Page 1 of 1

size of qev's

Posted: Sun Mar 28, 2010 2:14 pm
by sp1ke
I am making a break barrel QEV pistol in which the QEV will be housed inside a piece of 1&1/4" PVC to make it look more aesthetically pleasing. the PVC will also be used to have 2 sets of rails( 1 for lazer and 1 for a red dot ) and a pistol grip frame screwed into it.

i am trying to decide weather to make it a 1/2" or 1/4" gun.
will a 1/2" or a 1/4" QEV fit inside of a piece of schedule 40 1&1/4" PVC?

also what are some ammo ideas for a 1/4" barrel other than 1/4" ball bearings?

if you have either a 1/2" or 1/4" qev and could take a picture of it next to a piece of 1&1/4" pvc for a size reference that would be greatly appreciated

Posted: Sun Mar 28, 2010 3:32 pm
by Marffy
I've seen nice compact QEV's by Bellpro. (http://www.bellpro.net/xcart_program/pr ... 268&page=1) but i do not know if they will fit in that small of pipe. For a 1/4 barrel you could use nail darts. those are fun.

Posted: Sun Mar 28, 2010 4:14 pm
by MrCrowley
Don't think a 1/2" QEV would fit inside 1 1/4" pipe, a 1/4" QEV might though. If you're using small diameter projectiles like 6mm or so, a 1/4" QEV is plenty.

Sorry I don't have any exact dimensions, hope that helps.

Posted: Sun Mar 28, 2010 6:10 pm
by tatfree
I know exactly what you are trying to do because I have been after the same thing .
I can't answer your question , but I can say that a 3/4" QEV by Fastenels will fit inside of a 2.25" ID tube and that's with the 90 degree elbo that has to go on the top that goes to your air chamber. I just had to buy the QEV and take the chance it would work and it ended up clearing by only 1/16". That would have been a $30 mistake if it had not fit, but I had to take the chance since no one could have answered that question for me before.
I tried soooooo hard to find a rectangle QEV because they seem to be smaller, but they where next to impossible to find in the U.S.

May have to just spend the money to find out yourself. If it doesn't work out you can always sell it for a little loss or use it for another project.

Posted: Mon Mar 29, 2010 5:20 pm
by jhalek90
I just purchased a lot of 7 1/4'' QEVs from ebay.... and i can tell you that they have plenty of power for a .25 bore projectile.

Matter of fact... i doubt you would see much performance boost with a 1/2'' QEV, as the barrel would choke the flow of the valve, possibly enough to make a 1/2'' QEV the same as a 1/4'' qev.

If you have a 1/2'' port... reduced to a 1/4'' barrel.... you simply have a 1/4'' port with some dead space.

Someone will correct me if I am wrong. (aka D-hall, JSR, Tech, MR-C ect... )

Another note: my 1/4'' QEV says its rated for 150 psi.... but it can withstand 300 just fine.... and i may take it higher, as i have 7 and would like to know at what pressure the "Piston" (rubber like poly based disk) will blow out.

Re: size of qev's

Posted: Tue Mar 30, 2010 12:00 am
by jackssmirkingrevenge
sp1ke wrote:also what are some ammo ideas for a 1/4" barrel other than 1/4" ball bearings?
For an unrifled barrel,"diablo" shaped 0.25" pellets, or you could buy cheaper 0.22" pellets and flare them out.

Posted: Tue Mar 30, 2010 12:17 am
by POLAND_SPUD
If you can find 0.25 pellets, they'll fit in a 6mm barrel without modification.
assuming that 6mm barrel has an ID of about 6.05 how come it can fit 6.35mm ammo?

Posted: Tue Mar 30, 2010 1:48 am
by jackssmirkingrevenge
POLAND_SPUD wrote:assuming that 6mm barrel has an ID of about 6.05 how come it can fit 6.35mm ammo?
It depends on the brand, some of them need to be swaged down a little which is fairly easy to do, just stick them head first into a section of barrel material and push them through ;)

Posted: Tue Mar 30, 2010 8:50 pm
by sp1ke
thanks everyone for answering!

i plan to order a 1/4" rectangular qev off of ebay this weekend

tatfree you should just search "quick exhaust valve" on google shopping, amazon, or ebay, if you don't want to pay for shipping then you can just simply make your own

oops and i almost forgot... i have searched this site and cant seem to find people that have made 1/4" cannons other than coaxial's attached to wooden stocks.... any links or inspiration would be greatly appreciated