SpudFiles

...................... Full Metal Terror ......................
This is my first time working with metal, so i decided not to try anything innovative or new, just a plain ol' piston valve housed in a tee. There were no modifications to the fitting, just normal threaded pieces. It wasn't a planned project, i just had a tee and a hosebarb originally, the rest was bought for about 30$.
I haven't fitted a barrel on yet, nor have i taken it past 160 psi, so i don't know its full potential, but it sure makes a great noise.
I also tried for minimal parts on this cannon due to budget issues, so i pilot and fill through the same valve
Here's Some Pics

Piston:


Full Gun:


Watch this space for updates Including a barrel, damage pics and more

Looks just like something I'm putting together.... Get some regged co2 or a shock pump and you'll be set like a jet!

I could go un-regged with this monster, but thats outside of my price range. I might get a shock pump this week and try it out at its true potential, either that or i'll spend the money on a BTB style pilot/grip.
P.S.-good luck with you valve, i'd be glad to be of assistance

Nice. It's cool to see cannons that work good even with a limited parts.

Paintball tanks and fittings can be easily picked up from many sources so that you could go with unregged CO2 if you want. I just posted an addition to my library, detailing many features of CO2 if you have any questions.

Of course, a good shock pump is another option, but with such a tiny chamber, you are still limiting yourself.

As far as the launcher itself, it is looking nice so far and I'm looking forward to the finished product.

Looking good there! It's simple, but It seems to work just fine. What caliber are you planning on using on this gun? With such a small chamber I would go with a 3/8" O.D. (5/16" I.D.) or 5/16" O.D. (1/4" I.D.) brakeline. You can get this stuff prettyy cheap from any reputable auto store like NAPA. But of course it's your choice. Anyway, nice job, this should be able to take planty of pressure. Try gatting a shock pump that goes to at least 400 psi for optimum performance.

but it sure makes a great noise.

The bigger diameter and shorter the barrel is, the louder the bang will be. Have fun

I don't have any place to shoot small projectiles that will penetrate my fence, so i'll probably go 1" or 3/4", but its all threaded, so its interchangeable.
On another note, i flipped the chamber around, and it happens to be exactly as long as the fill/pilot area, it looks good this way, and the is probably how i'll keep it. Pictures will be up late tommorow with a temporary barrel

I don't have any place to shoot small projectiles that will penetrate my fence, so i'll probably go 1" or 3/4", but its all threaded, so its interchangeable.

Ok, fair enough.

Looks good man, what does the the piston push against?

it seals against a hosebarb that is about 5/8"

Ok cool. And your barrel is going to be attached to those threads sticking out of the T?

Maybe, ive been experimenting with it a little, and the threads are a little short, i will probably jb weld a male adaptor onto the end of the tee. I probably will not get pictures up by the end of the day of a barrel, sorry everybody.

Yeah the threads do look a little too short.

suddenly the piston isn't sealing. i figured out that it was not long enough, so i made it longer, but it still won't seal correctly. I have been modifying and testing it all night, its infuriating! i added a pic of the new piston below...

Does the piston need so many washers, it looks overly bulky. How about a single bolt with a single washer at the front and back respectively, and using thicker rubber for your sealing face?

Heavier piston -> more inertia -> slower movement -> less than optimal performance

Also