Cast Helix

I purchased Cast Helix by Akio Yamamoto about a year ago, back when it was first introduced by Hanayama. Since I am a big fan of their Cast Puzzles series, I was quite interested to see what this puzzle would be like.

The object is to remove the coil from the star shaped piece. This piece has two components that pivot with respect to one another. The back looks pretty much like the front, and the intersection of the grooves in both pieces leaves holes for the coil to rotate into, sort of like Wuurm.

I played with this one for a while and didn't have much luck until I noticed that I could easily remove the ring by putting it in any of the five inner holes, and lining up the other side of the ring with the adjacent crotch of the star. Since this didn't appear to have anything to do with the orientation of the two pivoting pieces, I was pretty sure it was a false solution. Indeed, when I peeked at the solution sheet, it was not correct. George Bell had a similar issue that he mentioned on this thread at Puzzle World.

I played around with it for a while longer and still didn't have any luck, so I decided to actually look at the solution sheet, which I avoid, but it felt like something didn't seem right. I tried doing the solution as described on the solution sheet, and it didn't work! Somewhat annoyed, I shelved this one and only took it out again yesterday to have another crack at it.

This time, after again playing with it for a bit fruitlessly, I looked up a YouTube video solution. The Hanayama solution sheet wasn't that clear, so perhaps I was just doing something wrong. Even with a very clear solution video, it still wouldn't work! Finally it occurred to me that my ring must be bent: this had the dual effect of allowing a false solution while also not allowing the correct solution! How annoying!

I tried to bend it just a bit to close the gap in the coil, and that did the trick. It has to be just right for the solution to work, and mine was a bit off. A few people on Puzzle World and YouTube cite similar problems, but I'm not sure how pervasive it is. Even after correcting mine, it does require a bit of force to execute the solution, which too bad. Based on this experience, this is one of the few Hanayamas that I would say not to bother with, unless you just want to collect the whole set.