I cobbled together a marsh mellow gun with the QEV to test the automatic functionality this weekend. The pressure source I was using was only 120 psi, so the pop off required a slight pull to get it to shoot. It worked quite well filling it from the chamber side. I had to restrict flow into the cham...

Are you using this piston inside of a tee fitting? If that's the case, have a look at my piston valve from my hybrid. https://dl.dropboxusercontent.com/s/up9uqcpdep1rp0l/SpudchukkerValveClosed.JPG https://dl.dropboxusercontent.com/s/n799m258jmoc6hm/spudchukkerIIISection.JPG For a pneumatic, you don'...

I've been shopping around for pipe to use as a cartridge that would closely match the ID of the 1/2" galvanized pipe I want to use for a barrel. The closest I could find was 3/4", which was very slightly bigger than the ID of the steel, while 1/2" copper tube is very very slightly less than the ID o...

I was thinking a bolt that is the same OD as the ID as the cartridge, with a tapered end and depend on friction, and perhaps an o-ring to pull the cartridge, rather than a rim and outer claw. As for the extractor, I was going to put it slightly behind where the cartridges come into the breech, and j...

Would shop air pressure be enough to actuate such a blow-back design? I think I can compact a blow-forward design quite a bit, by pushing the cartridge forward with the bolt like you have done, and bringing it back to the ejection port. Do you think I am better off with a blow forward or blow back d...

I completely agree with you. Having the magazine well closer to the trigger is something that I hope to achieve. Unfortunately, I think it would require moving the QEV back further to make room for the bolt. In that configuration, I don't know what I would do with the chamber, as a scope would look ...

Hey folks, Just wanted some input on my latest idea. For a while now, I've wanted to make a smaller bore cannon for those pieces of spud left over from my larger 2 inch and hybrid cannons. I also really like the idea of cartridge fed gun, by which I mean stuffing small pieces of pipe with potato to ...

I like your piston valve I'm wondering g if I can copy your piston design? That's the one thing I have on my hybrid to take care of. Only as long as we all get to see it! Just a quick question here, how did you take care of the little weld nub on the inside of that 2" 3inch galv steel pipe that you...

I posted this with the intention of adapting it to spudgun use, i.e. propane/air mixture in the primary chamber, and a light gas like helium in the intermediate chamber. But, as it was pointed out, there probably isn't much of a performance gain to be found over a standard hybrid.

Found some vids a friend sent me from his iPhone, made a gif:

Hey all, Found a particularly interesting article for those so inclined: http://history.nasa.gov/SP-4302/ch2.11.htm The article is about the history of wind tunnels and testing at NASA, but there's a bit near the middle about shock-tunnels and a shock-compression light-gas gun. It's basically a hybr...

Yes, you're right, the camlock is there only to facilitate breach loading at the rear end of the barrel. This section of the gun isn't pressurized pre-ignition, so it serves only for breach loading. I love the igniter. It's of the gas-grill variety, so it releases a rapid repearing spark rather than...

Noice! Awesome work even getting it finished, I can't seem to get passed half finished with projects simpler than this. Props on the rendering, video, 3D printing, and a working piston hybrid. + Rep :) How did you get rid of the ridges in the metal nipple? Where the larger o rings of the piston rid...

As a pure pneumatic, it is quite weak, though I estimate it has about a 100 yard range with a high arc. One could always start with a decent sized steel piston-pneumatic with a bigger chamber, and then you'd be only one spark-plug away from a pretty big manometric hybrid!

Spudchukker III - Venting Piston Hybrid https://dl.dropboxusercontent.com/u/25331835/tater%20cannon/Showcase/SpudchukkerIII%20Final%20Render.JPG Hey guys, I finally got around to making the showcase post for my hybrid since I feel it has more-or-less reached completion. You can find the build log f...