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QEV gun questions

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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QEV gun questions

Unread postAuthor: Benthehuter » Fri Oct 10, 2008 9:45 pm

I am thinking of making a copper QEV gun and I was wondering what the ratio of the volume of the chamber to the volume of the barrel should be.

another thing I was wondering was if there is any rifled barrels around .30 caliber for fifty dollars or less.
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Unread postAuthor: POLAND_SPUD » Sat Oct 11, 2008 5:41 am

1. the ratio depends on the pressure you are planning to use.... the higher the pressure the smaller the chamber V can be....

of course the bigger the chamber the more power you'll get but a rule of diminishing returns (or something like that) applies here so you won't get much power increase above a certain ratio...

what is more, there are certain advantages of using smaller chamber V: =pumping the gun will take less time
=the gun will be more quiet


I advise you to download GGDT ( http://www.spudfiles.com/spud_wiki/index.php/GGDT ) and thinker with it to find the ratio that suits your design best.
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Unread postAuthor: sniper hero » Sat Oct 11, 2008 9:36 am

why not rifle the barrel yourself
it isn't that difficult
and with a 100 ml chamber you need at least 8-10 bars for good power
about half a litre will be fine
:D if you have a compressor a bit more would be better
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Unread postAuthor: Bando_Red » Tue Nov 18, 2008 11:23 pm

I don't mean to revive a dead topic,but I'm in a similar situation with an extra problem.I'm not so great at ratios,so I don't know what the hell kind of QEV to get.All I know is the ammo I'll be using is .177 pellets.
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Unread postAuthor: FordGtMan » Tue Nov 18, 2008 11:31 pm

Bando, you wont be needing anything larger than a 1/4" QEV for .177. anything larger will just be a waste.
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Unread postAuthor: Baldwin1993 » Thu Nov 20, 2008 5:23 am

hey dudes..
any1 know how to make a qev??
HELP lol
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Unread postAuthor: sinper2006 » Thu Nov 20, 2008 6:01 am

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Unread postAuthor: Baldwin1993 » Thu Nov 20, 2008 6:07 am

yeah thnx mate.. i know hpw they work but i need some instructions on how to make them bra
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Unread postAuthor: sinper2006 » Thu Nov 20, 2008 6:23 am

Try looking in the how-to section of the forums
http://www.spudfiles.com/forums/how-to- ... s-f11.html
or using the search
http://www.spudfiles.com/forums/search.html
and if you can't find it on them links try here
http://www.instructables.com/id/Golfbal ... That-Shoo/
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Unread postAuthor: Baldwin1993 » Thu Nov 20, 2008 3:29 pm

thnx mate
didnt find it but ill just use a sprinkler valve
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Unread postAuthor: fan4tics » Sat Nov 22, 2008 8:56 pm

hi all

Baldwin1993 wrote:thnx mate
didnt find it but ill just use a sprinkler valve


yeah... only sprinkler valve mod. :(

i did found some instructions at You Tube (links below) but all in French..

http://www.youtube.com/watch?v=b4ZgXqiaySc

http://www.youtube.com/watch?v=2Q6HikU0vnI

http://www.youtube.com/watch?v=2B-92nA9NBM

http://www.youtube.com/watch?v=0Qf6Yvu9arc


could anybody translate it to english... please

:newb:
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Unread postAuthor: SEAKING9006 » Sat Nov 22, 2008 9:43 pm

There are better instructions here. Use the search function, the how-to section, or the Wiki.

For some reason, I'm beginning to think the search button is broken today..... :roll:
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