Sunday 6 June 2021

A Cube Made of Cubes - Easy? Nope!

Key and Keyway Cube
Today's post may be a little less coherent than usual - I have spent the lsat 45 minutes trying to provide computer support to the mother out-law who lives 250 miles away and things weren't working. Eventually got it all working but I think we both left the telephone conversation rather frazzled! 

I am all too aware that I do spend a lot of time writing about puzzles that are extremely hard to get hold of for most people so every now and then when something hits my radar that might be good and is available to order then I try to get a copy to write about and encourage you, my patient readers. I was alerted to this puzzle by Michel van Ipenburg, a very prolific and hugely talented puzzler who certainly knows a good puzzle when he sees one. Our interests don't completely overlap even if he is a huge advocate of the N-ary puzzle group like me but if he advises people to buy something then I sit up and pay attention.

Nicely presented.
He showed off the Key and Keyway cube designed and produced by John Kelly in Ireland. I have not heard of John before but dealing with his site ( was delightful with quick acknowledgement of the order and updates when manufactured and delivered. At the moment there is only this one puzzle on his store but after this experience, I look forward to more. The puzzle is only 20€ plus postage and was manufactured and posted within a couple of days. When it arrived it was nicely presented in a cloth bag with a label giving description and instructions strung onto it. This string didn't last very long in my house! Unfortunately I had left the label and string on the kitchen work surface after I took the puzzle to work (I had hidden the label reasonably well but nothing can keep my pussy-boys from finding string). The following morning the cats followed me into the bathroom for our habitual ablutions and to my disgust a very loud puking noise occured behind me followed by a large amount of bright green liquid and said piece of string in the middle (completely intact). Down in the kitchen, the label was waiting to be found in the middle of the floor! Doh!

Later that day, I got to have a proper look. It has been 3D printed in a vibrant matt purple plastic and very nicely done too. The pieces are pretty solid too and don't feel completely hollow. I guess that is important so that the screws can be screwed in securely. Each cube has 3 sides which are smooth and obviously expected to be the outer faces and 3 which will have either screws in various positions or keyways pointing in different directions. The objective is obviously to build a 2x2x2 cube by sliding the screws into the keyways and pushing them into locked positions (not allowing them to just sit in the entry hole). 

I began to play whilst at work (waiting for a surgeon to decide which urgent case took priority). Quite quickly it becomes apparent that this could get quite confusing and also it becomes obvious that there is a temptation to set it up and engage the screws using rotational moves of pairs of cubes. This is NOT allowed - everything should be done with linear motions and the trick is to find which pieces engage with each other and the correct sequence to make it work. Quite often I found that I wanted to slide two cubes together but they were blocked and I needed to start again. Clever!

Still waiting for the bloody surgeon, I actually solved it and surprised everyone waiting with me. They thought it might be impossible. It had taken me about 20 minutes in all. Quite proud of myself, I dismantled it (that took a bit of doing after losing track of which face was which) and handed it to the surgeon to play with whilst I anaesthetised our first victim. He handed it back to me in pieces with the simple word "NO!" Oh well - maybe not one for the novice? Later in the week, I gave it to one of my colleagues who expressed an interest in the pieces lying on our office desk - he had a fiddle and made a shape and then handed it back with a similar expression of discontent:

It's going to be easy isn't it?
This is the best that Dr Moll can do!
I took it home that day and tried again only to find that I seriously struggled - there was obviously a lot more to it than I initially understood. The sequence must be exactly correct. This time it took me about an hour and required multiple restarts. Interesting! I had better do it a few more times. No matter what, it always seemed to take me about 45 minutes. There is definitely something complex with this that requires proper exploration and thought to solve - I have tried not to just memorise the sequence from dismantling it. It locks together and looks quite attractive - John has also provided a stand to display the puzzle once solved:

Assembled with stand
Looks nice on display
Like Michel, I have really enjoyed this puzzle. It is not made from gorgeous wood but it is very nicely printed. It is a nice challenge that requires some thought and planning rather than loads of trial and error and is a great price. I highly recommend it - you can either buy it ready made from John or can buy the stl files to print your own (obviously you will need the right screws too). I think this is suitable for experienced puzzlers and beginners alike but probably not ideal for surgeons or less than bright anaesthetists - most of you out there should be fine! Go get it here.

Enjoy the rest of the weekend guys - I now need a large gin to calm my nerves after my computer support experience earlier!


  1. Is that a coffee mug in the background? It matches the color of the puzzle. This looks challenging and fun

    1. Hi Tom, it is indeed an insulated coffee cup in the background. Pure chance that it matches the puzzle! The key and keyway cube is a very nice challenge that is just the right difficulty.