I just found this really great article by Han Fey about a new lock design using a stepper motor key driving disc tumblers. Not only is the lock interesting but the article goes into the design starting with original concept, loosely based on a 1868 Jos. L. Hall padlock patent design. Huh, I didn't know he even made a padlock. Lots of pictures. Almost makes me want to start paying more attention to the modern stuff out there. Google "RKL lock" which stands for "robotic key lock" and many things come up but I know the article can be found at StantonConcepts website, the designers of the lock. Doug