The key or "object to be constructed", is a partial pyramid made from 30 cubes. The array of cubes that forms the surface adds a degree of difficulty. Puzzle 1 has 3 pieces all ten-cubes;
puzzles 2 and 3 have 4 pieces, 2 eight-cubes and 2 seven-cubes. In puzzle 2 the 8-cubes are identical and in puzzle 3 the 7-cubes are identical. OpenSCAD code is included.

MakerBot

MakerBot Replicator (5th Generation)

Yes

0.3 mm

All pieces were printed at draft resolution without support.

A tiling search was used to construct these puzzles see - tiling-04.tar - at http://djm.cc/dmoews.html - Many possible puzzles were found. These versions were chosen to be easily printed without support. The clearance between pieces is 0.4 mm and is a settable parameter in the openSCAD code. View_answers.scad shows the key with the pieces separately colored - see below.