For those who just can't get enough of burr puzzles... This puzzle's design pulled from the now defunct IBM research page. It was categorized under General higher level burr puzzles. This is a level 10 puzzle with a unique solution. These pages are still available through internet archives, see the links at the end of the wikipedia page. Note: I rotated piece 4 to turn an overhang into a bridge. This built cleanly on my cupcake with minimal sagging at the default size 6. While I found the Philippe Dubois burr slightly challenging, I found this one much harder. I have uploaded the puzzle file for Burrtools, see Burr Tools on sourceforge which can animate assembly too.I like to print the pieces individually, so I have included stls for both a tray of all pieces and each separate piece. The scad file requires the burr module this object is derived of. Assembly instructions on the research page above are probably more complicated than necessary, and assembling by adding one piece at a time is a bit difficult, as it unstable until the last piece is in and the first slide accomplished. I found it easier to assemble this burr by assembling the pieces as two groups of 3 and then merging those. The groups I chose were 135 and 246. There may still be more optimal ways to assemble it, and a possible shortcut/cheat involving rotating piece 4 into its slot.