This is a famous engineer Rubik puzzle cube. I'm designed this model myself in FreeCAD. As opposed to previous version with tolerance 0.2 mm this cube has a zero tolerance between parts.

It has a next parts:
1 core
6 center "cubes"
8 corner "cubes"
12 edge "cubes"
6 pins for connect center parts to core
189 small dots in different colour.

There are some zip-files for your convenience - it has a whole plate of parts with supports (not made by slicer). Before assembling the cube, you need to remove the supports with a knife.

Instruction of assembly:

1. Insert small dots into holes in each cube with glue (Dichloromethane for example).
2. Connect each pin into center "cube" with a click sound. See that a hole in center cube has a groove and a pin has a skirt.
3. Insert a central cube with number 6 into the core with a click sound.
4. Put this part on a table and assembly all of cubes (4 edges and 4 corners) with number 6.
5. Insert another 4 central cubes (number 2, 3, 4, 5) into the core. Note, that sum of dice number on opposite sides is 7 (1:6, 2:5, 3:4).
6. Put 4 edge cubes at a middle plane in according order.
7. Put 4 edge and 4 corner cubes with number 1.
8. Insert a central cube with number 1 into the core with a click sound.

For the best result, it is necessary to lubricate the internal rubbing parts with Teflon grease.

You can also apply acrylic paint to the inner points using a medical syringe.