Wednesday 29 February 2012

Twisty puzzle madness I - TomZ's curvy copter

Tommy and Roxanne, having played with this puzzle for the last few days, I can say that you are both forgiven for getting me so badly hooked on these damn twisty things again!

TomZ's Curvy Copter
I had not intended to start my reviews with this one! But, I can't resist it! It's absolutely fabulous! This particular cube was designed by Tom van der Zanden, an incredibly prolific young Dutch puzzle designer (dare I say, a new Oskar van Deventer?). He has been designing Twisty puzzles for years now and selling them via his Shapeways store - beware there is stuff there that will make your bank account curl up and die! He announced the initial arrival of this puzzle on the Twistypuzzles forums in February of 2010. He had based the initial idea on Adam Cowan's Helicopter cube and added curved surfaces to make the turning easier and  also to allow some of the hidden inner edge pieces to be visible on the surface, making for an extra twist to solving this puzzle!

So what is a Curvy copter? Why is it special? You are all familiar with a standard cube (I think the whole world must know what one is by now!) - a standard cube is a 3x3x3 face turning cubic twisty puzzle - it is easy to visualise and relatively easy to solve. Then we have a skewb (or skewed cube) this is a deep cut (2x2) corner turning cubic twisty puzzle - it is "deep cut" because one turn makes changes on every face of the cube. So the only thing missing from this progression is an edge turning cubic twisty puzzle - the 2 variants that do this are the Helicopter cube and TomZ's Curvy copter. He has also created a deep cut version called the Curvy copter II. The Curvy copter that I own was first mass produced by Uwe Meffert in July 2011 (having been made by a knock-off company before that) and is still available from him. He had been out of stock recently and I bought mine from the HKnowstore run by Calvin Fan who seems to work closely with Uwe. This puzzle is amazingly good value for money at $18 including P&P!!

So what happens when an edge turning cube turns? Well not much when you do only one, it actually looks quite pretty:

An edge turn
This seems very innocuous, doesn't it? I thought so too! Shortly after I got mine, I tried doing the usual pattern making by going round and round turning edges in order. This made for a rather interesting change in the cube but nothing terribly pretty (it did provide me with an algorithm for later though). During this, the present Mrs S, called me to set the dining table and I jumped to attention immediately as I always do!!! Unfortunately this was in the middle of a sequence of turns and whilst I thought I would remember where I had been turning last, I was wrong! When I got back to it and continued the sequence, it got partly scrambled and I couldn't get it back. What the hell! I completely scrambled it at this point and singularly failed to work out what to do next.

I took it to work with me the following day in the hope that I would get a small break during the day to try and solve it. I did get a small lunch break and began work on it and very quickly discovered that there was a really nice logical process to it. Just like doing the first face of a standard cube, you can solve this with just a little bit of thought. The next layer proved slightly harder but only really a progression of the first - centres first then align the edges if you find one the wrong way around. I was getting really excited as I progressed through it - the movement of this is just wonderful - really smooth with no catching at all. In fact it is hard to prevent all sorts of bits turning by accident. Finally it came to the top face and with some trepidation, I went for the centres and IT ALL FELL INTO PLACE!!! Yessss! Except all the corners were in the wrong places and pointing the wrong way!!!! Nooooo!

Most of the puzzle was assembled within 15 minutes and then I was stumped! Nothing I would do would make the corners right. After 2 hours of trying I was still stuck! In the end I turned it upside down and tried various manoeuvres with the completed bottom face to see whether I could work out an algorithm or two. Over the next 4 or 5 hours, I noticed something strange and then it came to me! Firstly, I was able to move all the corners to their proper positions and then lo and behold they were facing the wrong way! Another few hours and I had worked out how to rotate them. It takes 24 moves to do the rotations and may need multiples of this - BUT it is an easy to remember 24 moves!!! I then needed to apply this to get the right ones to twist. After about 12 hours of mucking about I had solved it - Hooray!!

Jumbling & changing orbit
Unfortunately the saga doesn't end there!! This sort of puzzle can undergo two rather special kinds of movement - it will jumble (this means that moving one piece will effectively block the movement of other pieces) and it will shapeshift (fairly obvious what this means!) So far I had only done 180º turns of the edges - this has the side effect that any centre piece has to stay within a certain series of positions (aka orbits). BUT if you do a jumbling move you block movements for a while but if you continue you then move the centres out of their orbits and they can now go anywhere!

When I have shown the puzzle doing this to my friends and colleagues their expressions change! They started out with a smile (feeling sorry for me or Mrs S) and rapidly they recoil and start muttering that some puzzles are "just plain evil"!

If you want to see what jumbling looks like here is TomZ showing it off. Go to the 30 second mark and you will see shapeshifting and the jumbling moves.

What a mess!
So after I had done the puzzle a few times without the jumbling moves, I decided to try it again - first I scrambled it the normal way and then I jumbled it a bit and then alternated these for a while. I finally jumbled and left it shapeshifted! What a mess!!!

After a small horrified pause, I had a go at this one! Just as I feared, I really struggled to get it back to cube shape. I ended up with either a sort of windmill thing going on with 2 pieces sticking straight out! After about 20 minutes of ever more desperate moves (I really thought I was going to have to ask for help from a YouTube guru!) I finally managed to "re-cube" it and when I calmed down a bit had a crack at solving it. Now it is pretty tough - it took me almost 45 minutes to solve all but the last layer! The last layer was really great fun - the same strategy is required as for the rest of the cube but you really need to concentrate on where the jumbling needs to be done. It was with huge satisfaction that I solved this one without aid from the internet and using just my own algorithms.

So, as you have realised, I luuurve this puzzle! Not only is it solvable by a normal human being, but it is really quite beautiful. Thank you TomZ and Mefferts for producing this. I can only recommend that you ALL run out and buy it asap! You really won't be disappointed. In fact, at least two of my colleagues at work have already gone out and bought one!

And finally! Tom, if you do ever read this, I hope to see much more from you soon. I have already ordered another one of your special puzzles that has recently been mass produced. I  am really hoping to one day be able to buy one of your puzzles directly from you - thank you again!


  1. At least the present Mrs. S. can't complain about the rattle coming from it...What a day! You've discovered and enjoyed a twisty!

    1. It's true, Rox! She actually liked the look of this one and I really loved it - especially as I managed to solve it all by myself! I have enjoyed a whole lot more too - just not written about them yet!