During 2010 I made four Sliding Puck puzzles. Three of them are three layer and one is six layer (The six layer will be shown in a separate video later).
Three layer Pucks have been around for a long time but not like mine. Mine slide length ways as well as the normal rotational move. The common ones turn end over end and are very easy to solve. Because of the way mine move the numbers or patterns on each end become lost and hidden inside the puzzle so it's unclear what goes where until they are once again brought to the correct end.
I have been working on these for a number of years. Not continuously but every now and again. I had the basic idea but wasn't sure how to use it in the finished puzzles. The main problem was the ends. I wanted them fully functional but how do you stop parts falling out when you make the sliding moves? I experimented with several ideas. I had lumps added on each end and I even went through the stage of gluing the end pieces together in an immovable lump. One solution involved using 3 1/2 Pucks. I liked this and almost used it. I felt it was different and original. However a friend remarked about how it looked messy so I knew I still wasn't quite there.
Eventually I solved the problems. Firstly I made it so it only slid one place in one direction. This was good since it also made the puzzle harder. The second most significant thing I did was to get semi circular clear pieces of plastic made to cover the ends. This keeps everything in place without ugly lumps attached to the puzzle.