dont worry, it will. thats what i thought and it worked just fine..

now lets saw that you have the best piston in the world, then you just take a file and make a very narrow groove in it. when i say narrow, i mean it. when you are dealing with 100 psi, it doesnt take much to get air in the chamber.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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Flying_Salt
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So you still need neoprene with hot glue right? (Sorry about the dumb question and/or thread hijacking)
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noname
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You probably would. I'd put it on just in case, so I wouldn't have to change it later.
666lucky369, there's some pill bottle that fit perfectly in 2" Sch 40. I used one filled with foam as one of mine.
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666lucky693
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o ok is there any other way to make a piston that small
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MrCrowley
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I used a deoderant can and re-inforced it, or you can use 1 1/4" fittings.
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666lucky693
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how long should the chamber be and how long of a barrel
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MrCrowley
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666lucky693 wrote:how long should the chamber be and how long of a barrel
The length of your foot.


What size chamber and what size barrel?

Did you not read my Private Messages? Please search instead of asking such useless and stupid questions that have no answers.
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hi
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Please search instead of asking such useless and stupid questions that have no answers.
i have searched extensivly and i still dont know why water is wet... just kidding.


anyway, it should be as big as you want it to be.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote

you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
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Jolly Roger
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Ill have to add a pic of mine sometime. I was impatient and was eating some kraft peanut butter on corn thins when I was searching for something I could use as a piston. It so happened that when I put the peanut butter cap againt the chamber they were the same size. So I got another cap and put a hole through the center of both and a few nuts in the center to space it out. A cut out of a car tyre tube on one face and a bolt through the center backed up by a nut on the opposite side and there you go... A large size kraft peanut butter cap piston. Works great. Because of the groves on the outside they dont stop the air flow but cause their very small its still enough to restrict air flow when fired. Hasn't failed yet.
Last edited by Jolly Roger on Mon May 04, 2009 9:39 pm, edited 1 time in total.
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666lucky693
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yea i hope upload it once i make mine ill upload a pic of it
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Instead of a sch40 2" pipe use sch80 2" pipe. if you did that you could make your piston from 1.5" pipe which fits perfectly into sch80 2".
Ecclesiastes 1:9 - What has been will be again, what has been done will be done again; there is nothing new under the sun.
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666lucky693
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well i made a mistake the pipe is only one inch so i made a piston for it and now all i need is the end cap and valve and its done
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