Check this out: conducting fibers, plasma, and ionizing laser beams instead of water:
http://www.newscientist.com/article/dn6014

@metalmeltr: yes, but only the nuts, and not the female part. I'd have to buy another length of brakeline to get two more of those, so it comes out cheaper to use the plumbing fittings. @JSR: thanks man! I agree -- I just don't know when I'll be home again -- graduate school does that. I don't think...

I had best luck with packing tape (for strength) and electrician's tape (which is soft, for a good seal) stuck sticky-sides-together. Flat sealing faces or rubber washers help. I started construction of my own high pressure pump, but unfortunately, I'm now back at school, so this project is official...

Heh, I just bought an Arduino for my Dad for Christmas. They are pretty neat, but that's overkill for a simple select fire system. I wager I could put a select-fire together with at 555 timer and a few other components, and it would probably draw much less power and cost less. Of course, I'm sure Ar...

They are bulky, but I wanted plenty of oomph (or in layman's terms, MOAR POWR!) :D As to mixes, that's the trouble -- I'm not really sure, b/c my pump doesn't have a pressure gauge. It's sort of a miracle that I managed to get it to fire at all. Yeah, I thought about the rim as a contact point for a...

JSR: okey-doke, I fixed it. Thanks for inquiring! Ilovefire deserves a lot of credit for this too, obviously-- I'd seen his design and basically reworked it to use the materials I have. I'm working making the rest of the cartridges with the schrader recessed into the rear of the chamber, using a was...

I suppose I should have added a caveat to that statement, concerning my abilities and the time I have available over break. I'm sure it's doable -- in fact, I'm pretty much just copying your homework on this one. The first prototype is curing a.t.m. I need to get thinner epoxy, and quicker-setting t...

Well, JSR et al have been bemoaning the lack of innovation on the spud forums; I've been itching to build something, and now that I'm on winter break, I've got a project. My target is to use 5/16" brakeline for the barrel, which is something between 0.25" and 0.22" ID, so I can use .22" airgun pelle...

Holy Mackerel, Poland_Spud's right! Looks like you could get 97% with this stuff, using my equation: http://www.aerogel.org/?p=1058 Hmm, now I'm having visions of pulling my own "Up"-styled getaway -- I wonder how hard it would be to make several hundred cubic meters of cross-linked aerogel in my ba...

Well, being a physicist, I have to chime in: The optimal vacuum balloon is a spherical metal shell. If I did the math right, the lifting capacity is given by L=L_0*(1-1.5*R*P) where L_0 is the ideal lifting capacity (ie, volume*density of air displaced), R=(rho_m/rho_a-1), (rho_a=density of air, rho...

Well, if you are inventive and/or have access to a machine shop, I could definitely see someone combining this blow-back mechanism and bolt with a slide-valve to pilot the gun, something like this:

I don't see why not. It'd just be kinda awkward to have to turn the crank like that to fire the cannon. I suppose you could modify it with a catch and a trigger of somekind to release the internal spring on command, instead of just letting it slip off whenever the crank is turned so far. We've kind ...

[quote='jack']my work in this area is well documented[/quote] Wow, sounds like something you'd expect to hear in a research paper, not a spudgun forum! :lol: But it's true, Jack basically does all the research around here, with his crazy epoxy rapid prototyping method, while we sit around and wait t...

What a monster! I like it. I'm really surprized that the muzzle brake made that much difference. OTOH, I did have a large pneumatic that gave significant recoil w/o a projectile, so I guess it's reasonable.

Very Nice! That's an impressive set of beancans you have to run that thing. 12 KJ is a boatload. How much of the projectile energy could the injector account for?

Never thought I'd see rogowski coils mentioned on spudfiles!