Experimenting with a REAL DIY vortex cannon!

[squeak]

hey guys ,

glad i found this post ! god there is such a lack of info on vortex cannons ..

anyways to the point, im building a costume that requires two cannons on the back, (heres a pic)
http://www.gundammad.co.uk/images/D/ZD063big1.jpg

i wanted them to fire but cant have projectiles, or compressed air, or explosives or gas (damn con rules), so after a good hard think i came across some toy vortex guns ( the airzooka ). who can moan about firing air?

the barrels themselves are 1.2m long and 11-12 cm in diameter, for propulsion i was thinking of doing a hybrid airsoft gun, ie. a geared system with half gear and rack on piston, and i found some small smoke machines that would allow the vortex to be seen on stage.

now the trouble i am finding is that i know vortex cannons scale, i have seen small ones to ones made from bins, even that jap one the size of a house !

but i have yet to fathom what dictates the range and stability of the vortex,

speed is not really an issue, i want it to be seen, but a range of 20 ft+ would be cool,

so whats more important, the volume inside the cannon, or the piston speed?

( i also heard baffles inside can help the air start to roll before it hits the main one at the end , but i dont know how true this is)

any help is appreciated as some other "sciency " forums have fobbed me off, and i dont really know where to turn.

[jackssmirkingrevenge]

http://www.freeinfosociety.com/electron ... hp?id=2281

This seems easy to replicate. You could power it with with a geared system with half gear and rack on piston.

Some internal ridges on the tube would appear to be useful:



If you're feeling adventurous, the diaphragm could be driven by compressed air...

[squeak]

oh yeah, i have been in a few airsoft gearboxes before,
but its just the issue of the barrel length and head speed, or even the sheer volume inside,

heres a quick diagram
[img=http://s13.postimg.org/adw2bks0z/gun.jpg]
i couldn't use springs much like a airsoft gun as the springs are gonna have to be like 11cm in diameter, so i may go with small bungee cords or springs that pull the head back ,
like i said before, its more the 1 mtr of tube the pressure wave has to travel down, im just not sure of the effect it will have,