Buy a box fan or pick one up at a yard sale, Goodwill, etc.
Go to Amazon and look for a MERV RATED Electrostatic Washable Permanent Furnace A/C Air Filter. Prices range from the $20-40's. I bought one at a box store years ago with a .3 micron rating for under $30.
Tape the filter to fan's frame on the inlet side. You could even put a cheap 99 cent filter on the fan exhaust side just taped (held in place) on the top to direct the air down.
I use one at my lathe instead of my dust collector. Three speeds, much quieter, and VERY effective.