Review on ROKR Wooden Puzzle Building Mechanical by Eric Kim

This was a fun project for my 13 year old grandson and I when we worked together. There were a few tricky parts to assemble, but overall it worked very well. The details are laser cut and very precise. It's amazing how strong it is put together as no fasteners or glue are used to hold it together. When we finished we had a small problem as the marble walkway didn't work properly. We found that we had assembled one of the blades backwards and while it was a slight deviation it made a difference. A small disassembly for repair and everything works as it should. We used some glue to keep some of the raceways at the right angle as they can move a bit when the finished assembly is moved. Upon completion, the operation is very fascinating as you operate the crank and watch the steel balls move and operate various mechanisms along the way. From time to time there is a breakdown where the ball can bounce over the track. We've found that a rod with a magnet glued to the end works well to catch a ball that has fallen into the mechanism. There is an exclamation mark next to the build steps to indicate a critical step. It is important to ensure that these steps are followed correctly for the mechanism to work properly. We spent 4-5 hours building it and now we have many hours playing with it.