This document discusses technical drafting and manufacturing processes. It explains that technical drawings must be created to determine the shape and dimensions of an object before manufacturing. There are different types of projections used in technical drawings like isometric and multiview projections. Engineering drawings also include details like general arrangements, exploded views, and developments. Diagrams are then used to explain operating principles and manufacturing considerations. Finally, the document outlines the manufacturing process, including measuring and laying out parts, machining techniques such as cutting and drilling, and assembling and finishing the final product.

1. The Technological
World

2. 3. Technical Drafting
 Before a technical object can be
manufactured, its shape and dimensions
must be determined. A technical drawing
must be created.
 Technical drawings can be made by hand
or on a computer.
 To understand these drawings, we must
be able to recognize and analyze different
projections.
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3. 3.1 Projections
 A projection is the representation of a
three-dimensional object on a two-
dimensional surface.
 Two of the most commonly used
projections are:
1. isometric
2. multiview.
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4. Isometric Projections
 A drawing is an isometric projection if the
lines representing the length, width, and
height make angles of 60° or 120°.
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5. Multiview Projections
 In a multiview projection, each face of the
object is drawn separately looking at it
from straight on.
 Usually only the top, front and right side of
the object are illustrated.
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6.  Isometric projections show the object in
perspective. It represents the three
dimensions of the object in a single
drawing.
 Multiview projections usually provide
greater detail without distortion.
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7. 3.2 Engineering Drawings
 A general arrangement is a technical
drawing representing the overall
appearance on an object.
 It usually includes the top, front, and right
side multiviews as well as an isometric
projection drawn to scale.
 The general arrangement will also include
a title block showing important
information about the object
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9. Exploded Views
 An exploded view is a drawing in which
the various parts of the object are
separated from one another so as to more
easily visualize the componet parts of the
object.
 The drawing will use an isometric
projection drawn to scale.
 The is accompanied by a list of parts
indicating their names and the number of
each part required.
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11. Detail Drawings
 A detail drawing is a drawing specifying
all of the relevant information for
manufacturing a part. It is almost always
drawn to scale.
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12. Dimensional Tolerances
 Since machines, tools, instruments, and
the operators of machines are not perfect,
the manufactured parts may be slightly
different from the dimensions indicated on
the drawing.
 A dimensional tolerance is an indicator
of the maximum acceptable difference
between a specified measurement and the
actual measurement on the finished
object.
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13.  If the dimensional tolerance applies to all
of the parts on a diagram, it may be
indicated in the title block.
 It can also be applied to a single part and
indicated as shown in the diagram.
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14. Functional Dimensioning
 The functional dimensioning of a
drawing specifies the information required
for the object to work.
 For example, the play required for a blade
to slide freely in a utility knife is shown as
the space between the blade and the
guide.
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16. Developments
 A development is the representation of
the surface area required to make a part
by bending.
 Sheet metal is often used to manufacture
a technical object. The development
shows the surface area of the material as
well as the lines where the sheet will be
bent.
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18. 3.3 Diagrammatic Representations
 A diagram is a simplified representation of an
object, a part of an object, or a system.
 Diagrams are used to help explain an object’s
operating principals as well as any other
characteristics that must considered during the
manufacturing process.
 Depending on the type of information that a
drafter wishes to display, one of the following
common diagrams will be chosen:
 Design Plan
 Technical Diagram
 Circuit Diagram
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19. The Most Common Types of Diagrams
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23. Standardized Symbols In Diagrams
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24. Checkup
 Observatory: The Environment
Page 419, Questions 1 to 10
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25. 4. Manufacturing: Tools and
Techniques
 Once the materials have been choosen and the
plans have been drawn, the object must be
manufactured.
 Manufacturing is a series of operations
resulting in the creation of a technical object.
 The various steps in the manufacturing of an
object require the use of various instuments.
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26.  A tool is and instrument used in the
manufacture of an object.
 A hand tool is powered by human force.
 A machine tool is powered by forces
other than human.
 The manufacturing process is usually
divided into three parts:
1. Measuring and laying out the parts
2. Machining the parts
3. Assembling and finishing the parts
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27. 4.1 Measuring and Laying Out
 The information needed for the
manufacturing of an object can be found
in the detailed drawings of the object, or
on its manufacturing process sheet.
 The manufacturing process sheet is a
document describing a series of operation
to perform in the manufacturing of a given
part and listing the materials and tools
required.
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28.  Measuring out is the act of determining
the size or position of a marking.
 Laying out is the act of tracing markings
or reference points onto a material.
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29. 4.2 Machining
 Machining consists of shaping a material
into a desired configuration.
 The first step in machining a part is to cut
it out roughly into its approximate shape.
 The most commons techniques used in
this step are cutting, drilling, tapping,
threading, and bending.
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30.  Cutting consists of giving a material a desired
shape.
 Drilling consist of making a hole in a material.
 Tapping is a machining technique in which
screw threads are formed inside holes drilled
into a material.
 Threading is a machining technique in which
screw threads are formed around a rod.
 Bending is a machining technique in which a
material is curved into a certain shape.
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31. Inspection
 Throughout the machining phase, the
parts are measured and inspected to
ensure that they match the required
specifications.
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32. 4.3 Assembling and Finishing
 Assembling is a set of techniques by which
various parts are united to form a complete
technical object. Techniques used for
assembling include: nailing, screwing, bonding,
riveting, bolting, and welding.
 Finishing is a set of techniques that complete
the manufacture of the parts of a technical
object. The finish protects the materials from
the elements and enhances the appearance of
the object. Finishing techniques include:
painting, vanishing, staining, and polishing.
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33. Checkup
 Observatory: The Environment
Page 420, Questions 11 to 14

34. Review
 Observatory: The Environment
Page 421, Review Questions A to D
Credits
 All images are from:
Observatory: The Environment
Editions du Renouveau Pedagogique Inc