Communications Systems EDU-2460 Topic: Computer Aided Design (Chapter 2) By Leetyler Edwyn Dailey

Drafting  The process of creating drawings needed so that a part or product can be manufactured or built. Traditionally these drawings were done by hand on paper, with the aid/use of pens, pencils, compasses, T-Square, Set Squares and Drawing boards/tables.

What is Computer-Aided Design?  This is the process of designing on a computer. It involves more than just creating drawings. It helps the designer make quick and accurate decisions about how a product should look and work.

of CAD over traditional drafting Advantages of CAD over traditional drafting Much faster method of creating drawings. Saves Time by producing some shapes automatically. Changes can be made quickly.

Advantages of CAD cont’d Its produces a more accurate drawing. People working in different locations can view and discuss the design. Some CAD programs help determine if the design will work as desired.( Ex. Structural Engineers can test the strength of a steel beam before including it in a design.)

The CAD System  CAD System consist of hardware and software. Hardware: The computer itself and devices (keyboard and mouse) used to enter or input information into the computer and devices (monitor, printer, plotter) used to display or output the drawings.

The CAD System cont’d Software: These are programs designed for a specific purpose (Architectural design and Inventor). Many of these programs are complex and require some sort of training.

CAD Software  CAD software can be used for 2D and 3D designing. What is 2D and 3D designing? Two-dimensional CAD or 2D programs show width and length, width and height or length and height. They are commonly used to design packages, signs and electronic circuits.

Two-dimensional CAD or 2D programs

CAD Software cont’d Three-dimensional CAD or 3D program show width, length and height. 3D is the more popular of the two programs because we live in a 3D world and it is easier to capture ideas in 3D form.

Three-dimensional CAD or 3D program

Types of 3D CAD  Wireframe Models: This is the simplest form 3D modeling.

Types of 3D CAD cont’d  Surface Models: This is like taking a piece of paper and shaping it into an object, like a square box.

Types of 3D CAD cont’d  Solid Models: The most realistic kind of modeling which shows the shape, area and volume of an object.

Use of 3D CAD  In Mechanical Design: An engineering activity that involves designing individual parts and assemblies.  In CAD/CAM: A combination of computer- aided design and computer-aided manufacturing. The CAD drawings are inputted into the computer that operates machines. The machines then manufacture the actual product.

Use of 3D CAD cont’d  In Rapid Prototyping: A prototyping machine uses a CAD file to create a physical object layer by layer. This may take a few hours to several days.  In Architectural Design: It is used to design components of a house, both interior and exterior and any possible landscaping.

Conclusion Until the 1980’s, nearly all drafting was done by hand, line by line, object by object. This was a labor intensive effort. Today virtually all drafting is done by computers. CAD software has made it possible to produce drawings faster and more accurate, so a drafter could be more productive.

References Technology Interaction by Glencoe/McGraw- Hill Google images