Post on 17-Nov-2020
Engineering Drawing
week Date Engineering Drawing Descriptive
Geometry Notes
1
Introduction / drawing instruments Introduction in Projection theory
2
Lettering / title block Terminology, Projection of an object
3
Type of lines Representation of the point in space
4
Type of lines Location of point in space
5
Geometric Constructions: introduction Orthographic projection of the point
on two perpendicular planes
6
Geometric Shapes Orthographic projection of the point
on three perpendicular planes
7
Geometric Shapes Representation of the straight line in
space
8
Angles & Tangents Horizontal line projection
9 Conic sections: methods of ellipse
drawing Front line projection
10
Methods of parabola drawing Profile line projection
11
Theory of projection/ multi-views
system
The way of finding the True length of
the line by the Rotation on the H.P
12
Views (flat surfaces) The way of finding the True length of
the line by the Rotation on the V.P
13
Views (flat & inclined surfaces) The way of finding the True length of
the line byRabatment on the H.P
14
Scales & Dimensioning The way of finding the True length of
the line by Rabatment on the V.P
15
Views with dimensioning Introduction to plane surface
Course Assessment
• Homework Assignments------8%
• Class work ------------12 %
• Lecturer assessment -----------10%
• Midterm Exams ------------30% Each
• Final Exam -------------40%
Textbook: Bertoline-Wiebe-Miller “Fundamentals of Graphics Communication,
3/e)
عبد الرسول الخف اف أستاذ /مباديء اوليه للرسم الهندسي : المصدرا
Chapter 1
Overview of an
Engineering Drawing
TOPICS
Drawing standards
Graphics language
Engineering drawing
GRAPHICS
LANGUAGE
• Engineers: People who use technical means to solve
problems. They design products, systems, devices, and
structures to improve our living conditions
• Technical Drawing: a clear, precise language used in
the design process for communicating, solving
problems, quickly and accurately visualizing objects,
and conducting analyses
• A graphical representation of objects and structures is
done using freehand, mechanical, or computer methods
Artistic drawing vs. Technical drawing
What’s the difference?
1. Try to write a description of
this object.
2. Test your written description
by having someone attempt
to make a sketch from your
description.
Effectiveness of Graphics Language
The word languages are inadequate for describing the
size, shape and features completely as well as
concisely or briefly.
You can easily understand that …
Graphic language in “engineering application” use
lines to represent the surfaces, edges, contours and
features of objects.
A drawing can be done using freehand, instruments
or computer methods.
Composition of Graphic Language
The language is known as “drawing” or “drafting” .
1) Freehand drawing The lines are sketched without using instruments other
than pencils and erasers.
Example
2) Instrument drawing Instruments are used to draw straight lines, circles, and
curves concisely and accurately. Thus, the drawings are
usually made to scale.
Example
3) Computer drawing
The drawings are usually made by commercial software
such as AutoCAD, solid works etc.
Example
Engineering Drawing
Elements of Engineering Drawing
Engineering drawing are made up of graphics language
and word language.
Graphics
language
Describe a shape
(mainly).
Word
language
Describe size, location and
specification of the object.
Basic Knowledge for Drafting
Graphics
language
Word
language
Line
types
Geometric
construction Lettering Projection
method
Traditional
Drawing Tools
DRAWING TOOLS
1. T-Square 2. Triangles
DRAWING TOOLS
3. Adhesive Tape 4. Pencils
2H or HB for thick line
4H for thin line
DRAWING TOOLS
5. Sandpaper 6. Compass
DRAWING TOOLS
7. Pencil Eraser 8. Erasing Shield
DRAWING TOOLS
9. Circle Template 10. Tissue paper
DRAWING TOOLS
11. Sharpener 12. Clean paper
DRAWING TOOLS
Drawing Sheet
Trimmed paper of
a size A0 ~ A4.
A4
A3
A2
A1
A0 (Dimensions in millimeters)
Standard sheet size
(JIS)
A4 210 x 297
A3 297 x 420
A2 420 x 594
A1 594 x 841
A0 841 x 1189
27
Standard Sheets sizes
A Series Formats (mm)
A0 841 × 1189
A1 594 × 841
A2 420 × 594
A3 297 × 420
A4 210 × 297
A5 148 × 210
A6 105 × 148
A7 74 × 105
Preparation of
Tools
Fastening Paper to Drafting Board
1. Place the paper close to the table’s left
edge. 2. Move the paper until its lower edge place
about the top edge of T-square.
3. Align the top edge of the paper with T-
square blade. 4. Attach the paper’s corners with tape.
Fastening Paper to Drafting Board
5. Move T-square down to smooth the
paper. 6. Attach the remaining paper’s corners
with tape.
Fastening Paper to Drafting Board
1. Remove the wood with penknife while expose a
lead about 8-10 mm.
2. Polish the lead into a conical shape with a
sandpaper.
3. Clean the lead with tissue paper.
Sharpening the Pencil
Preparing the Compass
2. Adjust the needle and the lead so that the tip of
the needle extends slightly more than the lead.
1. Sharpen the lead with a sandpaper.
needle lead
Drawing space
Title block
d
c
c
c Border
lines
1. Type X (A0~A4)
Orientation of drawing sheet
Sheet size c (min) d (min)
A4 10 25
A3 10 20
A2 10 25
A1 20 25
A0 20 25
الرسم مقياس15
15
المادة عنوان الرسم
التاريخ الاسم القسم المرحلة ت
15 33 45 45 45
183
Engineering line
Drawing Scales
Scale is the ratio of the linear dimension of an element
of an object shown in the drawing to the real linear
dimension of the same element of the object.
Size in drawing Actual size
Length, size
:
Drawing Scales
Designation of a scale consists of the word “SCALE”
followed by the indication of its ratio, as follow
SCALE 1:1 for full size
SCALE X:1 for enlargement scales (X > 1)
SCALE 1:X for reduction scales (X< 1)
Dimension numbers shown in the drawing are correspond
to “true size” of the object and they are independent of
the scale used in creating that drawing.
Using the Tools
Straight line
Arc, Circle 4. Circle template
1. T-square
2. Triangles
3. Compass
Tools Shape to be drawn
Function of the Tools
Using the Compass
1. Locate the center of the circle by two intersecting lines.
2. Adjust the distance between needle and lead to a distance
equal to radius of the circle.
3. Set the needle point at center.
4. Start circle. Apply enough pressure to the needle,
holding compass handle between thumb and index fingers.
5. Complete circle. Revolve handle clockwise.
Using the Compass
Draw a Horizontal Line
1. Press the T-square head against the left edge of the table.
2. Smooth the blade to the right.
Draw a Horizontal Line 3. Lean the pencil at an angle about 60o with the paper in the
direction of the line and slightly “toed in”.
4. Draw the line from left to right while rotating the pencil slowly.
Draw a Vertical Line 1. Set T-square as before. Place any triangle on T-square edge.
2. Slide your left hand to hold both T-square and triangle in
position.
Draw a Vertical Line 3. Lean the pencil to the triangle.
4. Draw the line upward while rotating the pencil slowly.
Draw a line at 45o with horizontal
2. Draw the line in the direction as shown below.
1. Place 45o triangle on the T-square edge and press them
firmly against the paper.
1. Place 30o-60o triangle on the T-square edge and press
them firmly against the paper.
2. Draw the line in the direction as shown below.
Draw a line at angle 30o and 60o
0 deg.
15 deg.
30 deg.
45 deg.
60 deg.
75 deg.
90 deg.
= 30 + 45 deg
Already
demonstrated.
= 30 + 45 deg
Already
demonstrated.
Draw the lines at 15o increment
A
B
Draw the line passing through
two given points
1. Place the pencil tip at one of the points.
2. Place the triangle against the pencil tip.
A
B
Given
3. Swing the triangle around the pencil tip
until its edge align with the second point.
4. Draw a line.
Basic Line
Types
Chapter 2
Lines
Hidden Lines
Center Lines
Dimension Lines
Extension Lines
Leader Lines Section Lines
Phantom Lines
Break Lines
Visible Lines
Line Types ………………………… الخطوط أنواع
Basic Line Types
Types of Lines Name, according
to application
Continuous thick line Visible line
Continuous thin line Dimension line
Extension line
Leader line
Dash thick line Hidden line
Chain thin line Center line
NOTE : We will learn other types of line in later chapters.
Visible lines represent features that can be seen in the
current view
Meaning of Lines
Hidden lines represent features that can not be seen in
the current view
Center line represents symmetry, path of motion, centers
of circles, axis of axisymmetrical parts
Dimension, Leader and Extension lines indicate the
sizes and location of features on a drawing
Example : Line conventions in engineering drawing
Class work
page (11): practice no. 4 , 7 , 10
Home work
page (10): practice no. 5 , 6
page (11): practice no. 1 , 5