Convolution's Cousin

Convolution's Cousin ("CC") designed by Stewart Coffin, was Dave Rossetti's IPP34 Exchange Puzzle. It's the "cousin" because it looks and behaves very similar to Coffin's Convolution. Except that this cousin is the smaller cousin, has only five pieces versus Convolution's seven. While I don't have a copy of the Convolution, I do have the Convolution Ball, which is spherical shaped and based on the former's cube design.

The CC is made from African Mahogany. Dave made the puzzle himself under the mentor-ship of Tom Lensch. The mentoring appears to have paid off as the CC is very well constructed with high quality fit and finish. In fact the fit is so good that the join lines of the separate pieces are very well hidden and pretty difficult to find.

This is an interlocking puzzle and the object is to disassemble and re-assemble the pieces. First task of course is to find the "locking" piece that keeps the rest together. Not too difficult as I pushed and prodded and after a short while, figured out how to move the first piece. Once the first piece is sorted out, its a matter of finding which piece comes next and so on. Despite the snug fit, all the pieces slide smoothly and no force is required. 

The dis-assembly takes 6 steps and there are two ways to take the puzzle apart; so it would not really count as a sequential movement puzzle. A bit of rotation is also involved in the process. While dis-assembly is not hard, the re-assembly is, especially if you forget the order and orientation of the pieces and how they interact with each other. It can then pose a huge challenge to get it back to the solved state. That's why its always advisable to document the steps with photos as you play.

The Rose Pennyhedron

Stephen Chin from Australia had named his IPP34 Exchange Puzzle the "Rose Pennyhedron", probably because it sounds better and also easier to pronounced than its scientific designation ie "Rhombic Dodecahedron". What a mouthful!

What is an "RD"? Well, you can check out its meaning here. You're not alone if you don't understand the explanation, I don't either.

The RD comprises three pieces, each of which is made up of several other triangular-shaped pieces glued together. The woods appear to be Maple and Cherry. Overall the construction fit and finish is very good and the tolerances are very tight. So tight at first that that I had to leave it in my dry-box for a couple of days to make sure the puzzle was dehumidified.

The object of the RD is to "open" it...separate the pieces. As I mentioned, the tolerances are very tight so it took me a while to find the join lines separating the three individual pieces; no easy task mind you.

Once I got past this bit, it was a matter of pressing and pulling to see how the three pieces would separate themselves. This is a co-ordinate motion puzzle and for most co-ordinate motion puzzles, generally no force is required, but for the RD, I did find that I needed to apply a tad more strength to split the pieces. When it opens, the puzzle does look like a flower opening, hence the name."Rose". But I am not sure what the "penny" refers to tho'.

While the pieces appear to be identical, I found that if I did not fit the pieces together as per their original positions relative to each other, the fit was not perfect and I could feel this in the join lines. Took me several tries before I got it right and the whole puzzle became smooth to the touch.   

[Edit 26 Jan 2015: Lionel Depeux has written to me about the name Pennyhedron (Thank you Lionel). Here are his comments below-

I believe there’s no hidden meaning to be found in the name: ‘Pennyhedron’ was the name for the original puzzle of that kind (designed and made Stewart Coffin), which was only a 2-piece puzzle.

As to where the original name came from, you’ll find an explanation on Eric Fuller’s website:

http://www.cubicdissection.com/html/purchase/discont/pennyhedron.html ]

Rik's Tea Box Mod - T42

Rik's Tea Box was Rik Van Grol's IPP34 Exchange Puzzle in London last August.

Designed and made by Rik himself, the puzzle consists of a box containing 10 real tea bags; two varieties, English Breakfast and Earl Grey (hence T-42). The object of course is to "open the box and enjoy a cup of tea".

The name of the puzzle would suggest that the box is a real tea box. It certainly looks real enough since the tea bags all fit rather nicely inside. Made of wood, it has a real glass top which allows you to look inside. 

As in most puzzle/trick opening boxes, the usual approach is to try to examine the outside of the box for clues but Rik's box didn't seem to shed any. I even tried to see if the metal latch and hinges yielded any luck, but none whatsoever. The usual trial and error prevails. Something kept the glass lid locked in its place. The accompanying instructions did contain a hint of sorts but it made no sense to me at the beginning (not until I finally opened the box later).

Nothing apart from the tea bags could be seen inside the box either...until I gave the box a shake and then I detected something inside which sort of gave me a vague clue as to how I might open the box. Let me state here that no force whatsoever is needed to solve this box. This box is a real tea box, and was not built to withstand the normal wear and tear associated with puzzling!

I have kept the lid closed so as not to expose the locking mechanism

After this, within a jiffy I discovered the solution and was able to open the lid. Not a difficult puzzle by any means but the locking mechanism is pretty tricky. I was then able to see how Rik had "modded" the box to retrofit a locking mechanism for the glass lid.

As long as you keep the locking mechanism unlocked, Rik's Tea Box is actually very useful for storing tea bags. But even if its locked, its pretty easy to open the box (once you know the moves). Now here's a puzzle which serves another purpose!

It's Decemburr (and my 250th Post!)

I wish it was still December (with Christmas and the New Year) but unfortunately it ain't! 

But this is my 250th post, since I started this blog three and half years ago; how time has flown!

But my puzzle of choice over the weekend was Decemburr by Goh Pit Khiam. Designed over 15 years ago in 1999, it was the highest level solution burr (level 13 at that time) for a 12 piece burr configuration. The highest known solution level then for any burr puzzle was believed to be level 18, which was from the Lovely 18-piece Burr, designed by Bruce Love. 

Goh named his burr Decemburr because it has 12 pieces and was designed sometime during December 1999. Mind you, the design was done solely by hand, not aided by any computer software. At that time Andreas Rover also hadn't come up with Burr Tools yet, so Goh used Bill Cutler's GENDA ("GENeral DisAssembly") programme to check his design to confirm a unique solution. Really quite a feat in those days!

My Decemburr came to me as a gift from Goh at the our first meeting several years back, after I found out he was a fellow Singaporean living just 14km away from me. It has been in my puzzle cupboard all this while. My copy was made by Mr Puzzle of Australia. Its from Mr Puzzle's higher end Craftsman range and constructed from Queensland Blackbean wood. Quality and finish is very good with nice detailing of the edges. And the pieces all slide smoothly (after a couple of days in my dehumidifying box).

The Decemburr has a total of 23 moves to fully disassemble and 13 to remove the first piece. The starting was straight forward enough and I got the first piece to move, then slowly the other pieces on the sides were also able to move which allowed the movement of their intersecting pieces. There appeared to be a sort of sequence to it but up to a certain point..and then I was stuck, nothing else seemed able to move. But after a bit more experimentation I finally was able to extract the first piece. In fact once the first piece was out, the rest was pretty straightforward. 

However once the 12 pieces were all strewn over my table, that was it...I was totally lost, not knowing even where to start. Anyway I was very pleased just to have disassembled it, as with most of my other burr puzzles. I contacted Goh and he kindly sent over Burr Tools which saved the day. following the Burr Tool steps, I managed to get everything back into place again.

The Decemburr is rated 10/10 for difficulty by Mr Puzzle because its very difficult to put back together unless the correct sequential 13 steps (in reverse order) are taken. It has 5485 false solutions! It is considered by many to be a classic and a must-have for collectors. Unfortunately, its not commercially available at the moment and perhaps the only route to acquiring one is via auction

Secret Box

This Secret Box puzzle was a gift from Otis Cheng during IPP34 in London (thank you Otis). Otis is from Hong Kong and an avid twisties collector.

The box is made of wood and produced by Mi-Toys. The designer is unknown (perhaps someone in-house from Mi-toys). Externally its a regular looking rectangular box with a lid but has two knobs on top. Quality is decent; I would say above average, considering this is a mass produced product. 

The object is to open the lid. Like most trick opening/puzzle boxes, the Secret Box requires a number of steps in the right sequence.It takes roughly five steps to fully remove the lid.

Not a very difficult puzzle so I am not sure why its been rated 4 out of 5 stars (graded as "Unbelievable") although the mechanism is pretty well disguised. A fun solve, nonetheless.

The box is functional and can actually store a number of small items. You will also notice it has two slits, one on either side of the box and this makes the Secret Box suitable as a piggy bank. The box would make a very good reasonably priced gift for someone or a novice puzzler. 

Slide Blocked Sliding Block

The Slide Blocked Sliding Block puzzle ("SBSB") was designed by Bill Cutler in 1986 and won the Grand Prize at the 1988 Hikimi Wooden Puzzle Competition. 

Start Position

The original design is not the "two arrows" layout you see in these photos although the solving principle is the same.

The "two arrows" version here is from Tom Lensch. The puzzle is made of Walnut for the frame while the pieces are Maple, Bubinga, Indian Rosewood and Yellowheart. Very well constructed with a nice fit and finish. The SBSB is also not to be confused with Goh Pit Khiam's Arrow Blocks puzzle which tho' the latter has a similar external appearance to the SBSB, the solution and method of solving is totally different (and a lot more difficult). 

The SBSB is a sliding block puzzle. Object is to slide the 5 pieces around to form a "complete arrow" on the left side, after removal of the Yellowheart start piece (which happens to be the only piece that can be removed from the frame). 

But the SBSB has a "trick" to it....the pieces have been constructed in such a way that certain movements are restricted (hence "slide blocked"); making it much harder than it looks. A normal 5 piece sliding block puzzle would have been a pretty easy solve. But here, the SBSB requires a minimum of 41 moves to complete.

Solved Position

Notwithstanding the restriction of movements of the pieces, the SBSB, while challenging is still quite manageable as it consists of only 5 pieces moving in rectilinear fashion. But I did find myself hitting some dead ends here and there along the way and backtracking before getting the arrows to their correct positions. With some persistence, one can eventually get to the end point, but probably taking more than 41 moves. To complete the solution, the goal is to get back to the original start position. Unless your memory is superb, you'll probably have to go through some trial and error to get it solved.

The SBSB is a different take on the traditional sliding block puzzle. And with the arrows design, it also displays very well. Available from Tom Lensch for US$125. [Edit 12 Jan 2015 - Someone has written to me to say that Tom does not have any more available]

Popplock T9

Update 23 October 2017 - Dear Reader, please check out my new puzzle blog and e-store at http://mechanical-puzzles.com

The T9 from Rainer Popp came out sometime in the middle of last year. At a behemoth 11.5cm x 7cm x 2.4cm and weighing in at 1.052kg, this is one of the largest locks in the Popplock collection. 

For previous reviews of Popplocks from T2 to T8, please click below:-
1. T2
2. T3
3. T4
4. T5
5. T6
6. T7
7. T8

Rainer manufactures and produces by hand a new model Popplock every year. I have had this lock since last August and its been in storage until several days ago. There have been two reviews of the T9 so far, from Allard and Kevin and both bloggers have sung high praises of the T9. Even though I only managed to solve mine with the help of the instruction manual, I have to agree with the two gents. It is really quite magnificent from a puzzling perspective.

There is really nothing more to be said about the T9's quality and finish. A real piece of superb craftsmanship with fine detailing. Damn expensive I might add. The body is made from a block of solid brass and the shackle is stainless steel.  At first glance, it looks like a large garden variety padlock with an ordinary looking key...except the front of the T9 has, in addition to the a key hole, a circular looking dial with rivets on the front, three of them imbued with red paint.

To solve the T9, there are basically three main stages, each with a number of steps. In most sequential discovery puzzles, the first step is usually easier (not easy) than the rest, but in the case of the T9, I was actually stumped right from stage one. Took me a while to figure out what needed to be done. Yes, the key can go inside the hole and turn round and round, but that's all to it, nothing more. With my small victory at stage one, I moved on to stage two. I had a good idea what was going on and even made progress (mind you all the while not being able to see what's happening inside the lock). However, I never made it completely past stage two. Here is where I was stuck for good and finally resorted to the instructions.

Stage three is even harder than stage two. And as Kevin mentioned in his post, you need good lighting. I would also add a good eye and make sure you have your reading glasses on too for this stage. I recommend playing under white or tungsten lighting if possible. The crucial steps in stage three are so very subtle and the mechanism so well hidden (that's provided if you can reach this point) that I don't think I would have figured them out without the instructions. With the last move, the shackle suddenly springs springs open...and there you go, the T9 is solved! Resetting the T9 is surprisingly easy, given the many steps previously....just turn the key!

Once you know the moves, sequence and what to look out for, repeat solving is quite manageable and can be done reasonably quickly, within a couple of minutes even.

With the exception of the T7 and T8, Rainer Popp has made a return to the traditional Popplock style of puzzle locks with the T9. Those who have played with the earlier versions from T2 to T6 would know what I mean. Puzzle/trick locks don't show up very often, in fact since the T8 in 2013, the only other metal puzzle lock at this level of quality and manufacture that came to the market is the Swing Lock from Splinter Justus (which I do not own). 

Very difficult yes, but overall the T9 is an excellent puzzle lock with multiple stages and steps to keep one well occupied with progress and a-ha moments along the way. Expensive also yes, but lots of puzzling value for money. The workings of the lock (from the internal diagrams in the manual) have to be seen to be believed.

As far as I can tell, unfortunately there are no T9s available commercially at the moment as all appear to have gone to private hands. Not surprising, since Rainer produces very limited units for each new model, just anywhere between fifty to less than a hundred.

[Edit 8 January 2015 - I have just been informed by Wil Strijbos that he still has one last copy of the T9 available for sale at 380 euros. If anyone is keen, please PM me via my blog email and I will put you in touch with Wil]

Karakuri Christmas Present #4 - Confetto Box 2

Update 23 October 2017 - Dear Reader, please check out my new puzzle blog and e-store at http://mechanical-puzzles.com

A Very Happy New Year everyone! 

Here's my first post for 2015...on my fourth and last Karakuri Christmas present which I received a couple of weeks back last Christmas.

This puzzle box was designed and made by Hiroshi Iwahara from the Karakuri Creation Group. 

This box is made (most likely) from Walnut with a different (unidentifiable) wood for the internals. There are also a number of steel parts (rods) inside the puzzle. Nothing more to add about its quality and construction other than its excellently made with very tight tolerances throughout. Everything moves and slides smoothly as intended.

This first three presents (see my last three blog posts) were very easy to solve, including #2 the "New Parcel Cube" from Akio Kamei, which was the hardest of the three. The Confetto Box here surpasses the previous three in terms of difficulty. In fact when I first played with it for the first few minutes...I said to myself...hmm, this one looks like a tough one!

The goal of this puzzle is to slide the side panels of the box (partially) open, as shown in the photo. To do this, the first moving panel needs to be found, which I did, after a bit of pushing here and there on all the sides. Thereafter I slowly discovered the rest, but not without some experimentation (and difficulty) especially for the first couple of panels.

In a way its similar to a traditional multiple-moves Japanese puzzle box. However, Iwahara's box is different in that there is greater (and more subtle) "interaction" between the panels, facilitated by the internal mechanism, which makes this puzzle not that easy. It takes a bit to understand how the puzzle is suppose to work. I am still not too sure how the internal mechanism functions (although I have a vague idea) as only a glimmer of the insides is visible. Peeking in, all I can tell is that it looks pretty intricate. 

And unlike the more typical traditional box, there is also no internal space or cavity (for storage of small items) to be found as none of the panels on the Confetto box can slide more than a quarter open. It would appear the box was intended solely as a puzzle. Well, unless I am way off tangent here, the solved state of the puzzle is the one as shown in the photo above. 

If anyone who owns this box knows otherwise and has managed to go beyond this stage, please PM me.

[Edit 1st Jan 2015 - Apparently what I have solved above is only half the solution to the Confetto Box 2. Peter Hajek had emailed me after reading my post to say he had reached the stage I was at and that he believed there was a hidden compartment in the Box. A short while later, he emailed again to let me know he had solved the Box fully. He very kindly gave me some instructions and following them, I also managed to solve it. 

The Confetto Box 2 is much more difficult than anticipated and is definitely the hardest of my four presents. Just look at the intricate and complicated internals and you can see the work and craftsmanship that went into the puzzle. A really great puzzle box. For the price, also a lot of puzzling and value for money]