These are cool, but can they be re-arranged to look more like the typical piston gun, where the porting is full-bore straight into the breach? I guess you'd need an awkward hammer that pulls, rather than pushes, the stem.

I'm thinking about ways to make a self-contained gun where the energy to fire it is delivered manually by pulling a more-or-less constant force across a moderate distance (3 feet). Supposing I can lift about 50lb, and suppose I can make the 'stacking curve' sufficiently flat that I deliver 80% of th...

Hey guys! It's been ages since I logged on [edit: almost 4 years!]. I still keep my cannons at my parent's garage, but I've lived in apartments in the city for the last 6+ years, so I haven't been able to build anything new. I don't foresee that changing for a long time either, unfortunately. It's a...

I used to do this with oxygen and gasoline or acetylene, no water. I was crazy enough to put some lead fishing weights or washers on top, along with fins and a nosecone. I'd say I got 300+ feet, but that may be generous. No idea how high the weights (read: shrapnel) went when the bottle exploded, wh...

I'm at school in the middle of a city, with a smallish apartment and no car. I don't have the space or the time right now to build anything. I'm sure I'll pick the hobby up again at some point in my life though. I'm consoling myself by building some water bottle rockets this summer. Oh, and when I v...

Edit: I want to move this to the showcase. Should I start another thread or can a mod copy the thread over? It's a bit louder at 10x, but still nothing like a .22 rifle. Unfortunately the epoxy around the schrader valve cracked & there's a slight leak now in the cartridge. I'll have to rethink my de...

I added the piezo trigger on the handle, you can see it in the video. The video shows the ignition system, the bolt action operation, and firing / damage. It's done at 5x. http://www.flickr.com/photos/57841472@N05/8336111558/ I had to reduce the burst disk thickness to one layer of paper & one layer...

Happy New Year! I finally got some time this winter break to put together a bolt-action gun to accept the cartridge I built last year(!!) Here's the scoop: http://farm9.staticflickr.com/8493/8330256309_7d84d54f72_k.jpg http://farm9.staticflickr.com/8074/8330257287_2c28e51f63_k.jpg The bolt is a piec...

Well, now that it's been revived:
I'm curious how you adapted the muzzle-loader barrel to the plumbing fittings. Is the barrel threaded NPT?

That is one freaking beautiful video! I'm jaw-dropped. Congratulations on all that hard work paying off! (And hooray for gov't money well spent for a change!)

I did this on a very small scale several years ago, and it was a lot of fun. I think my favorite part was when I melted a bunch of US pennies down with some copper, trying to make brass. I caught the zinc in the pennies on fire, it was a beautiful yellow-green color, mixed with the blue-green from t...

@JDP12:
Easy - the spring can be made so that there's no force on the hammer by the time it reaches the valve stem -- the momentum of the hammer then does the job of opening the valve.

@Brian: Freaking awesome gun, as usual! Can't wait to see it when you get through putting the furniture on it.

Very science-y! Me likey. I can't help too much with the GUI or experimental data, but I'd love to have a look at the simulation code. I'm decent in C/C++. What are planning on writing in?
Tech: clever use of the 'scope!

Sounds to me like a diode-pumped system to me -- maybe with a Q-switch or a Pockell's cell to create the short pulse width. No way any flash-lamp system is going to survive in an automobile. And I'm right: http://www.kigre.com/files/nd41.pdf . Looks like they might be heading away from Nd:YAG, thoug...

@ Crna Legija: dang it, I was in the office too! Blaspheming Sheen-roller....