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Air Delay Mine

Posted: Sun Feb 04, 2007 9:44 am
by PVC Arsenal 17
I've been trying to come up with some sort of pneumatic mine for ages. It had to be small, cheap, easy to build, and the most challenging- it had to have a delay.

So I came up with this and finished it today. It cost $10 and wasn't really hard to build. Best of all, it actually works as intended!

It consists of a 2" plug and a 2" x 1/2" bushing glued into a coupling.
A short length of 1/2" pipe runs through the bushing to the inside of the chamber and is capped. The cap has a pin-hole through it. The pipe extends out of the large bushing into a 1/2" x 3/4" bushing which connects to a 3/4" union.

The idea is simple. You fill the mine through the schrader valve and it fills up. Slowly, air bleeds into the small 1/2" chamber until it ruptures a burst disc, thus firing some baby powder or whatever you put in it.

It does work, but I'm still experimenting with burst discs to find the balance between power and an appropriate delay.

Image

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(more pics and hopefully a video soon)

Posted: Sun Feb 04, 2007 10:27 am
by VH_man
OOOHHH. If You could put a pin in that it would be very useful for airsoft/paintball. Mabey even Nerf........ Im Definetly going to have to try this.

Posted: Sun Feb 04, 2007 10:41 am
by PVC Arsenal 17
Mini nerf darts fit in there perfect.

Posted: Sun Feb 04, 2007 11:09 am
by Bluetooth
Cool. I want one.

Posted: Sun Feb 04, 2007 12:39 pm
by noname
For triggered actuation, you should try threading a long hook through the end of the main chamber and into the pin hole. Pressurize, unscrew a couple times, and it would start to let air into the smaller chamber. I mgiht have to try a couple of these. Glad you finally figured a simple design out.

Posted: Sun Feb 04, 2007 12:42 pm
by PVC Arsenal 17
Brilliant idea with the hook!

Searching for the right burst disc is becoming a pain in the ass. I think wide electrical tape will work best.... not sure though.

But I did paint it! Image

Posted: Sun Feb 04, 2007 12:58 pm
by noname
Try 1/16" rubber, it bursts at exactly 80 psi, how high do you pressurize it?
Also, with the hook, you could have like six hanging down from your belt and/or various pockets, like in all the shoot-em-up movies.

Posted: Sun Feb 04, 2007 1:15 pm
by PVC Arsenal 17
I've taken it to around 110 psi.

Posted: Sun Feb 04, 2007 1:34 pm
by noname
So the rubber would be pretty good, it's only $3 for a square foot, so you could get around 30 discs. See if you can get it at a local hardware store.

I'm going to make a couple of these, and experiment with diferent burst discs, different pin hole sizes for different times, etc. They could help with freaking people out on Halloween, considering how short the "barrel" is and all burst discs are frickin loud anyway. See someone coming up the street, pop in the rigth disc for the right time delay, load it up with flour, pressurize, and stuff it in a bush or something.

Another question, forget the variables, about how long does it take for the disc to rupture?
Aluminum Foil: ? seconds
Soda Bottle: ? seconds
Milk Jug: ? seconds
And whatever else you use for discs.

Posted: Sun Feb 04, 2007 2:13 pm
by StealthSpud
That's really sweet and it's a simple design!
Might have to try that out!

Posted: Sun Feb 04, 2007 6:44 pm
by dippydodo03
i'm gonna try these in paintball. me and my friends are always looking for somenew challenge in paintball. :rr:

Posted: Sun Feb 04, 2007 6:45 pm
by dippydodo03
i like the paint job

Posted: Sun Feb 04, 2007 8:18 pm
by noname
There's an edit button if you forget to put something into your first post.
What would you shoot out of it in a paintball game?

Posted: Sun Feb 04, 2007 8:33 pm
by Bluetooth
Ummmm... Maybe paint but I'm just pulling that out of my ass :wink: .

Posted: Sun Feb 04, 2007 8:35 pm
by noname
So I'm the dumbass now? Paint will just fly out when you chuck it, and there isn't enough space to get paint in there.