This is how i made the cubes before I had them casted. I modeled them in a program called Rhino, Added a sprue to them and then had them printed.
gLike
Casted Bronze Neck Piece
This a casted bronze neck piece that I made. I modeled the cubes in a 3D modeling software and then had them printed in wax. I then put them in a kiln for the lost wax casting process and casted them.