Engineering Design Graphics: Sketching, Modeling, and Visualization, 2nd Edition

CHAPTER 2

FREEHAND SKETCHING

INTRODUCTION

Prior to the introduction of the personal computer in the early 1980s and the accompanying introduction of computer-aided design (CAD) software packages such as AutoCAD^® shortly thereafter, most engineering drawings were executed manually using equipment like drafting machines, T-squares, triangles, and compasses. Today, however, nearly all engineering drawings are executed using a CAD system. This sea change in the way technical drawings are produced has had a major impact on the engineering graphics curriculum. Instrument drawing (with T-squares, triangles, and so on), for example, has largely been replaced with freehand sketching.

Engineering is a creative endeavor with roots that can be traced back to great Italian Renaissance artists like Leonardo, Michelangelo, Raffaello, and Donatello. Although it is certainly true that engineering is technology driven, it is important not to lose sight of the discipline's rich graphical and creative traditions. Great engineering is evidenced as much through the ability to communicate ideas via freehand sketching as it is by manipulating differential equations, by making a computer “sing,” or for that matter, by presenting carefully reasoned, well-crafted prose.

While some of us are blessed with the natural ability to draw, most are not. All of us, though, can improve in our ability to communicate, ...