Oskar van Deventer may be very well-known in the twisty puzzle circles for his unusual twisty designs. But he also has 15 Hanayama cast puzzle designs to his name! These include the Cast Twist, Cast Nut and Cast Duet. Not to mention he has also designed numerous other types of puzzles made either out of acrylic or wood.
I first saw the Mobius at the Singapore Puzzle Party in 2015, where Oskar was on a business trip to Singapore. A bunch of us puzzle enthusiasts met him for a nice puzzle evening over dinner. There, he showcased an array of twisty puzzles (a number of them new prototypes) and also brought along a Cast Mobius (prototype?). I didn’t get a chance to try the Mobius that night. Finally at IPP37 in Paris this past August, I snapped up one during the Puzzle Party.
The Mobius is based on the Mobius Strip. The object of the puzzle is to remove the round disk from the curving “strip” which has protruding bumps and forms a maze along both surfaces. Without “entering” the maze, the disk can actually travel along the curves of the strip and the orientation of the disk as it travels the entire length changes. The strip is made of zinc alloy and the disk aluminium. Talking about the Mobius strip, Japanese designer Hirokazu Iwasawa also designed the Zipper using the same concept.
The Mobius measures about 6.5cm x 6cm. Quality of construction is up to the usual Hanayama standards. The puzzle itself is not hard but will still provide a fair challenge for novices. It is rated 3 stars by Hanayama and that level of difficulty I think is about right. Perhaps maybe even 2.5 stars. Still a bit tricky somewhat and not as straight forward as one would expect. It took me a couple of minutes and I had the disk out in no time. Putting the disk back was just the reverse. One of those puzzles where persistence would eventually get you to the solved state.