gun ideas

[UTguy]

A few years ago I really became interested in pneumatic spud guns. I made a pretty decent basic gun but the barrel broke when it fell 15ft. Anyways the gun already had little flaws with it and now I'm looking for ideas for a fairly simple and durable pneumatic spud gun that can preferably launch a projectile a good distance. Advice on barrel-to-chamber size ratio, dependable firing mechanisms, and any other help would be greatly appreciated.

[OuchProgramme]

For a simple yet very effective gun, i suggest building a pneumatic sprinkler valve.

If you're looking for something even MORE effective, a piston pneumatic would be great.

[kablooie]

The Wiki can really help you on this one (button near top right corner of page). I'd say you'd want to use a sprinkler valve, they have decent flow and open very very quickly. Also this allows you the option to get more power by modding the sprinkler valve to use a blowgun (there is an how-to somewhere).

For the c:b ratio, I usually use 2:1 for lower pressures (i.e. 40-100 psi) but there is no ideal ratio really, it all depends on the pressure you will be using and what for. Generally for higher pressures I believe a lower ratio is used (1:1 or lower) but I am not completely sure.

I assume you will be using pvc, if not then things change somewhat (i.e. different valves and pressures).

This is kind of an earful, but some things I wish I had known when I built my cannon is how to solvent weld correctly (google it) and also that flow restriction = loss of power. The last part means that if you have a 3 inch chamber, reducing it down to one inch pipe will reduce the power (although it is often necessary for a sprinkler valve).

Welcome to Spudfiles!

[UTguy]

OK, do you know a good link for plans on how to build a piston pneumatic. Oh, and what's the most effective barrel - air chamber volume ratio.

[SpudFarm]

OK, do you know a good link for plans on how to build a piston pneumatic. Oh, and what's the most effective barrel - air chamber volume ratio.

read and give us the pressure..

[UTguy]

is using a ball valve as a firing mechanism instead of a sprinkler valve a big differnece?

[kablooie]

I am not sure if a piston valve is the right thing for a beginner, in my experience piston valves look (and are) extremely simple, however they can often be quite difficult to make (the seal is a major pain). Before you go asking for more plans, use the search function or browse the how-to database because there is already so much info on this site that repetition gets really old.

[hi]

A few years ago I really became interested in pneumatic spud guns. I made a pretty decent basic gun but the barrel broke when it fell 15ft.

make a more reliable gun...

[kablooie]

Yes, a ball valve has much more flow than a sprinkler valve BUT it opens way slower, resulting in the air escaping slowly while the valve is opening, so a sprinkler valve will be much more efficient than a ball valve.

Seriously, before you ask another question like this, please read the wiki, at least the parts that are relevant.

Another thing, if you are planning to throw your gun off fifteen foot cliffs, you may want to use a stronger material (like metal) and then check yourself into a mental hospital.

[UTguy]

ok, thanks alot for the advice and sorry if the questions got a little annoying. Oh and I didn't through it off a 15ft cliff it slid off my barn loft.

[pat123]

I would go with a over under sprinkler valve cannon. it would help to know what you want to shoot and at what pressures and materials you will use.

[starman]

OK, do you know a good link for plans on how to build a piston pneumatic. Oh, and what's the most effective barrel - air chamber volume ratio.

Actual plans are few and far between. You'll need to study the cannon showcases and search the forums. I recommend you run down to Home Depot and spend about 1/2 day roaming the plumbing aisles, getting a good idea of how parts fit together, what they are called, etc. Then go a few days later and spend another 1/2 day roaming the aisles...a few days after that go to a different store, say Lowe's and do the same thing.

Spend some time listening on the forums and go through the showcase history. There's a wealth of information here, there just isn't a package called "spudgun plans". Take your time and think about your project first. You'll be glad you did!

Here's my golfball piston pneumatic as an example. http://www.spudfiles.com/forums/bofors- ... 13488.html
A 1:1 c:b ratio works great for it.

[ALIHISGREAT]

if you want durable i would go for a copper cannon or antoher metal, QEVs (Quick Exhaust Valves) are good for smaller bores and homemade piston valves for larger bores....

[UTguy]

golf balls seem like a good projectile but I don't feel like buying them and I was looking to fire something a bit larger.

[pat123]

tennis balls? potatos? you should make a tennis ball gun