This standard lock illustrates several useful SOLIDWORKS techniques. The bitting sequence of the lock is set with variables in the key part. These numeric values determine the height of the key at each station. A standard station cut is defined, and derived sketches are placed with equations to determine the profile of the key.When the bitting sequence is changed in the key the assembly will update with new configurations for each of the key pins. This is done through a design table. Once the key has been changed edit the design table and accept the new (automatically generated) values to update the assembly. An ‘if’ statement in the BOM keeps configuration data display to a manageable level.The spring used in this lock features tightly wound, smaller diameter ends. Construction geometry allows a smooth blend between the sections, with a curvature continuous transition in both diameter and pitch.The key incorporates the use of a sketch picture and has examples of swept cuts, derived sketches, Delete Face and Replace Face. The spring has multiple helices and a composite curve to create the helical sweep.All features include comments. Download this file to learn more about how a lock works and learn more about equations and Design Table functionality.