75mm Piston with 2" Porting

[MaxuS]

Hi everyone, this is my very first piston valve, so I thought that I would make something quite powerful as bits and pieces cost the *bomb* over in the Uk.

Specs:
Wooden Piston bolted together with M6 threaded rod.
5 layers of Bike innertube as a sealing face.
Some kind of yellow bouncy stuff as the bumper.
Housed inside a 75mm PVC Tee.
2" Porting.
Piloted by 1/2" QEV - Piloted by 1/4" Blowgun.
Filled by Schrader which goes through a Check Valve.

It just needs a bit of a cleanup, has sawdust all over it from the making of the wooden piston pieces.Turned my drill press into a lathe and formed the wooden discs together.
Has been pressure tested to 40psi and holds completely airtight - no leaks.
I will go up to higher pressures once the weather clears up.
Oh yeah, I'm using the chamber and barrel from my Tennis Ball Launcher to test it, eventually I'll buy some more pipe to give it its own chamber and barrel.
No videos as of yet, but they'll be coming soon.
The piston sealing face needs to be greased up aswell, so its a good thing i made this beast serviceable.

[ALIHISGREAT]

that is beasty!!! and it must have cost the *bomb* i'm guessing £40-£50?
i can't wait to see that on a cannon, are you going to try it on your tennis ball cannon? it would give it a ton more power also make sure you don't use it when its too cold, you don't want something so cool to blow up.

[spanerman]

tis a beast....DAMAGE PICS, biggest uk piston as yet?

[experament-u2]

wow well done chap it looks great
and nice piston to, very clean and simple i love it

[jrrdw]

Ahhhhhh! Another wooden piston builder. Nicly done, i also used my drill press to turn mine down to size, and a piece of 250 grit sand paper stapled to a piece of 2X4 for a cutting tool.

[jackssmirkingrevenge]

looking good, if you're going to use lube make sure the wood is sealed otherwise it will absorb it and expand leadingto potential jam.

[jrrdw]

looking good, if you're going to use lube make sure the wood is sealed otherwise it will absorb it and expand leadingto potential jam.

I spray WD-40 in mine all the time, it's been over a year and no jams. It will only swell to the pipe size, kinda like self fitting. As long as there is a equalization hole, it should be fine.

[veginator]

Thats what he is saying that it will swell to the pipe size and get it self stuck in there.And let me tell you having to service it with all the pressure inside wouldn't be fun.

[iPaintball]

WOW! Excellently built valve! I love your pilot/fill setup too. Very nicely done! Man, I wish I could build valves like this. You should be proud of yourself. This is one of the nicest valves I've seen on here.

[sandman]

biggest uk piston as yet?

i can tell you the there is a bigger one but idk if he want people to know yet

[Acdcmonkey1991]

Wow! very nice, I'm working on a piston valve myself. It's a bit smaller though. Do you think I absolutely need a bumper for a 1 in. piston valve? BTW is that a qev that your using to pilot it?

[mark.f]

Nicely built! I don't see any cleanup needed, though. Do you see any?

A wooden piston, if built correctly, (which yours certainly is), will last for a very long time. Wood's good at handling impacts and if it's sealed and coated it will form a nice low-friction surface between the piston carriage and piston even without lube.

M6 means it's rated to 6 mPa pressure, right? I'm not too buffed up on international standards at the moment.

[Gepard]

Very nice.

Mark,

M6 is the threaded rod size (M(etric) 6(mm))

The Tee is rated to 1.6MPa IIRC - 16bar.

[Tom]

Looks very nice, back a while I tried to make a piston out of (inner)tire rubber but it didn't sealed . I also like the color of your PVC.
GR.Tom

[MaxuS]

Heres some up close pictures of the Piston if anyones interested. It does need a bit of a cleanup because its got sawdust over the sealing face and whatnot which just soaks up the all purpose grease i stuck on it, and I need to clean up the innertube sealing face, make the innertube discs slightly bigger so that the sealing face doesnt slip into the barrel at higher pressures. I also need to drill another 4 holes into the Pilot/Fill spigot to make sure it wont fly out when i take it up to higher pressures, although it shouldnt because its bolted in. Going out to get a Lathe in about a week, so say hello to my next project - 110mm Piston with 3" Porting.