4 Inch Piston Valve Cannon with Video and many Pictures

glass_05 · Sun Jul 19, 2009 11:43 pm

Gun Type: Barrel Sealer
Piston: Housed in a 4 inch tee.
Chamber: 4 ft x 4 in
Barrel: 7 ft x 3 in and 5 ft x 2.5 in
Exhaust: 1 inch modified sprinkler valve
Primary Ammo: Frozen Popcans and anything else that fits down the barrel

Shooting Video
[youtube][/youtube]

The whole cannon (pictures show gun with the short 2.5inch barrel)
Stand is made from a golf dolly. The wheels aren't attached. I still need to do that and make them adjustable for height.

The Valve Housing
I wanted to fit everything into a 4 inch tee. I see a lot of cannons that need a coupler at the end to make more room, but I wanted a clean look and a compact powerful valve.

Back Plug
Very proud of this. Used a router table to make the groove and some Teflon tape to make the o-ring nice and tight. Can't even count how many times we have taken this out.

Piston
Made from a 3 in end cap. For sealing face I used a plunger and I also used one for the bumper. I know the bumper shouldn't be attached to the piston, but for me I found it to trigger more consistently that way.

TV

VCR

Fridge

Tree

Chair

Any questions let me know!
Edited by jrrdw.

theBOOM · Mon Jul 20, 2009 1:41 am

WOw trully nice work man your piston looks clean Good JOB! 8)
You built a beast of a cannon

I really like your stand it seems like its easy to move around and stuff

smexysmileyPiston · Mon Jul 20, 2009 6:08 am

that is 1 of the smexyest Cannons iv seen on spuddy...wat psi i use???
just a beautiful gun

RDX, · Mon Jul 20, 2009 8:40 am

wow thats nice and just the right time.. I was just thinkin what to do with my big steel T-fitting that I found

.. 115mm steel T-fitting that has 11mm wall thikness and wights 8kg

.. the cannon would be quite same size as yours but made from steel. think that cannon at 50bar pressure ?

spudtyrrant · Mon Jul 20, 2009 8:44 am

damn you

did you get that plunger idea from mine or did we just both think independently and figure out the same thing
p.s. i said damn you because you got damage pics and vids before me

Moonbogg · Mon Jul 20, 2009 8:55 am

Awesome cannon! I especially liked the steel bar going through the refrigerator. That was pretty sick.

glass_05 · Mon Jul 20, 2009 10:08 am

smexysmileyPiston wrote:that is 1 of the smexyest Cannons iv seen on spuddy...wat psi i use???
just a beautiful gun

We didn't ever take the gun above 80 PSI, didn't see a need to do. I would feel comfortable going to 120 PSI though.

glass_05 · Mon Jul 20, 2009 10:22 am

spudtyrrant wrote:damn you
did you get that plunger idea from mine or did we just both think independently and figure out the same thing
p.s. i said damn you because you got damage pics and vids before me

I knew I needed thicker rubber, and I didnt know where I was going to get some so I thought a plunger would work well. And while I was using a plunger for the sealing face, I thought one would make a perfect bumper as well.

glass_05 · Fri Jul 24, 2009 11:37 am

now with adjustable front wheels!

LCTChamp · Sat Jul 25, 2009 10:57 am

I'm thinking about constructing one similar to this, I already have most of the parts. Hopefully mine can come close to as good as yours,

The valve looks clean. It always bugs me when people add the extra coupler and pipe.

How long does it take to fill this beast?

Technician1002 · Sat Jul 25, 2009 11:27 am

LCTChamp wrote:
How long does it take to fill this beast?

I can take a stab at that..

If my math is right the volume of the chamber is just a little over 600 cubic inches.

The t shirt launcher posted elsewhere the Arlington team built is right at 700 cubic inches. It would fill about as fast as in this video. In the video below, they are only shooting at 35 PSI. Going to 60 or 70 doesn't take much longer.

This launcher with a 3 inch valve would be almost identical in performance. The 4 inch piston seats on I'm guessing is a 3 inch valve seat. The launcher in the video below uses a 2 inch valve orifice. The 4 inch piston has better flow but a slightly smaller chamber.
[youtube][/youtube]

daberno123 · Sat Jul 25, 2009 11:38 am

Impressive! How deep did the steel bar get into the tree?

glass_05 · Sat Jul 25, 2009 11:41 am

LCTChamp wrote:I'm thinking about constructing one similar to this, I already have most of the parts. Hopefully mine can come close to as good as yours,

The valve looks clean. It always bugs me when people add the extra coupler and pipe.

How long does it take to fill this beast?

Thanks. The main thing I wanted to accomplish with this gun was to fit everything inside a 4 inch tee. It wasnt that hard to do so, I don't see why people always use the pipe and coupler to extend to piston housing, when all that is probably doing is adding more pilot volume and making the piston heavier.

As for filling it up, with my 32 gallon air compressor it doesn't take that much time at all. Under a minute easily.

glass_05 · Sat Jul 25, 2009 11:43 am

daberno123 wrote:Impressive! How deep did the steel bar get into the tree?

The steel bar doesnt go that far into the tree, maybe 4 inches? But we shot that at only 60 PSI or so.

I have since fixed the leaky piston sealing face, so we can now go up to higher pressures without worrying about the projectile rolling out the cannon before we are ready to fire.

Technician1002 · Sat Jul 25, 2009 11:56 am

glass_05 wrote: The main thing I wanted to accomplish with this gun was to fit everything inside a 4 inch tee.

May I inquire as to what size the valve seat is? Some people measure piston valves by the piston outside diameter and then specify the port size so the flow restriction size is known. I'm guessing 3 inch. 2.5 is too small and 3.5 is not a standard pipe size.