Piston problem again

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
nabu92
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Vids working now.
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elitesniper
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yeah change your pilot preferably a 1'' sprinkler.
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MrCrowley
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Two things

1) Try more pressure, mine pilots at 7psi, but try about 40psi anyway.
2) Try a 1/2" ball valve, I know my first 2" piston didn't pilot with a blow gun very well, but a 1/2" ball valve worked perfectly, 1" sprinkler even better.

Oh and when piloting try and hold the gun horizontally, shouldn't make much difference to a normal piston gun, but try anyway.
nabu92
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I usually pump it to 60, in that vid it was at 70 I believe. I'm going to buy a 1/2'' ball valve first thing tomorrow.

Actually, I have an extra 1'' sprinkler valve that I modded.

Also, any idea on how to stop the leaks from the screws?
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MrCrowley
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Epoxy.
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Ragnarok
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MrCrowley wrote:Epoxy.
The answer to all man's problems.

Except the ones where it wouldn't help. It is not a cure for Bird Flu for instance... actually, it might be, if you can get yourself encased in epoxy in a sort of Han Solo manner (or maybe the mosquitoes in amber), then the Bird Flu will no longer be your biggest concern.

So contrary to what I earlier said, epoxy is even a solution to bird flu.

Damn, someone's going to put that in a signature now, aren't they?
Does that thing kinda look like a big cat to you?
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jrrdw
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The first video is all I needed to see. Air isn't getting passed your piston. The ammount of air that comes back out is no way a chamber full. That 1/4" hole should pilot that piston just fine. You need equilization hole/s in your piston.
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MrCrowley
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Ragnarok wrote:
MrCrowley wrote:Epoxy.
The answer to all man's problems.
Except that one problem, you know... ah...um... JSR will explain :D
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Ragnarok
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MrCrowley wrote:Except that one problem, you know... ah...um... JSR will explain
Or the problem Fat Pants from UKSGC once had. That can't be solved with epoxy either.

But these are few and finite exceptions to the rule.
Does that thing kinda look like a big cat to you?
nabu92
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jrrdw wrote:The first video is all I needed to see. Air isn't getting passed your piston. The ammount of air that comes back out is no way a chamber full. That 1/4" hole should pilot that piston just fine. You need equilization hole/s in your piston.
Where exactly would I put the equilization holes?

And wait what? my gauge is half way down my chamber and reads 50-90 psi whenever I fill it up. So It must mean air is getting down there.
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thespeedycicada
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just dill a hole through the sid of the piston or just make a crack through the side its just so air can get through.
current projects: co-axial piston valve.Status DONE!
S.P.E.C.S update mk 1 construction begining in febuary all the maths for it are done plans are drawn up and parts are listed.
NEXT project:auto piston valve.
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jrrdw
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nabu92 wrote:
jrrdw wrote:The first video is all I needed to see. Air isn't getting passed your piston. The ammount of air that comes back out is no way a chamber full. That 1/4" hole should pilot that piston just fine. You need equilization hole/s in your piston.
Where exactly would I put the equilization holes?

And wait what? my gauge is half way down my chamber and reads 50-90 psi whenever I fill it up. So It must mean air is getting down there.
I couldn't see the gauge move, I'll take your word for it. What size is your chamber? Thats not much air that comes back out, chamber must be small.

The equilazation hole should come out of the top of the piston just outside the sealing area. Into your chamber. If you drill a hole, make it no bigger then 1/32nds, and drill it kinda diaganul so you don't wind up going into the barrel or sealing face. Is your piston lubed? Can you move the piston by hand? Is it easy to move or hard to move?

I looked at the picture, was that the end cap/plug with the primer on it? It's not blocking the piston by any chance is it?
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elitesniper
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You only need equalization holes if you have o-rings .
nabu92
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jrrdw wrote:
nabu92 wrote:
jrrdw wrote:The first video is all I needed to see. Air isn't getting passed your piston. The ammount of air that comes back out is no way a chamber full. That 1/4" hole should pilot that piston just fine. You need equilization hole/s in your piston.
Where exactly would I put the equilization holes?

And wait what? my gauge is half way down my chamber and reads 50-90 psi whenever I fill it up. So It must mean air is getting down there.
I couldn't see the gauge move, I'll take your word for it. What size is your chamber? Thats not much air that comes back out, chamber must be small.

The equilazation hole should come out of the top of the piston just outside the sealing area. Into your chamber. If you drill a hole, make it no bigger then 1/32nds, and drill it kinda diaganul so you don't wind up going into the barrel or sealing face. Is your piston lubed? Can you move the piston by hand? Is it easy to move or hard to move?

I looked at the picture, was that the end cap/plug with the primer on it? It's not blocking the piston by any chance is it?
The chamber is 2'' and about 2 feet long not including all of the handles which are part of the chamber.
I can easily push and pull the piston with my finger.
Yeah, my piston is lubed with grease, I tested it with and without the grease and didnt see any difference.
The endcap leaves enough room for the piston to move back (about 2 cm).
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jrrdw
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Is your sealing face centered in your tee?
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