Back from IPP28 in Prague, and a few days in Berlin.

In Berlin we visited several puzzle shops, including the shop Merlin's Spiel- und Zauberwelten ohG, and met owner Mr. Frank Lu, who shares our enthusiasm for puzzles. There were also several puzzle shops on the agenda in Prague, including SMYSL.

I got many great puzzles of all types at the Puzzle Party, and also finally got a wonderful collection of Wellingtons puzzles from the very generous Liz Burrow, by way of Watson Air Freight - a hearty Thanks to Liz and to Martin!

Naef's Kniff, Ubongo, PakoStar, Philos Magellan, Albertuv Puzzles #4 and #8 by Atlas, Tetrahedron into Octahedron, Philos Prisgon by Markus Goetz, Vinco "Not Quite Half Cubes", Philos Vesa Burr Simple, Bolaris Vastavari, the Fragmented Cube by Oskar van Deventer, the O.S.M. Ball by Jakub Dvorak (from Puzzlewood.de), a Sonneveld Box made by Tom Lensch, Stewart Coffin's "The Hill" also from Puzzlewood, a burr by Frans de Vreugd, Crossroads made by Walter Hoppe, Tirol, a Stegmann 2N's Cube #5 from Bernhard Schweitzer (Thanks again, Bernhard!), a Double Triangular Prism designed by Stewart Coffin (also from Bernhard), Half-Cubes from Vinco (Thanks!), a Perpetual Motion by Bill Darrah.

JVK's Tessellating Hexagons, Thick-N-Thin-7 by Serhiy Grabarchuk, Cherry Cocktail, Heart and Spade, Prague IPP28 souvenir, Wetten Dass..., Neo Sliding Block Puzzles by Serhiy Grabarchuk, IPP28 welcome puzzles by Serhiy G., 5 Yen in a Jam by Iwahiro.

"The Great British Puzzle" (cubes), Zoo Panic, Lagoon Jungle Mega Puzzle, Warning Puzzle, Philos Eightpack by Tom Jolly, Snookered, Snookered Again, Walk Up, Footsie, Bunkered, Frantic, 180 Top Dart, Frantic II, Bananas, Suit Yourself, Diabolical, Son of Cuss, Nuts.

Bolaris Vastavari, two oversized Rubik's Cubes, Magic Smile, 4-wing 4-color Roundy, Uriblock (prototype), Inca (large), Inca (small), 8-tile Magic, Perpetual Motion by Bill Darrah, Life's Maze by Kirill Grebnev, Chainbox, small black plastic burr (Dubois' pieces), The Flying Block Puzzle - thanks, Dirk!

Hybrid 15 from Dick Hess, Wolverine keychain tangle from Allan Stein (thanks!), #74 Orli Hnizdo Vyndejte Provazek, two sticks tangle (Bathke?), Hanayama Vortex, Philos Tricky 4, Grebnev Apple, Grebnev Spiral.

From Verdes Innovations, the long-awaited V-Cubes - 6x6x6 and a 7x7x7 twisty cubes:

From Pacific Puzzle Works, a Faberge Knot, Knot Mass, and Tubular Burr Box:

Two vintage puzzles from the UK, Journet Furrows, and The New 15:

I've added footer menu links to the following pages:

• Vintage French Boxed Wire Puzzles
• Puzzles by Naef
• Woods

I have added a page showing various wood types used in puzzles. Often when I've had the opportunity to order a puzzle in fancy woods, I've had trouble remembering how some of the woods appear, or what they're called - sometimes confusing different woods. This page will help.

Several websites to check out:

• Skyscraper 100
• Bruce Viney - Secret Box Plans
• www.hieke-wenzel.de
• Passion for Puzzles (some puzzle solutions)
• Crafty Puzzles
• Yoshi Shindo's site
• www.9spuzzles.com
• How to Solve the Square 1
• Lars Vandenbergh's Solution to the Square 1
• Edward DeBono's Games
• CarveWright's Customer Spotlight on Robert Yarger
• Haoyuki Iwase's collection

Brett suggested I add a Google search feature to the site home page, so I did. Select to search text or images (default is text), check to search only Rob's Puzzle Page (default is checked), enter your search terms, click Go. The page will be replaced with the Google results page. Note that until Google has fully indexed my new mirror at robspuzzlepage.com, the "site:" is set to the older ISP url.

"Ladybugs," a "3D Magna Puzzle" by Caeco, purchased from New England Hobby: 

The Starbix folding puzzle/toy, by Alan H. Schoen and issued by Bandai 1987: 

The "Irmo" Box designed and crafted by the multi-talented Eric Fuller, made from Padauk, Quilted Maple, Aluminum, Brass, Steel, and Acrylic. Pic on the right is the box bottom. The laser-cut inscription is a clue.

Several items from Doug Engel's PUZZLeaTOMIc:

Doug's Circle Puzzler's Manual is hosted online at Jaap's Puzzle Page.

Here is a tale of puzzle solving, of a sort with which some of you may be familiar...

You may have noticed I've changed the Ring Menu featured on the main page of this website, hopefully for the better :-)

I'm still not completely satisfied with it - in particular I need to make better transparent images - but I've added several features. In past versions, I attempted to enhance the perspective foreshortening effect by reducing the size of the images as they rotated to the background of the ring. However, I wasn't satisified, because the spacing between the items should also change with foreshortening.

I had been thinking about how to accomplish that and I've come up with a method that works pretty well, using what I believe is kind of a novel approach. Rather than rely on traditional techniques of perspective or a perspective transform, I used Kepler's Second Law of Planetary Motion. I now use a numerical approximation method to solve the equation that relates Mean Anomaly to Eccentric Anomaly, which allows me to space the slots around the trajectory of the items in the ring such that the foreground items are spaced further apart and the background items closer together.

Basically, the old version spaced the slots in the ring based on the parametric equations for a circle, then simply squashed the distances along one axis depending on the tilt sense - a legitimate and simple method for creating an Ellipse. I've replaced the old tiltFactor with one based on an inclination angle of the plane of the ring with respect to a view from above, and a calculation of the eccentricity of the resulting ellipse.

Using the parametrics for a circle is like using the Mean Anomaly and gives evenly spaced slots even after squashing. Using an Eccentric Anomaly gives a spacing where items are moving faster, i.e. spaced farther apart, when near a focus. Note also that it's the Eccentric Anomaly we want, not the True Anomaly, since we're calculating relative to the center of the ellipse rather than either focus, and plotting points on the Auxiliary Circle.

Also, the eccentricity of the ring itself cannot be used for the eccentricity in the calculation of the Eccentric Anomaly - they're two different things, really - they may be related but I am not yet sure how. A nearly-horizontal ring, with a tilt of almost 90 degrees and seen almost edge-on, results in an ellipse with very high eccentricity. But the "orbital motion" we want should create a reasonably small variation in the sweep of the items along the ring, moving fastest near the viewer at the side of the ellipse, not at a focus. So, I've jiggered the math to make it work. Some of the parameters are still fudged but overall I'm pretty happy with the result.

I've also used CSS opacity to implement a kind of aerial perspective effect.

UPDATE: modifying the opacity of the items caused a big performance hit in IE6, IE7, and Firefox 2.0.0.12 - the ring moves too slowly for my taste, so I have dropped that feature.

A vintage Egyptian Puzzle: 

Three great tray-packing puzzles by Edi Nagata - Shirt Case, Cup Case, and Baby Duck Case: 

And a copy of Stewart Coffin's Cruiser tray-packing puzzle, made by Walter Hoppe: 

Two puzzle events in one month! Close on the heels of the 2008 NYPP, Peter Winkler hosted a Mechanical Puzzles Day at Dartmouth College in New Hampshire. Several fascinating talks by prominent folks in the puzzle community, and a nice reception afterwards, with a few puzzles for sale. I bought Stewart Coffin's Four Fit, made by Tom Lensch, and Bruce Love's Dozen burr from Bill Cutler, in maple, without the D's, made by Jerry McFarland. Also got "Mind the Gap" - a gift from Chris Morgan, who designed it. Thanks Chris!

Tom Cutrofello hosted the 2008 New York Puzzle Party (NYPP) in Manhattan on the 16th, and with more than 50 attendees from all over the world, this was the most successful NYPP yet! Tom let me do a presentation on Sliding Piece Puzzles, and it seemed to be well-received. Please contact me if you'd like a copy of the slide deck PPT. There was plenty of puzzle buying, selling, and trading - here are some finds:

Several nice items from Bernhard Schweitzer, who flew in from Germany:

An Insoma Burr and a Cicada miniature puzzle sculpture, from Mr. Puzzle Australia (Brian Young), who certainly came a long way to attend! 

Other items from various folks:

An advertising premium for Molson Beer - make a square or a Greek cross: 

Der Umstulpbare Wurfel (the Invertible Cube) by Paul Schatz of Switzerland:

Scott T. Peterson made this Super Nova puzzle (Stewart Coffin design #14), in Bird's Eye Maple and African Blackwood:

Here are two puzzles designed by Pavel Curtis - Sleazier, and Six Tabbed Planks:

I've added some new material to the section on Puzzles from the World's Fairs.

I've also added a lot more info on the content of Hoffmann's Puzzles Old and New.

Inspired by the Wayne Daniel Burr Set, I've updated the section on the Traditional Six-Piece Burr.

I have created a new section on Vintage French Boxed Wire Puzzles, accessible from the contents listing at the top of the Tanglements page.

Merry Christmas! Or, Happy Holiday of your choosing!

Ending 2007 with a burr set by Wayne Daniel: 

Here are four of the nine Karakuri Creation Group Christmas Present puzzles for 2007:

Additional puzzle gifts from Susan:

The talented puzzle craftsman John Devost, of Canada, very kindly sent me an early Christmas gift - one of his copies of Stewart Coffin's Few Tile puzzle, made of Padauk and Birch. Thanks, John!

Fire Escape (sold elsewhere as "Tower of Logic Inferno"):     Spears Shape Puzzles: 

Milwaukee "Star" ring-in-plate maze (homemade?):   Milwaukee Key Maze (homemade?): 

a vintage advertising Over the Top:   a version of the vintage Perplexity puzzle, called Think of Jonah: 

A Filipiak bolt: 

I have become a published photographer! The November 2007 (Vol. 12) issue of Make Magazine contains an article on page 188 by Donald Simanek on how to build your own "Moses' Cradle" style puzzle. I supplied some photos for the article, of some existing manufactured puzzles of that type.

From George Miller:

From Family Games, Brain Burden, a new tanglement from their IQ Collection: 

The latest Hanayama puzzles, Loop and Quartet: 

A vintage (pat. 1896) Combination Lock sliding puzzle: 

Behind on site updates due to Comcast problems.

Took a trip up to Brookline to see a seminar on the Tavern Puzzles, run by Dennis and Donna Sucilsky, owners of Tucker-Jones House of East Setauket, NY. The event was sponsored by David Lechinsky and Eureka. Dennis is a blacksmith - he brought his anvil and a hefty hammer to the event, where he personalized some of my Tavern Puzzles, and a stand - maybe the first they'd done! - for me. Also picked up Peter Hajek's IPP27 "Matchbox" puzzle, Cmetrick Too Hard and Hanayama's Cast "Horse" at Eureka.

From Izumiya, Tamura's Six-Block Puzzle:

A Mozaika Ball, a Whipit Ball, and a racy Magic: 

Toll Gate card Number 1!    and a burr in a case: 

Several edgematching puzzles: 

Imported from China by CHH Games.

I have added a section on Ancient Puzzles, and Modern Puzzle Crazes.

We had a wonderful stay in Montreal, Canada. In between visits to some of Montreal's many and varied attractions, I managed to drop by several puzzle shops:

• Tour de Jeux (a chain) - Centre Eaton
• Le Quizz - 1500 Atwater Ave. Place Alexis-Nihon
• Boutique Strategie - 3423 rue Saint-Denis
• Franc Jeu (M. Guy Richer) - 4152 rue Saint-Denis
• Le Valet D'Coeur (had the best selection)

In addition to a booklet of solutions to many of Puzzle Master's tanglements (not pictured), here are some items I found:

Four well done puzzle challenges from Smart Games: 

Three of the latest puzzles from Philos: 

The Five Keys and Olymp puzzles from Constantin and the Bull's Nose from Eureka: 

A nice wooden Pigs in Clover, a Twist-'N-Slide 3D Truck, and a nameless but hefty nice pin puzzle in lucite: 

Scott T. Peterson made this beautiful copy of Stewart Coffin's new Involute design, in highly polished Padauk with Ebony corners.  

From Bits and Pieces:

I have added several new original designs on my Homemade Puzzles page. In addition to the 2 N's Cube No. 1, take a look at No. 2, No. 3, No. 4, and No. 5 (which might be my favorite).

From CubicDissection, RD001, Nested Burr Four, and Anderson's Delusion:

I have revised and much improved the section on Pentominoes and Other Polyforms.

Closterman 6x6x6 Caged Cubes, in Lyptus and Canarywood:

Three tanglements from Uncle's Puzzles, purchased at IQ Puzzles:

Visited Eureka on 6/17:

From CubicDissection, one of the second edition of the Stickman Chopstick Box: 

Try your hand at various mechanical puzzles that people have simulated online - open my new Virtual Mechanical Puzzle Compendium Box.

I have added a new page featuring a mapping among different classification schemes for mechanical puzzles.

I have also revised my books page.

Thanks to fellow puzzler Patty L. Smith, I learned that the wonderful Japanese online puzzle store Torito does in fact ship internationally and take PayPal orders. So I have several interesting items on the way to me:

From Norm Thompson, the first three puzzles in the Sacred Myths and Legends series, by Family Games: Da Vinci's Secret, The Equation, and The Legend of the King: 

I have re-vamped my links page and created a sorted list of over 200 Puzzle Vendors Around the World.

A trick lock engraved "MIOf[]" 

Scott T. Peterson is a talented craftsman from the state of Washington, who produces high-quality limited editions of puzzles in fine woods. He and I have been corresponding, and Scott will be making a few instances of my 2 N's Cube design. Scott has devised an attractive coloring scheme for the cube and made me the examples shown below - the first in Bocote and Yellowheart, and the second in Kingwood and Holly.

I would rate the 2 N's Cube of medium difficulty - it shouldn't take long for an experienced metagrobologist to solve it, but I think it presents a good challenge for the casual puzzler, particularly if one starts with it disassembled and hasn't seen the assembled arrangement. The design is the product of a search "by hand" (i.e. without a computer) for a selection of non-planar pieces formed from two n-tetrominoes each that would allow interlocking assembly into a 4x4x4 cube. My "theme" was the frequent mis-spelling of my last name, which has two n's. I was pleased to discover an arrangement that used four pairs of pieces - thusly again doubling the double-n theme - and yet assembled in a way that was not completely symmetric.

Scott's tolerances are so accurate that when I first received the cubes, I had trouble finding the disassembling moves! Naturally, wood tolerances vary with humidity, but Scott's pieces are very nicely made.

Made a weekend trip to Boston and visited both The Games People Play shop in Cambridge, and David Leschinsky's wonderful shop Eureka! in Brookline, Mass. Eureka has a fantastic selection of mechanical puzzles and is well worth a visit if you are in the Boston area. It is not far from downtown, out Beacon St. to the intersection with Harvard St. Eureka has a friendly, enthusiastic, and knowledgable staff who are willing to take the time to demonstrate puzzles, and help parents find suitable items for kids. Eureka also has a great hands-on attitude and provides open copies of many puzzles so you can try them out in the store. Here's what I found there:

The Games People Play had new Rubik's items, and also a stock of the KO Labyrinth in case you're looking for it - here is what I got there:

Trick Locks from wiredforfun:

The Tetris Cube, Tetris Ball, and Tetris Ball Twins, from Meffert's. These are actually made by IdeaOcean, where they're called the Idea Cube and Magic 16.

From the New York Puzzle Party:

A Split Star by Mark McCallum: 

Three WWII 1942 Slidem-Solitaire Puzzles: 

Four of the eight Karakuri Club 2006 Christmas Gifts:

Other Christmas gifts:

The Apple won an Honorable Mention in the IPP21 Design Competition.

John has graciously agreed to provide a 10% discount to all IPP members! Tell him Rob sent you.

An unexpected and wonderful Christmas present from Rocky Chiaro: one of four of his original plexiglass and brass Perplexity puzzles.

Many fascinating topics of potential interest to the mechanical puzzle afficionado, including:

Dissections Alignments Peg Solitaire Unicursal and Route-Finding Chessboard

Measuring River Crossing Solving Labyrinths and Mazes Misc. incl. Chinese Rings, Chain Links and Double-Dovetail Blocks

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