Spring loaded piston cannon question

[Gun Freak]

If a piston housed in a Tee is held foward by a spring and not only air pressure, then can it be filled by the chamber port or does it still have to be filled adjacent to the pilot valve? I am making a PVC piston cannon and need to know where to put the fill valve.
Thanks
~Gun Freak~

[deathbyDWV]

It can be filled from the chamber as long as the flow is kinda slow. If it is filled too fast it'll pop open...

[Gun Freak]

Yeah I figured that, but how strong does the spring have to be? If it too strong, then there won't be enough flow out the barrel, but if it is too weak, then won't the air just go right out?

[grock]

doesn't really answer your question at all, but it accomplishes the same thing.

if you use a T and a little bit of hose/fittings, you could fill both the pilot and the chamber at the same time, then it would work just like any other piston gun. or fill the pilot first, than fill the chamber, but that requires a fill and an exhaust on the pilot side

[Gun Freak]

but that requires a fill and an exhaust on the pilot side

Which would create more pilot volume, which is why I was asking. So a spring loaded piston cannon should be ok to fill slowly from the chamber end?

[chinnerz]

hey Gunfreak,

just want to start by saying, no offense or anything.
but can you like draw up a quick sketch on paint, or gimp shop, or like paint.NET when you ask a question? it takes like 2 min tops! and people know what you are talking about like straight away. as opposed to to not... and then trying to construct a mental image

thanks buddy!!

links:
gimp: http://www.gimp.org/
paint.net: http://www.getpaint.net/

^^ i use paint.net, super easy to use, super small, and heaps of plug-ins