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Suggestions for high pressure launchers?

Posted: Mon Apr 16, 2007 4:33 pm
by HenningNT
Does anyone have any suggestions about how a high pressure launcher could be made. I asked Gardenia (or was it Hozelock?), and the guarantee safe operation of their connectors up to 10 bar. That's not enough for what I have in mind...

I think a cable tie launcher can be made to hold pretty high pressure, it's just a question of tensile strength and surface area. And if the plastic isn't strong enough, steel wire could be used instead...

My boss suggested using a pneumatic or electrically operated valve, and have a separate fill connection.

Any others?

Re: Suggestions for high pressure launchers?

Posted: Fri Apr 20, 2007 12:25 pm
by Spaceman Spiff
HenningNT wrote:Does anyone have any suggestions about how a high pressure launcher could be made. I asked Gardenia (or was it Hozelock?), and the guarantee safe operation of their connectors up to 10 bar. That's not enough for what I have in mind...

I think a cable tie launcher can be made to hold pretty high pressure, it's just a question of tensile strength and surface area. And if the plastic isn't strong enough, steel wire could be used instead...

My boss suggested using a pneumatic or electrically operated valve, and have a separate fill connection.

Any others?
We had a discussion about using cable ties made from steel. They are quite exppensive, but they are exactly the kind of thing that you need for this application.

Posted: Sun Apr 22, 2007 3:30 am
by radiotrib
In fact, being a bass guitarist, it occurs to me that a steel guitar string has just the right fitting at the bridge end ...

A friend of mine uses an elaborate pneumatic release which is triggered by letting the pressure out of the inflater hose once the rocket reaches pressure. The hose is separated from the rocket by a non return valve. Naturally he has a pressure release valve on the rocket side of the contraption in case of emergencies. It smack to me of over engineering, but he's a "macro" kinda guy so he overbuilds everything ... as an exampple, he's the one who built Raschieticus ... http://wrockets.trib-design.com/index.p ... schieticus

K4

Posted: Tue Dec 25, 2007 8:09 pm
by U.S. Water Rockets
A tip for all you folks out there designing high pressure launchers: conventional release mechanisms tend not to actuate given the pressure forces involved. It appears from the discussions going on in this forum that some of you have already considered this in your designs. Good work anticipating the problem before encountering it. Keep doing this for all of the challenges of high pressure, and you are on your way to spectacular heights!