How-To: Make a pneumatic cannon with a 2" piston valve.

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.
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Fri Oct 12, 2007 6:27 am

oh lol sorry i couldnt see it on the top down view or vid
omgimonfrie2
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Fri Oct 12, 2007 10:22 pm

spudgunnerwryyyyy wrote:This is a great tutorial. I suggest omgimonfrie2 should start simple when he has gained enough knowledge then build a piston valve. It is a great learning process my friend.
I was going with a 2.5 in. barrel until recectly, so a ball/piston valve would be too restreicive. I'm not saying I'm a noob though. Will a golf ball fit in a .75in barrel?
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MrCrowley
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Fri Oct 12, 2007 10:28 pm

2.5" barrel would be bad as it is rare unless bought online, and fittings are also rare.

A golfball will fit in 1.5" SDR-21 if you are American, or 40mm PN18 PVC if you are Aussie/NZ etc
omgimonfrie2
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Sat Oct 13, 2007 9:47 pm

MrCrowley wrote:2.5" barrel would be bad as it is rare unless bought online, and fittings are also rare.

A golfball will fit in 1.5" SDR-21 if you are American, or 40mm PN18 PVC if you are Aussie/NZ etc
Well I did find a 2.5in barrel to day, forgot to look for fittings though. A golf ball fill not fit in a 1.5in barrel, I curently use one and they do not fit. What does SDR-21 and PN18 mean? I never can read the pipe much less understand it. As far as my knowledge goes pressure rated is pressure rated. And thanks for all the help.
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DYI
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Sat Oct 13, 2007 10:01 pm

SDR 21 pipe has thinner walls, and GBs will fit in 1.5" SDR 21 quite well.

As far as reading the pipe, it is a good idea. Pressure rated is pressure rated, but if it's only rated for 15 psi and you use it at 150psi, you may have a problem.
Last edited by DYI on Sat Oct 13, 2007 10:06 pm, edited 1 time in total.
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MrCrowley
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Sat Oct 13, 2007 10:05 pm

Thanks for explaning that DYI.

omgimonfire please search in the future, search and you shall find.

Read this, it's a sticky so if you had looked you should've found it.
http://www.spudfiles.com/forums/viewtop ... tml#117669
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Sat Oct 13, 2007 10:59 pm

Well it is possilbe that I am not using SDR 21, and I'll start looking for my own answers.

EDIT: I looked and did not find. Is super glue an okay solvent for brass piping? I just bought parts for a marshmellow sniper.
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MrCrowley
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Sat Oct 13, 2007 11:03 pm

What?

I just gave you the answer, probably the only answer and most practical (aside from metal pipes and making your own barrel)

Super glue may be fine for a marshmellow gun but nothing involving anything over 5psi.
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Sat Oct 13, 2007 11:20 pm

lol my pipe doesnt seem to have a rating or is the pn-18 a pressure rating if so could someone link me wiht a page of what the pressure is?
cheers Nato
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MrCrowley
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Sat Oct 13, 2007 11:28 pm

Where do you live? What does the pipe say?
Tell me everything that is written on the pipe.
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Sat Oct 13, 2007 11:32 pm

hr products
as1477.2 pn18
20mm pvc

cat 10
hr-p01020
barcode 0314538015247
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MrCrowley
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Sat Oct 13, 2007 11:43 pm

It's pressure rating is 260psi.
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Sat Oct 13, 2007 11:44 pm

could you please xplain that formula?
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MrCrowley
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Sat Oct 13, 2007 11:51 pm

PN stands for Pressure Number
DN stands for Diameter Number

PN18 means 18 BAR

1BAR = 14.5psi
18BAR x 14.5 = 261psi

10BAR = 145psi = 1mPa = 1000kPa

DN20 means Diameter = 20mm(nominal diameter)

So I take it you don't live in America then :P
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Sun Oct 14, 2007 1:53 am

abviously cheers for the help :P
Nato
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