SpudFiles

Holy Crap. This thing is unbelievable. The sound. OMG the sound. I though a fricken black powder cannon when off in my garage when I shot that thing.

VIDEO!!!

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pretzelperson wrote:Anyhow . . . I launched a chunk of steel bar that was about 6" long and about 1.5" dia. I guess it weighed a couple of pounds. I never saw it and I couldn't find it. You should have seen the neighbors. They all came running out of thier houses to see what was going on. They were very upset--especially the people behind my house. Fortunately most of the people in my suburban neighborhood are pretty cool about this kind of stuff.

Wait wait wait. You're telling me you live in the burbs, and you're just launching stuff not knowing where it lands?

yeah ^^^ good point

and how did you deal with the recoil of that? i know i can barely keep the recoil under control when firing a maglite out of my piston valved cannon. but then im a small person......

You are my hero dude. Seriously. We get so many people talking about the insane stuff they are building, and no one ever builds it for one reason or another. As long as you stay below 7kpsi or so, you don't really need to worry about gas liquification. The highest pressure I've used yet in a big cannon is 400 psi (and it will remain so until the winter is over), and it was a really impressive noise, especially since it was 2" bore and a piston valve.

I wish you luck in achieving 5000 psi with this, and look forward to seeing the results.

I launched a chunk of steel bar that was about 6" long and about 1.5" dia. I guess it weighed a couple of pounds. I never saw it and I couldn't find it.

Almost 3 pounds, that is a very substantial missile that could kill someone if it fell on them, let alone if it was launched through the air at any velocity - and you don't know what happened to it?

Not responsible spudgunning in my opinion.

I'm really curious to see photos/videos of your setup.

I'm hoping he didn't fire the steel towards any inhabited area... But wouldn't it be best to assume that he didn't?

Aside from being sceptical about the whole subject of this thread (because when you have something this AWSUM!!!!, the first thing you do is take pictures ) - but of course, I might be wrong - there is no way that a person or property hit by 3 lbs of steel is going to do any favours to our hobby, no matter what our assumptions are.

True... I also wondered about the pictures, but it would be kind of pointless to say anything at all if you actually had nothing. Better just to shut up and slink away quietly than dig yourself a deeper hole. But of course, all of this assumes that the original poster thinks in a relatively logical fashion, so it's likely just pointless speculation.

If the chunk of steel was fired, lets hope that it went far enough away for no one to link it to pretzelperson's cannon.

I'm a little sceptical, but I doubt I'm alone. Until I at least see pictures, and preferably a video, I'm going to have to hold back on heavy praise.

But if it's true, I believe that is the highest pressure ever attained in a pneumatic, other than BTB's unregulated CO₂ bullpup.
With a decent valve, supersonic projectiles, extreme recoil and deafness aren't far away. TAKE EXTREME CARE!!!

As DYI said, there are enough crazy plans, and not a lot get built.
I'd love to say that my combustion airsoft minigun will eventually see the light of day, but it's going to take at least a while. We'll see though.

I'd like to mention that although there would be liquid oxygen there would also be other liquids like co2, h2o, n2 so really it would be just like atmospheric air in liquid state, so a melting pot of gases or a melting pot of liquid aren't so diffrent just presure, besides the O2 is one of the latter liquifying gasses after inert gases like CO2 and N2

you'll have to order most of your fittings to sch80 or higher but it would awesome, I'd attempt something like a 1.5 burst disk for bragging rights

Just a slight correction, the oxygen will liquify before the nitrogen, but the difference is only about 1kpsi or so. If the chamber was full of atmospheric air, the nitrogen would be the last thing present in any meaningful quality to liquify. The dialogue was more for effect than anything, not particularly accurate. (isn't it funny that we're talking in kpsi here?)

@Ragnarok: Right now I'm getting parts to build a test launcher before attempting the BB gun in my sig, just to see how insane the 2400 psi will be before spending hundreds on a handheld design that I may be too scared to hold. As for progress, the tank is refilled, the fittings are on the way, and I'll pick up the pipe and valve in a few weeks. I'll post it whenever I get the chance, but it is a very simple design. Are you sure no one has used more than 600 psi before? That seems kind of low.

Not entirely sure, but I can't think of anything.
It's only "recently" that people have started exceeding much more than 300 psi in pneumatics.

It's only "recently" that people have started exceeding much more than 300 psi in pneumatics.

True. A look at the old SGTC archives will show that before its demise, the trend was still leaning towards PVC, low pressure high volume pneumatics, of which the illustrious DR was such a great proponent. Spudguns are looking and behaving less and less like spudguns every month, and more like commercial pneumatic weaponry.

I'm seeing more and more pneumatics and hybrids, and a declining interest in combustions with more pressure in each. There's a lot of drive for increasing power.

600 psi may not sound such a huge amount now, but in the past, that was a vast amount.
Other than Brian the Brain, few people were using any more than 300 psi. Now it's pretty common.

True. A look at the old SGTC archives will show that before its demise, the trend was still leaning towards PVC, low pressure high volume pneumatics, of which the illustrious DR was such a great proponent. Spudguns are looking and behaving less and less like spudguns every month, and more like commercial pneumatic weaponry.

I think I was in some ways responsible, at least for raising awareness that the easy availability of bicycle shock pumps meant than 300 psi+ pressures were withing everyone's reach, and that for small calibres at least, increasing the pressure raised the performance levels dramatically. From what I saw BrianTheBrain started a parallell movement to some extent on this forum.

I'm seeing more and more pneumatics and hybrids, and a declining interest in combustions with more pressure in each.

I believe that combustions will remain a starting point for many budding spudders, though these days with so much knowledge available on advanced projects it seems easier for those who wish to start at the deep end.