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).
|Removable magnetic lid. If only all mechanical puzzles are made like this!
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. Thankfully Tom had constructed a removable lid on the box for re-setting of the pieces within (so as not to torture the IPP34 participants), so the put-together was easily taken care of.