Has anyone got experience making pneumatic air cannons like on http://www.xinventions.com ?

All information online points to using the "rainbird" brand of sprinkler valve but I've scoured the net and can't find a UK supplier. In fact, the only electronic sprinkler valve i can find is from here :

http://www.cmsgardens.co.uk/hose.htm (near the bottem)

but there is no technical information available on this valve (even from manufacturers page) so i'm not sure whether it's suitable.

Has anyone got any substitutes for the rainbird valve, or a uk supplier of the rainbird?

Cheers,
HVD.

[edit]

Perhpas "Pneumatic air cannon" is a double positive? Pneumatic cannon is perhpas a better name :-).

Years ago I tried to build a pneumatic/solinoid operated air cannon for paintball. The main chamber was 100mm, which went to a 50mm barrel. The solinoid was a 24volt/high pressure device/1 inch pipe (still have two somewhere).

I was very over kill with the safety: extra strong PVC and using a large volume/low pressure chamber to push the projectiles in a non violent burst, but more of a blow pipe effect.

The results were hit and miss, as I kept developing air leaks and I cheated by adding a little water to the system which showed me the air leaves and water added mass to the firing and a little recoil for a much better result.

Sorry I have no pictures, this was years ago.

Drop me an email it you want more info.

Have you tried searching this website? There is tons of info on Spud cannons.

You can get a rainbird valve from any garden reticulation shop. You need must technical info of retic valves either, they are all pretty much the same.
If you ever get around to making one, makesure you use pressure rated PVC pipe and you glue everything carefully.

I have built 4 different air cannons over the years, only 2 of them are still on one piece, one of them has a broken barrel that I can't be bothered fixing (broken due to being dropped, not due to a failure during operation), the other one was dismantled to provide parts for a bigger, better one.

Any old solenoid sprinkler valve should do, all mine were bottom of the range, el cheapo $20AUD ones from Bunnings and I have never had a problem with any of them.

I really have no idea how anyone could get air leaks in their cannon, before building mine I had no experience whatsoever with PVC gluing, yet I have not had a single air leak in any of them. Just use plenty of glue and use teflon tape or silicone on all the threaded joins.

EDIT: Flake2m, nice sig, but I prefer "If you can't dazzle them with brilliance then riddle them with bullets" :)

Have you tried searching this website? There is tons of info on Spud cannons.

You can get a rainbird valve from any garden reticulation shop. You need must technical info of retic valves either, they are all pretty much the same.
If you ever get around to making one, makesure you use pressure rated PVC pipe and you glue everything carefully.

It's not information on consruction that i need, as I've already read quite a bit about them. It's the sourcing of a solenoid sprinkler valve of the highest switching speed and flow rate that is troubling me. And no, i've been into lots of shops, and looked on the web and the only electronic sprinkler valve i can find is on the link i posted. If i could get it in any garden shop, then i wouldn't have posted here.

HVD.

[edit]

To XYZ : Well, i think I'll just buy the one i found and hope for the best. I was looking for max flow rate and switching speed for my money but i don't have much choice it seems. I'll let you all know how it goes. Thanks.

What you're looking for is something like the 'Supah valve' created by Joel over at spudtech.com If you visit some of the yahoo groups catering to spudgun design, you will find that quite a few people have reverse-engineered Joel's design and have worked out what hardware you need to purchase to create your own. Solenoid-based valves just don't dump air fast enough to be very efficient, so forget about using them to directly release the air.

I suggest obtaining a sprinkler valve and pneumatically modding it with a blowgun threaded into the jartop. It makes a world of difference in flow and actuation.

Woah there biznatch! Don't buy that big brass mother of a valve...

Firstly, you can get the big green plastic solenoid valves that everyone uses in the US.

They are available mail-order from the spudgun technology centre.

Also, a company called http://www.arcadiairrigation.co.uk/ does sell them. Unfortunately, they are no longer featured on the website (along with a lot of other more minor products), but they were a little while ago. Along with some threaded fittings to suit. I'm fairly sure they will still sell them, maybe an email to them will help.

Also, if you haven't seen it, http://www.geocities.com/spudguns_uk/ might be of some use, although it hasn't been updated for quite some time.