PSI Question

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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n-strike
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Mon Jun 09, 2008 7:53 pm

7/16" didn't work on my 1/4" nipple. It was too small.
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Hailfire753
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Mon Jun 09, 2008 7:57 pm

n-strike wrote:7/16" didn't work on my 1/4" nipple. It was too small.
:shock: Tee Hee. Nipple.

Sorry. Get a smaller nipple? Actually, if you wiggle / gyrate that drill bit, you will be able to make the hole bigger.
UPDATED MARCH '08
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n-strike
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Mon Jun 09, 2008 8:10 pm

Hahahaha, nipple. I actually just made the hole bigger and was able to get it to work.
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Hotwired
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Mon Jun 09, 2008 8:34 pm

I'm fine without a gauge directly on my cannon.

Theres a check valve installed which is independant of the filling point unlike schrader valves so the pressure it's filled to on the pump gauge is pretty much what is going to be in there.

(give or take 5psi due to inaccuracies from overpumping buggering the bourdon tube a bit)

I've also leak tested my cannon for several minutes in a water container at 400psi with zero issues.

Finally I can always vent a little pilot gas using the safety valve I have to check if it is or is not under pressure.

It's not stranger-proof but since every shot I fire has it's own little ceremony as I'm not exactly in the most remote location, being in a suburb and all that I don't leave it waiting for very long after pressurising it before using it.

Whatever suits your needs :)
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starman
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Mon Jun 09, 2008 8:59 pm

7/16" is the right size hole if you are going to thread tap it for 1/4" NPT...any bigger than that and you've screwed it up. Don't try to tap the hole with your gage .... get yourself a real 1/4" NPT tap. It will last you forever just tapping PVC.

If you need a hole to slide 1/4" nipple all the way into (not thread it), then something slightly over 1/2" will be required.
Hailfire753 wrote::shock: Tee Hee. Nipple.
Was that an actual giggle at the word nipple?.. :roll:
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n-strike
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Mon Jun 09, 2008 9:19 pm

I was actually talking about a 1/4" brass nipple for my sprinkler valve...are they different in size? Even if they're both 1/4"?
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Hotwired
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Mon Jun 09, 2008 9:21 pm

Taps are tapered so it only ends up the full 1/4" thread at the end, it's tip is (usually) rather narrower to start the threading off in the hole.
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starman
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Mon Jun 09, 2008 9:59 pm

n-strike wrote:I was actually talking about a 1/4" brass nipple for my sprinkler valve...are they different in size? Even if they're both 1/4"?
Assuming you are doing a pilot mod, yes that's a 1/4" NPT. While I've seen others talk about threading with a pipe because the sprinkler housing plastic is soft, it's going to be tough to do with a small nipple...you need something you can grip onto, like a tee.

Just get a 7/16" bit and a 1/4" NPT tap and make yourself some nice threads in there...like I said before it's a tool that will last forever tapping into PVC.
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n-strike
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Tue Jun 10, 2008 7:25 pm

Just a few minutes ago, I pumped up my gun. Amazing, as I expected. Also 1 leak, as I expected. It was because I didn't fill the hole in the sprinkler valve with enough stuff, because I ran out just before I finished putting it in the hole. That's why I expected one, but it's all good now. Also, at the bottom of my blow gun, there's a small metal thing and it screws on the the bottom of the blow gun, and it looks like it makes less air escape from the blow gun. Is it necessary? If you want, i'll take a picture. And one last thing...when I pumped up my gun and shot it, only with air, after I heard the initial "boom" of the shot, I heard a weird ringing noise after it. Well, something like a ringing noise. I'll take a video of that if you want too. Any ideas on both of my questions?
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Hailfire753
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Tue Jun 10, 2008 7:29 pm

The thing on the blow gun is probably the nozzle. Remove it.
UPDATED MARCH '08
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n-strike
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Tue Jun 10, 2008 8:00 pm

Okay. Would that affect the performance? And what size are Pringles cans?
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psycix
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Wed Jun 11, 2008 3:41 am

The nozzle makes less air escape, and thus makes your gun pilot slower, which causes the valve to open slower, degrading performance.
Get rid of it and your fine.

Pringles cans? Grab a ruler then you know.
Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

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n-strike
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Wed Jun 11, 2008 5:00 pm

Haha, I wish...I don't have any Pringles cans right now...I'm pretty hungry for them though...I will probably buy some later...
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