So I’m a huge fan of fireworks and the 4th of July is probably my second favorite holiday. The obvious choice could be the printing of tubes for shooting mortars as many of these are already plastic.
The only thing I could find was this relatively dangerous use of 3D printing to make a fireworks bazooka (kids don’t try this at home). Many of the newer shells rely on shape charges to make shapes and the sky, so perhaps someday the cardboard and gunpowder itself may be printed. So what do you think could be potential firework applications?