Printable Interlocking Puzzle #2

Designed on Christmas Day 2012, here is the second of my series of printable interlocking puzzles, and this time it's a 4x4x4 cube.
'Printable' means no support material required.
'Interlocking' means the puzzle pieces fit together only in the correct sequence and will not fall apart when the puzzle is moved.

This puzzle is much more challenging than PIP#1 so I am happy to provide a solution video which is at http://www.youtube.com/watch?v=oNIwRid7390

If you like this puzzle and fancy an extra challenge, perhaps you would consider paying just £3 for my latest and best design from here https://www.etsy.com/uk/listing/831851235/digital-files-for-printable-interlocking