Extended vacuum cyclon

http://www.instructables.com/id/Cyclonic-Dirt-Separator-Using-Off-the-Shelf-Parts/

Mine will be a thein baffle with helix. Built out of a bucket to sit on top of a trash can. There will be a small opening from the baffle to the trash can (1/4 turn, 1" wide), the bucket will be off center so that the dust drops to the center, that should keep the air in the can from spinning.