Theatrical Prop

[theregoesthewindow]

My friend, a fellow spudgunner, is building a "cannon" for a play. He decided to use a pneumatic burst disk replica of a carronade, a miniature(sp) cannon. It is built with a three inch chamber and a sprinkler valve connecting it to a three inch burst disk. Then he is going to construct an ABS "cannon" out of 6" and slide the burst disc in. To create a smoke effect he is thinking of using flour on the burst disc. I am posting this on the forums to see if anyone has an better idea because currently there is no muzzle flash, and I have concerns about the flour settling on the ground to create a dusting of white.

[Brian the brain]

Ask BC Pneumatics...I think he's into pyro stuff.You need something that gives a nice flash and some smoke but not a real big bang.Electrically controlled would be nice

[theregoesthewindow]

See that's the problem, I think the principal is really freaked about fire or something and won't let there be any on the stage. That's why we built a pneumatic one instead of a combustion. Only problem is that with my friends design there is no muzzle flash and I have concerns about the flour coating the ground/audience.

[CS]

I cant see a principal be very excited about a cannon being used to shoot a materail to create a "smoke" effect.

Fog machine? Maybe you can google and find some "homemade" fog machine plans...

[Shrimphead]

You could put a little piece of dry ice and some water in the chamber. Then it will steam and when the gun is fired it will blow out, hopefully looking like smoke.

[theregoesthewindow]

Good ideas!
@Pimpman; I looked at smoke machines in general, seems that they use "smoke juice" which is then put into a chamber with a metal plate that heats it until it vaporizes creating pressure that forces the thick white fog into the room. It would work, if the play was organized differently. From what I understand the cannon will be kept offstage, but in an unaccessable place for about an hour. This is ample time for the smoke to then de-vaporize and condense in the chamber, creating a mess, that is of course if he fills it beforehand.
@Shrimphead; That idea should work in a pinch! There is only one problem that I can see, that the pressure created by the dry ice will blow the chamber. Otherwise it should work.

[Shrimphead]

Just make sure that it's a pressure rated chamber, and don't put too much dry ice and water in just to be safe.