The toys in this book are very unique. They can be set up in many different ways. Constructing them requires an extra measure of precision woodworking, as there are so many directions and positions that the pieces must fit. There is advice on the means to get this precise drilling accomplished and it should be followed if the toy is to work as designed. Some of the toys I made as single items with no positioning options, and they work just as well toward thrilling the youngsters. This is a challenging idea, and fun to work.