The Down Burst Chip Separator is essentially an air tight box mounted atop an inverted metal trash can. My Powermatic Dust Collector is connected to one end of the box by 4″ ducting, creating a vacuum in the box and trash can. Sawdust, from my tools, is delivered to a common 4″ duct that enters the opposite end of the box.
I’ve posted a video detailing its construction on YouTube:
Debris entering the box is immediately deflected downward by a Plenum Takeoff (a sheet metal hood sporting a large rectangular opening), and into the trash can. The debris scarcely has a chance to enter the duct opening leading to the Powermatic, because it’s located on the box wall behind the Plenum Takeoff’s hood, while the duct delivering the dust has its opening nearly tucked inside the hood’s opening.
Once the debris has entered the trash can, it’s no longer exposed to the air currents between the two 4″ ducts mounted in the box. The debris then has a tendency to stay put.
My separator is mounted on the shop wall, about 3′ above the floor. The apex of the inverted trash can’s convex lid is fitted with an opening, collar (Flowtite), and cover (TeeCover). This means clean-out of the separator requires no disassembly, only the pulling of the friction-fitted clean-out cover, to allow the debris to fall into a box or bag.
When I tested the Down Burst Chip Separator on a large box of wood chips and dust, 80% of the debris (by volume) ended up in the trash can. I’m going to extend the duct opening (of incoming debris) even further into to Plenum Takeoff hood, and see if I can bump up that percentage.