[martin417]

Another though on vacuums: some are single stage, and some have two or more. A single stage will have one rotating disk, while a two stage (like the one we used) will have two rotating disks separated by a stationary flow straightener. A single stage will flow more air at a given size and power, while a two stage will create a higher static pressure differential.

If you can get a two stage, you will probably be better off in this game because the ball area is relatively small.