The document provides an overview of engineering graphics and the process of producing basic engineering drawings using AutoCAD. It discusses key topics such as the different types of engineering drawings used in various fields; the principles of orthographic projections, scales, line styles, dimensioning, and standard views; and how to create drawings of sections, symbols, and details. It also introduces Computer Aided Drafting/Design (CAD) software like AutoCAD and illustrates its interface for both 2D and 3D drawings. The document serves as a guide for learning the basic concepts and steps for producing technical drawings digitally.

1. Producing basic engineering
graphics
Using AutoCAD
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2. • Engineering graphics is a set of rules and guidelines that
help you create an engineering drawing.
• Each engineering field has its own type of engineering
drawings.
– Mechanical : Design of machine elements,
machine tools, Robotics.
– Automotive : Kinematics, Hydraulics, Steering.
– Electrical : Circuit layout, Panel design, control
system.
– Electronics : Schematic diagrams of PCs, Ics, etc.
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Engineering graphics

3. – Communication: Communication network,
satellite transmitting pic, T .V Telecasting
– Civil : Mapping, contour plotting, building
drawing, structural design.
– Architectural: Town planning, interior
decorations, multi storied complex.
– Aerospace : Design of spacecraft, flight simulator,
lofting
• Surveying is the science of measuring
– distances,
– angles, and
– directions of characteristics of the Earth’s surface
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4. • Engineering drafters accompany survey crews to
collect data required to prepare or revise
construction drawings.
• civil engineering projects are designed in
– Two-dimensional (2-D)
• a view displaying only width and height,
width and length, or height and length.
and/or
– Three-dimensional (3-D) formats.
• a view displaying width, height, and depth.
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5. GRAPHICS AS COMMUNICATION MEANS
• When graphics are used for communication it is
called graphical language.
• one should be able to READ | WRITE | SPEAK.
• Engineering Graphics is the language of Engineers.
• Engineers use graphics to communicate technical
information without ambiguity to executives,
fabricators, customers, and each other.
• Engineering graphics has a well-defined set of
standards by which technical drawings are produced.
• Graphics language is universal.
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6. • Language of graphics is written in the form of
drawings that represent the shape, size, and
specifications of physical objects.
• The language is read by interpreting drawings
so that physical objects can be constructed
exactly as originally conceived by the designer.
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GRAPHICS AS COMMUNICATION MEANS

7. DRAWING AS A TOOL FOR DESIGNERS
• Drawing is a graphic representation /pictorial
presentation/ of a real thing, an idea, or a
proposed design.
• It’s a means of communication.
• Sometimes, thousands of words cannot able
to express the ideas, but with the help of
drawing, one can communicate most
complicated problems also.
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8. • The process of creating new ideas where none
exist also relies on drawing.
• Drawings produced can be regarded as tools
that designers use to
–generate,
–improve, and
–validate ideas.
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DRAWING AS A TOOL FOR DESIGNERS

9. • is a type of technical drawing, used to fully and
clearly define the requirements for engineered
items.
• usually created in accordance with standardized
conventions for layout, nomenclature, appearance,
interpretation, size, etc.
• Engineering Drawing can be Manual Drawing and CADD.
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2. ENGINEERING DRAWING

10. Drawings convey the following critical information
• •Geometry- Shape of the object; Represented as
views; how the object will look Side view, Front
view, Top view
• •Dimension- the size of the object is captured in
accepted units
• •Material- represents what the item is made of.
• •Finishes- specify the surface quality of the item,
functional or cosmetic.
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ENGINEERING DRAWING

11. ELEMENTS OF ENGINEERING DRAWING
• Graphics language: Describe a shape (mainly).
• Word language: Describe an exact size, location
and specification of the object.
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12. LETTERING IN ENGINEERING DRAWING
• Lettering is used to provide easy to read and
understand information to supplement a
drawing in the form of notes and annotations.
• must be written with:
• Legibility – shape & space between letters and
words.
• Uniformity – size & line thickness.
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13. Types of Lettering
• The two types of lettering are:
– Double Stroke Lettering: In Double Stroke
Lettering the line width is greater than that of
Single Stroke Lettering.
– Single Stroke Lettering: Thickness in single
stroke lettering is obtained by a single stroke
of pencil or ink pen. It is further divided into:
Basics of Single Stroking
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14. Types of Lettering
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15. Spacing
Uniformity in spacing of letters is a matter of
equalizing spaces by eye.
• The background area between letters, not the
distance between them, should be approximately
equal.
• Words are spaced well apart, but letters within
words should be spaced closely.
• For either upper case or lower-case lettering, make
the spaces between words approximately equal to
a capital O.
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16. Conventions for Lettering
• Use all CAPITAL LETTERS.
• Use even pressure to draw precise, clean lines.
• Use one stroke per line.
• Horizontal Strokes are drawn left to right.
• Vertical Strokes are drawn downward.
• Curved strokes are drawn top to bottom in
one continuous stroke on each side.
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17. Conventions for Lettering
• Use The Single-stroke, Gothic Style of
Lettering.
• Always Skip A Space Between Rows Of Letters.
• Always Use Very Light Guide Lines.
• Fractions Are Lettered Twice the Height Of
Normal Letters.
• Fraction Bars Are Always Drawn Horizontal.
• Use a Medium Lead For Normal Lettering.
• Use a Hard Lead For Drawing Guide Lines.
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18. SIZES AND LAYOUT OF DRAWING SHEETS
• ISO A Drawing Sizes (mm)
Designation Dimension. mm
A0 841 X 1,189
A1 594 X 841
A2 420 x 594
A3 297 X 420
A4 210 x 297
A5 148 x 210
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19. LAYOUT
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20. BORDER LINE AND TITE BLOCK
• Border line is a drawing all-round the drawing
sheet leaving margin of 10 mm but 25 mm to
30 mm on left side for filing.
• Title block is a rectangular frame that is
located at the bottom of the sheet.
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21. A3 Drawing sheet – Dimensions
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22. Title block
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23. SCALES
• Ratio of the linear dimension of an element of
an object as represented in the original drawing
to the real linear dimension of the same element
of the object itself.
– Full Size - A scale with the ratio 1: 1.
– Enlargement Scale - A scale where the ratio is
larger than 1 :1. It is said to be larger as its ratio
increases.
– Reduction Scale - A scale where ratio is
smaller than 1: 1. It is said to be smaller as its
ratio decreases.
• Verbal, numeric and graphic means of representation
scales
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24. • A reducing scale, say 1: 10 means that 10 units
length on the object is represented by 1 unit
length on the drawing.
– Scale 1: x for reducing scales (x = 10,20 ...... etc.,)
• An enlarging scale, say 10: 1 means one unit
length on the object is represented by 10 units
on the drawing.
– Scale x: 1 for enlarging scales
Representative Fraction(redu)
• = = =>1:x
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SCALES

25. LINE STYLES AND TYPES
• Line type and line weight provide valuable
information to the print reader.
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Typical Example of Types of Line

29. PRINCIPLES OF DIMENSIONIN
• Types
a) Functional dimension- A dimension that is
essential to the function of the piece or space
b) Non-functional dimension - A dimension that
is not essential to the function of the piece or
space
c) Auxiliary dimension- A dimension given for
information purposes only.
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30. Dimensioning guidelines
• Don’t over define or under define the object.
[MOST IMPORTANT]
• Dimension to the visible contour or shape of the
feature / don’t dimension to hidden lines.
• Don’t dimension to object lines (model edges), use
extension lines.
• Don’t overlap a dimension and the model. Place
dimensions away from the model’s surface.
• Don’t cross extension lines if possible.
• Group dimensions when possible unless it became
difficult to read.
• Place dimensions on the side of the view were
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31. Placement conventions
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Dimensioning Rounds

32. 3. STANDARD ENGINEERING VIEWS;
PROJECTION SYSTEMS
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33. • Parallel Projection: is a type of projection
where the line of sight or projectors are
parallel and are perpendicular to the picture
planes.
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34. – Orthographic projections are drawings where the
projectors, the observer or station point remain
parallel to each other and perpendicular to the
plane of projection.
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35. • Perspective Projections are drawings which
attempt to replicate what the human eye
actually sees when it views an object.
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36. QUADRANT SYSTEM
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37. The glass box method
• The object is placed in a glass box.
• The sides of the box represent the 6 principal
planes.
• The image of the object is projected on the
sides of the box.
• Things to notice:
– The projection planes.
– The projectors.
– How the surfaces are projected.
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Principles of orthographic projection

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43. Principles of orthographic projection
a = front view
b = top view
c = left side view
d = right side view
e = bottom view
f= rear view
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45. Example
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46. First angle projection
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47. Third angle projection
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49. CREATING AN ORTHOGRAPHIC PROJECTION
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50. Example
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52. Example
Isometric Drawing
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53. Example
The three principal views
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54. Example
Isometric Drawing
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55. Example
The three principal views
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62. Assignment
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67. Building Drawing
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SECTIONAL VIEW
• Sections and sectional views are used to show
hidden detail more clearly.
• Section views are used when important
hidden details are in the interior of an object.
• They-are created by using a cutting plane to
cut the object.
• A sectional view, displays the outline of the
cutting plane and all visible outlines which can
be seen beyond the cutting plane.

70. • The type of section used depends on the situation and
what information needs to be conveyed
• Basic Sections
– Full Section:
– Half Section
– Offset Section
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71. Cutting Plane
• Section views show how an object would look if a
cutting plane cut through the object and the
material in front of the cutting plane was
discarded.
• In a full section view, the cutting plane cuts across
the entire object
• Note that hidden lines become visible in a section
view.
Hatching
• On sections and sectional views solid area should
be hatched to indicate
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72. MATERIAL SYMBOLS IN SECTION
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73. MATERIAL SYMBOLS IN SECTION
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(1) or (2) Masonry Section Used in Elevation
(3) or (4) Masonry Pointing Used in Elevation
(5) Concrete Section Used in Plan or Elevation
(6) Plaster or brick concrete section Used in Plan or
Elevation
(7) Wood Section, having the section at right angle
of the fiber Used in Plan or Elevation
(8) Wood Section taken along the length of the fiber
Used in Plan or Elevation
(9) Soil Used in Elevation
(10) Glass Used in Elevation

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76. Full Section
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• To create a full section, the cutting plane pas
ses fully through the object.
• Used in many cases to avoid having to dime
nsion hidden lines.

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Fill the visible line in the front sectional view.
The material used is brick

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79. Half Section
• A half section exposes the interior of one half of
an object while retaining the exterior
of the other half.
• Half sections are used mainly
for symmetric objects
or assembly drawings.
• A centerline is used to separate the two halves.
• Hidden lines should not be shown on either half.
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81. Offset Section
• An offset section is produced by bending the cutting pla
ne to show features that don’t lie in the same plane.
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SECTIONAL TOP VIEW

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SECTIONAL SIDE VIEW

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90. SYMBOLS
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door
windows
SYMBOLS

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Detail Drawings
• A detail drawing, or detail, is typically an
enlarged view created to describe features not
shown on other drawings.
• Details can be created for any construction
feature.
• Details normally specify standards that govern
the project, and are used to guide construction.

94. ROAD SECTION DETAIL
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STAIR DETAIL

96. STRUCTURAL DETAIL
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Cross Section of an Isolated column footing

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98. AutoCAD
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99. Computer Aided Drafting/Design:
• Computer Aided Design (CAD) is a form of design
in which people work with computers to create
ideas, models, and prototypes.
• CAD was originally developed to assist people
with technical drawing and drafting, but it has
expanded to include numerous other potential
uses.
• A variety of software products designed for CAD
can be found on the market, with many being
targeted to a specific application or industry.
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AutoCAD screen (2D)

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AutoCAD screen (3D)

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Getting Help

103. The end
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