Some random bits and bobs

The last time I visited James Dalgety, he was having a bit of a clear-out and had put aside a bunch of puzzles in some plastic crates for swap or sale, including a special crate of interesting items to be offered on a future puzzle auction – those were well beyond my financial reach on the day! (I hadn’t ever seen a new-in-box Panex Gold Puzzle before … didn’t think they still existed …)

After I’d done a sweep of the duplicate books shelf and picked up some interesting titles and half of a set of Cubism For Fun magazines*, I turned my attention to the swaps boxes and picked through a veritable treasure trove. I seemed to keep stumbling across things I recognised as being rather special, from my puzzle-reading and it would have been very easy to spend a whole lot more.

I picked up three rather interesting little puzzles that afternoon.

Peppermint Twist was John Ergatoudis’ IPP17 Exchange Puzzle. Reminiscent of a twisted sugar cane, this is a sweet little puzzle. (Sorry, I’ll behave.) It consists of four twisted steel strands that fit together to make a stable, neat structure … as long as the pieces are in the right place.

Starting from the solved position, it soon becomes totally clear that the only way to get these pieces apart is to slide one of them out the end by twisting it out of the bundle, and once the first one is out, sliding the next one out is easier, and soon enough you’ll have four twisted bits of metal that all look rather similar.

Reassembly isn’t totally straight-forward as there are a number of ways of putting three strands together that look pretty good only to find that the last one won’t engage… and there are some almost-solutions that leave the last piece so tight that you may well damage something in the process of trying to slot it back in … but when you find just the right combination, the last piece slides in ever-so-gently, just like it was meant to.

A fun puzzle to fiddle absent-mindedly with…

I first spotted a copy of the Perplexity puzzle on Rob Stegmann’s mammoth web-site and thought it looked neat, so when I found a copy in the swaps-bin I put it on one side.

According to Edward Hordern’s Sliding Piece Puzzles book (acquired from James on an earlier visit) these puzzles were the subject of a 1900 patent and have been produced in several forms over the years.  Rob’s collection includes several variations on the theme in his section on Sliding Block Puzzles.

The one I got is a pretty tidy example of the main variant that was first produced in 1919 – I’m not sure exactly when this copy dates back to – but it’s almost certainly just become the oldest puzzle in my little collection, by a very long way!

The letters slide up and down the main track, with a couple of branch lines permitting a bit of storage and shuffling space and the aim of the puzzle is to spell out PERPLEXITY along the main track – first backwards, then forwards. 

My first thoughts were that it wasn’t tremendously difficult as a puzzle because there’s a fair amount of space on the sidelines and there are a couple of pairs of letters that are interchangeable – however I’d totally missed a couple of subtleties about the buttons and totally failed to understand why sometimes there seemed to be a lot more space to work with than other times ... and I only discovered those after reading Edward Hordern’s notes on this little puzzle...

It’s a cute little historical artefact that’s survived many years so far – I’ll try and keep it going for a bit longer… 

[Jerry wrote about his copy over here if you're interested in some more thoughts...] 

My third interesting little find in the swap-boxes was a copy of Allan Boardman’s IPP13 exchange puzzle – a Circular Tangram. At about two inches across it’s a dinky little puzzle, as you might expect from the chap whose burrs are usually measured in single-digit millimetres across. It’s a maple tray with a set of tangram pieces resting in it –and when I first had a look at the pieces I assumed they were some sort of thin acrylic sheet – they’re only about 1.64 mm thick and are black as night. 

I was somewhat embarrassed when a bit more research on t’internet informed me that the pieces were in fact finely cut ebony – wow – of course I then added to the embarrassment by admitting this to one or two more experienced puzzlers who had a good laugh at the fact that I could have thought mister Boardman would have used acrylic – I mean, really! <Blush>

* … and since then I’ve been in touch with Rik van Grol at the Nederlandse Kubus Club and managed to purchase copies of all of the other Cubism For Fun back issues that I was missing, so I now also have a complete set of (the English editions of) those magazines as well – plenty reading lies ahead.

Eis puzzle

I was delighted a little while back when an opportunity to acquire a copy of Roger’s Eis puzzle fell into my lap. I’d first read about it on Rob Stegmann’s website – notably the fairly recent story of how this puzzle has remained unsolved in his collection for ages, until a friend miraculously opened it – and how even after studying it opened, he still struggled to repeat the solution back at home. Suffice it to say that this story filled me with no small amount of respect for this puzzle, and a fair amount of trepidation when I started playing with it.

The puzzle looks like a kids’ ice lolly – hence the name – with a brass stick protruding out of the end of an aluminium lolly. Close examination of the lolly bit shows that it’s made up of two parts that overlap and join in the centre. The brass stick bit can be rotated and sometimes pushed in and out of the lolly bit… and when it’s quite far out, the two bits of the lolly feel a little looser – suggesting that you’re trying to disassemble the puzzle.

I took my copy of Eis along to our last Midlands Puzzle Party and a few folks had an unsuccessful bash at solving it … and it was one of the Rogers being played with at James D’s Easter Saturday Puzzle Party down in Devon. At one point Oli was fiddling around with it and all of a sudden a flash of inspiration flew across his face and he said “this thing’s a Revomaze!” – and sadly that actually meant quite a lot to a few of us. He described something that he was feeling in the movements in Revo-speak and it made sense (walls, paths, traps and resets anyone?), and a couple of minutes later he had the thing open in bits on the table! [He was on a bit of a roll that day – and that wasn’t the only tough Roger puzzle he solved that afternoon!] Simply amazing …

I had a look at the bits and thought I’d recognised some of those Revo-like features (remember this puzzle pre-dates Revomazes by at least a decade!) before Oli reassembled it only for it to remain closed for the rest of the day.

Back at home I had a quick fiddle with my copy again and got absolutely nowhere before setting it aside until last Sunday, when I decided that I should approach it like it was a Revomaze, and try some rudimentary mapping of what was going on inside there … so armed with my trusty Sharpie pen, I started sketching out some paths on the brass shaft (it’s a Revo-puzzle now, not an ice lolly!) and soon enough found that I could explore some new areas and go where my little map suggested I shouldn’t be able to … which got me to the point where I could pull the shaft right out and open the two aluminium parts – job done!

Examining the innards of this puzzle has given me a huge amount of respect for Roger’s eye for engineering design. He’s used several elegantly simple ideas in a very restricted space to make a rather interesting little maze – one that you cannot navigate by luck. The symmetry in the pieces is beguiling and in fact a careful analysis of the outside of the puzzle will actually help you understand the insides – although you may not realise that until it’s too late! 

The implementation of the “springy bits” is one of the most sublimely elegant solutions imaginable … except I wouldn’t have imagined it in a million years! … and the kicker – you could show someone a picture of the bits and they will still struggle to open this puzzle – witness the fact that Rob has a picture of the bits on his website, I looked at them when Oli opened it and it still defeated me until I took out my trusty Sharpie pen – well that’s my story, and I’m sticking to it!

DIY Twisty mods...aka Rebuilding a Mosaic Cube

A couple of weeks ago I splurged a bit (I know, dear reader, you’re struggling to imagine that, but bear with me!) on some twisty puzzles from Kayleb’s Corner – there were quite a few twisties listed so I took the opportunity to add a couple of unusual twisty puzzles to my rather limited collection (I hadn’t really been a huge fan of twisty puzzles). 

One of them was a Mosaic cube designed by Oskar van Deventer (yip, him again!) and produced by Mefferts. It’s a corner turning cube with an interesting design that creates pretty patterns when you play with it (Yes, I’m very shallow!) While it looked great, playing with it left you with the distinct feeling that it was about to disintegrate in your hands – which isn’t so great. Turns out this is reasonably well-known and documented out there in internet-land: it stems from the design of the central frame that leaves quite a lot of space free inside the cube, so pieces can slide and shift a bit more than they should in the wrong places. 

While I was reading Rob Stegmann’s latest updates, I noticed that he’s just rebuilt a Mosaic cube on a new centre and reported that it is was much improved – intrigued, I  read a bit more about it and discovered that Oskar has designed a new centre-piece and made it available via his shop on Shapeways, so I ordered one (and a couple of other things while I was there) and soon enough I had a firm black ball with 8 holes in it sitting on my desk staring at me waiting for some spare time to rebuild the Mosaic cube...

Knowing I was going to have some time to rebuild it on Saturday morning, I started taking the cube apart on Friday evening – the hardest part is popping off the caps on the corner pieces – in the end I realised the easiest way was to prise them off bit-by-bit from each of their three corners using a flat bladed screwdriver ... most of them popped off fairly easily, some were real sods to lever off without stabbing yourself with a screwdriver (once too many in answer to your next question!).  

The corner caps are aligned with three little pegs mating into three holes on the corner pieces. Some of those pegs will break off during this process – but the caps need to be glued on anyway, so don’t worry if that happens.  Once the corner caps are popped off, a Philips screwdriver will unscrew the corner pieces and the puzzle effectively disassembles itself. 

Screwing the corners into the new centre is a piece of cake and everything fits absolutely perfectly. Once the corners are screwed in, you can assemble edge and centre pieces (I found it helpful to sort them into the right layout and then work from one face to the next, building up one edge at a time). The only slightly tricky bit in the assembly process is inserting the last edge piece, but I found that unscrewing the final corner allowed enough play to squeeze in the last edge piece without the rest of them falling out... from there you need to adjust the tension on the corners to taste and pop the corner caps back on again with a little glue. 

End result – a Mosaic cube that looks as good as new, but works a lot better!  

Thanks to Rob for writing this up and telling us about it – it’s transformed my Mosaic cube from a display-only piece into a nice working puzzle. If you have an unmodified one lying around, get the new centre and rebuild it – you won’t regret it!