Reply by ND2ELK

6” for the main lines, 4” and 2 1/2” for the drops with blast gates at each drop, 2 to 2 1/2 hp unit, metal pipe, one or two drops can be open at the same time. Grizzly has some bag units on sale right now. I have a cyclone but my friend did the same thing with a 2 hp bag unit. I did a blog on dust collection in. It might give you some iedas on lay out.

-- Mc Bridge Cabinets, Iowa