Piston Help

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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SpudFarm
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Tue Apr 15, 2008 3:12 pm

MrCrowley wrote:
spudfarm wrote:not much to say the diagram says it all.

ask if you don't understand (Crowley did not understand)
What the hell is your problem dude? I didn't understand my ass, i've probably had more piston experience then you. Members even recommend me as a good guy to talk to for building a first piston.

Oh and I do understand, more then you. You don't understand many things, refer to the bottom of this post.

You just wanted a damn sticky and had no clue what to do to get one. Anyone can make a diagram of a piston, that does not mean it should be a sticky.

cool down!!
why do you yell that fu(king much at me? i said it was you that did take it as confusing and bad..
now that the topic got a life again i may change and make numbered diagrams..

can you just lay this one dead now? i really don't want to mess around with someone who can get me banned!

and if you continue to yell i just get PCGUY to delete this topic if it is a really big problem that i am Norwegian and aren't the best to explain in English.

but as said i may update it if it lives longer.

Edit: your piston pics is a bit bad.. try to get something clearer. and the diagram you said you did not understand is not suitable for a seamed pipe since it includes steel.
if you get some better pics up it will be easier to understand.
Last edited by SpudFarm on Tue Apr 15, 2008 3:16 pm, edited 1 time in total.
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Sergeant Dotson
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Tue Apr 15, 2008 3:14 pm

Don't get PCGUY to delete this man. I still need help....
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Blitz
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Tue Apr 15, 2008 3:17 pm

Sergeant Dotson wrote:Don't get PCGUY to delete this man. I still need help....
I can try to help you, that's in your other thread right?
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MrCrowley
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Tue Apr 15, 2008 3:18 pm

spudfarm wrote:
MrCrowley wrote:
spudfarm wrote:not much to say the diagram says it all.

ask if you don't understand (Crowley did not understand)
What the hell is your problem dude? I didn't understand my ass, i've probably had more piston experience then you. Members even recommend me as a good guy to talk to for building a first piston.

Oh and I do understand, more then you. You don't understand many things, refer to the bottom of this post.

You just wanted a damn sticky and had no clue what to do to get one. Anyone can make a diagram of a piston, that does not mean it should be a sticky.

cool down!!
why do you yell that fu(king much at me? i said it was you that did take it as confusing and bad..
now that the topic got a life again i may change and make numbered diagrams..

can you just lay this one dead now? i really don't want to mess around with someone who can get me banned!

and if you continue to yell i just get PCGUY to delete this topic if it is a really big problem that i am Norwegian and aren't the best to explain in English.

but as said i may update it if it lives longer.
Spudfarm I don't care how much English you know, you obviously know enough to chuck in a few insults around the forum in previous posts.

Discussion over.

And this is someone elses thread, not yours. You can't ask for it to be deleted unless a mod or the OP has a problem with it. You can complain all you want though.


@Dotson

Don't worry it'll stay open to help you out.
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Sergeant Dotson
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Tue Apr 15, 2008 3:19 pm

What is in my other thread, Blitz?

BTW, Thanks MrCrowley... :)
Last edited by Sergeant Dotson on Tue Apr 15, 2008 3:21 pm, edited 2 times in total.
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SpudFarm
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Tue Apr 15, 2008 3:20 pm

sorry.. i was really talking about my topic since it was that topic that started the argumentation with MC..

no danger for this ;)
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Blitz
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Tue Apr 15, 2008 3:27 pm

Sergeant Dotson wrote:What is in my other thread, Blitz?

BTW, Thanks MrCrowley... :)
Durr, I meant this thread, I'm so sorry. :) So where were we?
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Sergeant Dotson
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Tue Apr 15, 2008 3:30 pm

It's ok... Back to the subject, when I start to pressurize, I doesnt seal very well. It does seal a little, but it leaks enough to not let the air compress. I'll do a little tweaking, but are there any suggestions to the piston? :?

Oh BTW,
When I put my finger over the barrel, and let it pressurize, then pull the trigger, it does pull the piston back. I can tell it pulled it back when I unscrew the back.
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SpudFarm
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Tue Apr 15, 2008 3:35 pm

are your "seat" straight?
seat=the pipe the piston seals against
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Blitz
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Tue Apr 15, 2008 3:37 pm

Without treading back into the thread, I would suggest using a mroe solid sealing face. THere could be a few things going on here, this is what I can think of off the top of my head.

1. Your seat (the end of the barrel inside your chamber) isn't square, or lined up properly. A smooth and straight sealing face is important.

2, Your piston's sealing face is not compressing against the seat very well. What are you using for that? (Again, I didn't go back to the original post you made -- I just wanted to get the facts here so it's all in one place).
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Sergeant Dotson
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Tue Apr 15, 2008 3:38 pm

Yea, it's straight. Come to think of it, there is the slightest bit of not being straight.

OK, I'm back with some more test results. It turns out that the piston moves back perfectly! The problem is that the sealing face is off by juuuuust a hair. So I guess (as far as I know) what I need to do is to either:

1) Straighten the barrel.
or
2) Make some mods to the sealing face.
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Blitz
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Tue Apr 15, 2008 4:48 pm

It's all good.

On my coax, the barrel is very slightly off-center (I did not put any kind of guide inside, I felt the barrel was short enough to not affect its alignment), but my sealing face is soft enough to conform to this and therefore it works.

What material is your sealing face (know the kind of rubber, or where it came from)? I checked out the picture you had but couldn't really tell. And what's the outer diameter and the hole diameter (the diameter of the screw that's holding it in)?
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Sergeant Dotson
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Tue Apr 15, 2008 4:54 pm

Well the barrel is 1/8 inch. I have some very soft rubber tubing on the tip of the barrel in the chamber (for better seal.) The seal face on the piston is from a dart tip, I think. BTW what do you mean by the screw that's holding it in?
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Blitz
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Tue Apr 15, 2008 5:10 pm

What'd you use to hold the sealing face to the piston? (What you said is from a dart tip). Since that curves up, it's hard to tell.

In my experience, it's only necessary to have a rubber seal on only one component or the other, not both. So having either a rubber sealing face or a rubber seat on the end of your barrel. Sounds like you have both -- try removing the sealing face from your piston altogether and leave the one on the end of hte barrel. As long as the end of your piston is smooth, that could solve your problem perhaps.

For what it's worth, I don't have any kind of rubber on the end of my barrel, just bare PVC (My gun's plastic unlike yours).
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Sergeant Dotson
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Tue Apr 15, 2008 5:12 pm

I used silicon to attatch the dart tip to the rubber washer, and crazy glue to attach the rubber washer to the wood. I'll experiament around.
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