SpudFiles

i am going to build my first airgun. but i want to know what would be a good material to use as an air resivoir? i want to have an operating pressure around 500 psi. and if i were to make a tank that could do that would it have to be very large or could it be a compact size like a little bigger than an airsol can or something.

You need to do more research before you ask questions like this, but I'll answer your question anyway.

Everything depends on the bore of the gun, what you are launching, etc. It you want to launch something small, say, .50" bore, copper would be best as a chamber, and could definitely take 500psi, but I wouldn't recommend such high pressures for a beginner. For a gun this, size, you would not need a big chamber. Big chambers are better for larger bore guns

On the other hand, if you want a powerful large bore launcher (1.5"+), you could make it out of galv steel or aluminum, or just about any metal pipe. Again, size of the chamber would depend on many different variables.

But seriously, you could find all this stuff in the Spudfiles Wiki. I suggest you take a look at it. Also, download GGDT. It's a simulation tool made by D_Hall on this forum, and can help you design your pneumatic gun.

or a small welding tank, ive seen one n the showcase that can be taken past 500psi

The air resivour, Is this for a chamber or is this bulk storage for on site shooting, much like a paintball tank?

This is important as the size of the port will vary greatly depending on the supply rate required. A chamber to connect directly to a QEV will need a large fitting and small tank. A tank to re supply a launcher through a regulator to a lower pressure can be something else such as a Nitrogen or Argon welding cylinder, or for lower pressure but higher volume, a BBQ propane tank (up to 300 PSI).

its its supposed to be a small tank for on site shooting. also this might be a stupid question. but the gun im making i decided to make it fire using a home made poppet valve. im wondering will the air pressure really make it more difficult to open the valve?

I would buy a small HPA rig (tank, regulator, airline fittings, etc.) premade from a paintball shop or industrial supply.

If you want to supply an air reservoir on the cannon with a tank, to 500 PSI, it would have to be a very large tank with slightly higher than 500 PSI in it, or a smaller tank with much higher pressures. Neither of which can be built easily or safely by a hobbyist.

ok here is an example of the gun (please excuse the crappiness of it but i hope i get my point across)

oh and the two lines are supposed to be pointing to the barrel incase you didn't figure that out

You can edit your post, you know.

It will be very hard to pull that trigger unless the bore is like a 1/4", and your trigger system looks very flimsy.

i know but its just an example. im gonna find a way to intergrate a valve hammer that will have enough force to push it open but i have to learn how to make one first.

If you are going this complex as a first build, just make a piston valve.

here get a mead fluid dynamics qev 1/2 get a 12oz paintball tank and a 1/2 barrel and a 1/4 qev this will take 700psi and more and is easy to open the trigger

ok thanks guys sounds like qev is the way to go. im probably gonna have to make some of that stuff myself though becuase there isn't a paintball show for miles around here.

You don't need a paintball tank, you can use a brass or galvanized, or something similar, nipple.

i was giving my simple idea of easily constructing a qev gun but yes you can use black iron or galvinsed or brass or copper