SpudFiles

So i need a piston to go in 3" sch40 pvc.

i know that the ID of this pipe is ~3.04". i was looking on the how to section and well and i found a how to for 3" pistons and well thats just 3" pipe on top of 2" pipe. okay well now, my main question is that the extra thickness that the 3" on 2" gives, is that the same as a 2" fitting on 2" pipe?

so literally, will a 2" end cap, fit nicely into 3" sch40 pipe. i'll add orings but thatll only add like .1"

or if that doesnt work, what else will fit inside 3" sch40 pvc??

a small pvc primer can? mabey

Pringles can?

I hear pringles cans do.

Good question about the 2" end cap thing, let me know the result

well yeah a pringles can i know will fit cuz theres a thread about it on the how to, but wouldnt that cardboard piece ripp off if i put 250psi on one side of it??

you can take two end caps, glue them together with a piece of pipe, then wrap duct tape around it until it fits. thats what i did with my piston gun. its a 3/4'' end cap and i wrapped it in duct tape until it fit in the 1.25'' pipe. works perfectly.

umm yeah but im putting orings on it and i need a 100% seal.

cwazy1 wrote:umm yeah but im putting orings on it and i need a 100% seal.

thats not true if you are just building a normal piston cannon. it cant be a 100% air tight seal either because air has to flow around the piston to fill the chamber. you could put a check valve in it though. i know my way is cheap and ghetto, but it works if you dont have a lathe to make O ring grooves. i know you can make the grooves with hand tools, but its so much easier to go around a couple times with duct tape.

yeah about that, im not making a piston valve. im making a piston for a 3" compression chamber pogo.

There is a how to on here somewhere that explains how to make a 3" piston I think, I will try to find it.

Edit: Found it http://www.spudfiles.com/forums/3-piston-t313.html

yeah that was the one i was refering to in my first post.

well i made one. it fits nicely, the rubber rings are not orings but are like spigots.

Ive always thought about using <A HREF="http://www.boatbits.co.nz/shop/Chandler ... ">These</a> for a chamber sealing piston.

They're made from solid rubber, so making o-ring grooves would be childs play and they have a hole in the middle to equalise the pressure.
They may be a bit heavy, but nothing some useful drilling couldn't do.

You could even cut the flanges off and just use the middle part for a barrel sealing piston. Just clog the hole in the middle.

Oh and if it's too big, it wouldn't be difficult to make it smaller.

yeah that was the one i was refering to in my first post.

Sorry I must of missed that when I scimmed over it
And btw the piston looks pretty good.