Steel/Copper Marble Gun + 300 PSI = ...

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Postby markfh11q » Sun Mar 04, 2007 6:44 pm

Well, call me crazy, but...

I just learned that your average "Husky" bike pump, (sold by the air compressors in Home Depot), can reach all the way up to 300 PSI.

It's ridiculous... the hose on the pump expands to around 1-1/2 times it's original diameter. You have to put your entire weight on the handle and actually jump to get the last few pumps out of it. Firing it is a completely different ball game as well. I made a video below, but it really doesn't do the sound and feeling any justice. It actually sounds like a .38 or 9mm going off, and the marble is only visible for a second. Here's some stuffs:

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<center><a HREF="¤t=DSCN0318.flv"><img src=""></A></center>
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Postby Mr.Plow » Sun Mar 04, 2007 8:12 pm

Crazy? Maybe. Crazy awesome? Probably ;)

Glad to see that the QEV held up, even though it's rated for ~125 PSI-ish IIRC.
To be honest, I'd be more concerned that the actual diaphragm would fail before the body at that pressure.
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Postby markfh11q » Sun Mar 04, 2007 8:28 pm

Yeah. That's why I watched the muzzle carefully after attaching the barrel. ;)

And yeah, that particular Q.E.V. was only rated to 125 PSI. I figured it could take it, though.

<font size=1 color="biege">But also the blowgun valve is only rated to 90 PSI, and the pump 100 PSI. Oh well...</font>
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Postby An Apple Pie » Sun Mar 04, 2007 8:35 pm

That is pretty cool. Is that just your old marbel gun or is that a new one?

Haha that reminds me, I was at a plumbing aupply place about a month ago and they had a 350PSI guage that I was looking at. I saw some little text on the bottom of the box and it said"WARNING: only for use up to 250PSI." I mean WTF a 350PSI guage that isn't meant to be used over 250. I don't get it.

Anyways pretty cool that you can get it up that high, and I hope it doesn't blow up in your face.
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Postby markfh11q » Sun Mar 04, 2007 9:42 pm

Ahh... it varies. That was my "Revamped" gun with a 1/2" copper marble barrel and a pressure gauge I added a while ago. I wanna see what a paintball will do at that high-power, but I'm out.

I think I may understand the whole gauge thing. Manufacturers add that extra room so you can see if you're going to high. I mean, if you've got a system that can only handle 250 PSI, and you have a gauge that pegs at 250, how do you know if you're at 250 or past it?

Yeah, I also know it's not very safe, but oh well. I'm thinking about a re-sealed refrigerant compressor to get stuff up to 400 PSI, so maybe I'll work on some higher rated guns after that?[:p]
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Postby SpudMonster » Sun Mar 04, 2007 9:59 pm

I think that gauges are more accurate in the middle, so if you have a 150 PSI air line, you'd want a 0-300 gauge.

Crazy gun Mark. Too bad I won't get to see it in person :(
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Postby fullmetaljacket » Sun Mar 04, 2007 11:23 pm

Nice, I've been using mountain bike shock pumps to take my mini pneumatics to 400 psi+ (though the gauge only goes up to 300 :D) and it *really* makes a difference - I'd love to see some chrony data & damage shots...
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Postby Velocity » Sun Mar 04, 2007 11:31 pm

I too am suprised that the diaphragm didn't pop. But if you ever opened up a QEV and looked at the diaphragm, you'd see that its pretty tough...

Anyway, how is the kick with the marble? Is it noticeable at all compared to lower (<100 PSI) pressures?

I bought a 100 PSI gauge once, and they recommended that it only be used in 50 PSI and below situations. I would pump it up above that (around 80 PSI) on occasion, and after a while, it became worthless. This is a quality Ashcroft gauge that retails at around $50 (I got it for $1 off ebay though :P)
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Postby joannaardway » Mon Mar 05, 2007 5:47 am

QEV's are often rated to 150 psi (even though this is a 125psi valve) and that'll have a considerable safety factor on top as well. 300 psi is probably safe, but will need care.

I've used cannons that are so loud at 150 psi that it's dangerous to use them without hearing protection* - and the recordings of those really don't sound anything like reality.

*It was once let off inside without the barrel - that was ear-bleedingly loud, and is exceptionally painful.

I can only imagine what 300 psi sounds like. Don't try it indoors!
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Postby markfh11q » Mon Mar 05, 2007 6:32 am

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">
<I>Originally posted by Rmich732</I><br>
Anyway, how is the kick with the marble? Is it noticeable at all compared to lower (<100 PSI) pressures?
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
You can't really feel the kick, but one second the muzzle is on target and the next it's 30 degrees above it.

Joannaardway: already did.8)[:p]
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