Intended as a demonstration of combination lock principles, the Wooden Combination Lock from Matthias Wandel is also fun piece of woodworking. A post on the Make blog has a YouTube video of the lock’s operation (which includes a short clip near the end about a Master combination lock vulnerability). Matthias has more details and photos on his web site. You can get detailed plans (which include a SketchUp model) from him for $7 .
The above two pictures show the tabbed rotors and unlocking slot. An additional video on the web site illustrates how to work out a left-right-left combination for these locks that’s different than the usual right-left-right combination.
Wooden Combination Lock [Manufacturer’s Site]