Danlock Model B

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

Every puzzle review that I have come across on the Danlock has praised it. I have always wondered what was so special about it, after all, the lock looks like any another padlock. From an aesthetic point of view, it certainly does not have the Popplock-style embellishments nor the typical over-the-top dimensions.

It was only several weeks ago that I received the Model B from it's designer Dan Feldman. I waited for nearly 9 months as it was out of stock then. 

The lock itself looks pretty ordinary. Dan had chosen to use a stock lock made by the Nabob company in Israel for his puzzle. The lock measures about 8.5cm tall and 5 cm wide. It is larger than a Popplock T6, but smaller than all the other Popplocks in terms of size and weight. It has the usual brass body but instead of steel, the shackle is also brass. As a real functioning lock, the quality is very good and looks well capable of deterring break-ins.

The "trademark" of the Danlock which makes it recognizable is the broken key that comes with the lock. The object of the puzzle is not just to unlock the shackle but to relock it with everything back to their original place. Dan states in the puzzle instructions that everything that is needed to solve the lock is present; the ring that hold the two pieces of the broken key is not needed, neither is the draw-string pouch that accompanies the puzzle. In a way, the Danlock could be classified as a sequential discovery puzzle.

Unlocking the lock is easy part. When you look at the pieces you have, it is obvious that the broken key shard has to be used somehow. Using the broken key, I happily unlocked the lock in a jiffy. The real (and very difficult) challenge is to restore the lock back to its original state, with both the unbroken key and broken key attached back to the shackle. 

I was stumped for a number of days at this stage; trying different things but with no success. Finally I contacted fellow puzzle blogger Kevin Sadler for a clue. He gave me a hint and I re-examined carefully everything I had in front of me again; the lock body, shackle and the 2 keys. I decided to experiment with some moves I hadn't tried previously nor thought of. Lo and behold, my efforts were rewarded not too long after that. I managed to reinstate the Danlock to its original state. Certain aspects of the solution is very well disguised and the action steps required to completely solve the puzzle were quite surprising and totally unexpected. 

I feel it's by far the best and perhaps one of the most difficult trick locks I have come across. The only other lock that I would consider which can give the Danlock a run for the money is perhaps the Popplock T4. The real appeal of the Danlock lies in its ability to hide a really amazing mechanical puzzle design within the confines of an ordinary and non-script looking padlock. And unlike most other trick locks, here, both the opening and closing are part of the solving process.

Not cheap but the Danlock is good value-for-money given it's puzzling aspect. Definitely worth acquiring. The Model B is available directly from Dan Feldman.

AlCyl / Blue Cylinder

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The AlCyl (alternatively called the Blue Cylinder) came to me from Wil Strijbos. It first made its appearance in 2009 but for the last couple of years, I searched for it everywhere but could never find one, not even in the puzzle auctions that take place now and again. Well, finally, just not too long ago, Wil made some available for sale and I quickly grab the chance to put in an order for one.

The AlCyl (I didn't know what "AlCyl" meant), but I was informed by 4 very experienced puzzlers (see below comments), 3 of whom are also well-known puzzle bloggers; Oli, Allard and Kevin, that it's a combination of Aluminium + Cylinder = AlCyl, thanks guys... gosh I am dense! It was designed by Hirokazu Iwasawa, who also gave us the triangular-shaped Tritalon, which was reviewed earlier in this blog.

The puzzle measures about 6cm tall and 4.8cm across in diameter. It is made of aluminium and anodised blue and looks very much like a Revomaze Blue Extreme with the ends lopped off. Construction, fit and finish of the AlCyl is very good and the puzzle feels solid.

AlCyl next to the Revomaze Extreme Blue

The object of the puzzle is to open the AlCyl and remove a 1-yen coin inside. This is not at all a difficult puzzle but perhaps could be considered a bit tricky, especially for non-puzzlers. The solution requires 3 steps. Not hard to figure out once you start playing with it for a while. I opened the AlCyl and extracted the coin in just a minute or two. There is enough space inside the AlCyl for more than a 1-yen coin....in fact you could put quite a lot of small(ish) items such as jewellery, rings, money etc.

However do be gentle if you are going to open and close the AlCyl often... assuming you are going to use it as a repository for things. Its tough looking exterior does belie its slightly more delicate interior construction.

From a puzzling perspective, the AlCyl may not really be value for money; but well worth the price if you are looking for a rare, hard to find and high quality collector's item.

Heptagon 48

The Heptagon 48 is one of the most beautifully made puzzles I have come across. The marble (yes marble!) version of this tray packing puzzle was Japanese designer Koshi Arai's competition entry at the IPP 32 Nob Yoshigahara Puzzle Design Competition held in Washington, USA this August. It was also one of three entries that won a Jury Honourable Mention at the competition.

When I first saw the marble Heptagon 48, I immediately contact Koshi-san for price and availability but the quoted price was a bit too high for me so I decided to settle for his wooden (less expensive) version instead. And I have no regrets buying the latter.

And now to the scientific bits. A heptagon is a polygon with seven sides. Together four heptagons can be joined together at the edges to form a "tetrahept", which in turn become the individual packing pieces of this puzzle. 12 "tetrahepts" consisting of six different designs (making a total of 48 heptagons) make up the pieces required to fill the tray. If you are confused like I am about all this technical stuff, check out Koshi-san's website where he has loads more information about his puzzle and Heptagons.

This puzzle is made of two different woods. Both the individual pieces and tray are made of dark rosewood for the top surfaces and light coloured birdseye maple for the bottom. The tray measures about 17cm x 13cm x 2cm. Quality of construction is excellent with incredible finishing. All the individual pieces have been (laser?) cut to very tight tolerances and fit just nicely with each other into the tray. This puzzle even comes in a nice beige gift box.

The object of the puzzle of course is to fit the 12 tetrahepts into the tray with all the pieces dark side up. The puzzle comes to you partially solved with 2 tetrahepts wrong side up (ie light pieces facing up). The tetrahepts do not cover the entire tray, even when correctly packed in, but will leave "pentagonal" spaces in between, which is intended.

According to Koshi-san, there are an unknown possible number of solutions, of which he has discovered 57 to-date; all with a combination of dark and light pieces facing up but only two that have all pieces dark (correct) side up. So far all my attempts have yielded only one solution; ie one remaining piece that can only be inserted but wrong side up. I only managed to solve the puzzle properly when Koshi-san sent me his 57 solutions in PDF.

The Heptagon 48 is very challenging.  There are no straight edges; all the 4 sides of the parallelogram-shaped tray cavity are "jagged" to fit the tetrahepts. You have to grapple with pieces that not only look geometrically similar, but work with the same dark coloured woods for both the pieces and tray, which provide no contrasting reference points to aid in solving. And because the pieces fit so well and closely together, inserting and removing the pieces from the tray is not an easy task either, which makes it all the more difficult.

If you are into tray packing puzzles and want serious quality, well, the Heptagon 48 definitely should not be missed. It is available directly from Koshi Arai via email.

Lee Valley Burr Puzzle & Trick Bolts

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

Who would imagine a hardware supplier like Lee Valley Tools would have a couple of steel puzzles as part of their inventory. From Jeff Chiou, I knew that they sold the behemoth Indian Puzzle Lock. But I did not know they also sell a steel burr as well as a pair of trick bolts until I chanced upon the latter on Rob's Puzzle Page. Given my penchant for metal puzzles, I decided to check out the Lee Valley offerings.

The burr and bolts are all made in Canada. Quality of construction, fit and finish are very good. The burr is about 6.5cm all round, solid steel and zinc plated while the trick bolts are between 3.5cm to 4cm and finished with a very nice matt gray. 

The burr consists of six interlocking rods, with five of the rods each with grooves cut out while the sixth is a solid piece which locks the other five together in the solved state. The fit of the pieces is very good. Unlike aluminium which is lighter, this one being made of steel weighs a hefty 480 grams. There are very few metal burrs I have come across so far, except for Wil Strijbos' 7 and 10 Move Burrs and Charles Perry's Ball Puzzle, all of which I already own, so this was another welcome addition.

I struggled with the burr for quite some time. Although only six pieces, the burr is pretty challenging, partly because its difficult to try to handle several heavy pieces all at the same time; but mainly because I am pretty lousy with burrs. I used my Charles Perry Ball as a guide but comparing both, the Lee Valley Burr has a different design to its pieces. This made the Lee Valley Burr much more difficult to assemble. Eventually I gave up and checked the solution offered on their website. Without the solution, I would have taken a good while longer to solve.

On the other hand, the pair of trick bolts were pretty easy to figure out. Solved both within seconds, and that's because I have played with other trick bolts with similar mechanisms. The bolts are well constructed, so no chance of any moving parts getting stuck, unlike some other poorer quality ones. 

All three puzzles came at a very reasonable price making them excellent value for money. If you do not own a trick bolt, and not sure whether to plonk down the dough for the Rolls Royce of trick bolts; ie one of Rocky Chiaro's, well, here is a chance to own a pair of high quality ones at a very affordable price.