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Iron Forged Chamber + CPVC Barrel
Posted: Tue May 13, 2008 12:23 pm
by neeewwww
Hi... I will build a SpudGun, but I´m very afraid about the PVP/CPVC chamber, because, i guess i wouldnt find the Sch40 here where I live... Even other Pressure Rated Pipe, with large (5mm+) pipe walls... So I´m wondering if I can build a Chamber like a Fire Extinguisher, with a ball valve, and cpvc barrel...
Stem Valve -> Iron Chamber -> Iron Pipe -> Ball Valve -> Pipe Reduction -> Barrel
What do you guys think about it?
Any size comments?
Posted: Tue May 13, 2008 12:25 pm
by Carlman
yea sounds good to me just don't go with the ball valve use a modded sprinkler valve instead.
Posted: Tue May 13, 2008 12:28 pm
by neeewwww
Oh man... The valve looks too expensive here >.>
Brazil sucks ;-;
And... I take a look at some stores, and I cant find it O.o
Or I searching wrong... or... I dont know...
Using this type of Chamber... no risk about explosion... right?
Lol ;~
Afraid ;D
Posted: Tue May 13, 2008 12:29 pm
by neeewwww
Just one question, do uou guys know how to "glue" the Stem Valve into the Iron Chamber?
Some questions about the project...
http://www.instructables.com/id/End-Aro ... ic-Cannon/
I will copy this project, just change the PVC Chamber into Iron Chamber and the Valve to a Ball Valve... Just to confirm...
Keep the measures, right? Or increase/decrease to compesate the changes?
Posted: Tue May 13, 2008 4:14 pm
by jrrdw
Look up MrCrowley's golf ball cannon, it uses 2 fire extinguisher if I'm not mistaken. Also, there is a edit button at the top of your post, use it to edit your post instead of double posting, thanks.
Posted: Tue May 13, 2008 4:16 pm
by DYI
Just tap 1/4" threads into the bottom of the finished chamber.
After you make the threads, screw in a 1/4" male quick connect, and you have yourself a filling valve. Then you can simply adapt whatever filling system you're using to the quick connect. You can do the same thing with shrader valves, but they're often harder to find, especially the female ones.
I have to wonder what kind of pressure you plan on using, if you're going so far as to forge your own chamber. And why iron? Mild steel is easier to get than iron, and in most cases, stronger as well. A 4" steel pipe with 5mm walls will have a burst pressure of over 2000psi, with the lowest grade possible, and a Schedule 80 one (with 8.6mm walls) will fail at over 4000psi. If you need even more than that, you could buy a SCH 160 pipe, with a failure pressure of over 12000psi. But you're going to make your own because you're scared of failure? Whatever you're building, I want to see it when it's done.

Posted: Tue May 13, 2008 4:46 pm
by MrCrowley
jrrdw wrote:Look up MrCrowley's golf ball cannon, it uses 2 fire extinguisher if I'm not mistaken. Also, there is a edit button at the top of your post, use it to edit your post instead of double posting, thanks.
That's the paintball cannon.
Just search DSGR in the pneumatic showcase section.
There's also a recent thread addressing a similar problem from not that long ago.
Posted: Tue May 13, 2008 4:47 pm
by psycix
There are some differences in fire extinquishers.
CO2 extingquishers are rated to a very high pressure, usually over 1000 psi.
Powder extingquishers are lower rated.
If you cant find any pressure rated pipe, and if your looking for a valve, check out the spudfules store.
http://www.bcarms.com
Posted: Tue May 13, 2008 5:27 pm
by STHORNE
not to get off-topic, but neeewwww has made more than 1 post, yet his post count still says 1. WTF?! lol
Posted: Tue May 13, 2008 5:33 pm
by bigbob12345
On your fire exstiquisher it should say pressure tested to XXXpsi
So if you stay below what that says then you are fine.
Posted: Tue May 13, 2008 6:46 pm
by jrrdw
STHORNE wrote:not to get off-topic, but neeewwww has made more than 1 post, yet his post count still says 1. WTF?! lol
I've all ready sent word of this, just so you guys know.
Posted: Tue May 13, 2008 8:21 pm
by OuchProgramme
Carlman wrote:yea sounds good to me just don't go with the ball valve use a modded sprinkler valve instead.
Yeah but you can take the fire extinguisher above what the sprinkler can handle
Maybe spring actuated ball valve?
Posted: Wed May 14, 2008 6:17 am
by psycix
OuchProgramme wrote:Carlman wrote:yea sounds good to me just don't go with the ball valve use a modded sprinkler valve instead.
Yeah but you can take the fire extinguisher above what the sprinkler can handle
Maybe spring actuated ball valve?
Nah that sucks.
Burst disk!
Posted: Wed May 14, 2008 9:13 am
by neeewwww
Thanks guys...
@jrrdw Sorry about the double posting
@ DYI I Will look for other alternatives to the Stem Valve... I´m not sure about the pressure rating... but <150psi, or the maximum I can get with my house compressor... Iron because its cheaper than Mild Steel (or no?),
I´m planning to build a cilinder like a fire extinguisher, with size of 2 or 3 soda cans in line... Yeah, failure gets me afraid...
Yesterday I just found a PVC Pipe with 1cm thickness, I will buy some and make a prototype.. If I get good results, I will start the second part of the project... The Forged Iron Chamber... I hope the Iron project dont get too expensive.
Oh... Some delay expected on Iron Chamber Project... I checked the state of my compressor... and i guess its dead... I will re-check on the weekend...
Thanks again guys

Posted: Wed May 14, 2008 1:14 pm
by Carlman
OuchProgramme wrote:Carlman wrote:yea sounds good to me just don't go with the ball valve use a modded sprinkler valve instead.
Yeah but you can take the fire extinguisher above what the sprinkler can handle
Maybe spring actuated ball valve?
i was the first post when he sounded like he had not a clue what to do, so i was steering him away from a BV and onto something more powerful. and even if you could take the FE above the valves rating does that matter? you use the gun at the lowest rated pressure on the weakest part.
spring BV would suck compared to a sprinkler unless done really good.