Numlock - Pit Khiam Goh by Tom Lensch

Years ago I thought I had experienced this ‘nary’ type of puzzle with Pit’s ‘Ternary Burr’ but as it turns out, not so much.  I recently had a chat with the authority on this subject Michel Van Ipenburg and he had this to say about it:

“I consider the ‘Ternary Burr not the best example of a ‘pure’ ternary puzzle.  It’s a complex burr with some ternary elements.  Once the centrepiece is out the ternary sequence is done and the puzzle that remains is an ‘ordinary’ burr (a beautiful one, but quite difficult).

Numlock is a more pure ternary puzzle.  The sliders and knobs follow a predictable logical pattern that will move forward or backwards, nothing else.  Once the first slider is removed the puzzle is basically done. To go back to the start (without opening it) takes the exact same number of moves in reversed order.”

Here’s Jerry’s Description from his Blog:

“NumLock was Goh Pit Khiam's entry for the IPP34 Nob Yoshigahara Puzzle Design Competition in London this past August. 

This is a "N-ary" puzzle. Don't ask me what it means because I don't really know, but it has something to do with mathematics. For an explanation of N-ary puzzles, you may wish to refer to Dr. Goetz Schwandtner's dedicated N-ary puzzles page on his website. My only other experience with an N-ary puzzle is the Lock 250.

Made by Tom Lensch, the NumLock comprises three woods; Cherry, Canarywood and East Indian Rose Wood. As with all Tom Lensch puzzles, the quality of construction and finish is excellent. All the pieces fit nicely and slide smoothly.

The object is to remove all the pieces from the box frame which consist of 4 sliders interacting with 6 moving blocks (with finger holes).The sliders and blocks all move in linear fashion.

According to Goh, a staggering 143 moves is required to extract the first piece. From my very limited understanding of N-ary puzzles, they usually comprise a repeating sequence of moves to solve, unlike high level burrs with a similar number of moves, so technically speaking, they are somewhat easier (not easy). 

As I was trying to solve the NumLock, I really couldn't figure out the sequence although I did detect some sort of a pattern. Well, repeating sequence or not, I was quite happy when I finally got the first piece out, after a good while of fiddling! Did I take a 143 moves? I don't know....would have lost count along the way anyway. I figured I would not be able to reassemble the pieces so I didn't bother trying.”

For more info about nary puzzles see Goetz Schwandtner page