This unique puzzle original idea is around since the beginning of the 20th century, however, the modern version was created in 1981 by NOB (Nobuyuki Yoshigahara), a talented Japanese puzzle designer and inventor. NOB had also designed several Cast puzzles for Hanayama (for example, the Cast News metal puzzle by Hanayama is based on the same solution mechanism as the Crazy X wooden puzzle). Also known as 'X Marks the Spot'.
Object
A very clever and tricky wooden brain teaser puzzle.
The objective of this puzzle is to remove the X from the square wooden frame.
Seems like impossible to solve, but can be solve in one second.
Don't be tempted to think it is an easy job.
A hint for the solution is in one of your physics lessons.