I've just gotten into woodworking. I'm definately a novice, but a quick learner. I bought a little 1hp dust collector that is rated for 914cfm. Here's how it's set up: out of dust coll. with reducer from 4" to 2"(in my shop attic)...90 degree down thru ceiling to a Dust Deputy(cyclone)...Dust deputy is mounted to 20gal. trash can(everything is sealed)...come off of the dust deputy and branch out to 3 workstations. My problem is...my shop vac has more suction than want I'm getting.
First, a 1hp collector is really just a "one-machine-at-a-time" unit.
Second, lose the reducer and keep the line as large as possible between the collector and the machine. Reduce-- if you have to-- as close to the machine as you can (bigger duct=more air volume=better collection)
Third, keep the duct runs as short as possible and the turns, Y's, etc. as few as possible. (Tight turns = more friction = less air flow).