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Posted: Sat Jul 28, 2012 12:24 pm
by jackssmirkingrevenge
al-xg wrote:With light projectiles like that, it is very likely they are leaving the barrel before the valve is fully open.
When you consider a piston valve though, there also is an interval between piston initial movement and full flow being achieved, so in practice I would think performance is pretty comparable.
al-xg wrote:I've since rebuilt it to have a much higher initial tension, which also serves as a brake just at then end to prevent the ballvalve handle from distorting as it hits the stop.

I've done shots at just over 1000psi with that airgun.
... recorded?

Posted: Sat Jul 28, 2012 2:53 pm
by al-xg
so in practice I would think performance is pretty comparable.
Well I don't have any proper evidence of this, but the QEV canons I have built in the same calibre did seem more powerful. I'll have to try a comparative shot at some point.
... recorded?
Quite possibly, I'll have a search.

Posted: Mon Jul 30, 2012 10:24 am
by beastmode986
Very nice build! Shoot marbles out of it or ball bearings they should work great.

Posted: Thu Aug 02, 2012 12:19 pm
by josephlys
I finally got my shock pump, brands RockShox. Don't know if it's good, but so far holds up pretty well. It's max psi is 400 but trying to go beyond 350psi takes too much effort, it's killing me. So far I find 300psi comfortable, I mean not so back breaking and pumping 4x in a row killed me, now my abs hurt Lol ;D Here's some pics
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2 1/2'' (6g) naildart penetrated almost 1'' into hardwood @ 300psi. Paper cone was intact after the shot, apparently it was thick enough. What I find interesting is that the nail bent on impact. Backward recoil is slight with the 2 1/2'' naildart, using an (11g) 3'' naildart had a heavier undesired recoil effect.

Posted: Thu Aug 02, 2012 10:23 pm
by jackssmirkingrevenge
josephlys wrote:I finally got my shock pump, brands RockShox. Don't know if it's good, but so far holds up pretty well.
I prefer this type, because you can independently depress the schrader stem, but for this particular launcher it doesn't affect you.

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It's max psi is 400 but trying to go beyond 350psi takes too much effort, it's killing me. So far I find 300psi comfortable, I mean not so back breaking and pumping 4x in a row killed me, now my abs hurt Lol ;D
You can mod it for comfort:

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... or get yourself a fridge compressor/paintball tank/scuba tank/airgun pump :)
What I find interesting is that the nail bent on impact.
Typical of darts on impact, the nose decelerates while the tail wants to keep moving hence the tendency to "fishhook".

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Posted: Thu Aug 02, 2012 11:54 pm
by dahakka
you should make a stirpump
it's not very hard to make and it can reach 50-60bar easy , and much more faster than shock pump

Posted: Fri Aug 03, 2012 3:45 am
by josephlys
jackssmirkingrevenge wrote: Any chance of a video of it firing?
I noticed my valve was not opening fully & fast enough, so today I just doubled the bands. Now it takes some effort to cock but the performance is much better.

Here's a video of the firing action:


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Posted: Mon Aug 06, 2012 10:26 am
by josephlys
I got some damage pics, I found a piece of plywood only 2mm short of 1/2''. I used .45cal leadball and patch @ 400psi. Aimed at the 3'' target at 20feet, then boom felt a jerk from the recoil and there was a hole in the target.
The entry and exit plywood wounds. There was a lot more splinter at the exit, but I couldn't help picking at them.
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