Balance Tetris Box for Ender 3

This is a remix of the Balance Tetris box to fit the Ender 3 build plate as well as to enable multi-colour with inserts of the letters and the bottom of the holes for the pieces. This model uses less material while able to fit the same amount of pieces as the original Tolerances for the inserts are 0.1mm so a bit of squeeze may be required but then no glue.