magic eight ball

Here are a bunch of files That I used for an Instrucable. http://www.instructables.com/id/Magic-8-Ball/
Any top will fit any bottom as long as you scale them both the same amount. Bottoms can be printed with no support. Tops need support.
Both halves have mating flanges which can be glued or held with tape. I plan on painting mine black and then use electrical tape to hold the halves together.