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. The helix will also be 1" wide and make one full rotation.