history of drafting

1. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
MODULE 1
BASIC DRAFTING
(Draw 101)
Christian Paul E. Era, LPT
Instructor

2. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
Brief History of Drafting
The earliest historical record of drafting goes back to 2000 BC, as proven by a recovered
fossilized plan showing an aerial view of a Babylonian castle. This showed that, even in the
early eras, people used drawings to guide them in building structures.
Meanwhile, during the Renaissance era, Leonardo da Vinci was one of the people who made
use of the art and science of drafting. History has it that da Vinci drew mechanical
constructions that, years later, gained recognition among civil engineers, mechanical
engineers, and other professionals from various fields.
Before the 1960s, the idea of drafting was limited to drawing on paper by hand or with the
use of a drafting machine that was invented in 1901 by Charles Little. In the modern age,
however, computerized technologies started to be developed and used by a wide population
of drafters. As the decades went by, CAD technologies continued to grow until they became
the CAD programs that we know today. Currently, many companies rely on these
technologies. Manual drafting, however, has never left the scene.
Drawing
 A drawing is a graphic representation of a real thing, an idea or proposed design for
later manufacture or construction. Drawing may take many forms but the graphic
method representation is a basic natural form of communication of ideas that is
universal and timeless.
 Drawing is a valuable means of expression to anyone -- an effective way to get an
idea across when words fail.
 Drawing, according to Spencer is “the principal means of expression of ideas in a
technical world… a graphic language has its own alphabet, grammar, penmanship.”
 Drawing is the ability of a person to put facts and truths in graphic form that us by
means of lines and tools and a person who prepares drawing and portrays graphically
is a draftsman.
Drafting
 Drafting is an art of making drawings.
 Drafting is a process for preparing drawings to communicate ideas and instructions to
others. Lines, words and symbols are used to clearly and accurately record the shape,
size, color, material, finish, and construction of objects to be made. The drawing must
be accurate and clear. A mistake on drawing or unclear item, which causes someone
else to make mistake, causes financial loss to the employer.
 Drafting is a career in which intellectual ability and manual dexterity are important. It
does not require unusual physical strength.

3. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
Drafting Standards
An important thing to know about drafting is that it uses a certain language. This means that
anyone who knows that language will be able to understand or even replicate a given
technical drawing. This is especially important for designers who need to communicate very
strict specifications to their colleagues or clients, including their co-designers, the people who
will acquire the necessary parts or equipment, and the engineers who will construct the
design.
To clearly communicate the important details of the design, a technical drawing must be able
to show the materials that should be used, the dimensions, the shapes or geometry of objects,
and how the parts will fit together. In some cases, the tolerances of parts--meaning, the range
of allowable variations from the original design--are also indicated.
There’s no single set of standards that all drafting technicians and engineers around the world
follow. However, there are common practices in every country, mostly based on what the
United States and Great Britain use. For instance, in the US, the use of third-angle projection
has already become standard practice. This is followed by many other countries except for
Great Britain and a few others that use first-angle projection.
In some manufacturing and engineering companies, unique standards are made so as to unify
the elements of their own technical drawings.
DEFINITION OF TERMS
After this brief survey of historical development of the graphic language and before we began
a serious study of theory and applications, a few terms need to be defined.
 Descriptive Geometry- this is the three-dimensional geometry forming the
background for practical applications of the graphic language and through which
many of its problems may be solved graphically.
 Instrumental drawing or mechanical drawing- these terms properly apply only to
a drawing made with drawing instruments. The use of “mechanical drawing” to
denote all industrial drawings is unfortunate not only because such drawings are not
always mechanically drawn, but also because that usage tends to belittle the broad
scope of the graphic language by naming it superficially for its principal mode of
execution.
 Computer Graphics- this is the application of conventional computer techniques
with the aide pf one of many graphic data processing systems available to the
analysis, modification and finalizing a graphical solution. The use of computers to
produce technical drawing is called computer aided design (CAD) or computer-aided
design and drafting (CADD).
You can use CAD to create a useful database that accurately describes the three-
dimensional geometry of the machine parts, structure, or system you are designing. This
database can be used to perform analysis directly machine parts or create illustrations for
catalogs and service manuals.

4. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
 Engineering drawing and engineering drafting- these are broad terms widely used
to denote the graphic language. However, since the graphic language is also used by
much larger group of people in diverse fields who are concerned with technical work
or industrial production, these terms are not broad enough.
 Technical drawing- this is the free hand expression of the graphic language.
Technical sketching is the valuable tool for engineers and others engaged in technical
work because most through it, most technical ideas can be expressed quickly and
effectively with out the use of special equipment.
 Blueprint reading- this term is applied to the “reading” of the language form the
drawing of the others. Actually, the blueprint process has now been replaced by other
more efficient processes, but the term “blueprint reading” has been accepted through
usage to mean the interpretation of all ideas expressed on technical drawing, whether
or not the drawings are blueprint.
Types of Drawing
There are two basic types of drawings: artistic and technical. Some experts believed there are
actually three types: the two mentioned and another type, which combines these two. The
third type is usually referred to as an illustration or rendering,
1. Artistic Drawing
 range in scope from the simplest line drawings to the most famous paintings.
Regardless of their complexity or status, artistic drawings are used to express
the feelings, belief, philosophies or abstract ideas of an artist. This is why the
layperson often finds it difficult to understand what is being communicated by
a work of art. In order to understand an artistic drawing, it is sometimes
necessary to first understand the artist. Artists often take subtle or abstract
approach in communicating through their drawings. This gives rise to the
curious interpretations often associated with artistic drawings.

5. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
2. Technical Drawing
 The technical drawing, on the other hand is not subtle or abstract. It does not
require an understanding of its creator; only an understanding of technical
drawings. A technical drawing is a means of clearly and concisely
communicating all of the information necessary to transform an idea or a
concept in reality. Therefore, a technical drawing often contains dimensions,
notes and specifications.
3. Illustrations or Rendering are sometimes referred to as a third type of drawing
because they are not completely technical, neither are they completely artistic; they
combined elements both. They are technical, that they are drawn with mechanical
instruments or on computer-aided drafting system and they contain some degree of
technical information. However, they are also artistic in that they attempt to convey a
mood, an attitude, a status or other abstract, non-technical feelings.
Purpose of Technical Drawings
To appreciate the need for technical drawings, one must understand the design process.
Thedesign process is an orderly, systematic procedure in accomplishing a needed design.
Any product that is to be manufactured, fabricated, assembled, constructed, built or
subjecteddesign process is an orderly, systematic procedure in accomplishing a needed
design. Any product that is to be manufactured, fabricated, assembled, constructed, built or
subjected to any other type of conversion process must be first designed. For example, a

6. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
house must be designed before it can be built. An automobile must be designed before it can
be manufactured. A printed circuit board must be designed before it can be fabricated
Technical drawings are the common language of those who work in technology. Engineers,
architects, designers, technologists, technicians and specialized workers use them to
communicate with each other. This universal language varies little from one country to
another. Unlike spoken languages, it ensures unequivocal understanding of the definition and
construction of technical objects. This means that two engineers who do not speak the same
language can understand most of a technical drawing, with the exception of annotations
written in a specific language.
Division of Drawings
Drawing is further divided into divisions: they are freehand drawing or technical sketching
and the mechanical drawing or instrumental drawing. Freehand drawing or technical
sketching is the technique of making drawings without the use of drawing instruments, while
mechanical drawing is the instrumental expression of it.
OBJECTIVE OF DRAWING
The following explains the correct methods for instrumental drawing. Students who practice
and learn correct manipulation of their drawing instruments will eventually be able to draw
correctly by habit and will be able to guide their full attention to the problems at hand. The
following are the important objectives student should strive to attain;
1.Accuracy.
No drawing is of maximum usefulness if it is not accurate. The student cannot achieve
success in professional employment if the habit of accuracy is not acquired.
2. Speed
Time is money in industry, and there is no demand for a slow drafter, technician or
engineer. However, speed is not attained by hurrying; it is an unsought byproduct of
intelligent and continuous work. It comes with study and practice.
3.Legibility
Drafters, technicians, and engineers must remember that a drawing is means of
communication to others, and that it must be clear and legible to serve its purpose well. Care
should be given to details, especially to lettering.
4. Neatness
If a drawing is to be accurate and legible, it must also be clean. Untidy drawings are
the result of sloppy and careless methods and will be acceptable to an instructor or employer.

7. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
TECHNICAL DRAWING AND ITS SPECIALIZED BRANCHES
1. Architectural Drawing- that branch of technical drawing, which is devoted to the
representations of buildings and similar structure. The drawing for architectural
structures includes plans, elevation, sections and details sufficient to define
adequately in graphic form the construction so that it can be executed in complete
accord with the architect ideas.
2. Machine Drawing- that branch of technical drawing, which is used in machine
industries. A machine shop drawing omits all information concerning the pattern of
the foregoing process and conveys only those needs for machining.
3. Structural Drawing- includes all layout and detail drawings connected with the
design and construction of buildings, bridges, viaducts and other similar structure in
which structural steel, timber, concrete and other building materials are used.
4. Sheet Metal Drawing- used in heating, ventilating and air-conditioning industries. It
includes problems involved in finding intersections of surfaces and developing
surfaces of various kinds into flat patterns and templates, which have many
applications in industries mentioned. Broiler, smoke, stocks, breaching and ducts also
involved problems of this kind.
5. Electrical Drawing- used in electrical industries. Electrical engineers need the basic
knowledge of drawing, as do chemical engineers and other engineers. This drawing
includes diagrammatic drawing using conventional symbols for electrical equipment
and conventions, which form an important class of electrical drawing.
6. Aeronautical Drawing- which is a composite of mechanical, structural, electrical and
sheet metal drawing in which some deviations are made form each other in order to
establish uniformity as a single basic system. A distinctive feature of aeronautical
drafting is the planning of logical assembly and installation sequences as well as
designing for maximum strength for maximum weight. It is used in aircraft
manufacturing.
7. Marine Drawing- deals with the making of drawings or plans of boats, ships and
other sea-going vessels.
8. Furniture Drawing- includes designing and planning of pieces for furniture like
cabinets, tables, chairs, beds and other furnishing found in an office, home, hotels and
many more.
9. Map Drawing- that branch of technical drawing, which represent a portion of the
earth’s surface area. Since it usually represents a relatively small part, all the third
dimension (height) is not shown except in some cases by contour lines. A map may be
thought of as a one view multiview drawing.
Maps are classified into eight groups in accordance with their purpose on intended
use. Cartography is the science of art of map making.

8. Republic of the Philippines
TECHNICAL INSTITUTE OF ILOILO CITY
M.H. Del Pilar, Molo, Iloilo City
a. Geographical Map- includes large areas and consequently must be drawn to small
scale. They show important towns and cities, streams and bodies of water, political
boundaries and relief.
b. Topographic Map- complete description of certain areas and show larger scale the
geographical positions of the natural features and the works of man such as buildings,
bridges.
c. Hydrographic Map- deals with the information concerning bodies of water and
shorelines, soundingdepth, sub-aqueous contour navigation aids and water control.
d. Cadastral Map- one of the very accurate control maps for either cities or towns
made to large scale with all features drawn to scale. They used to control city
developments and operations particularly taxation and transfer of property lot of city
additions, mineral rights, form surveys and the like that fall on this group.
e. Engineering Map- working maps for engineering projects are classified for
specific purposes such as for the reconnaissance of construction maintenance
purposes. They provide accurate horizontal and vertical control data and show objects
on the site along the right way.
f. Photogrammetric Map- represent features on the earth’s surface from territorial
and aerial photographs. These photographs and perspective are sources from which
orthographic views are obtained by stereoscopic instruments. Ground control stations
are necessary to bring the photograph to the required datum.
g. Military Map- designed to contain information of military importance in the area
presented.
h. Landscape Map- used in planning installations of trees, shrubbery, driveways, etc.
In the artistic design of area improvement.
 Contours- lines drawn on a map to locate in the plan views, points of equal
ground elevations. On a single contour line, therefore, all points have the same
elevation.
 Hatchures- short parallel or slightly divergent line drawn in the direction of
the slope. They are closely spaced on steep slopes and converge toward the
slopes and converge toward the tops of ridges and hills. Hatchures are shade
lines used to show relief.