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Need help for a 1" projectile HPA gun...

Posted: Tue Oct 04, 2011 8:54 pm
by getter128
Hello. I am relatively new in joining this site, and have recently started building multiple pressure-based systems for airsofting. I have completed a few cloud and vortex guns, and now am building a ball launcher that shoots 1" balls. The issue I am running into right now is how to propel these solid balls with any force. I would do a combustion gun, however, it really would not be safe at my airsoft arena, as there are plenty of propane based pistols used there. Any help/ design tips would help. I have already constructed 1 unsuccessful prototype, with an o-ring used to block the ball until enough pressure had accumulated to sufficiently shoot the ball out. I will post a quick draw of this below. Anyway, thanks or the help!

Posted: Tue Oct 04, 2011 9:05 pm
by Gun Freak
QEV seems like it would do the job. A 3/4" perhaps. Or if you know how you can build a larger piston valve. Depends on the pressure you have access to. Also, how long are you trying to make it, how fast should it shoot, budget, etc. You could put the ball in a pipe and blow it out and call it a launcher. :)

Re: Need help for a 1" projectile HPA gun...

Posted: Tue Oct 04, 2011 9:16 pm
by Lockednloaded
getter128 wrote:Hello. I am relatively new in joining this site, and have recently started building multiple pressure-based systems for airsofting. I have completed a few cloud and vortex guns, and now am building a ball launcher that shoots 1" balls. The issue I am running into right now is how to propel these solid balls with any force. I would do a combustion gun, however, it really would not be safe at my airsoft arena, as there are plenty of propane based pistols used there. Any help/ design tips would help. I have already constructed 1 unsuccessful prototype, with an o-ring used to block the ball until enough pressure had accumulated to sufficiently shoot the ball out. I will post a quick draw of this below. Anyway, thanks or the help!
A one inch HPA gun shooting solid projectiles at LIVING things!?
A decent piston valved/QEV at high pressures may maim or kill your airsoft friends[/b]

Lethal 1 inch cannons

Posted: Tue Oct 04, 2011 10:00 pm
by Technician1002
A large valve can create a hazard to life. I have put a 1 inch gumball through 1/2 inch plywood and dented a car door with a nice soft marshmallow with my 1 inch launcher. Please be carefull.

Car door dented with a marshmallow using only 100 PSI air pressure.
Image

Posted: Tue Oct 04, 2011 10:25 pm
by getter128
Let me clarify myself, I was looking for a projectile shooter for airsofting. however, with my previous designs, the 1 inch ball shot about 3 feet. I am looking for a way to shoot it at least 30. Thanks you for the help, although I strongly doubt tht the notion of shooting someone with a uber-powered version of this would ever cross my mind. I do not, unfortunately, want to kill my friends...Keep in mind that I also have not built a QVD before, and I had no idea of its existence until you guys mentioned it. Thank you for the input! However, one question remains, is there any way to build a small-scale launcher that will not kill people?

Re: Need help for a 1" projectile HPA gun...

Posted: Tue Oct 04, 2011 11:00 pm
by jackssmirkingrevenge
getter128 wrote:I have already constructed 1 unsuccessful prototype, with an o-ring used to block the ball until enough pressure had accumulated to sufficiently shoot the ball out. I will post a quick draw of this below. Anyway, thanks or the help!
In theory this should be the best design. Any idea how much pressure it was holding before letting the ball go?

As others have said one of these cheap-o QEVshooked up to a couple of feet of barrel and a few cubic inches of chamber will give you more than enough performance even at low pressures in the 50-75 psi range.

Posted: Tue Oct 04, 2011 11:00 pm
by Lockednloaded
Ok, HPA generally is related to power, you could get what you want with compressor pressures. Some shameless self-promotion, This was one of my earlier projects: 1" bore, cheap, fairly easy to make if you can grasp the piston concpet

Posted: Tue Oct 04, 2011 11:04 pm
by getter128
Thanks for the help! I am just wondering how a qev works, as I have had no previous experience with them...
As for the psi mentioned earlier, I believe it was around 80.

Posted: Tue Oct 04, 2011 11:11 pm
by jackssmirkingrevenge
getter128 wrote:I am just wondering how a qev works, as I have had no previous experience with them...
The principle is identical to what we call a piston valve - exhausting the area behind the piston causes a pressure imbalance which opens the valve and dumps the chamber.

A little animation showing the concept in action:

Image

Posted: Tue Oct 04, 2011 11:13 pm
by getter128
Thanks again for the help. I will be sure to post the pics of my attempt at this later.