I was inspired to make this Thein cyclone dust collection system for my shop, from a previous post https://www.instructables.com/id/Making-a-cyclone-chip-separator-for-a-dust-collect/. I recently refurbished a bedroom in my house and the job required me to plane a number of MDF 1x4’s. I’m still trying to clean the dust out of my shop 2 months later.
My requirements were ; run the ducting above the rafters, direct venting outside with no filter, as few bends as possible (thus the idea of mounting the cyclone at rafter level) and an easy way to empty the chips and dust. The Harbor Freight 2 HP dust collector is the heart of the project.

Step 1: The Cyclone Conversion

I used ½”OSB plywood to laminate several rings to lift the blower high enough to clear the mid-section.

Step 2: Cut the Thein Baffle

I traced an outline of the mid-section on a piece of OSB then used a compass to draw an 1 ½” slot 2/3rds of the way around.The mid-section is not a true circle so I had to fudge the lines a bit to get it right. If it looks right, it is right. I laminated a piece of ½” Baltic birch on top of the OSB to get a smooth surface inside the cyclone.

At this point I also glued some blocks on the baffle to attach it to the mid-section. Then I put a bead of silicon down to seal it together. At this point I cut and bent the original stanchions to hold the mid-section to the baffle.

Step 3:

Mount the cyclone assembly overhead and build the chip and dust gathering box underneath.
I used latex caulk to seal the dust box during assembly. The box wound up being 2’x2’ by 4’ high. I also added a hinged trap door at the bottom.
I added 4" PVC duct pipes overhead and used 2 Harbor freight dust collector accessory kits to connect my Unisaw, radial arm saw, planer, home brewed panel saw and bead blasting cabinet.