I can not find the measurements for cutting the recess area on the baffle. From what I read I think you remove a radius of 240 degrees but I do not know how much to remove. Also would it help to install a wall from the input to past where the relief cut starts so as to direct all of the dust to that area? I was thinking that way you could help prevent some of the fine dust from making it back to the discharge tube. I am building a separator lid for a 55 gal barrel with a 6 inch inlet and outlet.
The main page says that he reduced the Diameter by 2.25 meaning that the slot is 1.125 wide. I was wondering today if that is wide enough for a 6" duct to operate effectively. My Calculus is rusty so figuring out the square inches of that slot is not as easy as it looks.
I finally worked it out: a 2.25" reduction in diameter over 240 degrees is about 1.15 sq/ft of area, which is about 5.9 times the area of a 6 inch opening. I would think that it would not have to be changed for a 6" duct.
That means that its just leaks that is causing me pressure drop, and I have to fix that tomorrow.
By the way did you know you can shape PVC with a propane torch?