TABLE OF CONTENTS Sketching, in its original meaning, is defined as a quick means of communicating, a simple way of recording, and an evolvable process of thinking/ assessing design ideas in early stages. It does not require the assistance of drafting equipment to complete. A sketch is composed of a set of two-dimensional curves. Although this basic definition of sketching is still as alive as ever, new meanings of sketching have been emerging, especially because of the advancement of modern CAD systems. In Chapter 5, we introduced a few methods to create base features. The detail features are created one-by-one onto the base feature as if they are accomplished in real manufacturing or machining processes. The approaches in Chapter 5 provide simple, quick solutions to creating basic models with common geometries such as cylinders, blocks, cones, and spheres. Although hybrid models can be generated by the combinations of these geometries, it is not practical; it is meant to be used for enhancing the understanding of how to use WCS, and further, for top-down design schemes.
The example in Figure 8-1 is a simple connecting bracket. The design intent of this bracket is: (1) the two end arcs are concentric with the two end holes, respectively; and (2) the top and bottom edges are tangent to both ends of the end arcs. It will take a number of steps to complete the design intent using the base feature approach.
When we create this model using a sketch, the design intent can be easily...
