...rip off of Thien design?
I'm sure for several years many on this forum, like myself, have watched Phil Thien develop HIS fine particle separator. I built one for a previous HF dust collector, and made a smaller version for a 5-gallon bucket. Others as well as I shared with Phil and his community results and tweaks we made to HIS design.
Please see this post: Linky
Thanks,
Mike