This rather interesting puzzle first appeared at this year’s Nob Yoshigahara Puzzle Design Competition. Designed jointly by Goh Pit Khiam and Jack Krijnen, the competition entry had four interfering sliders to produce a new incarnation of n-ary puzzle. The rounding across one of the corners produces a great lump of puzzle that fits easily in the hands and makes operating the sliders quite comfortable.
Sadly I didn’t get to spend much time in the competition room at IPP34 and apart from a cursory fiddle, didn’t get to enjoy this puzzle at all … so when Jack mentioned he’d made a couple of copies I registered my strong interest and managed to collect a copy from him at DCD in October… only the new version is a serious development on the competition entry – the International Space Station compared to a Sputnik, so to speak.
At first glance it looks as though Jack’s just given it a couple of extra sliders, which would have been nice on its own… but he’s gone and done a lot more than that! He’s introduced an optional magnetic stageblocker piece that can be used to block off one of the last three channels – pop this piece in place and you can select to have either three, four, five or six sliders in play… I don’t need to tell you what that means for move counts!
But wait, there’s more!
The puzzle arrives in a neat little wooden box to keep the main part and all the “spare” sliders together so you don’t lose them… which would be a little over the top if the only extra sliders were the few you weren’t using out of the set of six sliders you might expect… but here’s the real kicker! Jack supplied two sets of slider pieces – one binary and one ternary set… so you can choose to set it up as a binary or a ternary puzzle. [In fact Goetz has a copy with a quaternary set as well!]
…now all of that would make this a worthwhile puzzle, but the last little touch is what makes this thing awesome for me – the way they’ve designed the sliders, ANY combination of sliders can be used… so you’re not limited to having “just” a binary set or a ternary set – you can mix and match them in any combination… so you can choose a puzzle from 3 up to 6 sliders, any of which can be either binary or ternary … trust me, even if you know all of this, getting an unknown set-up courtesy of a fellow puzzler with a rogue slider thrown in there for good measure can really disrupt any sort of rhythm you might develop when trying to solve it. (Thanks Ali!)
To give it its full name, this is the mixed base, variable stage Power Tower. It is a great idea that’s been brilliantly developed to the limit to provide a super little
puzzler’s kit for experimenting with n-ary puzzles. It’ll give you 120
different configurations and anything from 11 to 727 moves.
It goes without saying that Jack’s handiwork is simply superb, yet again, and he’s produced a puzzle that’s an absolute delight to fiddle with.
Thanks Jack and congrats to you and Pit Khiam on the design – elegant and clever!
...and if you'd like to read more - there's a great article in the latest edition of CFF from Pit Khiam on The Design of N-ary Mechanical Puzzles... which features the development of the Power Tower.