SpudFiles

ok guys i am in the midst of making a coax for airsoft and i have everything completed but when i fill the gun up the piston seals but when I open the ball valve the piston doesnt actuate so and i used a syringe as my piston with hot glue. oh and I got the idea from eather jsr or vh-man cant remember wich

Too much pilot volume by the looks. How tight of a fit is your piston? Are you using lubricant?

Your barrel also looks pretty bent. When I made a co-ax with metal pipe and fittings, I had to line part of the chamber (the piston end) with PVC pipe so the piston had a good surface to slide in.

Try getting rid of the hose, it looks like a ball valve on the end, which is good. If it's a blowgun, replace it with a ball valve.

my piston is the right fit it can slide easily with out lubricant but i am still using lubricant yeah the reason why my barrel is bent is because i like touched my sisters phone and she bent my barrel

it's just a suggestion you know but you should take pics in a way that doesn't show your face... not that it is ugly or something but sometimes it's better to be anonymous

ckman wrote:my piston is the right fit it can slide easily with out lubricant but i am still using lubricant yeah the reason why my barrel is bent is because i like touched my sisters phone and she bent my barrel

It shouldnt exactly slide "easily". There should be some resistance. If you put the piston in and turn the gun upside down it should not move. But you should be able to move it with one finger with some resistance.

ok thanks guys but now i got the gun to work but when I pump it up to 140 my piston's sealing face breaks

That's hot glue for you.

You need something tougher and stronger on the piston face to stop the barrel from cutting in.

Is your sealing face getting ripped off or if not, how is it breaking?

when i pump it up a little hole is being punctured in it

You sure it's a little hole and not the sealing face not sealing properly?

Don't you hate sisters for that? Mine breaks my nerf darts Is the piston 1/2''? I made a 1/2'' piston for my 5mm marker gun a while back it had a hot glue sealing face which worked perfectly. Is the syringe seal the barrel seal or just the chamber seal? I am thinking it is the chamber seal and the hot glue is the barrel seal. EDIT: I forgot to add I made a larger co-ax with a hot glue piston,3/4'' which was a little retarded it would stick for some reason and wouldn't pilot maybe you are having the same problem maybe you should make a resin piton with a hot glue seal

ckman wrote:my piston is the right fit it can slide easily with out lubricant but i am still using lubricant yeah the reason why my barrel is bent is because i like touched my sisters phone and she bent my barrel

Ahh children.. I'm sorry that just hit me funny...so typical.

ckman, and what lesson did we learn here? Let's see...something about a woman scorned.....look it up....you'll be a wiser man for it.

You look mighty young for your intellectual form of speech (sorry if i am offending you, I am not trying to).

It pleases me to see younger people getting into spudding. Many people don't know it but as you learn more and more about combustion, advanced combustion, hybrids, pneumatic, coaxials, minis, bbmg/strafers, etc. you are actually learning the basic properties of.... dare i say it.... SCIENCE!!!

I can't tell you how much easier some of my science classes have been since i have started/learned about spudding and the properties of how the different classes of guns work and c:b ratio's etc.

Just makes me happy that the spudding community is making an impact on the minds of younger people, and on the plywood in front of them

And yeah, so I'm not totally off-topic...
NICE GUN!!!! lol

Haha it's funny to see all of the reactions of my friends when I talk to them about how piston valves work it looks somthing like this :confused4: . I like being smart but not looking anything remotely like the picture people get in their mind when they hear the word ''nerd''.
I mean really, there are people who think I'm stupid just because of the way I look well back on topic are you going to have any special filling setup? Sights?

You might try wrapping your piston in tape, preferrably electric tape for reduced friction and a tighter fit. It seems as if the piston isn't a tight enough fit. Another problem could be the surace area on the sealing face, but I doubt that's it.