I am just posting my journey for my upgrades to the Harbor Freight Dust collector I got. I have been using it stock except for the wynn filter cartridge and have been happy with it so far, however I have been getting some leaks and will smell the wood dust coming from the collector after cutting items.
So I figured if I am going to seal the leaks, I better just build a whole new cart and add a Thien Separator.
The first post here is detailing the Thien Separator. I went over to his website for the bible of dust separators. I wanted to retain the 4 inch hoses that I have on my tools. I have been designing it in sketchup based on the plans on his site, and a build done by Retired2. (http://www.jpthien.com/smf/index.php?topic=563.0) With the help of some others in his thread, I came up with this finished product.
It has a bellmouth outlet and side entry inlet. I will have to fabricate both of those to match my needs.
Below is the link to the sketchup plans for anyone else wanting to build this dust separator.
Retired2's Thien Separator by Justin Hill