I had posted this elsewhere on the net but thought it might be of interest to anyone who hadn't seen it or are new to woodworking.
I built this shop air filter using plans fom woodsmith #95 provided by friend Jim Young.
I had an old squirrel cage fan sitting under the bench and some scrap plywood so this shop air filter cost me nothing other than the filters. I misread the directions and made room for a extra filter at both the inlet and exhaust ends of the filter.
I built this a year ago and it has worked fine for what it was intended to do.