There is a technique for aligning the two halves. The half with the flat side needs to be placed on a tabletop, then carefully align the two halves starting at the blunt end with the blunt end in the snap groove. Without squeezing the sides bring the two halves together from the blunt end and then snap the pointed end into the groove. Most important is not to compress the sides in while bringing the top and bottom together, if they are compressed, the halves will not align. It took me several tries to master the technique. Once snapped together, the resulting ball is very stable. Good idea that once the halves are snapped together, add a couple of strips of clear tape on the seam to make sure that the ball with added contents does not pop open if dropped.