Cartesian coordinate system snap together

Coordinate System Axes for teaching translations, rotations and other alignments. I have created this object for teaching students Coordinate measuring machine basics. Initially I had used some screws to attach the arrows, but that had a drawback of leaving an ugly hole on the opposite side, so I decided to add a snap fit pin construction. The vertical snap pin needs to be printed separately, because in vertical orientation the pin is simply not strong enough and it will brake when assembling the cube. i have also added some 30mm long plexiglas tubes with ID 16mm to protect the cube (and people) and for more appeal, but this is optional of course. I have applied some UV curing glue to the face side of the tube and glued it to the cube body, not the arrow.