Dual Valve Cannon

[kiwi of nitro]

It's triggered by a safety pop-up valve set to 165psi, pulling the trigger releases the air in both pilots FAST. It's really powerful and works great, plus the camo scheme looks awesome. I used krylon fusion.

Here's some pics, please tell me what you think.





Barrel isn't attached in pics.

This went together really fast too, I got it all done in an afternoon.

[jackssmirkingrevenge]

Nicely done, I abhor the dead space but performance must be nonetheless impressive, los damage peectoors por favor

[Cosmic Muffin]

slight waste of a valve. because the there is not an equal distance from the valves to the barrel. you should have just kept the one on top

[Mitchza89]

Very clean job and a cool looking gun mate I think you should have two barrels going, it would be like grampa's good ol' dual barrel shot gun

[Technician1002]

slight waste of a valve. because the there is not an equal distance from the valves to the barrel. you should have just kept the one on top

The 2 small valves do not make up for a single large valve in both flow and dead space.

If you double the size of 1 valve the area increases 4X. A single 1.5 inch valve may outperform two 1 inch valves in flow and will be much better in regards to dead space. (space between the valve and projectile)

As for ergonomics, unique trigger, and overall layout I like it a lot. Nice job. It looks fantastic and must be a blast to use.

[Ragnarok]

...Because the there is not an equal distance from the valves to the barrel...

Pretty irrelevant. The second valve will still improve flow.

I would've said the order you put this cannon together in was a little awkward and unintuitive, but you clearly put thought into it in advance, so good job on that one, many people would have fallen into doing it in a way that left them stuck.

[AdiabaticManiak]

Nice gun you've build there!

I'm in the opinion that twice the valve; twice the fun. No matter thinking about the percentage of improvement; just the feeling of a dual valve setup in your hands make it worth it; am I right?

But please show us the full setup with barrel and such; would be fun to see.

[mister pointy]

Nice job, the trigger is pretty intuitive and the paint job looks good as well.

[kiwi of nitro]

I tried my best to minimize dead-space, but this is the very best I could do (I've seen many launchers with a whole lot more dead-space). It is far louder and has much more kick than any of my single valve launchers. Having a little more space between one of the valves and the barrel won't have any effect because both valves are connected to the same air chamber. Everything had to be cut real precise in order to fit the parts together, but it worked flawlessly.

[ssgnort]

So could the same trigger set up be used to fire off nine piston valves. For a single trigger in a nine tube mlrs.

[kiwi of nitro]

NINE PISTON VALVES?! That's insane! Just make one great big one!

[Technician1002]

So could the same trigger set up be used to fire off nine piston valves. For a single trigger in a nine tube mlrs.

It would be very difficult to get them to all fire together. As a few pop open the pilot area would see a rising pressure that may slow the others until the outlet pressure rises to compensate so you would most likely see a rapid sequence instead of a single unified opening.

The dead space could be a problem. I would go for a single larger valve myself. Plans are on the drawing table for a 3 inch and 4 inch valved cannon.

Note a 1 inch valve has an area of 0.785 square inches. 10 of them would be 7.85 square inches.

A single 3 inch valve is a little over 7 square inches with much less dead space and higher efficiency (less drag) that the extra plumbing would provide. A single 3 inch valve will outperform 10 1 inch valves.

[kiwi of nitro]

I've found a use for this cannon!
[youtube][/youtube]
Very handy!

[Reactor4]

Plans are on the drawing table for a 3 inch and 4 inch valved cannon.

Verrrry Nice! how big are you going to make the chamber? any design details e.g. paint job? I have been using 1" diy piston valves and sprinkler valves, I gotta move on up.

[Technician1002]

Plans are on the drawing table for a 3 inch and 4 inch valved cannon.

Verrrry Nice! how big are you going to make the chamber? any design details e.g. paint job? I have been using 1" diy piston valves and sprinkler valves, I gotta move on up.

They are started, a little behind schedule. I have an 8 gallon steel tank for the 3 inch. (Propane tank) and a second tank the same size.

I was given a piece of 2.5 inch UHMWPE rod and I located some nice 2.5 inch pipe so a 2.5 inch is in the works which is being built into an 11 lb propane bottle.

I'm still trying to scrounge (cheap) a decent piece of 3 inch iron pipe without a huge ridge or groove for the pipe seam.

Here are the pictures of the propane tanks with the valves removed. The large one is about 1/3 taller than a standard BBQ tank and the little one is about 1/2 the size of a BBQ tank. The little one will become a 2.5 inch valve cannon and the large one will become the 3 inch. In the future the other large one (I have 2) will become the 4 inch. The small tank is being purged with air to remove the remaining propane.



No paint schemes are picked out yet.

I am sanding the 2.5 inch pipe out to a smooth finish (Lots of work) and getting it ready to cut the ports. I have a date with a lathe in November to turn the piston to the final size and add the o ring grooves. With luck the 2.5 inch will be launching stuff by Thanksgiving.

The yellow tank is already bored out to take the 2.5 inch pipe (sorry no picture yet) so when the valve is ready, it can be welded inside. The foot ring on the bottom of the tank is cut off. I left a tab of metal to weld a link of chain to provide an attachment point for a sholder sling (like a guitar strap).