Piston Burst Disk

[Atlantis]

In this design, the burst disk is built into a piston which moves forward towards the sharpened, serrated barrel when the pilot chamber is vented. When the burst disk hits the barrel it breaks releasing all the air behind the piston to go through the piston and into the barrel. This gives you a triggering mechanism to fire on command.

P.S. Please don't say "It would be easier just to use a burst disk"

[zvallance1]

and how do you expect to replace the burst disk each time?
the only way i could see you doing it effectively would be with a screw on endcap...which really isnt pressure rated...

[Atlantis]

They make pressure rated, threaded caps, they are basically female encaps that screw onto male adapters.

[djt]

looks like it would work. i have always wondered can you trigger a burst disk with a little nichrome wire? you could just put that on the burst disk and flip a switch to heat and melt part of the disk, causing it to rupture. If your wanting a piston to be incorperated then i think your ideas the best way of doing it.

[Atlantis]

Thanks for the input. Where would one get nichrome wire? Is that the stuff they use on electric grills?

[Rambo]

I think the best way to triger a burst disk is to ignite the high presure mix in the chamber.

[Atlantis]

That would be a hybrid which I don't feel comfortable with. Normal air does'nt ignite. I just thought this would be a nice simple design for a pneumatic. I need to build something before July 4th, besides my current combustion cannon.

[djt]

hm im not sure where to get nichrome wire except ebay around here. its really cheap on ebay though. With shipping, 30 feet of it comes out to be like six bucks.Nichrome is the stuff in toasters, the wire that gets red hot when you run electricity across it. im not sure how long it would take weaken the disk enough to rupture though.

[frogy]

Nichrome wire would be stupid....

Atlantis your first design is really good... all you have to do is keep adding air until the burst disk is pierced then it vents instantly down the barrel, causing the diaphragm to go back, letting more air down, causing lots of air to rush down the barrel very fast, causing great power.

[rna_duelers]

Frogy i believe he is using a trigger mechanism where the preassure is the same on both sides of the piston and he vents the front half andit moves forward piercing the disk.
I like the idea atlantis and i wouldnt mind having to unscrew and replace the burst disk everytime besides the flow and power of this valve would be amazing.Good job i might design something like this and use hyrdogen see how fast you can get a projectile.

[Atlantis]

I hope I get a chance to build this, I'm gonna try to make a homemade union that will better fit this concept. I plan on using one of my current 1.5" barrels.