Cube In Cube / Sputnik

The Cube-In-Cube (aka Sputnik) was designed by Marcel Gillen, best known for his Chess Piece puzzles, some which have been reviewed in earlier postings. My copy of the Cube puzzle came from Finnish online retailer Oy Sloyd Ab. Produced by Bits & Pieces, the larger hollowed-out outer cube is made of aluminium and measures about 5 cm all round. The inner cube is solid brass and about 3 cm. Quality of the puzzle is above average and the overall finishing could have been better. Nonetheless, the combination of the two makes the puzzle very heavy in the palm.

This is a take-apart type puzzle similar to the Cast Cage and Aluminium Hedgehog, where the object is to remove the centre piece, in this case the inner brass cube. There is only one solution to the puzzle; the brass cube can only be extracted from one of the 6 open circular holes on one of the sides of the outer cube. Each of the circular holes have 4 tiny v-grooves cut into the sides. In order for the brass cube to be freed, the corners of the brass cube must fit nicely into the v-grooves for a smooth exit out of the hole. The difficulty is enhanced by the fact that the brass cube itself is not a perfect cube with equal dimensions (although this is not obvious), as the differences in lengths of the edges are approximately -/+ 0.5mm. Similarly the v-grooves for each of the 6 holes are also not all identical in their respective positions. As a result, there is only one correct side of the brass cube where all 4 corners will be able to pass through the v-grooves of the correct hole. 

Notice the 4 v-grooves cut into each side of the 6 circular holes

The solution is purely trial and error here and a good memory certainly helps when you try the various combinations and not repeat the ones that don't work. It is not a difficult puzzle; just that it requires a bit of patience (and dexterity) to try to match the correct side of the brass cube with the correct hole of the outer cube. Puzzlers with big fingers may also find it a bit cumbersome to try to manipulate the brass cube within the confines of the outer cube. Notwithstanding, there is some replay value here.....unless you have marked the puzzle to remember which side of the brass cube can be removed from which hole, you will invariably find yourself doing the trial and error thing in order to repeat solving the puzzle.