I have a question about diaphram valves. I have read the wiki but still can't find an answer.
What I want to know is if the diaphram is 'fixed' or 'floating'
Is the edge of the diaphram attached to the wall of the pipe, like a sprinkler valve diapram, or is it 'floating' where it is just sitting in the space between the end of the barrel and the back of the valve.
I've attached some badly drawn diagrams to show what I mean. Both pics are for a co-axial launcher. Sorry about the terrible diagrams but hopfully they will help convey what I am saying.
Diaphram Question
I wedged mine between two pieces of pipe cut for as a spacer. If you do it that way you will need to put a small hole in the diaphram to let air thru to the other side. I go about 3/32". I used a piece of rubber cut from a rubber cap for a pvc pipe. It very soft and it will be curved outward on one side. I put that side to where it barely touchs the barrel. When you add air and it goes in the chamber above the diaphram it should seat tight againest the barrel. Good luck. PM me if you have any questions and I will try to help. PVC Arsenal 17 was a great help to me.
sgehring: Thanks. I have been browsing this forum for nearly a year, dad just wouldn't let me sign up. I know about the equalisation hole, I just couldn't find an answer to this question. I am not actually building a diaphram gun, pressure rated pvc is expensive in Australia, and I have no experiance glueing pvc so I am staying away from pvc launchers for the moment. I was just curious. My gun is built with threaded irrigation parts, and uses a 3/4 inch pvc ballvalve. I might upgrade to a modded sprinkler, but I'm happy with its power and design at the moment. The only problem is that aiming a ball valve pnumatic is soooooooo hard, especially as the irrigation pipe isn't as rigid as pvc.
Take a look at this page: http://www.xinventions.com/main/spud/ho ... _works.htm
It explains and shows how the floater method works.
It explains and shows how the floater method works.
Thanks a million, I had already seen that diagram but was wondering if they left somthing out. It seems like the diaphram would get knocked out after each shot, I guess I was wrong
Your post made me laugh though ' It explains and shows how the floater method works.'
lol
Hey cool I'm a Private First Class and this is my first day as a registered user
Your post made me laugh though ' It explains and shows how the floater method works.'
lolHey cool I'm a Private First Class and this is my first day as a registered user
Last edited by Insomniac on Tue Dec 19, 2006 12:50 am, edited 1 time in total.
hmm guess that did sound a little funny..when I tried the diaphram asa floater it did pop out of place when I went above 40psi. The other methosd was good to about 80psi. But then the diagphram would not pop back so I put a spring behind it and it now will work at 100psi. Used the spring out of a older Chevrolet starter solinoid the kind that mounts right on the starter.
Yeah, It seems like the fixed diaphram would be better because it could be made of more flexible rubber and would be pretty well sealed save for an equalisation hole....say, I wonder if anyone has used one of those tiny one way valves off a football inflater needle to make a one way equalisation hole!