Cast Coaster

Name
Cast Coaster

Designer
Serhiy Grabarchuk; who is very well known for a number of sliding puzzle designs including One Fish Another Fish reviewed here in this blog. To see his many puzzle designs, some which have been commercialised, click here. If you wish to play his sliding puzzles digitally, click here.

Manufacturer
Hanayama. Launched back in 2006, the Cast Coaster is available from various online retailers and Ebay.

Type & Classification
Take-part; disentanglement

Dimensions
6.5cm (Length) x 6.5cm (Width) and 0.5cm (Thickness)

Materials & Construction
Made of zinc alloy (I think) covered in shiny chrome. Quality of construction, finish and fit is very decent. Again I would have personally preferred a matt surface.

Overview
Its obvious why the puzzle is called "coaster". It fully resembles one (even looks like one of those Celtic designs). From a practical standpoint, not that useful as a coaster especially for cold drinks since the condensation will go through the cracks and gaps.

The object is to "break" apart the Coaster and reassemble it. The Coaster consists of three interlocked triangular shaped "rings" giving the Coaster its round shape.

Disassembly was simple enough, easily done in seconds. The reassembly is where the real challenge is. On each of the triangular rings are grooves which allow the rings to intersect and fit within each other. All three rings are non-identical in the sense that the grooves are all in different positions on each ring and the number of grooves are also different for each ring.

I went through a good couple of hours trying to fit the pieces back together but somehow the solution just eluded me. Whenever I thought I could fit two and get the third on, I'll be stuck. Not easy to solve by trial and error since the tolerances are tight and leaves little room for chance solutions.

Eventually I lost patience and went for the solution. There are about half a dozen videos on YouTube on the Coaster. But only one or maybe two of the videos are easy to follow for the solution. I will leave readers to figure out which ones.

Difficulty Level
Hanayama rates the Coaster at 4-stars (out of 6). I am more inclined to give it a 4.5 or even a 5 instead.

Summary
This is one of those puzzles very hard to figure out, but once you do, easily repeatable solving. After I learnt the solution and memorised the few necessary steps, I could re-fix the Coaster in under thirty seconds. Visually its aesthetically pleasing given its charming pattern. Certainly something you can leave on your coffee table for show!