Engineering Freehand technical sketching

FIGURE 4-3 Engineer s freehand technical sketches of a proposed new product. 

FIGURE Urk Engineers and designers use freehand technical sketching to record design ideas for products such as these light switch cover plates, bridge parts, and floor plan. 

FIGURE 4-8 Three types of freehand technical sketches used by engineers and designers (a) thumbnail sketch (rough layout conveying ideas),... 

This is also known as scale. If an object is drawn to full size, it would have a ratio of 1 1 (read as one-to-one or full scale ). If the object is drawn at one-half the actual size, it would have a ratio of 1 2 (read as one-to-two or one-half scale ). When doing freehand technical sketching, an engineer may need to draw a shape at full scale while on the same paper drawing the same shape at one-half scale. By doing this, the engineer makes sure the two sketches are proportional (see Figure 4-10). 

Freehand technical sketching can be done anywhere. All you need is a no. 2 lead pencil or softer, eraser, paper (grid or plain), and a hard smooth surface. This is one reason why designers and engineers often carry clipboards or engineer s notebooks with them (see Figure 4-15). 

An engineer s notebook is usually a bound book with graph paper and lined paper with numbered pages and a place to write important information such as the name, date, and title of the sketch. This information should be written with an ink pen freehand technical sketches should be drawn in pencil. This book becomes a permanent record of the engineer s concepts and ideas (see Figure 4-16). 

Freehand technical sketching is an important skill used by engineers, designers, drafters, CAD operators,... 

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