Dwarf Planet D

I am not terribly good at solving interlocking or burr puzzles, unless they are relatively low level. But now and again, I do come across one that I manage to dis-assemble AND re-assemble without any help (eg Burr Tools, photos etc).

The Dwarf Planet D is one such puzzle. In the past I would just have casually termed the Dwarf Planet D an interlocking "burr" but having corresponded with James Dalgety on the use of the right terminology, I shall refer to the Dwarf Planet D as an interlocking puzzle. For those who are interested, James said that...."originally back in the 1960s and 1970s the word "burr" was used to refer to interlocking puzzles made from straight rods with grooves cut out of them.  Like the standard 6-piece burr and Coffin's "Hexsticks"...

Terminology aside, the Dwarf Planet D was Jerry Slocum's IPP36 Exchange Puzzle. Designed by Australian William Hu, the Dwarf Planet D was produced by Brian Young of Mr Puzzle, Australia. 

The puzzle measures 7cm x 7cm x 7cm and comprises 6 "board" pieces each 10mm thick. Three of the large pieces are made from clear acrylic while the smaller ones are sandblasted (looks frosted) to give the puzzle more contrast. A nice touch here! Construction and finish is first rate and all the pieces are precision laser cut to allow for a good fit and sliding of the pieces. Nice details include the fine laser etching of the designer's and exchanger's names etc.

According to Brian, this is a level 6.8.2.3.3 puzzle. When I played with it, I estimated it to be around 28-30 moves! But who's counting? so long as I manage to take thing apart. The first piece is not that difficult to remove but its the second that got me stumped a bit. I practiced the various steps quite a few times before finally taking the puzzle fully apart, so as to remember the reverse for re-assembly. Thankfully the number of moves are not that high and I actually managed to get everything back together on my own. To be honest, if the puzzle had come un-assembled, I wouldn't have even known where to begin...let alone solve it.

A great interlocking puzzle that is well made and good looking; challenging but not frustratingly so, the latter which is important for me:-). I think most puzzlers (novice or experienced) would enjoy this puzzle, as there are only 6 pieces of which 3 are rather simple looking. Moreover you can see whatever you are doing (nothing hidden) and chart your progress as you go along. I certainly enjoyed playing with the Dwarf Planet D. Available from Mr Puzzle for US$22.62/- 

Square Dissection

I don't normally spend too much time on a single puzzle, because I have many puzzles in my collection (a lot of them Exchange Puzzles) that I have yet to go through. From my last count from two exchanges, I have still over 140 more which are untouched. I know there are those who persist with a single puzzle for weeks at an end, eg Kevin Sadler and I truly respect their efforts! But I am not one of them. 

But Square Dissection got more than my usual fair share of attention because firstly I quite like packing puzzles and secondly, I also enjoy designing them and producing working copies in plexiglass for myself or for sale. So when I selected Nick Baxter's Square Dissection from my stash, which was his IPP34 Exchange Puzzle, and thinking to myself that its JUST 9 ordinary rectangles into a tray, I decided to test my solving powers on his design....and failed quite miserably!

First the specs...the tray measures 9.5cm x 9.5cm x 0.6cm. The pieces are all rectangles with differing measurements for each like 18x20, 24x25 etc. These are not actual measurements but unit values of the length x width of the pieces. Both tray and pieces are made of translucent red and green acrylic/plexiglass. Everything is laser cut to perfection...and tight tolerances are indeed needed for this puzzle! 

The goal is to place all the 9 green rectangles into the tray with none of the pieces sticking out. Your regular 2D tray packing puzzle right? Yes, but nothing regular about it. In fact after trying for several days on and off and not getting anywhere (there is always just one last piece that refuses to go in), I did what I usually advocate; that is to ask the designer for help. Nick came back with a series of questions which were actually hints on the solve. Needless to say, these hints were lost on me and another round of email exchanges resulted in yet more hints. Still no luck and a couple of weeks later, I threw in the towel and asked for the solution. Damn...everything fits so easily and nicely into the tray! Actually there is a bit more to this puzzle that meets the eye but I shan't mention anything more here as I don't want to have any spoilers for those who may still be tearing their hair out over the Square Dissection.

This puzzle may look innocuously ordinary, but there is a lot of "mathematics" behind the design and IMHO, very difficult and challenging. According to Nick, there are 23,224,320 ways to lay the pieces in a 3x3 format but only one will enable the correct fit inside the tray. And before I forget, don't waste your time with Burr Tools, it won't work.

For hardcore packing fans, this is a must have! Dave Holt, hope you are reading this. Go for one!

Bob's 5x5 & Jerry's 4x4

When I first saw Bob's 5x5 during Nick Baxter's recent puzzle auction, I knew I had to get it. This was because I was a little surprise (and also a little disappointed) to find out that someone else had already earlier (in fact some 16 years earlier) come up with a design concept similar to my "Interlace 4x4" puzzle. More about the latter later.

The Bob's 5x5 I won at the auction is a reproduction of Robert Darling's IPP18 (1998) Exchange Puzzle. This is a huge puzzle, measuring a good 15.5cm (6.1in) square with a thickness of 3.5cm. Can you imagine the size of the box or crate needed to hold 99 exchange copies! 

It is very well made of wood (either teak or walnut I am not sure) and really solid and heavy. The bottom is even felt lined (so it won't scratch the surface it sits on). Displays nicely on the coffee table and one might even mistake it for a cigar box. Definitely well worth my $48 winning bid!.

Its a packing puzzle and the object is to pack 10 notched burr pieces (or sticks) flush into the box frame. 

Now to my Interlace. Its not a packing puzzle, although at one point in time I did consider making it so, but decided a free form interlocking solid with curved edges looked far more sexy. But as mentioned, the design concept is similar to Bob's 5x5. Until the Baxterweb auction in November, I had never even seen Bob's 5x5 or anything similar. The Interlace was something I came up with around September this year. 

My design consists of 8 board burr pieces that "interlock" to form the shape in the photo. I had it cut from 10mm thick plexiglass. While Bob's 5x5 pieces are two units thick, the Interlace is four. And both puzzles each have a unique solution.

The Interlace also became the starting point for my CrossRoads interlocking board burr with a level 12 solution. There are probably other puzzles out there with a similar design to Bob's 5x5 or my Interlace. If anyone knows, please drop me a note, thanks!

One Fish Another Fish

Name
One Fish Another Fish

Designer
Serhiy Grabarchuk. One of his many numerous sliding puzzle designs (see here). Serhiy also designed the Cast Coaster for Hanayama.

Start Position

Finished Position...well sort of...the lower  left  corner
blue tile is actually supposed to be on the top left corner)

Manufacturer
Diniar Namdarian.

Type & Classification
Sliding

Dimensions
15.1 cm (Height) x 12.1cm (Width) x 1.0 cm (Depth).

Materials & Construction
Entire puzzle is made of acrylic (plexiglass). Construction fit and finish is very good as the puzzle pieces are laser cut to tight tolerances.

Overview
The One Fish Another Fish came to me courtesy of Diniar Namdarian, puzzle designer and collector (thank you Diniar). From the design, you can tell why its called the name its called. The very good combination of colours for the pieces consisting of orange, blue and yellow enclosed by a white tray gives the puzzle a very bright, cheerful and attractive appearance.

Initially one would not think its a very difficult sliding puzzle given that its only 11 moving pieces (one space is left empty). This is what what I thought too (after my most difficult encounter with my Cat & Dog sliding puzzle, which still remains unsolved).

Well I should have remembered after so much puzzling that a puzzle that looks simple usually isn't and true enough as I started playing, I realised that not every single piece will move in every direction when it came to the corners. This clever restriction limits the movements of the pieces and makes the puzzle far more challenging than it looks.

I took a good forty five minutes with trying all sorts of moves before arriving at the "finished" position ie the reverse image of the fish...but alas, still not quite there. But I was happy with my personal result and didn't go further.

Difficulty Level
Moderately difficult. Moving the quarter-circle shaped pieces to their intended locations do require some forward planning of sorts since movements may be restricted now and again at the corners.

Summary
Overall a nice well-made sliding puzzle that provides enough challenge (and one that does not take a lot of time to complete). Good for puzzlers that don't have much experience with sliding puzzles (like me). I should have started with this one instead of the Cat & Dog.