Chapter 1 Geometric Dimensioning and Tolerancing Essentials 29 Copyright Goodheart-Willcox Co., Inc. A model usually supplies geometry in a “basic,” or theoretically perfect, condition. The designer defines product data and uses correct practices to communicate GD&T information that is usually not expressed in the “basic” model. Annotated model data can be used to draft associated detailed drawings, or it can be used as a replacement for drawings for collaboration, manufacturing, analysis, and inspection. When the lat- ter approach is the objective of using MBD, defining the model annotations with PMI tools offers a number of advantages. In the MBD system, the model serves as a single source of information and is used by all collaborators, manufacturing personnel, and suppliers throughout design and production. MBD is commonly used in conjunction with computer-aided manufactur- ing (CAM), discussed later in this chapter. PMI directly applied within a model is soft- ware-readable and can be used by CAM software to generate machine tool path data. Advanced mechanical design software programs such as Siemens Solid Edge pro- vide PMI tools for applying 3D annotations to models. Example 1-24 shows the Solid Edge Feature Control Frame Properties dialog box accessed with the Feature Control Frame command. This command is used within the 3D modeling environment to cre- ate 3D feature control frames and apply them directly to the model. N O T E Although CADD and specialized GD&T tools and symbols improve accuracy and productivity, it is the responsibility of the designer to apply correct draft- ing practices and adhere to ASME Y14.5-2018. Your CADD system may not offer specific GD&T tools, or it may not allow compliance with ASME Y14.5- 2018, especially when dimensioning 3D models. When possible, you must set up or change specific dimension styles, system standards, and variables. To document certain GD&T applications, you may have to create symbols or customize the software. Consult with your instructor or supervisor for more information about using CADD tools to apply GD&T to drawings and models. Goodheart-Willcox Publisher Example 1-24. Using the Solid Edge Feature Control Frame Properties dialog box to create a feature control frame on a 3D solid model.