SpudFiles

Good evening to all, I found this today whilst bumming around and thought it was rather nifty. (For those who don't want to read my nonsense the link can be found underneath my disclaimers and such.)

Firstly, I don't think this has been posted before, if it has I do apologize in advance. (For all I know this probably has been done already in one of ants' or someone elses guns, I didn't entirely understand how they all worked though)

Secondly, this isn't my creation nor do I know the person who did do it, so I'm not trying to spamvertise or anything of that nature. (my goodness my grammar is bad)

And at lastly, I'm not sure if this belongs in the pneumatic section, it is air orientated, however because of its small scale it may well belong in the bb airsofty section, I figure it could be scaled up though...maybe...

Finally, if you read through my more than likely pointless disclaimers here's the link:

http://www.instructables.com/id/Airgun- ... ase-Valve/

I came off sounding kinda douchy didn't I? Damn, I always do.

Hey man be a bit more confident!:) In presentation or whatever its not good to talk about the things you are bad at or are missing out. If you dont talk about your weaknesses"" then nobody will notice:)

Well k, thnx for posting anyways. Looks like a nice gun> the only problem is that it is singleshot, and that it only works on a small amount of air. But 30bars from a pump is damn high! Here is a pic of the valve:



It is a poppet type of valve, where the barrel is the valve and has holes at the side so the air can pass through it. I have made these valves as well, but the problem is that the holes have to be as far back as possible, otherwise you loose power bc the air leakes beside the barrel.

I don't know if it's already on the forum but I like the idea of a homemade inline valve I am planning on makeing a replica of the condor and I can't get a cheap sprinkler over here
ant what is small ? you can make a bigger valve with this pricipe right?

Forget amateurish sprinkler valves. Look no further than this type of valve for making airguns or anything where you need the air released explosively. This is my own design inspired by the valve inside an airbrush.

In truth, exhaust valves (pistons, sprinklers, QEVs etc.) are much more efficient and easier to make and use than poppet valves, if you're going for a high powered single shot. Their major advantage (and the reason that they're used in practically all commercial pneumatic airguns) is that they release a limited amount of air from a pressurised vessel, meaning that they're more practical for getting multiple shots from a single chamber.

hotknife ralphie wrote:....I came off sounding kinda douchy didn't I? Damn, I always do.

Not at all, I thought you were well prepared and clearly presented your ideas. The only thing I noticed was your speaking pace was slightly fast, otherwise it was fine.

Most people freak out when they hear themselves speak, especially the first few times. The more you do it, the better you'll get at it and the more comfortable you'll be.

Nice job!

I've seen these before at instructables.. I wonder if it could be used for a 25mm coaxial? Apparently it says it releases vast amounts of air quickly, could it compensate for its small size?

flamerz14 wrote:I've seen these before at instructables.. I wonder if it could be used for a 25mm coaxial? Apparently it says it releases vast amounts of air quickly, could it compensate for its small size?

Considering a 25mm barrel, for a poppet valve to give as much flow as a coaxial piston valve it would have to be massive and be actuated by a correspondingly enormous hammer and spring. If you're using high pressures like most precharged airguns do, in the region of 3,500 psi, then the increased pressure compensates for the lack of flow. However, with spudguns we're typically working with less than 10% of that pressure, meaning efficient high-flow valves are essential for good performance as well as managable construction.

You might consider it as a pilot valve for your piston if the pilot volume is small enough - for example, if I were to put a hammer that strikes the schrader valve stem on my mini pistons - but certainly not as the main valve for anything bigger than airsoft calibre.

It's a shame these valves are difficult to scale up. The thing always holding me back from building a "mini" pneumatic cannon is the fact that I could just buy one for $50.

Then again, mabye if you're handy with copper tubing, you could make a bigger one.

Hmm...i'll take that as a no then but what do you mean by

if I were to put a hammer that strikes the schrader valve stem

?

TurboSuper wrote:It's a shame these valves are difficult to scale up. The thing always holding me back from building a "mini" pneumatic cannon is the fact that I could just buy one for $50.

Why buy when you can build?

flamerz14 wrote:what do you mean by

if I were to put a hammer that strikes the schrader valve stem

?

Something like the attached diagram, pull the trigger which releases the spring loaded hammer, that strikes the schrader allowing the air to escape thus piloting the piston - et voila, hammer valve pilot

jackssmirkingrevenge wrote:

Forget amateurish sprinkler valves. Look no further than this type of valve for making airguns or anything where you need the air released explosively. This is my own design inspired by the valve inside an airbrush.

In truth, exhaust valves (pistons, sprinklers, QEVs etc.) are much more efficient and easier to make and use than poppet valves, if you're going for a high powered single shot. Their major advantage (and the reason that they're used in practically all commercial pneumatic airguns) is that they release a limited amount of air from a pressurised vessel, meaning that they're more practical for getting multiple shots from a single chamber.

why do half of the paintball markers on the market still use the poppet idea then? I do admit that the ion eg. is more efficient but it also needs higher'' technology(solenoids) and tight fits to be machined. My input is that if you want to build a multiple shot bb gun that shoots max 400fps and works on 8 bar (0.5liter> 95 shots) use a poppet valve with a moving barrel. For single shot and bigger bore use a piston> and yes for higher pressures it is harder to open a poppet valve, but there is a patent for that, ill look it up> it uses a pin that is attached to the back of the valve that is connected to a piston at the otherside(with a spring at the back) like this the hammer only has to overcome the spring and not the air as its equalized''.

ant wrote:why do half of the paintball markers on the market still use the poppet idea then?

jackssmirkingrevenge wrote:Their major advantage (and the reason that they're used in practically all commercial pneumatic airguns) is that they release a limited amount of air from a pressurised vessel, meaning that they're more practical for getting multiple shots from a single chamber.

jackssmirkingrevenge wrote:

ant wrote:why do half of the paintball markers on the market still use the poppet idea then?

jackssmirkingrevenge wrote:In truth, exhaust valves (pistons, sprinklers, QEVs etc.) are much more efficient and easier to make and use than poppet valves, if you're going for a high powered single shot. Their major advantage (and the reason that they're used in practically all commercial pneumatic airguns) is that they release a limited amount of air from a pressurised vessel, meaning that they're more practical for getting multiple shots from a single chamber..

I did read that lol, I thought u were referring to the pisons and QEVs. I didnt get that by "Their" you meant the poppet valves lol. But k coola

This valve I think works on the same idea, only with more volume. Its 1/2" npt. when you press down the lever a piston type thing opens just like the valve in the video..