I gotz a 35 bar pushbutton valve : )

[Brian the brain]

Like the title says,..
I built a push button valve, or hammer valve , that has greater flow than a blowgun, yet it can be pushed open by hand ( without lever) at 35 bar..


I took a 1/4" tee.Put a pipe in one end, with a piston on a rod in it.Piston has floating O-ring.Piston consists of 2 nuts, drill-lathed to match inside of the pipe, on the end it has a capnut, same diameter..

On the other end I put a 1/4" nipple.
On the rod, wich extends through the nipple, I put another O-ring and a nut.Creating a poppet valve opposite to the piston..
A spring keeps it all under a bit of tension.
The piston is pressurised and pulls the opposite side closed.

The trick is...the surface area of the poppet side is just a bit smaller than the piston.
The difference in force generated is therefor very small..
Even more so when compared to a normal blowgun or hammer valve..

It goes off like...BOOM when I press it at 30 bar...

Perfect high pressure hammer valve!
It would be ideal for Sniperhero's upcoming gun!

Pictures will come later...

[twizi]

any pics

message to short

[Brian the brain]

any pics

Message to short

Using a question mark and two O's on TOO makes it longer already..

Pictures will come later...

I know I was a little vague on the matter.

By that I mean...pictures will come...LATER!

Just messing with ya...

I understand pictures are important and I really should have included them, but the camera's batteries are dead and I really wanted to brag about my project..

I'm a jerk like that...

[twizi]

it's alright i forgive you brian

[psycix]

Neat. Now attach a nice grip or build it into a stock.

[Gaderelguitarist]

It would be ideal for Sniperhero's upcoming gun!

I get the feeling that it would be perfect for a lot of peoples' guns!

It sounds like something that could be easily made in a good afternoon. (Especially if you have a lathe like me >:P)

[Brian the brain]

In that case...you could scale it up massively..

Just keep the surfaces almost equal..the piston side only slightly bigger.

You could make an easy 2" hammer valve this way.
Wich resets..
so..

Easy large bore repeater, wich saves air, both because it shuts off before the chamber is empty and better yet...no pilot!

[SEAKING9006]

Oh dammit, you already solved the problem I was working on for a pressure-independent button valve. It would work kind of like the flow-through valve I designed for my X-ACS program, but instead of a sprinkler valve pushing it forward it's a hammer, and instead of the flow taking a 90-degree turn, it goes straight through. Think a 4-way tee with a rod going through one side blocking all the flow, and a hole through it so if you push it the air goes right through. Add a small spring and you have a pressure-independent valve. I thought it up for a rifle I'm working on using a double-action hammer so I don't have to worry about the issues of re-cocking a hammer valve. But now I'm stuck on getting the air into the blow-back bolt. I think I'll use YOUR valve now. Just one question... What exactly is 35 bar in PSI? I don't have a converter on hand and I'll be using either HPA or CO2 anyway. I found out there's a 'gas shop' nearby, so after this I might dabble a bit in super high pressure work. (Yes, I can get helium. And also any other gas I want. Including argon. Why I'd want that I have no idea, I don't do welding.)

[Gaderelguitarist]

In that case...you could scale it up massively..

Just keep the surfaces almost equal..the piston side only slightly bigger.

You could make an easy 2" hammer valve this way.
Which resets..
so..

Easy large bore repeater, which saves air, both because it shuts off before the chamber is empty and better yet...no pilot!

All I would need then is a nice, efficient loading system figured out and it'd be one hell of a nice gun..

I'm going to break out the drawing board and storm up some brains right away...

[Technician1002]

I've been toying with making the QDV into a high pressure pushbutton trigger with the intent on multi shot ability. Here is a quick sketch.

The spring holds the valve closed so it can be filled. When pressed, the release of air to the top drives the piston to the bottom. The piston has a large bleed hole in it so as it bleeds down, the spring will return the piston to the closed position possibly before the air chamber is fully depleted. This would be thumb operated trigger.

It would use the avalanche characteristics of the QDV to ensure a solid pop when triggered. It could be built in 1/8 inch or larger pipe to work with marble guns on up.

[Brian the brain]

In theory that's a nice design.
Not neccesarily better, or worse.
Only trouble is, the O-rings will be cut up.That is, if you use ones big enough to seal under the pressure.

I think I'll use YOUR valve now. Just one question... What exactly is 35 bar in PSI?

You'll have to prie it out of my cold dead hands...

Build your own ( I know that's what you meant)
35 bar = 500 psi

[Technician1002]

In theory that's a nice design.
Not neccesarily better, or worse.
Only trouble is, the O-rings will be cut up.That is, if you use ones big enough to seal under the pressure.

I think I'll use YOUR valve now. Just one question... What exactly is 35 bar in PSI?

You'll have to prie it out of my cold dead hands...

Build your own ( I know that's what you meant)
35 bar = 500 psi

If you change the openings (Ports) to be smaller and have rounded edges, the damage to the o rings can be minimized. Using slots like this one shown by ShureShot may be a solution to the cut o rings issue.

http://www.spudfiles.com/forums/forward ... 18162.html

Look most of the way down the page to the ShureShot post. That port design using an internal piston with all edges rounded may work in a small push button valve. I've tested the 1 inch valve to 120 PSI with no issues. Smaller sizes at higher pressure should scale OK.

Oh, found an online BAR to PSI converter.. http://www.centauro-owners.com/articles/psibar.html

It gives 507.633 PSI.

[Brian the brain]

That would work very well indeed especially for larger models.

I had thought of something like that, but I have no way of deburring it..and no lathe at the moment either.

the damage to the o rings can be minimized

There should be none...

Oh and ...40 bar isn't a problem either.

I guess I could hammer this thing at 900 psi without using a ridiculously large hammer...

[Technician1002]

That would work very well indeed especially for larger models.

I had thought of something like that, but I have no way of deburring it..and no lathe at the moment either.

the damage to the o rings can be minimized

There should be none...

Oh and ...40 bar isn't a problem either.

I guess I could hammer this thing at 900 psi without using a ridiculously large hammer...

For my ports, I used a jewelers file to round all the edges the o rings cross.
I expect some o ring wear, but haven't noticed any yet. After all it is a rubbing part under stress. So far I have had zero o ring failures.
Here is a photo of the valve body in the t shirt cannon. It is in the process of having all the edges filed and made smooth.

As you can see, this was not made with a machine shop. The lengthwise cuts were simply a series of holes drilled by hand (not perfect but works) and the cross pipe cuts were made by hand with a hacksaw. After the ports were open, the edges were filed by hand to remove the burrs and make the edges somewhat straight. This is not a precision job.

It was done this way to see if a typical high school shop could make one for the shirt launcher competition. They could and did. They won.

[far_cry]

can you but some video to see how he is work
and a picture for the parts