After trying many times to get a working air tight pressure switch using the brass components in the previous post, I decided that it wasn’t going to happen. So I set about trying something new.
I stumbled across this on the Yahoo water rocket forums:-
http://groups.yahoo.com/group/water-rockets/photos/album/930791471/pic/list
I decided that this looked like a very reliable method of making a pressure switch. The only down side is that it needs to screw onto the top of the bottle, this means that you need to join the bottles together by bottoms, instead of the normal top to bottom arrangement.
I am glad to see, as you can see below that the new switch works really well and there is no sign or any leaks. The switch operates at about 20psi, slightly higher than the previous design, but probably due to the slightly thicker rubber.
