Hi Futterama! Getting a machine-gun sound from a small combustion cannon is super simple, the only hard part is if you actually want it to shoot something! The most important question is... what's your payload capacity? It would save a lot of headaches if you could carry a small hpa tank. Where you ...

Oxy hydrogen is the same thing as H2 + O2... You can make it from water. Any fuel mixed with *pure* oxygen instead of air needs to be used in a metal gun, not PVC. If you're having trouble understanding anything, I could simplify the description and run it through a translator (if you think it would...

Hmm, lets see. On one hand we have a substance that's intended to keep your hair in shape, and on the other we have a substance which is liquified and used to launch rockets into space. We have a very detailed wiki page for this. http://www.spudfiles.com/spud_wiki/index.php?title=Common_Fuels_for_Co...

The second is less efficient but there may be exceptions to this rule. Because the gas accelerates to a significant velocity before it encounters the projectile, it will experience shock heating from the sudden recompression. With the right type of projectile, valve and barrel you can see some notic...

And pressure rated pipe to boot!

Oh there he is. Half life 3 confirmed?

Post a picture of the gun and we'll be able to give you more reliable advice. To begin with, try starting fluid instead of gasoline. It vaporizes easily from an aerosol can, and tends to leave less soot behind. I've had limited luck with gasoline sprayed from a windex bottle, try a squirt for every ...

In all honesty, if this is your first hybrid or first large-scale build with a college machine shop at your disposal, just go for a standard 10-20x mapp/air gun with a piston valve. After that goal is achieved, the breech and fueling can be automated with a bit of pneumatic/EE work. 5-10 shots per m...

In my 1.5" valve there's a small bleed hole in the diaphragm that lets air into the chamber. Maybe you have a bit of debris plugging it up?
You should take pictures of the internals if possible, just so we can rule out any defects.

Checking his numbers, I think he's short by an order of magnitude. (Although it is past four in the morning here, so maybe I'm the one that's wrong). Your numbers are closer than mine, since I didn't do any 'real math' to come up with them: 1.6 megajoules muzzle energy / gun efficiency (assumed an ...

Paper cone skirts soaked in superglue are fairly durable, and if it gets shredded you can just add more layers until it holds together.

I am looking for someone to build me a cannon that shoots golf balls from the tee box to the green 450 plus yards I am willing to pay someone to build me 2 Lmk if you can help me P̶o̶s̶t̶i̶n̶g̶ ̶a̶ ̶v̶a̶g̶u̶e̶ ̶r̶u̶n̶-̶o̶n̶ ̶s̶e̶n̶t̶e̶n̶c̶e̶ ̶w̶i̶t̶h̶ ̶t̶x̶t̶-̶t̶l̶k̶ ̶a̶c̶r̶o̶n̶y̶m̶s̶ ̶a̶n̶d̶ ̶n̶o̶...

I think it is just a matter of selection the high quality piston that will work awesome. I know a lot of users there can recommend us the best quality piston. :) This is kind of off topic but I am wondering how this guy has flown under the radar for over two years now. He's either an uncanny valley...

Just checking in and came across this semi-old post. Bump. Ignoring material considerations and inevitable destruction of moving parts, I'm wondering where one would acquire the 5 megawatt DC power supply needed to run this gun at full power? And also how to deal with multiple megawatts of waste hea...

Ragnarok wrote:

mark.f wrote:Look who decided to show up.

Benedict Cumberbatch?? Where?

No, it was just Hasselhoff again. Nothing to see here.