SpudFiles

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.

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

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

O.....

sorry

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

Now that I know they work, I'm off to make my own.

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.

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.

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.

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/i ... evalve.jpg">

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.

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

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.....

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

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?

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?

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