It was designed by Kasimir Landowski and won an IENA gold medal at the 2008 Nuremberg Trade Fair. You can read about the history of the puzzles and order them online at the Casland Games website. Various virtual examples are available at the website and each physical puzzle includes a disk offering some virtual puzzles.

Moeraki is a type of sliding piece puzzle, which I would categorize as of the No Gap, Rigid Frame (Interlocking Orbits) variety. Moeraki No. 3, the one I have, has a square tray and two interlocking oval tracks of pieces in five colors. Moeraki No. 4 has a triangular tray and three interlocking circular tracks of pieces in four colors.

I received my No. 3 as a gift at IPP32, on the condition that I review it. Normally, I don't blog or review puzzles per se, but I accepted it since I had planned on buying one anyway. A policy of mine in general is to try not to say anything if I don't have something nice to say (in print, at least). I don't always succeed in keeping to my policy, but happily I will be in no danger here since I honestly like the Moeraki puzzle.

The concept of a set of markers riding in interlocking circular or oval tracks, which can be mixed by alternate rotations of the groups of pieces in the different tracks, is certainly not new. An example called "Race War Puzzle Between Gold & Silver" designed by William Churchill was awarded U.S. patent 507215 in October of 1893. More recent examples include the Hungarian Rings puzzle by Endre Pap et al (EP0050755) , and the Magic 8. On the Casland website it is mentioned that Ivan Moskovich also received a patent for a similar idea in 1979 (see U.S. patent 4509756), and is now collaborating with Landowski. Original concept or not, the Moeraki puzzle stands out as a very nice implementation and is probably among the most user-friendly of this class of puzzles in my collection.

You can find analysis and solutions of the puzzles at Jaap's Puzzle Page. Jaap gives the total number of possible arrangements for No. 3 as 3,969,069,923,590,200, which, surprisingly, is still larger than the U.S. national debt. Jaap notes that any two diametrically opposed beads will always remain diametrically opposed no matter what moves you make, which I find non-obvious on initial inspection, and fascinating.

Dieter Gebhardt has also published some analysis about this type of puzzle. Dieter's article "Rotational Puzzles with Two Tracks and Two Intersections" can be found in the March 2002 issue #57 of the journal of Cubism For Fun (CFF). Dieter's article supplies a notation convention and a general theoretical basis for deducing useful move sequences, and would be of interest to one attempting to gain a more than superficial understanding of such puzzles, although it deals with types of only two intersections.

These puzzles may appear to be intrinsically simpler than puzzles such as Rubik's Cube and its ilk, and in truth it is possible to attack them without extensive knowledge or analysis of solution procedures or "operators." And, as with twisty puzzles in general, the large number of possible states is not a reliable indicator of difficulty. However, it should be noted that some piece swaps may require upwards of 100 moves to solve, so patience and perseverance will definitely be assets to the recipient of these puzzles. At his website, Diniar Namdarian gives instructions for accomplishing a last swap of two pieces.

When I played with mine, I found the very first challenge to be simply opening the package! The puzzle ships in a cardboard box, which contains a clear plastic case for the puzzle, secured by four clips. A clip can be removed by prying its rounded end away from the case, but the force required makes one leery of breaking something. The puzzle is 135mm square and about 15mm thick. Production values are high - the plastic is good quality and brightly colored. A thoughtful touch is a removable block on the perimeter of the base, which will allow you to extract the sliding pieces from the puzzle in order to effect a brute-force restoration of the solved state, should you deem that necessary. The case also holds a CD-ROM containing additional puzzle software.

For me, assuming one enjoys this class of puzzle, two criteria determine whether a puzzle of this type succeeds or fails as a mechanical puzzle worth playing. First, do the pieces remain securely in their tracks? I have had copies of Hungarian-Rings style puzzles where the beads just fell out. I can report that the puzzle is well-engineered and well-built, and the Moeraki beads will not come out by accident. Second, is it easy to rotate the pieces along their tracks, preferably while holding the puzzle in two hands and using only one's thumbs to slide the pieces? Here I can also give the Moeraki a good grade. As with all interlocking-orbit type puzzles, the orbits must be properly aligned so that the pieces do not catch and impede movement. Out of the box, the movement of the Moeraki beads is somewhat stiff, but a benefit is that the tracks of beads do not tend to overshoot on a move, and a simple tilt of the puzzle will not cause unwanted movement. I gave it a shot of CRC Industrial Food-Grade Silicone spray and now the action is silky smooth!

I think the Moeraki would make good Christmas presents for the puzzler in your life (or for yourself). See what other puzzlers have had to say about the Moeraki puzzles here, here, and here.

A Level-5 Burr Set in mahogany and plane woods, made by Jack Krijnen. The attention to detail is superb! This set provides 35 (42 including duplicates) out of the 837 possible traditional six-piece burr pieces, at length 6. (The same as in a similar set made by Interlocking Puzzles ca. 2000, shown on Jim Storer's site. The piece numbering employed by Krijnen, David Winkler's scheme, is also identical to that used for the IP set.) The particular pieces are all notchable, and are those needed to build level-5 burrs. The set includes a small pair of wooden tweezers with which one can extract pieces from the box. The box is about 118mm x 90mm. The pieces measure 3x1x1 cm.

This is one of Trevor Wood's Teaser Tiles puzzles. Nine tiles, each composed of two slightly different sized layers, with various overhangs. The objective is to fit the pieces flat into the box - i.e. so that all pieces have their two layers parallel to the bottom of the box. Obviously, the particular juxtaposition of piece edges and overhangs will be crucial. Thanks, James!

I found a Tigerwood version of Wayne Daniel's Golden Rhombic Icosahedron.
I already had another version I believe to be the IPP17 exchange gift from Abel Garcia, made from Chechin wood. They have different pieces.
John Rausch describes the full set on his PuzzleWorld website.
Each puzzle has only four pieces, but they are difficult to take apart and to assemble.
The Zebrawood version has a slightly rounded interior edge to permit [dis]assembly.

I found what I believe to be another member of the Nervous Breakdown dexterity puzzle series
each of which features ball bearings inside a transparent puzzle board that one views via a mirror in the puzzle's base.
This version features a rocket background, but the case is more narrow than the others in the series.

I found a copy of the Idiot's Delight sliding piece puzzle issued by Roalex.
The goal is to move the pieces such that no color appears more than once in any row, column, or diagonal.
The space must end in a corner.

My friend Brett had showed me a puzzle he has had since childhood which was an advertising premium. Since then I have been on the lookout for one and I finally found it. The puzzle features "sand" inside a transparent plastic apex, and four moving sliders in the base. The objective is to discover the slider settings which allow all the sand to be drained into the base, revealing a totemic icon on the pyramidal apex.

The Chinese twisty puzzle company DaYan has offered a series of five 3x3x3 cubes, each with a different internal design.
I took this comparison photo showing an edge piece and corner piece from each, to help keep them straight.
From left to right: 1 Tai Yan (Big Goose); 2 GuHong; 3 Ling Yun; 4 Lun Hui; 5 ZhanChi.
My current favorite is the DaYan 4 Lun Hui.

I finally found an example of the vintage Maze Puzzle, patented in 1892 by Joel W. Thorne (483820) (483820 on Google Patents)
This is a ring-in-plate type maze - mine is missing the ring. Interestingly, the patent specifies an extra "decoy" hole, and a bull motif not used by the actual puzzle. The gap in the ring is supposed to be only just wide enough to fit the plate, not the raised maze walls. Also, note the elongated holes, which will allow the ring position to be adjusted for certain moves. Both those features are unusual for a ring-in-plate maze.

This is a vintage Ace of Diamonds puzzle. It is a four-piece dissection of a diamond shape. The four pieces can also be used to make several other shapes as shown on the back of the envelope, including a rectangle (but not a square) and the interesting "Goose-Step," so this puzzle is a tangram-type as well.

This vintage six-piece, square-tile edgematching puzzle from Germany is called the Matador Dominoes-Puzzle.
The backs of the tiles are blank. I have solved it, so it can be done.

The vintage Red Cross Puzzle is a twelve-piece dissection of a cross (or the letter t).
The small instructions slip identifies the source as The Gamo-Jig Company of 33 North Charter Street in Madison, Wisconsin.
The pieces are heavy cardboard - the backs are plain, not red, so the pieces must not be flipped over.
I have solved this one.

I found a second Draught Board puzzle - but this second one (the gold-hued one in the comparison photos) is an inferior copy of the original silver-hued version I have. In particular, see the photos of the backs of the two puzzles. The copy is blank, while the original has instructions and a registry number (594918).

A vintage Horse and Rider cardboard puzzle.

Two new puzzles from Smart Games: Bendit and IQ Fit.
Both were designed by Raf Peeters.
I found these at a Barnes & Noble store near me.

 
This puzzle is called Pulsar. It is based on a design by Victor Genel, modified by Benji and Ginda Fisher, and served as the Fishers' exchange puzzle at IPP 20.
It was made by Wayne Daniel. In the modified design, two pieces are fused to two others, and the cubic central cavity is occupied by a bisected cube.

The pieces were designed by Seattle artist Tara Flannery, who has designed several other puzzles for Artifact. The cutting style was inspired by John Stokes III, and while this puzzle has no "whimsy" pieces per se, all the cuts are so intricate that each piece is a tiny work of art. Using Bob Armstrong's classification method, I'd say this type is interlocking (of course), with curl knobs, 1:1 contour lines, a scroll pattern, and irregular edges - and to me, it looks like a map of someplace out of Dr. Seuss!

In the completed puzzle, no adjacent pieces have the same color. This puzzle is of special interest because it incorporates the idea of a famous mathematics/graph-theory problem called the Four Color Theorem, which holds that any set of contiguous (touching) regions on a plane, no matter how convoluted their boundaries, can be colored such that no adjacent regions are the same color, using no more than four colors. (Regions that meet only at a point are not adjacent.) Although it was proven as far back as in 1890 that no more than five colors are needed, proving that only four suffice was very difficult and was only accomplished in 1976, by Kenneth Appel and Wolfgang Haken, using a computer.

Artifact Puzzles' Four Color Map Puzzle has been favourably reviewed by several puzzle bloggers, including Brian, Neil, and Allard. I had fun with it, too - it took me about an hour to complete. I found the no-adjacent-pieces-the-same-color rule helpful (colorblind puzzlers will be more challenged).

You can now own a copy of one of George's beautiful designs - it's called Frabjous and is available from the folks at Artifacture in Dallas, who sent me this 6" x 6" x 6" Special Edition Frabjous, laser cut from Acrylite Radiant Acrylic. Thanks, Michael!

This type of acrylic material reflects light in different colors from different angles and provides a fascinating display of varying hues as you move around the sculpture. The puzzle sculpture comes unassembled, in a package that includes instructions, 31 S-shaped pre-notched interlocking pieces (one extra piece is thoughtfully provided), and even a pair of cotton gloves to wear during assembly, so that you can avoid getting fingerprints in hard-to-clean places! Artifacture sells direct through various online outlets (see links on their product page), including their Etsy shop. Artifacture has produced Frabjous for MoMath (the MoMath logo, and George Hart's name, are engraved on one piece) and Frabjous is also available at the MoMath online shop. (A less expensive version is available in blue.)

It took me about an hour to assemble Frabjous. I had to recover from a false start when I realized I had been careless while interweaving some of the pieces. I disassembled what I had so far and started over, being much more deliberate. The pieces lock together by friction/pressure fit using simple rectangular tabs and notches at apexes where three pieces meet - the hold is secure, but it is possible to work the pieces apart again without too much trouble. One thing I was pleased about is that though acrylic in general seems to have an unfortunate tendency to crack at angular cut-outs, I experienced no faults in any of the Frabjous pieces even after I had attached and detached them multiple times.

During my second try at putting Frabjous together I actually found that if I ignored the included instructions and instead concentrated on the five-fold symmetry of the structure, adding five pieces at a time in symmetry around the growing assembly, I could much better ensure the correct relative placement of the pieces. Something to note is that you cannot simply create a bunch of "tripods" and then expect to link them together - it is too difficult to properly interweave such sub-structures. I took photos along the way - I think you'll agree that Frabjous is a beautiful object! I can also attest that Frabjous is a puzzling challenge to assemble, and you will enjoy a nice sense of satisfaction on completing it. My wife even let me put this one on display in the family room!

The Tanacube Too is Oskar's solution to a challenge originated by Peter Rasmussen and Wei Zhang,
to create a cubic puzzle having the classic Tangram Square dissection appearing on each face, and meeting other criteria.
You can read about the challenge at ChinesePuzzles.org/tanacube, also at George Miller's Puzzle Palace website,
and in CFF #65, November 2004, in the article Tangram Cubes: A Collaborative Effort, by Peter Rasmussen and Wei Zhang.

George Miller had offered 3-D printed copies of Oskar's Tanacube Too (at $550), but George has shut his online shop.
Oskar kindly created a Shapeways model of Tanacube Too at a more reasonable price.
Oskar then created the smaller, less expensive, Tanacube Too Small shown here.

Bill Darrah created the first solution to the challenge, called the Tanacube.
You can see Bill Darrah's Tanacube at George Miller's Puzzle Palace website, at Bernhard Schweitzer's Puzzlewood website,
and in Neil's Puzzling Parts blog entry of May 23 2011 (California Puzzle Party).
The wooden versions were made in the Pelikan workshop and originally cost $350.

Both Tanacube and Tanacube Too were entered in the IPP 2004 Design Competition,
but neither won an award - they were up against some stiff competition!

The three classic wooden vintage secret-opening puzzles Takitapart (U.S. Patent 2181116 - Boyle 1939), Pick-A-Peg (U.S. Patent 2469364 - Boyle 1949),
and Tri-'N'-Do-It (U.S. Patent 2207778 - Boyle 1940), all invented by John D. Boyle,
were issued in this boxed set, called the Masterpiece Puzzles.

Our electricity was out for over a week due to the storm on October 29th - 30th 2011. This is a shot of the trees in our back yard, bowed (with a few broken limbs) due to the load of snow on them. We lost power on Saturday night the 29th and it wasn't restored until the evening of Monday November 7th. The unseasonable accumulations of about 12" of heavy, wet snow onto trees that had not yet fully shed their leaves brought down many trees and limbs large and small and wreaked havoc with the above-ground utility lines across the northeast. The extent of the damage was unbelievable - nearly every street had issues. Fortunately, we had the option to stay with a kindly nearby relative who had power (thanks, Pat!), and the temperatures were not frigid enough to cause pipes to freeze in the unheated house.

Quadrus is a large (140 x 140 x 30mm) and attractive traditional rolling-ball multilevel maze in a gold-tinted transparent acrylic case, nicely packaged in a cardboard slipcase tray that shows off the ambigrammatic XMATRIX logo. Quadrus is also available in a blue tint, and has a smaller cubic sister puzzle called Cubus.

In Quadrus, the maze network is defined by three layers of internal latticework structures and interstices - one lattice on each large face, and a third suspended between them, with an empty thickness between pairs of adjacent layers - giving an overall thickness of 5 layers between the "floor" and "ceiling" faces. The walls in a layer are 4mm wide, and the pathways between walls are 8mm wide. Walls and pathways in a layer are arranged on a 34 x 34 virtual grid of 4mm x 4mm squares. The ball occupies a 2x2x2 space within the lattice.

The maze contains a central 12x12 square compartment - a white panel with a stylized 'X' cutout separates the compartment into a gold-framed side and a silver-framed side. Each side of the compartment has a single entrance into the maze. To solve Quadrus, one must navigate the ball from the central gold-framed compartment to the central silver-framed compartment on the opposite side, by tilting the puzzle and guiding the ball through the maze. I have found that the occasional ill-planned tilt can send the ball somewhat further than one intends, adding a dexterity dilemma to the already-considerable routefinding challenge.

This style of maze is similar to the Boston Subway puzzle designed by Oskar van Deventer for the 2006 IPP Exchange. (See Boston Subway at Oskar's website.) Boston Subway is a much smaller puzzle, but also comprises a "sandwich" of 5 layers of transparent acrylic, through which one navigates an internal metal ball from point A to B and back. Unlike Quadrus, Boston Subway requires the solver to use an included magnetic wand to move the ball through the maze. As interesting as Oskar's Boston Subway puzzle is, I find the Quadrus more convenient to hold and manipulate, and it is far easier to see and keep track of where the ball is. While less portable, it is more engaging to the casual puzzler.

For the 2009 IPP, Oskar also designed Next Floor. (See Next Floor at Oskar's website.) Produced from laser-cut MDF, this maze is formed from 5 grooved layers with four interstices. A version of Next Floor is marketed by Bits and Pieces, but unfortunately folks reported that the layers can be loose and the ball can squeeze through unintended paths or even fall out, spoiling the fun. No such issues plague the robust, high-quality Quadrus puzzle.

I found an older seven-layer version (in an eBay auction). Unfortunately it included no documentation and I am unware of its provenance.

You can read some reviews of the XMATRIX puzzles here, here, here, and here.

My own impressions? When solving a maze, I do not typically sit with the puzzle tilting it to and fro. I manipulate and study the puzzle enough to systematically create an accurate representation of the network "on paper" and then exhaustively map it out. The physical object itself becomes somewhat unimportant and is usually stored away. With the XMATRIX Quadrus, however, two things are true: It is just as much a pleasure to hold and play with the physical object as it is to intellectually solve the maze, and this is one maze puzzle that will be left out for others to enjoy rather than being put away and forgotten.

Schlitten - Constantin, Rings with red cord (?), The Squared Fish - A. Jacob, Batwing and Batwing 2 - PuzzleMaster,
Puzzle Up Nails - Rick Irby, IPP 31 Gift - Markus Götz, Hybrid 55 - Richard Hess

IPP Burr - Mr. Puzzle Australia