Super Piston :p

[SquishY]

Well here it is, I decided to make it this way for a few reasons. 1: It was easy and required no more tools than a drill, dremel, and hacksaw; 2: It was pretty cheap and is universal.

Still working a way to fill it with air, it's to bit to use a foot pump and I'm not sure if a footpump would actuate the piston anyway, oh well it will be figured out once I get 60$ to buy a compressor.

Whole cannon will be posted later but since its just the valve I'm proud of it's all that will be posted for now.

[killagorrila99]

Woh, Nice design there, Are you gunna use it with a 2 inch barrel?

[rna_duelers]

I like it,its a barrel sealing piston i gather.Cant wait to see it being used on a cannon.Maybe have a T before the ball valve and have the filling point in there such as a shrader or compressor quick-disconnect.

[SquishY]

That's what I was thinking, and yes it's a barrel seal, I'm going to get some screws later to tap in to hold the back in place and maybe two big washers to support the sealing face a litte more.

[saladtossser]

piston looks simple and neat
still dont think you need the rear seal though

[SquishY]

Because it would fall and when piloted it wouldn't suck back, regular pistons have an oring or enough surface area to achieve this.

[CS]

No, you still need it.

From what I can gather the purpose of the recently dubbed 'rear seal' is to provide a seal in which the space can be vented to inturn cause the pressure difference in which you need to do to get any piston movement.

[SquishY]

Thank you Pimp, that is damn near the exact wording I wasn't able to get out, when I replied to that it the jewelry in my septum was so cold it hurt so there wasn't room for much else on my mind.

[Tyro]

Man I've been tryna find some pics of a Piston which i could understand from, How a piston works, do you just pressurize behind it and in the chamber?

[SquishY]

It is pressurized from behind the piston which would be where the ball valve is, this pushes the piston foward to sea off the barrel and the chamber is filled with air, the rear seal creates the pilot chamber. When the air is vented from the pilot chamber the pressure drops and the higher pressure in the chamber pushes it back and the air exits the barrel along with the projectile. Good explanation for ya?

[Tyro]

so you do pressurise from both ends, or does the piston let some of the chamber air come through to the other side like thing a diaphragm

[SpudBlaster15]

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[Tyro]

err i'm not a member of that, was that intended for me?

[SquishY]

I'm sure it was intended for you, pressure is only put in from behind the piston, it seeps into the chamber around the seal, it can't be pressurized from both ends as all three sides are taken up as in the first pic, the left leg goes to the barrel, the bottom to the chamber, and the rear for pilot/ fill.

[Tyro]

Sorry man i don't get it, could you draw a simple diagram?