trying out for 3rd cannon need a little help

[cannon monkey]

ok well i done 2 cannons 1 ball vaule one modified sprinkler
now i am going to make one and try a piston
any tips i should know or links i should go see about how to make one
here my basic idea on how this thing works
thanks in advance for all who gives me help


items i buying for the value are as listed

2 inch t

1.5 bushing ( 1.5 to 2 inch)

2 inch end cap

1.5 inch pipe

this rubber mat thing ( 6.99 or is there somthing cheaper i can use)

1.5 inch end cap
is that all i need?

almost forgot
a ball value to put on the 2 inch end cap

[starman]

There are plenty of examples in the showcase for you to gather "tips". Just get started on the project and ask for help if you run into a roadblock.

[cannon monkey]

ok and how do i get to the showcase?

[ALIHISGREAT]

you need to understand the basic principals of how a piston valve works before you make one... and you don't seem clear on t as you needed to post an animation to get confimation, you should look around in the showcase and look at the 'piston valves explained visually' thread.

but yes, you have the right idea of how one works. (although its important to note one things - the piston seals despite equal pressure on both sides because of the smaller surface area on the barrel side and as the pressure drops as it is piloted, the piston is pushed back by the air on the barrel side of the piston, not sucked back)

to get to the showcase, click the 'cannons' button at the top of the page.

[cannon monkey]

ok run that by me one more time


the piston ( 1.5 inch end cap ) is pushed back from the air on the side with the barrel

[ALIHISGREAT]

yeah, so you need to have a piston of a larger diameter than the barrel/sealing face

[cannon monkey]

sooo 2 inch t
with 1.5 inch end cap as a piston with rubbing on the end
and a bushing 2 inch down to 1 inch?
thats goign have 1 inch pipe stickin out of it ( on inside to seal off)

[MrCrowley]

Read this:
http://www.instructables.com/id/Golfbal ... That-Shoo/

Any questions, just ask.

[cannon monkey]

thank you so much every body this is THE BEST site i ever signed up for
and every body is so helpful

[cannon monkey]

ok umm on ur site u gave me
nice cannon by the way
but it gives me plans to make a piston out of a can or wood
i want one from an end cap


can i use an endcap with the rounded end or does it
HAVE to be flat?

and wat is the rubber thing on the top to make the seal

and wat do i use on the bottom ( open end) so it dont break over time

[MrCrowley]

An end cap is fine, as long as you have something behind the sealing face, like a metal gasket, to stop the sealing face bending around the end cap.

The rubber sealing face is an rubber gasket from a hardware store.

The thing on the bottom is a bumper, anything that can compress fairly easily but wont fall apart, like a strong foam (found in kneeling pads used for gardening or floating boards used for swimming).


I think you need to do a lot more research before starting construction, you have quite a bit to learn. Terminology for one.

[cannon monkey]

ok i have not gone out to buy any thing i wanted to learn more and i am
i slowly making part list and talking to every body mrcrowley u been A LOT of help

so need something behind the sealing face( the closed side of the endcap )
open side i need something for a bumper ( any thing to cushion the end cap when pushed back

[iisthemuffin]

I made my piston out of an endcap as well. But the one i found was actually flat rather than round.

You will also want to fill in the open side on your endcap. I didnt at first, and i had weird things happen. The inside of my cap was pressurizes and making my piston bounce. Also, having it open just creates more pilot air, which is bad.

[cannon monkey]

ok so i find one flat as i can....
my friend telling me i should use a spring and when i fill it i should put the end cap in so it goes over the pipe that goes into the barrel.... will that work or do i use the flat roundish end with somthing rubber to press onto the pipe

[ALIHISGREAT]

i wouldn't put the sealing face inside the piston for this setup, because there are no advantages for a barrel sealer in this configuration and it could harm performance quite a lot.

i would however do that in a coaxial....

and as for the back of the piston, you could fill in the back of the piston with epoxy or something less dense to reduce the pilot volume or you could probably get away with epoxying a metal disc on to seal it and keep the weight down.