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wooden piston

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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wooden piston

Unread postAuthor: singularity » Sun Apr 22, 2007 1:50 pm

it there any reason why i have never seen a wooden piston before? im thinking about making one from oak on a lathe, that way it would be easy to add o-ring groves.
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Unread postAuthor: Arborman » Sun Apr 22, 2007 1:54 pm

I'm absolutely no expert, but wouldn't all the pores leak the air? And if this was true, oak would be bad cause of its high count of big pores
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Unread postAuthor: hi » Sun Apr 22, 2007 2:02 pm

i have made two pistons out of wood. one was a dowel and the other was a piece of ash that was turned on a lathe. they both work just fine.

Arborman- why would it leak? mine seals just as well as my piston made out of pvc. you would have to drill holes in it to make it leak. it will work just fine, mine did.

Just make sure you have a bumper because oak is really hard and heavy, so if it slams into the pvc it can shatter. just use a tennis ball cut in half or a spring.

EDIT- you dont need O-rings. I have made a total of 4 piston valves and none of them have O rings, yet all of them work. You just have to make it fit well
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Unread postAuthor: Arborman » Sun Apr 22, 2007 2:08 pm

O.....

sorry

Like I said, I'm no expert :joker:

Now that I know they work, I'm off to make my own. :)
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Unread postAuthor: mega_swordman » Sun Apr 22, 2007 2:12 pm

I suppose you don't see very many of them because it takes too much effort to make one. People are naturally lazy and unwilling to do too much work.
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Unread postAuthor: Hawkeye » Sun Apr 22, 2007 4:19 pm

Cut off piece of dowel, glue/screw piece of rubber to front.
You're right, that does sound more complicated than any of the other methods.
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Unread postAuthor: hi » Sun Apr 22, 2007 4:31 pm

please note that you need a very good bumper in a wooden valve because the pvc cant take the force. the wood weighs a lot. you would need something like a light spring AND some foam with a peice of hose. it may sound like over kill, but mine blew up because it didnt have a bumper. the valve worked very well, but because it didnt have a bumper it cracked and blew into a million pieces. so if you make one, make an even better bumper.
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"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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Unread postAuthor: singularity » Sun Apr 22, 2007 4:44 pm

the valve is 3/4 inch bore, and its a tee valve so it needs o-rings. heres a simple diagram of the valve, and the spring pushing the piston on the pilot chamber side is not shown

<img src="http://i78.photobucket.com/albums/j85/irwinner_2006/teevalve.jpg">
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be sure to check out my <a href="http://www.spudfiles.com/forums/ak-style-airsoft-vortex-gun-t10959.html">AK Styled Vortex Gun</a> and my <a href="http://www.spudfiles.com/forums/at-4-t9627.html">AT-4 Rocket</a>

upcoming projects... finalized clip fed BBMG and ball point pen sniper
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Unread postAuthor: hi » Sun Apr 22, 2007 7:34 pm

uhh, that set up completly wrong. that would never work the way you have it set up. i think you need to look around and study some more.
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"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

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Unread postAuthor: super spuder » Sun Apr 22, 2007 7:52 pm

yea, it would work, that is the excact same one that i am making now. the piston moves to the left (in that picture) and unseals the barrel
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Unread postAuthor: hi » Sun Apr 22, 2007 8:07 pm

its not going to work, i promiss you it wont.

the chamber needs to be where the barrel is, the barrel needs to be where the pilot is, and the pilot needs to be where the chamber is.....
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"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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Unread postAuthor: singularity » Sun Apr 22, 2007 9:09 pm

the specifics of my newest cannon require a valve like this. but think about it if there is equal pressure on each side of the piston and on the pilot side i have a spring providing about 5 to 10 pounds of pressure then it piston will stay in place and seal the barrel. now when the air is vented from the pilot chamber there is still 100psi on the firing chamber side. this causes the piston to slide to the right allowing air to pass through to the barrel.

and yes i do know this is not the usual configuration for this type of valve but i need a low profile valve for the cannon or the bolt mechinism wont work right
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be sure to check out my <a href="http://www.spudfiles.com/forums/ak-style-airsoft-vortex-gun-t10959.html">AK Styled Vortex Gun</a> and my <a href="http://www.spudfiles.com/forums/at-4-t9627.html">AT-4 Rocket</a>

upcoming projects... finalized clip fed BBMG and ball point pen sniper
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Unread postAuthor: noname » Sun Apr 22, 2007 9:13 pm

Hi, you are dead wrong. It's a chamber sealing valve, not a barrel sealer. It should work, although you forgot to erase the line above the piston. Maybe that's why hi was confused?
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Unread postAuthor: hi » Sun Apr 22, 2007 9:16 pm

ok, i guess it will work, but the O rings will have to be 100% airtight and they would have to be very well lubed because they would cause alot of friction. You will have to almost get lucky for this to be airtight, maybe you need more like 4 or 5 O rings.

and by the way, the "normal" set up is the exact same size and much easyer to make air tight. you really arent saving any space at all.

get a piece of paper and draw the gun you want to make with both plans, they are the same size arnt they?
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"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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Unread postAuthor: super spuder » Sun Apr 22, 2007 9:17 pm

i will promis you that this will work if it is done right
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