I have watched all the videos and the shots seem somewhat inconsistent in power. Do you use some kind of wadding before you load the projectile (you said that the size of the marbles vary)?

I agree with Gippeto. In all vortex cannon that I have seen so far there was a controlled "bottleneck". You can see it at the example of an airzooka. http://www.thinkgeek.com/images/products/zoom/airzooka.jpg You could try to put a expansion chamber in front of the funnel. Edit: This video has been ...

So this version isn't coaxial anymore? cam locks

jackssmirkingrevenge wrote:Shame you're going to add a handle, I really like the "file" look. Guess that makes me a fileophile

IMO a lanyard handle would be a good compromise.

Have a look at these whistling tips for arrows. They are quite simple in design and could be implemented in a way that fits your needs.

Agree but unfortunately we don't have a awesome/useless category on Spudfiles :wink: . The cost efficiency of this device is pretty good I would say, what could make it attractive to certain organizations. Another wall breaking alternative would be this device even though it is not intended to be us...

Found this on Youtube, looks like fun !!!
[youtube][/youtube]

350°F would obviously be to hot for a computer fan. You could salvage a fan from a baking oven on a scrapyard.

Are some people really that dumb?
I think that is fake but see for yourselves.
[youtube][/youtube]

You could order the center drilled balls and fill them with lead.
How they would behave in flight is another question.

Of course we are ready for Brian the Brain.

Bring it on!!!

IMO this would be the ultimate troll choice.

You could get a ton of light in, too, considering 50/1.4 and 135/2.8 lenses are available very cheaply on ebay. The objective lens sure helps but the main factor is the CMOS chip. Compared to a p&s the chip of a DSLR is gigantic. I have a bridge camera with a rather large objective and it is still ...

That looks really promising. I assume the screw will hold some kind of sealing?
It doesn't look like there are any flaws in the design, the only weak spot I see is the sealing face and possible blow outs over time.
Considering your experience with your hpa coax, that shouldn't be a problem.

In the area where I life the scumbags are stealing less traceable stuff like metals. At the current prices on the market you get 1200 euro per metric ton for scrap metal and much more for copper. They even steal from churches that are hundreds of years old, it's disgusting.