Chimmy Chonga Piston Cannon

[jmeyer1022]

I couldn't think of another name so I figured I'd go with a simple yet fun burrito name. Anyways here's my cannon

Specs:
2" Piston 1.5" porting
2' x 3" Chamber
1.5" SDR 21 sleeved in sch 80 2" x 4'
Floating O-ring(check valve piston)
1" sprinkler valve pilot

My old cannon was 5' barrel and 4' 2" chamber, I wasn't a fan of the long chamber and I managed to mess up on gluing the 90 straight.
I am enjoying the shorter chamber and the redone valve/piston.

My old valve which you can find here :
http://www.spudfiles.com/forums/viewtop ... 086#239086
The new valve is simpler and more efficient.

I took a about 3" of 2" sch 80 and sleeved 4" of sch 40 1.5" pipe into that,sanded it down then slid it into the horizontal port of the tee( 1.5" side first) with that being into the tee I added a 2" female adapter for barrel switches to the extra length that was hanging out.


Pipe glued together.


Sealing face.

On the pilot side I did the same thing except with 3" x 2" SCH 40 with a female adapter for access incase the piston needs work.

The old piston was a 1 1/4" coupling and I just never liked its performance. Here is the new piston,


I used a 2 1/2" hole saw to cut wood disks then put the disks on a bolt and sanded them down to fit perfectly into 2" pipe. The plastic piece I got off a old bike pump that wasn't working. One of these would be insanely simple to make with a table saw and a drill. Anyways it works as a floating O-ring (check valve concept) and it works perfectly.

Here are pics of the cannon:





I can port it through the 1/4" ball valve with a quick connect for filling, but there is a small delay, and I love the blowgun trigger on the sprinkler valve. I know I need a barrel support, but I haven't shot it with the barrel on yet due to the noise (my neighbors are terrified up finally after seeing my old piston cannon destroy 3/4 plywood) This is louder and by far stronger than my old piston cannon. I think mainly due to the small changes. Any comments or questions be sure to ask.

Video camera is broken(uploading cell phone video now)

[youtube][/youtube]
Quick cell phone video

[MountainousDew]

As far as I can see, it looks like a great cannon...
Damage Pics please.
For some reason its not letting me watch the video, I don't know why and I really wanted to this baby in action.

[Mitchza89]

Very nice gun mate. Job well done

[daniel323]

nice gun

had a little kick on that dry fire even

job well done.

[jmeyer1022]

Thanks for the response. I wish the video quality wasn't so terrible. The shot was done at 70 PSI. At 90 PSI the gun will kick itself back 9-12". Hopefully I can fix my video camera and get some real footage/damage.

Any suggestions for damage shots? My old cannon at 75 PSI blew through 3/4" plywood at 30-40'.

[daniel323]

what do you plan to shoot for damage shots? (the target)

and also is that sdr21 1.5" pvc? if so it is a perfect fit for golf balls.

have fun be safe


EDIT: sorry it is sdr 21 i didnt see that.

i would suggest ply wood for some damage shots, but thats just me 8)

[Gippeto]

Looking and working great! Well done.

[mark.f]

Very nicely done!

The way you attached the outlet for the piston to seal against is all at once unique, effective, and safer. Most people like me simply use two bushings, either by themselves unmodified or sanded down to fit into the tee and female adapter flush. Thing is, your idea gives more material to hold the two together, reducing the chance (however slim) of the female adapter snapping off of the tee during moments of high stress.

Also, the piston seems to be working good. The sprinkler valve is a little overkill if those O-rings seal well, but it's not going to hurt performance, and you still may loose a TINY bit if you were to use a smaller pilot valve.

God job again!

[jmeyer1022]

Thanks again for responses.

Mark, I can pilot it through my 1/4 ball valve, but I had the 1" sprinkler valve laying around not being used and I love the trigger idea with the blow gun. I believe the SCH 80 sleeved with SCH 40 1.5 is the way to go, only problem is getting it.

[jmeyer1022]

Here's damage on my dad's windshield cause my friend is an idiot and likes to fill the chamber with his hand on the trigger facing the truck. He's paying for it and it didn't hit the jaguar 10 feet away. I do give my friend some credit for sneaking the ball through a 2" gap on the driver window side.

This shot was done at 80 PSI and with a 1.5" tennis ball.
Shown here,
http://www.petco.com/product/6937/Toy-B ... =201381053

I'll get actual damage pics rather than stupidity ones up tomorrow.

[covey12]

my cannons have always been louder with out a barrel on, normally it sounds like a blow horn until i do put on a barrel, but that was with a sprinkler cannon and not a piston so it could be different

[daniel323]

haha to bad your friend shot out the windshield.. but hey it makes for a good damage pic

[spudtyrrant]

@ convey
yeah piston valves tend not to honk, they usually sound like a combustion gun going off from my experience

[CpTn_lAw]

A small combustion then. PIston valves still have the rushing air sound. It's much more quick than with another valve, especially if your piston valve is well made, but a combustion still makes more noise.

[Technician1002]

A small combustion then. PIston valves still have the rushing air sound. It's much more quick than with another valve, especially if your piston valve is well made, but a combustion still makes more noise.

I found the smaller marshmallow cannon has the loud pow with a short or no barrel. When smaller diameter barrels are screwed on, it changes to a sharp crack which sounds more like a 22 rifle. I'll try to capture it with a video later. It's most noticeable with the 1/2 inch barrel 7 feet long.

I noticed this shooting nails into a 2 X 4. 6 penny nails are fully embedded with the heads countersunk about 1/3 inch.