75mm Piston with 2" Porting

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
User avatar
MaxuS
Specialist
Specialist
Posts: 198
Joined: Sun Sep 02, 2007 5:11 pm

Sun Oct 28, 2007 5:06 am

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.

Image
Image
Image
Image
Image
User avatar
ALIHISGREAT
Staff Sergeant 3
Staff Sergeant 3
Posts: 1778
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK

Sun Oct 28, 2007 5:11 am

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 :twisted: also make sure you don't use it when its too cold, you don't want something so cool to blow up.
spanerman
Specialist 4
Specialist 4
Posts: 437
Joined: Sun Sep 17, 2006 2:54 pm

Sun Oct 28, 2007 6:01 am

tis a beast....DAMAGE PICS, biggest uk piston as yet?
Image
User avatar
experament-u2
Specialist 4
Specialist 4
Posts: 469
Joined: Tue Dec 26, 2006 11:18 pm

Sun Oct 28, 2007 7:12 am

wow well done chap it looks great
and nice piston to, very clean and simple i love it
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6569
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Sun Oct 28, 2007 7:19 am

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.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Sun Oct 28, 2007 7:22 am

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.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6569
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Sun Oct 28, 2007 7:36 am

jackssmirkingrevenge wrote: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.
User avatar
veginator
Specialist
Specialist
Posts: 186
Joined: Tue Apr 10, 2007 4:02 pm

Sun Oct 28, 2007 7:42 am

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.
User avatar
iPaintball
Corporal 2
Corporal 2
Posts: 695
Joined: Sun Mar 04, 2007 8:37 pm

Sun Oct 28, 2007 8:04 am

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.
Summer Projects:
CO2 tank hybrid: Gotta fix the meter :(
Cane gun: Needs a pilot/fill setup
1.5" piston valve gun: Almost done
sandman
Corporal 2
Corporal 2
Posts: 672
Joined: Thu Mar 15, 2007 6:59 pm

Sun Oct 28, 2007 8:05 am

spanerman wrote:biggest uk piston as yet?
i can tell you the there is a bigger one but idk if he want people to know yet :)
User avatar
Acdcmonkey1991
Specialist 3
Specialist 3
Posts: 386
Joined: Fri Mar 30, 2007 3:33 pm
Location: Florida

Donating Members

Sun Oct 28, 2007 8:57 am

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?
VH was awesome!!
Current projects:
C02 Jetpack (CIIJ)
Waterjet vehicle
.177 cal. piston rifle
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3627
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 52 times
Been thanked: 53 times
Contact:

Donating Members

Sun Oct 28, 2007 9:03 am

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

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
Specialist 3
Specialist 3
Posts: 342
Joined: Mon Jun 18, 2007 11:12 am

Sun Oct 28, 2007 9:22 am

Very nice.

Mark,

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

The Tee is rated to 1.6MPa IIRC - 16bar.
Tom
Specialist
Specialist
Posts: 187
Joined: Fri Aug 24, 2007 8:22 am

Sun Oct 28, 2007 10:02 am

Looks very nice, back a while I tried to make a piston out of (inner)tire rubber but it didn't sealed :x . I also like the color of your PVC.
GR.Tom
Really really proud member of the Dutch Spud Clan!
User avatar
MaxuS
Specialist
Specialist
Posts: 198
Joined: Sun Sep 02, 2007 5:11 pm

Sun Oct 28, 2007 12:06 pm

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.

Image
Image
Image
Post Reply