1. ES 101 Engineering Graphics
Gaurav Srivastava
Assistant Professor
Civil Engineering
Fall 2017

2. Last time [5.1] bisecting a line [5.2] to draw perpendiculars
[5.3] to draw parallel lines
[5.4] to divide a line
[5.6] to bisect an angle
[5.10] to construct equilateral triangles
[5.11] to construct square
[5.16] to draw tangents

3. Types of Lines Types of Lines Applications Example
Thick Continuous Line
Visible Edges and Surface Boundaries
Thin Continuous Line
Extension and Dimension Lines, Section Lines
Construction Line in light stroke
Dashed Line
Hidden Outline and Edges
10 mm

4. Types of Lines Types of Lines Applications Example Dash-dot Line or
alternating Long-Short dash
Center Line, Line of symmetry
Dash with pair of dots Line
Phantom Lines
Continuous zig-zag Line
Partial Views Discontinuation Line

5. Example: Center Lines

6. Example: Hidden & Center Lines

7. Example: Construction Lines

8. Example: Many Lines 1 Viewing-plane line Dimension Line 3 4
Center Line 2
Extension line 5
Hidden Line 6
Break Line
Cutting-plane Line 7 8
Visible Line 9
Center Line (of motion) 10
Leader
Chain Line 14
Phantom Line 13
Section Line
SECTION A-A 12
VIEW B-B 11
ES-101: Engineering Graphics - Amit Prashant
ES101: Lecture 2 (28 August 2014)
Source:

9. Scale
Dimensions of large objects must be reduced to accommodate on standard size drawing sheet. Similarly in case of tiny objects dimensions must be increased.
1: 2
1: 0.5
Large Objects
Ex: Table or chair
Drawing Size
1:1
Ex: Keyboard of a computer
Small Objects
Ex: Circuit of a mobile phone

10. Scale Representative Fraction, RF:
RF = 0.2 or 1/5 means the actual object is five times larger than the size shown on drawing Scale = 1:5
RF = 5 or 5/1 means the actual object is five times smaller than the size shown on drawing Scale = 1:0.2

11. Scale 1 : R Hence, the Scale is written as (Drawing : Real) i
Full Scale :1
Reduced Scale 1:R R>1.0
Enlarged Scale 1:R R<1.0
on Right is the Real size

12. Plane Scale For dimensions up to ONE decimal Example:
Scale of 1 cm = 1m to read decimeters
Maximum distance of 6 m
Show distance of 4 m and 6 dm
What is the R.F.?
4 m 6 dm 10
METER 1 2 3 4 5
DECIMETER

13. Diagonal Scale For dimensions up to TWO decimals Example:
Scale of 1 cm = 1m to read centimeters
Maximum distance of 6 m
Show distance of 4 m and 46 cm 5 10
CENTIMETER
4 m 46 cm 10
METER 1 2 3 4 5
DECIMETER

14. Diagonal Scale: Example
Construct a diagonal scale of R.F. =1/500 to read up to 60 meters and to read millimeters on it. Show a length of meters on it. 5 10
MILLIMETER m
100
METER 10 20 30 40 50
CENTIMETER

15. Curves
Sections of Cone at various inclinations result into different plane geometries - Curves
Circle
Ellipse
Parabola
Hyperbola

16. Geometric construction
[3.1] lines
[4.2] scales
[6.1.1] ellipse
[6.2.1] cycloid
[6.3] involute
[6.5.1] Archemedian spiral
[ ] dimensioning

17. Ellipse – Rectangle Method
Very useful in making inclined views of ellipses/circles in isometric/perspective projections

18. Parabola – General Method
Focus

19. Parabola – Rectangle Method
RISE
SPAN

20. Cycloid C1 C2 C3 C4 C5 C6 C7 C8 7 6 5 4 3 2 1 8

21. Involute 1 2 3 4 5 6 7 8 D D D

22. Spiral

23. Dimensioning – good practices
Should be complete but not redundant
Should be placed outside views/objects
Avoid crossing of dimension lines
Should be placed at a reasonable distance from the object/feature
Use uniform arrow type (typically 3:1 ratio between length:depth)