I built one on that idea. I went to HD and found a workable size Furnace filter, and built the box to the size of the filters. I doubled the furnace Filters back to back, then took an old screen window frame cut that down to the size of the filters and put a ShopVac bag in that frame using the cord like a screen. The dust goes thru the 2 filters, then the ShopVac bag with the cleaned air thru the squirrel cage blower. Works great.