This is a fully parametric combination lock that uses digital thumb-wheels to set the combination. It can be used for locking drawers or cabinet doors, or just about anything else where two surfaces come together. You can customize it using the MakerBot Customizer.

The uploaded STLs are perfect for making a three digit combination lock. If you want a different configuration (more digits, different number of options per digit, different diameter wheels, etc.), feel free to use the customizer, or just download the .scad file and play with it in OpenScad. Print one each of the base and the clasp. Print three of the rosettes. And then pick any three of the numbers you would like to use in your combination, and print one each of those.

Press fit the rosettes onto the number wheels. If necessary you can use a little super glue or ABS glue.

Slip the wheels into the appropriate slots in the base (be sure to put them in the right order). Assemble the parts together using an M3 x 50mm bolt with two nuts locked together on the end. Make sure the nuts are loose enough that the wheels turn easily.

Now cut a rectangular hole into the face of the drawer or cabinet door that you want the lock on. Put it in a location where there is a solid base behind the drawer/door, so that you can mount the clasp on that. Make sure that the appropriate combination is entered into the lock before closing the door/drawer.

The locking mechanism for this is loosely based on the mechanism use in http://www.thingiverse.com/thing:64168 .