In a factory there a huge machine. Maintenance team must change the old gears of this machine with new ones. But gears aren’t easily accessible. And factory engineers decide to use the machine turntable. But there are some problems. Machine turn table turns only 90 degree with missing gears and also some other pieces from gear box enters into the turn table. Now they must find a solution with less possible move.
This puzzle is one of my sliding puzzle designs. Different from classical sliding puzzles. The aim of this puzzle is changing red and blue pieces in correct order. At the center of the board there are a disc with four slot. Disc rotation is limited and can rotate only 90 degree clockwise and after back again counterclockwise. That movement make this puzzle difficult and confusing.
There are four different variation. But two of them is more interesting. First I like describe XL version. This is the version seen on the left big picture. I mounted the clear acrylic top cover. At the center of each pieces there are a small hole that make it easy to play with a toothpick. (I take other photos without a cover because of reflection risk.). This version is the most difficult version. There are three extra green disk that make more difficult it. For this puzzle I count only the quarter rotation of the center disk as a move. Because shifting operations isn’t too much important and also counting only the center disc rotations is easier. I tested it with some friends and they find it very confusing. Some of them, in half way of the solution confuse also which color goes up and down. My solution for this starting to solve always with blue ones on the upside. I played a lot of time. I have a score for minimum number of move. But I will not share here. That may be a shame for me later.
The other variation is S version without any green disc. It’s very easy with 6 empty space at the beginning. But if you search the minimum number of move, this puzzle require a different style of thinking. Differently then other sliding puzzles, instead of thinking sliding operations you must try to use center disk better and keep it busy in each turn.
The other variations with one and two disc has an increasing difficulty.
For puzzle enthusiasts and mathematicians finding the minimum number of move may be a good challenge. I don’t know minimum number of moves as I haven’t a computer analyze tool for this. Also it’s possible to write a java applet and play online or make a mobile device application with four level of difficulty. If you can make you can publish it in anyway that you like.
I made this puzzle from acrylic with laser cut. It’s very easy to make if you have access to a laser cut machine or a scroll saw. I put labels on each pieces for decorating. My puzzles has a clear acrylic top cover. But if you like you can make also an open version. By making one you can play also four variation by adding green discs. If you want make one for you, you can download or preview free PDF file including scroll saw patterns,instructions, and labels from here (0.5 MB on secure server box.com)
And if you need laser cutting file asci DXF file is here. You can transform easily to other formats. I made a few design change for better center mechanism for this reason laser cut file is a little different from my puzzle. I made a clear acrylic cover for this puzzle. But this make difficult to play. For playing I prefer an open top puzzle.