The 4 Steps Visible Lock ("4SVL") designed and made by Robrecht Louage won the Jury Grand Prize in the 2011 IPP Competition held in Berlin during the month of August. After seeing his puzzle on the IPP 2011 entries list with the different combination of materials used in its construction, I knew I just had to get one. Fortunately Robrecht's email was listed and I promptly emailed him to buy a copy of his prize winning entry. A week later, the puzzle arrived at my doorstep.
The object of the puzzle is of course to remove the 1 Euro coin out of the block, by moving the center acrylic slab towards the left so that the coin and be extracted from a hole in the top cover. Here is where the "lock" part comes in; the center acrylic slab is "locked in" by the ball bearings and can only move sideways within certain limits. The way to solve the puzzle is to use (some) dexterity to manipulate the ball bearings around the maze to "unlock" the center acrylic slab and allow it to slide towards the left, so that the coin matches up with the hole on top. But wait! It's not just the ball bearings that have to be dealt with; there are a couple of other necessary challenges as well.
I think Robrecht Louage has designed a very nice and well made puzzle and while not very difficult in terms of puzzling, it nevertheless poses a fair challenge. I would dare say that the 4SVL epitomises the term "mechanical puzzle" and justifiably deserves it's IPP award. Definitely worth acquiring for keeps.