Backpack water cannon

[Biopyro]

I'm creating a water cannon with a 6l water and pressure chamber in a backpack, connected to a handheld copper gun part. The designs are below - any criticisms?
22mm pipe is a very good fit to water bottles, and is tight to 7bar+. the bottle's thread is also equal to 3/4" BSPT so I'll clamp an olive onto the pipe then use the bottle like the male part of a compression fitting.

Edit: Here's the workthrough, and the final result on page 3. Very much more simple than the original plan, and easily as good, if not better.

[trollhameran]

sweet finally a thread about this, looking good man, look forward to seeing in in action

[Biopyro]

I am going to use a bike pump instead of the homemade one, since I won't need the check valves or have to fiddle about with it not sealing or whatever.
I'm also gonna swap the nozzles around so that the larger one gets a higher flow.
Anyone got any ideas how to block the front handle easily?

[THUNDERLORD]

....Anyone got any ideas how to block the front handle easily?

Could you use T's and grind the ring out and slide them over the other pipes maybe? (Got the idea from MrC.'s work and piston T's)

This time of year water stuff is getting interesting.
Cool design 8)

EDIT: For us in the Northern Hemisphere Of course.

[trollhameran]

What THUNDERLORD said would probably be the best way of doing it.

I am also working on something involving lots of water now but im keeping it under wraps until a later date

[THUNDERLORD]

What THUNDERLORD said would probably be the best way of doing it.

I am also working on something involving lots of water now but im keeping it under wraps until a later date

Thanks! I am working on a water design myself also.
Probably using PVC (old stuff I don't trust for pneumatic use) and a piston.
I plan on using surgical tubing for the springs to press the piston rod against the water.
And end cap nozzle.
Hope to see more water designs maybe.

By the way, you don't have to use all caps when writing my username, even just TL is sometimes cool too. (caps lock was on when I opened acct. but it comes in handy when I scan through topics for myself) 8)

[Biopyro]

Yeah that's what I was thinking - hotwired did it on his cannon Copperhead prime too, but I think polyurethane expanding foam may do the trick, since it just has to be watertight
It's well worth looking at the homemabe cannons already around. Some of them have real power. This may suit you TL?

[benstern]

http://www.thehalls-in-bfe.com/UberSoak ... oaker.html

[trollhameran]

lol that ubersoakers pretty cool, could do with a kahuna blast fitted to it though

[psycix]

Looks nice. Only one thing holds me back.
You use copper, and because of the coke bottles, you have to stick to 7 bar.
Get better chambers (4" pvc rated to a good pressure would be better) and crack up that pressure.

[Biopyro]

Apparently the increase in pressure yields very low returns past 60 psi. Bear in mind that I would also have to hand pump it up to that and the price of 110mm PVC fittings in the UK it really isn't worth it.

[POLAND_SPUD]

lol I can't wait to see some dammage pics...
I agree with what others say 0 up the pressure to 20 bar

[TheTrooper]

Hey, does anyone know different ways on how to secure a 2 litter soda bottle to PVC? Any kind of help is greatly appreciated.

[Biopyro]

In the UK it's a perfect fit to 3/4" thread, but apparently you can use a bird feeder adapter like they did at advancedspuds

[THUNDERLORD]

....It's well worth looking at the homemabe cannons already around. Some of them have real power. This may suit you TL?

That "Supercannon II" is one heck of a soaker!!, That's getting into dangerous to play with almost.
Got power comparable to a fire hose!

I was planning to use some old PVC I don't trust for pneumatic use.
Too bad that uses air pressure to push the piston(still pneumatic pressure)
I was thinking of a constant pressure against the water directly by the piston and springs(rubber tubing).

Although that design is cool enough to maybe buy some new PVC for.

LOL, When I saw all the purple primer and the one with the styrofoam and tape barrel support, I doubt those designers are also spudders.
(Although myself, I don't mind purple primer streaks)

Thanks for the link! 8)