I started with a simple sphere and sliced it in several pieces in ZBrush. Next, I created "Panel Loops" which gave each piece a nice thickness. With only four pieces, it certainly isn't much of a puzzle. But the technique can be extended to other shapes and more pieces.

All four pieces are in one object to print. I spaced them apart so they can be separated easily once the printing is done. I like it when the printable thing looks interesting besides the finished object.

When I was photographing it, I stuck an LED light inside to see what it would look like. With the room lights off, it reminds me of putting a candle inside a pumpkin. Again, it gave me some ideas about what I could do with this type of design.

I used ReplicatorG to prepare the file, a MakerBot Replicator2 with the Replicator2 slicing defaults and the following settings with white MakerBot PLA to do the printing:

Infill = 10%
Layer Height = 0.200
Shells = 1
Feedrate = 90
Travel Feed = 150
Temperature = 230

I used a raft with full support. It took almost 6 hours to print at 70 mm high. Removing the support structure wasn't bad at all.

I tried using MakerWare V2.3.2.37 to print it, but the inside of the top piece didn't print that well. MakerWare uses minimal support structure which is okay for some things, but not for this design. I like the MakerWare interface much better than ReplicatorG but the slicer isn't as good. Anyone know if this might be change in the future?