piston not opening, help me please

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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covey12
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my piston valve will not open when i pilot it it, all of the air comes out of the pilot, which is a 1/4 inch ball valve, on a 2" piston, when i push a stick down the barrel and push the piston back manually, the air does come out
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jackssmirkingrevenge
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What's the diameter of the barrel? How tight is the piston?
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covey12
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jackssmirkingrevenge wrote:What's the diameter of the barrel? How tight is the piston?
barrel is 1.5inch, and the piston is a 1.5in. endcap so it has about 1mm of clearance between it and the housing,
i do have a spring pushing the piston onto the barrel, it only has about 2lbs of force though
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jackssmirkingrevenge
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You don't have a lot of difference between the external diameter of the barrel and the diameter of the piston, this can be an issue.

Try wrapping duct tape around the endcap until it's tight but you can still push it with one finger, see if it works.
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Ragnarok
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jackssmirkingrevenge wrote:You don't have a lot of difference between the external diameter of the barrel and the diameter of the piston, this can be an issue.
No, let's be fair - this is almost certainly the issue.

Like Jack says, you'll need to cut blowby on the piston - or seriously upgrade your pilot valve.
Does that thing kinda look like a big cat to you?
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covey12
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jackssmirkingrevenge wrote:You don't have a lot of difference between the external diameter of the barrel and the diameter of the piston, this can be an issue.

Try wrapping duct tape around the endcap until it's tight but you can still push it with one finger, see if it works.
any tighter and it wont move, i think that is my problem, 1mm is probably not right, it may be a 1.75 inch endcap
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jackssmirkingrevenge
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Try getting rid of the spring then ;) you don't really need it assuming you're filling through the pilot chamber.
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CpTn_lAw
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Get rid of the Spring. grease the endcap.
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Ragnarok
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@CpTn_lAw: That's what she said.

Sorry, couldn't resist.
Does that thing kinda look like a big cat to you?
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jackssmirkingrevenge
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Ragnarok wrote:That's what she said.
I could conceive of a situation where one would be told "Smear some KY and stop bouncing!", but I think this is veering somewhat off topic :roll:
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POLAND_SPUD
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:shock:
boys will be boys.... lol
Children are the future

unless we stop them now
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covey12
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Ragnarok wrote:@CpTn_lAw: That's what she said.

Sorry, couldn't resist.
that helps me, come on now were not in middle school anymore
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jackssmirkingrevenge
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covey12 wrote:come on now were not in middle school anymore
Considering some of us are grown men discussing the acceleration of vegetables, I think that assertion is open to debate ;)
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Ragnarok
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@ covey12: The true mark of maturity is to be able to controllably allow oneself to be immature at times.

Anyway, you're not helping us help you... you're expecting us to troubleshoot on inconsistent or lacking information - and pictures are ALWAYS a help in problem diagnosis.
Does that thing kinda look like a big cat to you?
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far_cry
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make the seat diameter smaller
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