Career & Technical Education Computer-Aided Design & Drafting Explain and demonstrate basic CAD commands and techniques

Career & Technical Education Computer-Aided Design & Drafting Explain CAD terms and concepts

CAD Computer-Aided Design – Generally reflects design utilizing a 3D modeling database. Computer-Aided Drafting – Appropriate if one is producing mainly 2D documents. Computer Aided Design/Drafting – A combination of the two.

Reasons for Using CAD Can reduce drawing time and improves productivity Prevents having to make repeated drawings of often-used symbols Improves overall appearance and readability of drawing Allows for easy revision of drawings Can be transmitted electronically

Reasons for Using CAD 3D models, as the 3D database can be used to:  generate multiview drawings  construct prototypes  generate code for CAM  increase visualization  analyze mass properties of objects (volume, center of gravity, moments of inertia, etc.)

Career & Technical Education Computer-Aided Design & Drafting Explain 3D modeling commands and concepts

Types of 3D Modeling Systems Wireframe Model Surface Model Solid Model

Wireframe Modeling Wireframe modeling is the simplest of all modeling techniques Based on edges, vertices, and faces

Wireframe Modeling Wireframe modeling suffers from uniqueness and ambiguity issues

Surface Modeling Surfaces define the shape of a hollow model. Surface modeling gives designers a great amount of control and flexibility.

Solid Modeling Objects are defined as a solid mass. May contain information about the density, mass, moment of inertia, volume and center of gravity of the object.

Solid Modeling Primitives Rectangular Prism Triangular Prism Cylinder Sphere Cone Torus

Solid Modeling Primitives can be used to build solid geometry with Boolean Operations SUBTRACT INTERSECTION A B UNION DIFFERENCE INTERSECTION A  B A - B A  B