remix of thing:199871 that snaps together like building blocks. no need for a box to roll it! also there is a trick hole that doesn't go anywhere! put is together wrong and end up with 2 fives:-0
use pla. pla has better layer bonding than some others like abs. solid fill for good feel. supports are pre-added in files. may need to adjust extrusion width/multiplier.
"squish-out" can make bottom holes too small. use a 2.75 mm to 2.8 mm wide flat head screwdriver or a 2.5 mm hex wrench to bore these holes bigger.
use a good sharp hobby knife to remove supports, burrs, and squish-outed edges.
how I did it (in a nutshell)
downloaded the "assembled" version of original for reference. measured a die. it was about 16.2 mm. took off 0.2 mm for extrusion width; left with 16mm. made a blank piece (16x(16/3)x(16/3)) and closed file. copied 9 more of file. renamed. opened the 9 files (the other is for backup). for each file added holes and studs with a 3 degree taper. holes are 3 mm (min d) x 1 mm (deep). pegs are 2.8 mm (min d) x 1 mm (tall). arrangement of the pegs and holes are the same as reference except an added hole for laughs :-D
front is the 6, bottom is the 4.
bottom (front to back):
files 1,2, and 3
middle (left to right):
files 4,5, and 6
top (front to back):
files 7,8, and 9