Customizable Balls in Cage
This is a modification of http://www.thingiverse.com/thing:348861, correcting the ball placement for vertical printing.
The original always placed the balls in the center of the open space, and spaced the balls apart; This causes problems when printing the model, since the balls start in mid air (don't know about your printer; mine really doesn't like this). This version moves the balls to the bottom of the cage, and removes the gap between them, so that each has a surface to begin on. This makes for a much happier printer, and a better print of the model.