Sunday, 7 December 2014

Cross & Crown 2013

The Cross & Crown (C&C) puzzle you see here is not a modern puzzle design by any means, no, not at all. In fact, the C&C has its roots in a puzzle designed by Louis S. Burbank in 1913, which was patented by the US Patent Office.

The C&C was Dr Goetz Schwandtner's IPP34 Exchange Puzzle. It all started when Goetz had a chance to see and play with a very rare metal version of the original design belonging to puzzle collector Rob Stegman at IPP32. Goetz collaborated with another collector, Michel van Ipenburg and together, worked with IPP31 award winning designer Robrecht Louage to reproduce the version that we have today, making it available to puzzle enthusiasts.

The modern C&C is made of trespa, a strong and durable material widely associated with table surfaces. Metal would have been too expensive and impractical for production in large quantities. The puzzle is precision cut to tight tolerances but everything slides smoothly as intended. Quality of construction and finish is very good like in all of Robrecht's work.

The C&C is a N-ary puzzle. I still have little idea what this means but you can see examples of these and read more about it on Goetz's site. Like the original design, the C&C consists of a "cross" pivoting on a circular disc containing cut-outs. Both the cross and disc are "linked" by four rivets that can slide along each arm of the cross as well as along the channels of the cut-outs. The object is to move all the rivets through these zig-zag channels and reach a point at the end where the cross can be disengaged from the circular disc.

Like an N-ary puzzle, there is a kind of repeating pattern of moves (this aspect I know!); sort of a back-and-forth motion. I have played with several other n-ary puzzles such as the Lock 250, Alles Schiebung and Numlock and have solved them without help. Yet, for this C&C, despite spending a lot of time on it, I just could not get beyond a certain point and found myself keep getting stuck halfway. Perhaps I am way off-tangent on this one, but I am finding the C&C very difficult!

N-ary puzzles exist in all styles, shapes and sizes. The Chinese Rings is perhaps the early originator of such puzzles but it is binary rather than N-nary. The C&C is yet another example of a growing number of N-ary puzzles that have come to the market since Jean-Claude Constantin's 1250-move Kugellager a while back. For those keen to acquire a copy of C&C, you can contact Goetz via his puzzle site.

Puzzle Master of Canada and Mr Puzzle of Australia also retail different N-ary puzzles, as do Wil Strijbos.


  1. Not solved it yet? That's shocking!! Get to it man!

    It's linear with no choices so the only issue is losing track (usually when you put it down for a rest) - if I need to take a break then I ensure it is at a change of direction and it take a quick note of what comes next!


  2. I really enjoyed solving this puzzle. So well made too. I've wondered, if I'm somewhere near the middle, is there somebody who can recognize which way to go and how many moves are left.

    1. Tom, I am still always stuck somewhere in the middle. Thanks for reminding me; I need to ask Goetz how many moves there are for C&C.

    2. I might be able to tell, but I am not 100% sure. Sometimes with such puzzles I start moving on with the solution at such a point, just to find out that it was the wrong way maybe a couple dozend moves later.

      Jerry, overall it is 1250 moves. In the patent they have a lower move count, which should be due to a different and less consistent counting method, I guess.

    3. To add to my comment: Actually, I believe they only count the radial moves in the paten, i.e. when a rivet is going away from the center or towards it. Should be 650 then (half the moves) -- not sure why it is 681 in the patent. :)

  3. Thank you for the nice review, Jerry. If I look at your picture, you have come quite far already, well done! One rivet is already in the outermost "circle", one next to the outermost circle. Now the rest is mainly patience and concentrating. Trying to avoid that you are going back where you came from ...

    Without giving away too much, please notice that the first rivet will have to travel from the outermost circle to the middle (reverse the move sequence), so that the second one can go from the fourth circle to the outermost/fifth circle. It is a lot of back-and-forth. Maybe that was causing confusion here. :)

  4. 1250 moves needed from start to end. For any given position I'm able to tell what the next move is to.go forward or backward...find me on facebook for contact ;-) Michel van Ipenburg

  5. I agree there is something weird about this puzzle. You think you have it figured out but then in the middle something unexpected happens and you have to shift your strategy to keep going. That's how it felt to me, I eventually solved it.

    One nice thing is you can reset it by taking it apart, because I am not sure I could solve it backwards!