Diagonal Burr Puzzle Ball

This is a symmetrical version of the classic diagonal burr puzzle (which dates back to at least 1905), with a modern twist that when solved it forms a sphere. 

This is an easy print, no supports are required, and you'll need to print six of the pieces to form a complete puzzle.  As designed, the assembled model will be 7 cm in diameter, but the pieces should easily support scaling if you'd like a smaller or larger version.

Once you know the trick this puzzle is fairly easy to solve, although the spherical nature of this version creates some additional challenge.  If you'd like to take a peek at the solution, this video will give you the general idea.