I'm designing a cyclone-on-a-budget, and right now leaning toward using some thick walled plastic barrels as the basis. For the cone I would make about 4 triangular cuts from the bottom to about 2/3 the way to the top, then plastic weld the cuts together to form a cone.
But that would make the cone section not exactly circular in diameter. I can fiddle with the smoothness (circularity?) a bit by making more triangular cuts or by heating and shaping the plastic, but it will never turn out as smooth as a sheet metal fabricated cone.
So, if you engineers out there can tell me how important the cyclone's circular-diameter smoothness is, I can proceed or trash this idea.
Thanks, H