Various systems for compressing and loading an expandable medical device into a sheath are disclosed. One system comprises an array of moveable blades radially disposed about a central axis and forming a radially contractible aperture. The blade array includes at least a first plurality of blades and a second plurality of blades. The first plurality of blades is independently moveable with respect to the second plurality of blades. Additional aspects of the invention include methods of using the various compressor systems to compress and load an expandable medical device into a sheath.