Ugears Mechanical Wooden 3D Puzzles are educational and a great way to fill in your time.
There's a model for everybody from beginners to advanced including STEM models for students to learn basic principals of engineering and science. Once made, these models move, spin, walk and tell time powered by springs, rubber bands or gravity - no batteries or power is required. No tools or glue is required. The large range includes, cars, trains, planes, motorbikes, marble runs a a Harry Potter range. Each model come with instructions and are a great show piece once completed.