QEV pop-off guns plus trigger

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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i-will
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Wed Apr 29, 2009 5:14 am

yeah, cuz that first shot of every bust will be too strong and leave the pop-off open a little longer than the rest of the burst. a regulator and pop-off would need to be equalized to each other. but that only if ur a neurotic perfectionist like me (i don't step on crack and everything is a pattern( it's hell). the sound of that uneven burst would drive me up a wall. i addressed that in the (super long) ramblings above the crappy painting.

i like the way u think :wink:
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SubsonicSpud
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Wed Apr 29, 2009 5:29 am

A bonus of having a trigger valve prior to the gun is less of a need to have everything perfectly gas tight, as it will not be required to store the commpressed gas 8)
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i-will
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Wed Apr 29, 2009 5:40 am

to me the issue of an air tight seal is one of safety. if the coax, hoses, etc can't hold it's pressure then it's not safe nor a very good cannon in the first place. unless ur cool with leaks and wasted gas. for storage purposes a shut-off between the source and the coax would be installed. u don't want a pressurize cannon siting in a closet for too long. for me that means an apartment full of gaseous propane when the coax fails. i'm glad i don't smoke.
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Gaderelguitarist
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Wed Apr 29, 2009 5:53 am

A bonus of having a trigger valve prior to the gun is less of a need to have everything perfectly gas tight, as it will not be required to store the compressed gas
And i just realized that it would be easier to route that valve up onto the gun with hoses rather than use a second valve. :oops:

All this is because of my wanting to create a triggerable full auto gun that would fire small metal bbs.
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SubsonicSpud
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Wed Apr 29, 2009 5:54 am

Definitely not saying that a leaky cannon is a good thing, just on a QEV pop off cannon a small air leak is not really an issue, unless it is powered by a combustible gas :shock:

Compressed air or inflamable gas = good
Propane = Bad
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psycix
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Wed Apr 29, 2009 8:34 am

jackssmirkingrevenge wrote:What I don't like about these designs is that aside from the fact that pilot volume is wasted, you still have a flow into the pilot chamber during firing. It's probably really not that much of a loss in terms of total air usage but the idea irks me.
Easy: have a second little piston close up the air feed.
Ill show you what I mean soon when I get the design ready to machine.
Last edited by psycix on Wed Apr 29, 2009 8:43 am, edited 1 time in total.
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Ragnarok
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Wed Apr 29, 2009 8:41 am

SubsonicSpud wrote:Compressed air or inflammable gas = good
I hope you mean non-flammable. Inflammable means... well, pretty much the same as flammable.

The "in-" prefix is a bit odd. Mostly it makes it the opposite, but with the words flammable and valuable, it's more of an "amplifier" of the original meaning.
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jackssmirkingrevenge
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Wed Apr 29, 2009 8:45 am

Ragnarok wrote:The "in-" prefix is a bit odd. Mostly it makes it the opposite, but with the words flammable and valuable, it's more of an "amplifier" of the original meaning.
In the case of "valuable" it's not that odd, in the sense that an object is deemed so valuable that to attempt to quantify its value would be doing it a disservice ;)
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Ragnarok
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Wed Apr 29, 2009 9:11 am

jackssmirkingrevenge wrote:In the case of "valuable" it's not that odd, in the sense that an object is deemed so valuable that to attempt to quantify its value would be doing it a disservice ;)
Something like the word priceless then. However, on that note, contrast the word worthless, which means quite the opposite.
However, that makes it's own kind of sense. A lack of a price is very different to a lack of worth. Of course, priceless is a bit of a misnomer, because almost anything can be purchased if you've got a few million spare. (If you've got a spare few billion, then you're really in business, literally and figuratively).

However, it's not too odd with inflammable either. It's core is the word inflame. It just happens that that makes it appear to have the "in-" prefix.

Hmm, linguistics discussion. It's disappointing perhaps that most people don't take more interest in the formation and structures of language.
There's wonderful words out there like deliquesce, scintillate and prestidigitation. (Respectively, to melt away, sparkle/flash/twinkle, and sleight of hand.)
And they just don't get used - mostly because people look at you like you're an idiot if you try.
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Gaderelguitarist
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Wed Apr 29, 2009 11:17 am

Haha! Prestidigitation is one of my favorite words. Ubiquitous (going on forever) is also up at the top.


Language structure is an infinitely interesting topic. Especially when concerning language patterns and sentence structures over different languages.

My first language is English and I'm trying to learn Finnish.

It's proving to be quite the challenge simply based on the length of some words and numbers ( nine thousand ninety nine is yhkedsantuhattayhdeksankymmentayhdeksan)
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rcman50166
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Wed Apr 29, 2009 12:02 pm

Hijacked thread...please lets stay on topic. Well actually can an author hijack his own thread?
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i-will
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Wed Apr 29, 2009 1:17 pm

wow, when did this become grammar class? i throw a lot of shorthand in my messeges. so grammar is not a big deal. and i misspell half the words i type. i'm pretty sure we all knew wat he meant. lets get back to blowing things up and crazy cannon valves. :wink:
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ramses
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Wed Apr 29, 2009 2:59 pm

rcman50166 wrote:Hijacked thread...please lets stay on topic. Well actually can an author hijack his own thread?
I have, in the past

there I go again...
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Gaderelguitarist
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Wed Apr 29, 2009 3:14 pm

My bad. I got caught up in that too.

Back on topic though...

I remember a thread not too long ago seen here
http://www.spudfiles.com/forums/hammer- ... 17843.html

If such a valve were constructed with high pressures in mind (i.e. solving the failing o-ring problem) wouldn't that work as a triggering valve to allow air into the pop-off? It would be placed between the Qev and the pop-off and could be struck with a hammer that resets itself.
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Ragnarok
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Wed Apr 29, 2009 3:20 pm

i-will wrote:i throw a lot of shorthand in my messeges. so grammar is not a big deal. and i misspell half the words i type.
Grammar is a bigger deal than you might think. Given that most people are judging you only on the content and quality of your posts, letting your posting quality become lax (or as I've put it elsewhere: "Your post looks like a reject ream from the Infinite monkey room") can only lower people's opinions of your intelligence. As I don't want to be judged at a lesser level on the basis of poor post quality, I endeavour to make myself as readable as possible.

Even if we disregard that part of it, I consider it a common civility to pay to the other forum members that I put the effort into writing my posts so that they don't have to put unnecessary effort into reading them.
Also, as not all members of this forum speak a form of English as their first language, it will triply hard for them to interpret anything. I'd be willing to bet that even if I do have a habit of using sesquipedalian terms on occasion, my posting is less of an effort to interpret than one which is poorly put together.
At worst, if I've used the correct spelling, then it's possible for people who don't know the meaning of the word I've used to look it up.

I don't pretend I'm completely perfect myself. I have the habit of using It's when I meant Its - similar with Who's and Whose. I know the correct way to use them, but I sort of type on autopilot at times, and throw in the apostrophe where it shouldn't've been put in (Ah, multiple apostrophe contractions. What fun.). I don't always get Who and Whom right, as well as the correct use of I, Me and Myself.

However, I do try as hard as I can, and unlike some people, I use the shift key and punctuation. I don't manage to pass as one of the forum boffins for nothing.

Generally, these days, I'll only correct people if they've actually used the wrong word and actually change the meaning of their sentence as a result, rather than just a conventional misspelling or grammar mistake.
Like in this case for example - indeed, most official documents avoid inflammable entirely and just use the words flammable and non-flammable to avoid any chance of confusion.

Anyway, I'll stop my loquacity on the subject of grammar now, and go and find something else to rant about.
Does that thing kinda look like a big cat to you?
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