I did not know what to name this piece that has the typical shape of 2D puzzle pieces, since, more than a puzzle piece, it looks m...ore like a tile since printing multiple identical pieces these fit perfectly in an articulated way like a hinge that allows generating three-dimensional shapes, one of them is the cube. But the forms that can be achieved with a little imagination are many.
The initial design was based on the 8mm modulus. Later I have added the 10mm module and the 16mm module.
3d model print parameters
Print with any rigid filament
I did it with PLA with 1mm walls and 10% fill with triangular pattern and horizontal expansion of -0.1mm
To obtain a... cube you will have to print 6 pieces of the same size.
To fit the pieces together, carefully force the protrusions in the shape of a small cone with the holes in another piece.
If you want to use the cube as a box to store things, the piece that has to act as a lid will be convenient to sand the cones on the sides that we want to be able to open easily.