Sunday 6 January 2019

Starting the Year With a Winner!

RDS Interlock PLUS
Back in October at an MPP, I had seen Allard's copy of the RDS interlock puzzle made from wood by the absolutely incredible craftsmanship of Jane Kostick. I think I gently had a look at it then and shied away from doing any more than pulling the first pieces out and then adding a reminder to my todo list to ask Jane about getting one of these. I did not proceed as I did not want to leave Allard with a pile of sticks that I had been unable to put back together - others seem not to have the same compassion when it comes to my own puzzles! I sort of forgot about the puzzle until the last MPP of the year when we gathered again and Stefan from Bulgaria (Trifcho on Facebook) showed off a puzzle that he had spent hundreds of hours working on manufacturing. The puzzle he had produced was the RDS Interlock puzzle (complete with extra inner puzzle(s) too). He had gotten permission from Jane Kostick to make a few but not commercially - he could only make a few and they could be for his own personal collection and a few could be gifts (not for sale). I am well known for having a wood fetish but when I saw these I was absolutely staggered by the sheer beauty of them and the quality! These did not look like they had been 3D printed at all, I actually thought that he had cast them. I have never seen such quality before and waxed lyrical about them. One of the reasons for the length of time it had taken him was the resolution of the printing - it is pretty much impossible to see any printing lines in these. Getting the alignment just perfect also required metal rods to bridge the joined pieces and this was also was incredibly time-consuming. The other feature of them that makes them so special is the speckling that showed so beautifully in the dark grey plastic ( several of the later photos will show this off very well).

Having been so enthusiastic about them and having a very brief fiddle with them and grilling him on the manufacturing methods, he offered to let me have one of them as a gift! I was flabbergasted that he would just give me something so special and slightly ashamed that he may have felt pressured into it by my rabid enthusiasm. At the end of the day when we packed up, I didn't mention it again just in case he wanted to forget his rash offer. Over the next week or so my goldfish memory let it go and I settled into puzzling on other stuff. Then in December, he dropped me an email asking what my postal address was and I was delighted to realise that the offer had been genuine and not under pressure. With bated breath, I waited, hoping for an intact package and was so pleased when I got even more than expected:

The RDS interlock (with hidden but interesting filling) and "extras"
In the meantime, Stefan had been working with the genius that is Derek Bosch to perform a full analysis of the puzzle with Burrtools. The outcome of that is that there could be a series of puzzles if you have the requisite pieces - thanks to Stefan, I have those required pieces and have even more puzzling to do.

Stefan had asked that I not release any more photos after my initial one that I posted on Facebook - he wanted for the other recipients to receive their copies first. Of course, I obeyed this wish and ended up putting the puzzle aside for a couple of weeks. It turns out that my workload around the Xmas period was pretty high and I barely had enough time to solve a puzzle and write a blog post. Even on Christmas day, I worked and then had no time to puzzle when I got home in the evening. New Year's Eve was a normal working day for me and only on New Year's day did I finally have a chance to play! We sat together in our conservatory (heated floor for the cats!) and alcohol in one hand, the puzzle in another and a very happy cat moving back and forth from floor to lap and back.

I first found one piece that could be removed and then another and finally a third. After this, I was able to remove the contents of the RDS interlock and placed that on the arm of my sofa to be played with next. At this point, the rest of the RDS interlock puzzle fell apart on me and I was left with a whole pile of pieces:

RDS Interlock puzzle and central 4 Directional Trapsticks
Beautifully presented in net bags
My plan was to play/solve the assembly of the outer puzzle a few times before working on the 4 Directional Trapsticks puzzle. Whilst Rich had managed to assemble all of the puzzles made by Jane Kostick separately, I seriously struggled with the dexterity required to assemble the outer puzzle - it tended to collapse in on itself. My solution to that was to assemble a base and then put the inner puzzle onto the base and thus give some support as I proceeded to add pieces around the outside. Assembling the RDS Interlock is not trivial - I struggled for about 20 minutes - it may have been the alcohol, it may have been the distraction of chatting with Mrs S and it may have been watching the TV. I failed several times to put it together and put it all down "safely" to take another sip/glug of my fizz and watched in horror as a really enthusiastic cat who had been happily chewing the ribbon tie of the nice bags that the puzzle came in, jumped up and knocked the 4 Directional Trapsticks puzzle off the arm of the sofa - Aaaaargh!

This was NOT what I intended!
I had absolutely no idea how the inner puzzle had been assembled! Did it split into 2? Did it come out piece by piece? Not a clue! I figured that I had better work on the inner puzzle first and then form a nice stable centre to work on the RDS interlock afterwards. There is a third little puzzle inside the second one - it is a variant of a Stewart Coffin design that Stefan had modified to fit. I didn't even dare try that at this point!

Another puzzle inside!
That's a good plan! But... I'm not very bright! I'm not good at assembly puzzles! I had had a moderate amount of fermented grape juice. AND I was really quite tired from overwork and insomnia. Absolutely NO CHANCE that the 4D middle puzzle was going back together that day!

It actually took me 2 days to assemble the middle puzzle - the pieces initially look similar to the RDS but it is a totally different puzzle:

It looks impossible! For me at least.
Finally! 3 days had passed!
I think that there is only one way to assemble the 4 Dimensional Trapsticks puzzle and it took me 3 days to do it. After that, I had a play with the inner puzzle and struggled to find a way to take it apart! Nothing moved despite pushing and pulling all over the place. It's almost a bit like one of Stephen Chin's beautifully made Pennyhedrons. To my surprise, it popped apart into 2 pieces and to my great relief it did not collapse into a heap:

Beautiful - no further disassembly is possible.
I finally went to work on the RDS Interlock outer puzzle. The analysis by Derek revealed that there are 11 possible assemblies using the original pieces - I have found 4 or 5 of them so far. They are great fun to play with. I am not sure whether I will be able to find all of them as it is quite hard to remember what I have done before in terms of assembly positions.

Now the additional pieces come into use as more challenges are possible. The third picture in the post shows that there are three types of puzzle pieces: Receivers (R) are composed of five sticks (top row in that photo), Standard pieces (D) are composed of four sticks (middle row) and Sliders (S) are composed of three sticks (bottom row). Stefan provided me with an extra 4 standard pieces giving multiple challenges:

16 pieces, 3 different groups of puzzle assemblies, 27 total solutions
The challenges are to assemble 12 pieces around a hollow centre:
Use 4 R's, 4 D's, and 4 S's (11 solutions) - the original puzzle.
Use 3 R's, 6 D's, and 3 S's (14 solutions)
Use 2 R's, 8 D's, and 2 S's (3 solutions)
So far I have singularly failed to find any solutions to the other challenges! This is a tough one and ENORMOUS fun! I know that these have been modelled in Burrtools and I may just try to do this myself for another challenge - I know Derek would share his file with me but I am really bad at using the rhombic and triangular grids in BT and so might enjoy the learning process that goes with modelling these puzzles myself. Of course, it is highly likely that I will fail and still have to ask my genius friend for help!

This puzzle is absolutely FABULOUS - both in quality and puzzling challenge - I am so so sooo grateful to Stefan for his wonderfully generous gift and have to say that on week 1 of 2019 I have probably found a contender for the top ten already! Wow!

Please don't badger Stefan for a copy - he has only been given permission to make a limited number to give away as gifts - he cannot make more for all and sundry. If you wish to have a copy of this wonderful puzzle then you have 2 options: 1) Contact Jane Kostick for a glorious wooden version (I have and will get a wooden version later this year) and 2) the pieces can be purchased from Derek's Shapeways store with Jane's permission - I think that would be well worth your money.

What a great way to start a new year - thank you, Stefan and Jane and Derek!

There might have been a delivery already! Whack! Ouch! Bernhard offered to make me a few of the best of the cubes designed by Derek Mayer - the boyz were delighted to see another box:

What are they looking at?
I love interlocking puzzles and cannot wait to play with these:

From the left:
Christmas cube 3, Mayer's cube 9B, Mayer's cube 10C, Mayer's cube 7B
Drool!!! Thank you Bernhard!


  1. Thanks for the great review, Kevin! Design credit really goes to my husband John Kostick though. I only designed the various jigs so that I could execute the puzzle design in wood, but it was John who came up with the concept of dissecting and reassembling the sticks in both RDS and Trapsticks. Also, there's no need to get my permission to purchase the pieces on Derek's Shapeways shop, so you might want to edit that line out. Glad you enjoyed these puzzles!

  2. The Shapeways model works quit well. Though I have a wooden one from Jane, I also have a Shapeways one that I dyed the different pieces different iPoly Dye (for polyester) colors in order to see the see placement after an assembly. This made it easy for me to search for symmetrical solutions that appeal to me. I posted a few pictures on Facebook of a couple three-color symmetrical solutions. Once you push in the final slider on the wooden one (or Stefan's) the piece locations disappear.

    Trapsticks can also be solved with a different handed "slider" piece. There is only one solution for it too, but the assembly is not very stable and fairly easily pulls apart in your hands.

  3. I love my wooden one. Quite the challenge. But oh man I love these new inner pieces! Mine just has 4 rhombic shaped pieces that fill the inside. However I can't complain. Having 4 kosticks in my collection makes me a happy boy! Now to wait for the epic 30 stick insano magnetic assembly cuz who doesnt love magnets!?

    1. Lucky you! I only have one very small wooden Kostick puzzle.