1000psi+ semi auto marble gun

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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Ragnarok
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Sun Feb 01, 2009 10:18 pm

maggotman wrote:I think you will find that i am well with in my limits working with copper. pipe
http://www.airlink-compressors.co.uk/Tu ... r_tube.htm
near the bottom copper pluming pipe.
And I think you'll find I know what I'm talking about - the site you've chosen to provide your data has mixed up psi and bar (which it certainly has), and you'll trust those berks over me?

Trust me, do not take UK copper, unless you've sourced the very rare and expensive thickwall variety, beyond 500 psi. I mean it.

If you take 22mm copper to 1000 psi, it won't burst, but it will stretch permanently outwards under the force - it will take the force once, and then most likely be useless to you, because it'll be the wrong damn shape. The presence of the conduit will affect things slightly - but even at best, you're going to be right on the wire.
I am not going to disagree what I am doing is not the cleverest of things but if i thought i was going to get blasted with bits of shrapnel under very high pressures i would not be doing it.
There is a difference between whether I think you're going to get shrapnel blasted, and whether you think that you're going to get shrapnel blasted.

This is an important difference. The difference is that if you go with what you say, and you're wrong about the safety limits, you potentially get injured and become the proud owner of a pile of scrap.
If you go with what I say, and I'm wrong about the safety limits, then no one gets hurt, and your cannon is still plenty powerful.

Be sensible. Err on the side of caution - I am not a moron (I'm also wearing full body armour*) and I am doing a degree in engineering - my knowledge of materials, safety limits and parts failure is not lax.

*Woo, slightly obscure reference for the win!
Does that thing kinda look like a big cat to you?
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Lentamentalisk
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Mon Feb 02, 2009 7:56 pm

As you may have noticed from every response to all of your posts, no matter what the concept is, everyone on this site is 100% against everything you are doing. You are putting your self in excessive danger, for next to no gains.
Listen to Rag, he knows more than you or I could ever hope to know (at least for the next few years, until I get my ME degree.)
The last thing that we need is another spuding related death. Its not that we don't like you, its just that you are endangering our hobby.

*that is no obscure reference, that is the greatest reference in existence
Last edited by Lentamentalisk on Mon Feb 02, 2009 8:46 pm, edited 1 time in total.
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maggotman
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Mon Feb 02, 2009 8:38 pm

So having a bit of paper with a degree on it makes you more clever, get some life experance and get out more.


"everyone on this site is 100% against everything you are doing"
If that is true why am i not banned it would make life simpler would it not ?
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Lentamentalisk
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Mon Feb 02, 2009 8:45 pm

No, having a bit of paper with a degree on it indicates that you have dedicated four entire years of your life to one of the hardest majors out there, and have learned a great deal about the world in the process.

You are not banned because we see promise and energy in you, that just needs to be directed in the right direction. You are obviously passionate about your work, and I love to see that. I too had my phase of trying to make a 3000psi helium cannon, to break mach 2, so I know where you are coming from. You just need to back off on the pressure some, be weary of anything that isn't explicitly rated to the pressure you plan on using it at, and heed the warnings from other members.
Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
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Ragnarok
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Mon Feb 02, 2009 9:45 pm

maggotman wrote:So having a bit of paper with a degree on it makes you more clever.
If the fact that I'm working towards my degree doesn't mean anything to you, I think the fact that Solar contacted me with regards helping develop the Eclipse further tells you quite enough about what other members around here think of my experience and knowledge.

I'm interested to see that you think more highly of what's printed on a plumbing website full of errors than what a website full of members with huge collective experience in the area has to say.
If that is true why am i not banned it would make life simpler would it not?
Because we're not fascists who sweep anyone who's a bit of trouble under the carpet.

Also, because we're kind of hoping we can talk you out of being a plonker.
Does that thing kinda look like a big cat to you?
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MrCrowley
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Mon Feb 02, 2009 10:04 pm

maggotman wrote:"everyone on this site is 100% against everything you are doing"
If that is true why am i not banned it would make life simpler would it not ?
Two words..well one...but it's two words joined together to form one: RogueSci.

They run that website like the Third Reich, don't really blame them either. They talk about and carry out experiments far more dangerous then most of us could dream of. You would've been banned for not capitalizing your "I's"...i'm serious.

They had a member from Finland who eventually blew him, and several others, up in a shopping mall. Typically, the media and the police quickly learned he had been part of this (RogueSci) forum and in turn generated a lot of heat, forcing them to take out special measures to stop them being shut down or members traced.

If you killed yourself because you wanted to take copper pipe to a very dangerous pressure, the first thing they are going to find when they search your computer for information on the device that killed you, is Spudfiles. The media is going to love this, young teens who cannot spell properly (they will generalize your posts to include the entire forum, remember it's the media, they do that) searching for a cheap thrill and an alternative for a gun or cannon.

Spudfiles would probably generate a sh|t load of traffic, overloading the server and crashing the site. Not being able to issue a proper disclaimer on Spudfiles because the site has crashed the media will take this as a sign the Admin (PCGUY) has shut down the site, when really it's just been overloaded. PCGUY will probably have several hundred emails from 'Mother's Against' societies and he'll probably have a few media personal wishing to interview him for his thoughts on your tragic, but stupid, death. Who knows what would happen from there.

Anyway, long story short, it's in our best interests, not yours, to stop yourself from maiming/killing yourself or others. It's probably just a sh|t load easier to lock the topic if it gets out of hand anyway.
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