Separated Board Burr Set

Separated Board Burr puzzle set by Frans de Vreugd — Separated Board Burr set by Frans de Vreugd

I’ve never been one to stand on ceremony here at B&B. While this blog is ostensibly a (more occasional) tribute to the stories behind some impressive, artistic and befuddling “box” creations, with a toast to boot, I’ve always insisted that it’s not just about boxes. Or booze, for that matter. There are plenty of posts about non-box puzzles. To make certain I never got boxed in, I even launched the entire blog, many years ago, with something decidedly non-boxy.

Burrs, on the other hand, are not my typical cup of tea-quila, and although there are a few burr puzzles that have been featured here, there is definitely something sneaky about those particular puzzles that set them apart. Herewith I present something never before seen on these virtual pages, a set of special burrs that are sneaky only in how disturbingly difficult they are to disassemble. Why do this to myself, and to you? Well, I am fond of the maker, and, I must be … Board.

Frans de Vreugd is a successful architect from the Netherlands who has also designed many celebrated interlocking burr puzzles, such as the Japanese Wood Joint Burr, the Dovetail Burr, and Around the Bend. He told me some of the history behind these puzzles. “The Japanese Wood Joint Burr is definitely my favourite. When studying architecture in Delft in the 1990s, I became fascinated by very elaborate wood joints in Japanese architecture. Being the son of a carpenter this was a great combination of traditional woodworking and architecture. In total I have designed four different interlocking puzzles based on Japanese wood joints. Three of them are well-known, the fourth one (The Gooseneck Burr) never made it past the prototype stage. Josef Pelikan made that prototype, a few years before he tragically lost his life in a car crash. It took the Pelikan Workshop several years to recover from this blow, but luckily they have been a very successful puzzle making company ever since they restarted.

When I was designing the JWJ Burr, I sent a prototype to Edward Hordern, who was by far the best puzzle solver at that time, Edward suggested several improvements to the puzzle design. Wayne Daniel (another legend, who recently passed away) made this puzzle as my exchange puzzle for IPP 19 in London. Not only is it a good puzzle design, it was extremely well made by Wayne (and it was far from easy to manufacture). Many years later Eric Fuller did a remake of this puzzle, which sold out in no time. Some time later he did a second batch of that puzzle (showing how popular it was). Eric also did a remake of the Dovetail Burr (my exchange for IPP 20). All three of my designs based on Japanese Wood Joints are really nice and challenging as puzzles, but I consider the JWJ Burr the best one, as it has a very unusual solution. It was both an honour and great pleasure to work with all these great names in puzzle history during the design of these puzzles based of wood joints. Unfortunately all four of them are no longer with us.”

Burr sticks with notches that fit together in a complex sequential way represent the basic form of this type of puzzle, and of course there are so many interesting variations. Board burrs use flat pieces with slots and notches in place of the sticks, which come together flush. Frans has explored these designs as well. Many years ago, he also began to explore a variation on this theme, in which the boards are not flush, but rather are separated in the final assembly. The “Separated Board Burr” idea was first introduced by Jim Gooch. In Frans’ excellent article on the subject from Cubism For Fun published in 2002, he notes that “Based on the fact that there are 16 empty spaces in the basic shape, you get a theoretical maximum of 216 = 65,536 pieces.” Fortunately, not all of those piece shapes will actually work in reality.

Frans has recently compiled his most famous separated board burr designs into two collector sets that also include specially selected additional assembly problems. The pieces are contained in a very nice wood box which is itself engraved with each assembly challenge, in case you misplace the helpful booklet included with each set. He told me a bit about this new project.

“In the last 7 or 8 months I have been working on two boxed sets of so-called 'Separated Board Burrs'. I researched this specific type of puzzle some 25 years ago and at that time it resulted in three interesting puzzle designs:

Zigzag (made in lasercut acrylic by George Miller)

Torture (made by several people that make wooden puzzles, e.g. Josef Pelikan, Tom Lensch, Brian Menold, Jean Carle)

Extreme Torture (made by several woodworkers, e.g. Tom Lensch and Brian Menold)

Gordian's Knot (same puzzle as Extreme Torture) was mass-marketed in plastic by ThinkFun as 'The hardest take-apart puzzle in the world!'

In the early 2000s there was a tv-series called 'Numbers', which was based on mathematical subjects (I think Ed Pegg was the connection to the puzzle world). One of the episodes featured Gordian's Knot. I wonder how many puzzles have ever been shown in movies or tv-series. Apart from Rubik's cube I know very few!

Early last year I went back to this research and noticed that there were many more interesting designs. I thought it would be a nice idea to make a boxed set, where the pieces allow you to make many different puzzles with unique solutions. The first set (which I call the regular set) has 18 pieces and can make 10 different designs (all with unique solutions). In some cases you can make two puzzles simultaneously. The set of pieces was chosen such that the minimum number of pieces can make the maximum number of different puzzles. Later I considered that it would be nice if you also make the three well-known designs mentioned before, so I made a second set (the extended set) which has 24 pieces and makes all the designs from the first set plus the 3 known designs.

For this puzzle set I did not want a simple and standard box, but I designed a very special box showing drawings of the 10 different puzzles engraved on the outside of the box. That means that the box itself is the manual that comes with the pieces. Desiging and fine-tuning the box was a long and labour-intensive process. I wanted the box to be assembled from lasercut wooden parts (because I like wood), and use 3D-printed plastic for the pieces (as the pieces have weird and fragile shapes). Furthermore, I wanted every puzzle piece to have a different colour. That in itself was quite a project! I had to order material from three different companies to get the required palette of colours.

The parts of the box were lasercut / engraved by William Waite (he's the expert on lasercutting wood). It took us 3 or 4 iterations (spanning several months) before we had all the dimensions and tolerances correct and have the required aesthetics of the box. When I visited G4G16 in San Francisco last February I picked up the lasercut parts from William (who was also present).

Each of the different puzzle pieces has its own colour (in some cases a piece comes in two different colours, so each puzzle with six pieces always has six different colours. For the pieces I wanted to have an embossed letter in each of the pieces to easily identify them (and visible when stored in the box). The location of the letters is chosen such that each puzzle can be assembled with all the letters hidden from view (or all six visible if you turn the puzzle around). In the drawings you will see a small black dot that shows the location of the text.

When I received the lasercut parts the real work started! The lasercut parts have a sheet of protective paper of both sides of the wood, which has to be peeled off after the lasercutting. As I had an incredible amount of text and drawings engraved on the outside of the box, it was very labour intensive to clean them up (see photos of the process). All the small 'islands' inside the letters (e.g. O, R, A etc) have to be removed one by one (and some of them are really tiny!). Cleaning up the parts of the boxes was a very time-consuming job, but it was definitively worth the effort.” The sets also come with “a small booklet with instructions (e.g. showing drawings with the different colours of the pieces and some additional information).”

Frans made ten copies of each special boxed set. He planned to release them during a gathering of puzzle enthusiasts this year, but many have already found a new home. He does have a few remaining sets, and is considering making a few more as well if there is interest. While board burrs are not my forte, I felt obligated to pay my respects, and have zigged and zagged successfully so far. The set is a very colorful tribute to this unique type of puzzle and to one of its greatest designers.

A toast, then, to this talented architect of delightful designs. My initial brainstorm on the topic of cocktail pairings for a burr set led me into familiar territory. The “Last Word” is a reliable classic cocktail made with equal parts gin, green Chartreuse, lime juice and maraschino liqueur. It’s tart, herbal, well balanced and quite popular. I have featured many a Last Word variation here over the years. It’s fun to play with the basic template and equally fun to adjust the cocktail name accordingly. For example, the “Last Burred” has a clever ring to it. But it sounded almost too familiar to me, and I realized I had already made this cocktail for a different puzzle in the past.

I took a detour into etymology and learned that the Dutch word de Vreugd translates roughly as “joy” in English. I grant you, not everyone associates burr puzzles with joy, but clearly these confusing puzzles have their passionate fans. Which led me to the Joy Bird, a delicious way to celebrate Frans de Vreugd’s puzzling contributions to the world. The cocktail is a simple variation on another well known classic, the Jungle Bird, a richly flavored and unusually bitter tropical rum tiki cocktail invented by Ong Swee Teik at the Kuala Lumper Hilton the early nineteen seventies. Modern tiki pioneer Jeff “Beachbum” Berry rediscovered the drink in an old ‘eighties bartender’s guide, changed the original “dark” rum to specifically Jamaican rum, and added it to his book Intoxica, 2002. What is really unusual about the Jungle Bird is that it includes Campari, which of course makes everything better. Because of this, the drink found its way onto many non-tiki bar menus, until Giuseppe Gonzalez really popularized it by dialing down the pineapple juice ration and changing the rum to deeply flavored, molasses heavy blackstrap rum. Like all great classics, there are now many interesting versions. This one replaces the simple syrup with orgeat, an almond syrup also found in many tiki drinks. The orgeat brings some almond joy to an already delicious cocktail, and that’s always a good thing. Cheers!

Separated Board Burr puzzle set by Frans de Vreugd and Joy Bird cocktail — burred watching

Joy Bird adapted from Giuseppe Gonzalez

1 ½ oz blackstrap rum

1 ½ oz pineapple juice

¾ oz Campari

½ oz lime

½ oz orgeat

Shake ingredients together with ice and strain into a favorite glass. Orange slice garnish traditional.

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Separated Board Burr Set

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