Flash paper cannon
This is one of the most simple effect to make, and on it's most basic level requires very little.
1. a chamber
2. Source of Ignition
3. Flash Cotton
4. Flash paper.
The one I made was modelled roughly on the one used in "The Phantom of the Opera". A multi cannon contained in a skull on a staff.
My chambers were three 9mm Aluminium tubes embedded in a moulded Skull sitting on top of staff.
I debated what way to go with the ignition, many source pointed me toward using Pyro igniters. To me this seemed an unnecessary cost. I opted for high resistance wire. That way it could be reused without having to rewire anything. These wires were connected to a threeway toggle switch on the staff and an button to launch.
A completed version can be seen here >>>> https://www.youtube.com/watch?v=_v90_fA9i64