1. THE WORLDWIDE GRAPHIC LANGUAGE FOR DESIGN
C H A P T E R O N E

2. OBJECTIVES 1. Describe the role of drawings in the design process.
2. Contrast concurrent versus traditional design
processes.
3. List five professions that use technical drawings.
4. Describe four creativity techniques.
5. Explain why standards are important.
6. Identify uses of the graphic language.

3. UNDERSTANDING THE ROLE OF TECHNICAL DRAWINGS
Technical drawings serve one of three purposes:
• Visualization
• Communication
• Documentation
(Courtesy of Seymourpowell.)
(Courtesy of Woods Power-Grip Co., Inc.)
(Courtesy of Dynojet Research, Inc.)

4. Concept Sketches Exploring many design options through quick sketches
(Courtesy of Lunar Design.)
(Courtesy of Seymourpowell.)

5. The Stages of the Design Process
1. Problem identification: First, a clear statement of
the need for and objectives for the design must
be written.
2. Ideation: Technical sketches are often used to
convey concepts to multidisciplinary teams.
3. Refinement/analysis: Designs may be rethought,
based on engineering analysis. CAD models and
sketches are useful during the analysis and
compromise stage. Accurate 2D or 3D CAD
models and drawings are created to refine the
design.
4. Implementation/documentation: Production
and/or working drawings providing the details of
manufacture and assembly are finalized and
approved.

6. Concurrent Engineering
Traditionally, design and manufacturing activities have taken place in sequential order rather than concurrently (simultaneously). This step-by-step approach seems logical, but in practice it has been found to be wasteful.
Concurrent engineering
is a systematic approach that integrates the design and manufacture of products with the goal of optimizing all elements involved in the life cycle of the product.
The Concurrent Process

7. Life cycle design
Life cycle design means that all aspects of a product (such as design, development, production, distribution, use, and its ultimate disposal and recycling) are considered simultaneously.
The basic goals of concurrent engineering are to minimize product design and engineering changes and to reduce the time and cost involved in taking a product from design concept through production and ultimately to introduction into the marketplace.

8. Computer-Aided Design and Product Development
Computer Aided Design (CAD)
Computer Aided Engineering (CAE) Computer Aided Manufacturing (CAM)
CAD allows for a range of activities, from modeling 2D and 3D geometry to creating drawings that document the design for manufacturing and legal considerations.
CAE allows users to simulate and analyze
structures that will be subject to various temperatures, static loads, or fluctuating loads.
CAM provides computerized control for manufacturing processes.

9. The Digital Database
All the information to manage, design, analyze, simulate, package, market, and manufacture a product can be shared with a diverse group of users through a single complex digital database.
(Courtesy of Parametric Technology Corporation)

10. Designing Quality into Products
DFSS Design for Six Sigma is an approach that uses engineering and statistical tools to design products in a way that predicts and minimizes customer and manufacturing problems.
Six Sigma is a process originated at Motorola to improve quality by reducing or eliminating defects.
DMAIC Define, Measure, Analyze, Improve, and Control are steps defined in a continuous improvement process that attempts to define and ensure critical to function (CTF) characteristics.
QFD Quality Function Deployment is a tool for decision making that helps companies focus on a customer-driven approach and set of product characteristics.

11. ENGINEERING DESIGN STAGE 1
Identify the Customer and the Problem
The engineering design process begins with recognizing or identifying these needs and considering the economic
feasibility of fulfilling them.
A successful design must not only solve the problem but also meet the needs and wishes of the customer.
(Project developed and created by Philips Design.)

12. ENGINEERING DESIGN STAGE 2
Generate Concepts
During this stage, often called the ideation stage, many ideas—reasonable and otherwise—are collected.
The ability to freely create technical sketches lets you present and share ideas and record them so you can refer to solutions, inspirations, and breakthroughs that come to light during this creative stage of the process.
(Courtesy of Seymourpowell.)

13. ENGINEERING DESIGN STAGE 3
Compromise Solutions
The design team
selects various features of the concepts generated in the
ideation stage and combines them into one or more promising
compromise solutions.
2D CAD Drawing. (Courtesy of Seymourpowell.)
Many of these problems are solved graphically, using schematic drawings in which various parts are shown in skeleton form. For example, pulleys and gears are represented by circles, an arm by a single line, and a path of motion by centerlines

14. ENGINEERING DESIGN STAGE 4
Models and Prototypes
Design teams often construct a model to scale to study, analyze,
and refine a design.
3D CAD Model. This 3D CAD model of a design for the Mars rover was constructed to act as a virtual prototype for the design. (Courtesy of Byron Johns.)
3D CAD Model of the SAAR Brake. (Courtesy
of Dynojet Research, Inc.)

15. Rapid Prototyping
Rapid prototyping systems allow designers to generate parts quickly, directly from 3D models, for mockup and testing.
Rapid Prototyping. The ZPrinter 450 from Zcorp “printed” the colored part shown in about four hours. (Courtesy of Z Corporation.)

16. ENGINEERING DESIGN STAGE 5
Production or Working Drawings
The drawings, showing the necessary views, include the material, dimensions, required tolerances, notes, and other information needed to describe each part sufficiently for it to be manufactured consistently. These drawings of the individual parts are also known as detail drawings.
Detail Drawing for the SAAR Brake Air Can Mounting Bracket.
(Courtesy of Dynojet Research, Inc.)

17. Assembly Drawings
An assembly drawing, shows how all the parts go together in the complete product.
Assembly Drawing for the SAAR Brake. (Courtesy of Dynojet Research, Inc.)

18. DRAFTING STANDARDS
There are standards that support a uniform, effective graphic language for use in industry, manufacturing, engineering, and science.
In the United States, providing these standards has been the work of the American National Standards Institute (ANSI) with the American Society for Engineering Education (ASEE), the Society of Automotive Engineers (SAE), and the American Society of Mechanical Engineers (ASME).
International standards, often defined by the International Organization for Standardization (IOS), and the ASME or ANSI standards for drawing practices are similar in many respects.

19. CREATIVITY TECHNIQUES
How do you develop new ideas?
Examine Manufactured Products
Study the Natural World
Research Patent Drawings
Watch the Web
Design Groups
The following websites are useful for engineering design:
• Yahoo’s site for the latest technology news and a one-week archive
• site from CMP media
• U.S. Patent Office on-line search site

20. PRODUCT DEFINITION
Product definition refers to the collection of digital or hard copy documents that specify the physical and functional requirements for a product.

21. SHOWING THE DESIGN PROCESS IN A PORTFOLIO
A portfolio is a representative sample of work that helps communicate your skills and talents, usually to a prospective employer or client.
(Courtesy of John Mountz.)

22. LAYOUTS AND LETTERING
C H A P T E R T WO

23. OBJECTIVES
1. Identify six types of technical drawings based on the projection
system they use.
2. Identify the line patterns used in technical drawings and describe
how they are used.
3. Read and measure with the architects’ scale, engineers’ scale, and
metric scale.
4. Identify standard drawing media and sheet sizes.
5. Fill in a standard title block

24. PROJECTIONS
Behind every 2D drawing of an object is a space relationship involving the object and three “imagined” things:
1. The observer’s eye, or station point
2. The plane of projection
3. The projectors (also called visual rays or lines of sight).
Perspective Projection
Parallel Projection

25. Types of Projections
There are two main types of projection: perspective and parallel. These are broken down into subtypes, as shown below:

26. Drawing Vocabulary A B C A B C Drawing Lines Lettering
Measurement Systems
Scale
Title Blocks
A B C
A B C mm
Inch
Title Block

27. ALPHABET OF LINES Thick and Thin Drawing Lines Freehand line technique
Line styles

28. FREEHAND LINES
The main difference between an instrument or CAD drawing and a freehand sketch is in the appearance of the lines. A good freehand line is not expected to be precisely straight or exactly uniform, as is a CAD or instrument-drawn line. Freehand lines show freedom and variety.
Freehand construction lines are very light, rough lines. All other lines should be dark and clean.

29. MEASUREMENT SYSTEMS U.S. Customary Units The Metric System
Dual-Dimensioned

30. DRAWING SCALE
Drawing scale is the reduction or enlargement of the drawn object relative to the real object
Reduced and Enlarged Scale. Many drawings must be shown at reduced scale for the object to fit on the paper.

31. SPECIFYING THE SCALE ON A DRAWING
For a part that is shown on the paper at half its actual size, the scale is listed in one of these three ways:
SCALE: 1:2
SCALE: 1/2
SCALE: .5
Architectural drawings list
the scale based on the number of fractions of an inch on the drawing that represent one foot on the actual object. Example:
List the predominant drawing scale in the title
block. (Courtesy of Dynojet Research, Inc.)
SCALE: 1/8" 1'

32. SCALES Scales are measuring tools used to quickly enlarge or reduce
Drawing measurements.
Types of Scales

33. METRIC SCALES
Full Size 1:1 scale
The triangular scales have one full-size scale and five reduced-size scales, all fully divided.
Using these scales, a drawing can be made full size, enlarged sized, or reduced sized.
Half Size 1:2 scale

34. ENGINEERS’ SCALES
An engineers’ scale (also called a civil engineers’ scales) is a decimal scale graduated in units of 1 inch divided into 10, 20, 30, 40, 50, and 60 parts.
Because the engineers’ scale divides inches into decimal units, it is convenient in machine drawing to set off inch dimensions expressed in decimals.

35. MECHANICAL ENGINEERS’ SCALES
Mechanical engineers’ scales are divided into units representing inches to full size, half size, quarter size, or eighth size.
To draw an object to a scale of half size, for example, use the mechanical engineers’ scale marked half size, which is graduated so that ever ½” represents 1". In other words, the half-size scale is simply a full-size scale compressed to half size.
Triangular combination scales are available that include full- and half-size mechanical engineers’ scales, several architects’ scales, and an engineers’ scale all on one stick.

36. Architects’ Scale
The architects’ scale is intended primarily for drawings of buildings, piping systems, and other large structures that must be drawn to a reduced scale to fit on a sheet of paper.
AutoCAD software users sometimes become confused using architectural units. When selecting architectural
units and entering lengths, keep in mind that a value of 1 is one inch, not one foot.

37. LETTERING
Lettered text is often necessary to completely describe an object or to provide detailed specifications. Lettering should be legible, be easy to create, and use styles acceptable for traditional drawing and CAD drawing.
Engineering drawings use single-stroke sans serif letters because they are highly legible and quick to draw.
Sans serif means without serifs, or spurs

38. An Example of Lettering and Titles Using CAD
LETTERING STANDARDS
Most hand-drawn notes use lettering about 3 mm (1/8") high.
CAD notes are set using the keyboard and sized to be in the range of 3 mm (1/8") tall according to the plotted size of the drawing.
An Example of Lettering and Titles Using CAD
CAD drawings typically use a Gothic lettering style but often use a Roman style for titles.
When adding lettering to a CAD drawing, a good rule of thumb is not to use more than two fonts within the same drawing.

39. SPACING OF LETTERS AND WORDS
Spacing between Letters
Uniform spacing between letters is done by
eye. Contrary to what might seem logical,
putting equal distances from letter to letter
causes them to appear unequally spaced.
Spacing between Words
Space letters closely within words to make each word a compact unit, but space words well enough apart to clearly separate them from adjacent words.
Spacing between Rows
Be sure to leave space between rows of lettering, usually equal to the letter height.

40. LETTERING FOR TITLES
In most cases, the title and related information are lettered in title boxes or title strips
When lettering by hand, arrange the title symmetrically
about an imaginary centerline

41. DRAWING PENCILS
High-quality drawing pencils help produce good quality technical sketches and drawings.
Hard
The hard leads in this
group (left) are used
where extreme
accuracy is required,
as on graphical
computations and
charts and diagrams.
The softer leads in this
group (right) are
sometimes used for
line work on
engineering drawings,
but their use is limited
because the lines are
apt to be too light.
Medium
These grades are for
general-purpose work in
technical drawing. The
softer grades (right) are
used for technical sketching,
lettering, arrowheads,
and other freehand work
on mechanical drawings.
The harder leads (left) are
used for line work on
machine drawings and
architectural drawings. The
H and 2H leads are widely
used on pencil tracings for
reproduction.
Soft
These leads are too
soft to be useful in
mechanical drafting.
They tend to produce
smudged, rough lines
that are hard to erase,
and the lead must be
sharpened continually.
These grades are used
for artwork of various
kinds, and for full-size
details in architectural
drawing.

42. Style of Pencil
You might be surprised how much your drawings benefit from finding a style of pencil that suits your use. Soft pencils, such as HB or F, are mainly used in freehand sketching.
Choose a pencil that:
• Is soft enough to produce clear black lines, but hard enough not to
smudge too easily.
• Is not so soft that the point breaks
easily.
• Feels comfortable in your hand.
• Grips the lead without slipping.

43. THE COMPUTER AS A DRAFTING TOOL
Most people who create technical drawings use CAD. The advantages include accuracy, speed, and the ability to present spatial and visual information in a variety of ways.
Even the most skilled CAD users need to also be skilled in freehand sketching, to quickly get ideas down on paper.
One benefit of CAD is the ability to draw perfectly straight uniform lines and other geometric elements. Making changes to a CAD drawing takes about a tenth the time that it takes to edit a drawing by hand.

44. SKETCHING AND DRAWING MEDIA
Many choices of media (paper and other) are available for particular
sketching or drawing purposes. Whether you are sketching or are plotting a drawing from a CAD workstation, choose the type of sheet and size that suits your needs.
Small notebooks or sketch pads are useful when working at a site or when it is necessary to quickly record information.
Graph paper can be helpful in making neat sketches
Sketch on Graph Paper

45. STANDARD SHEETS
There are ANSI/ASME standards for international and U.S. sheet sizes. Note that drawing sheet size is given as height width. Most standard sheets use what is called a “landscape” orientation.
* May also be used as a vertical sheet size at 11" tall by 8.5" wide.

46. Typical Sheet Sizes and Borders
Margins and Borders
Zones

47. Title Block
The title block is located in the lower right corner of the format. Standard areas in the title block provide the information as shown below.

48. PLANNING YOUR DRAWING OR SKETCH
When laying out a drawing sheet, you will
need to consider:
• the size and scale of the object you will
show
• the sheet size
• the measurement system (units) for the
drawing
• the space necessary for standard notes
and title block.
The object you are drawing is the “star” of the sketch. Keep the object near the center of the sheet. It should be boldly drawn, using
thick visible lines. Make it large enough to fill most of the sheet and so that details show clearly