[thefro526]

The disadvantage of Venturi Driven suction is that it requires a Pneumatic System to function which means you're adding a minimum of an extra 10lbs or so if you have the compressor on board and a reasonable amount of air tanks.

There are other options available to create a reliable vacuum driven mechanism, perhaps the most common is to take a commercially available vacuum impeller and retrofit one of the KOP motors to it. The motor only has to run while you need the vacuum, which should draw less power over the course of a match than a compressor. This method has been used by teams in the past to hold Soccer Balls, Track balls, and Tubes so it's proven as long as you can get your implementation right.

One of the downfalls of suction is that the surface of the object has to be relatively uniform which makes positioning key. You may or may not be better off pursuing another option.