MD 121
Machine Construction
Saturdays, 10:00 am– 12:00 am @ Room 420
Instructors:
Office Hours:
Tel:
e-mail:
Dr. Khaled Ahmed, Assistant Professor
Dr. Wael Khair, Assistant Professor
Saturdays 2-3;
1058;
dr.kh.ahmed@gmail.com
Textbook and Reference Materials:
 K.L. Narayana, P. Kannaiah, and K. Venkata Reddy, "Machine Drawing", Third Edition, NEW
AGE INTERNATIONAL (P) Ltd., New Delhi - 110002, 2006.
 K. Venkata Reddy, “Text Book of Engineering Drawing", Second edition, BS Publications,
Hyderabad - 500 095 - A.P, 2008.
Colin H Simmons, and Dennis E Maguire, "Manual of Engineering Drawing", Second edition,
Elsevier Newnes, Burlington MA 01803, 2004.
 Class notes handouts
Intended Learning Outcomes (ILO’s)
Knowledge and Understanding:
You will learn how to;
 Understand the basic methods for machine assembly
 Distinguish between the data and instructions used for both working and assembly drawings
 Professionally deduce and sketches both working and assembly drawings according to the
international standards
Intellectual
You will learn how to;
 Motivate your intellectual abilities to imagine and deduce machine parts and a whole machine
from the drawings views.
 Motivate your imagination for producing new ideas and methods in machine drawings.
 Create new concepts for the design of machine components and also for assembly of them.
Professional Skills
You will learn how to;
 Practice the standard drawing methods to generate both working and assembly mechanical
drawings.
 Write and specify correctly and according to standards the instructions and machining marks
and the dimensions on mechanical drawings.
General
You will learn how to;
 Cooperate to work in groups through small scale projects
 Work coherently and successfully as a part of a team.
Course Outline
Topic
Weeks
1. Revision
Chapters (1-4)
1
2. Reading A Drawing
Chapter (17)
1
3. Free Hand Sketching
Chapter (13)
1
4. Assembly Drawings
Chapter (18)
1
5. Fits and Dimensional Tolerances
Chapter (15)
1
6. Geometrical Tolerances
Chapter (20)
2
7. Engineering Materials
Collections
1
8. Working Drawings
Chapter (19-20)
1
9. Mechanical Joints (1- Threaded Joints)
Chapter (5)
3
10. Machine Parts
Collections
2
Total
14
 Problems Sheets will be handed in the class after discussed in the lecture
 An extra class will be given to students with Mark “C” every next Saturday
 A term project will be given by Dr. Wael and will be submitted at the end of
the term
Course Assessment and Evaluation
We shouldn’t learn to get marks
We shouldn’t learn to get certificates
We shouldn’t learn to get titles
 Why do we learn?
 To gain knowledge
 To achieve objectives
 To build career
 Why do we need assessment and evaluation?
 To measure the achieved objectives
 To point out what in need for improvements
Class Work ……………………………………………………..
10%
Extra Class Work (Mark “C” students will get bonus) ……..
10%
Course Project ………………….………………………………
10%
Lecture Quizzes ……………..…………………………………
5%
Mid Term
(November 27th 2010)……………………………
Final Exam (Sit in Exam)………………………………………
10%
65%
Revision
How to Keep Your Drawing Clean
Do
Don’t
Drawing Sheet Size
Assembly Drawing
Working Drawing
Types of lines and their applications
Types of lines and their applications
Types of lines and their applications
PROJECTION SYSTEMS
PROJECTION SYSTEMS
1. First angle system
- European country
- ISO standard
First Quadrant
2. Third angle system
- Canada, USA,
Japan, Thailand
Third
Quadrant
ORTHOGRAPHIC PROJECTION
1st angle system
3rd angle system
ORTHOGRAPHIC VIEWS
3rd angle system
1st angle system
Folding
line
Folding
line
Folding
line
Folding
line
ORTHOGRAPHIC VIEWS
1st angle system
Right Side View
Front View
Top View
3rd angle system
Top View
Front View Right Side View
PROJECTION SYMBOLS
First angle system
Third angle system
Quick Quiz
3. Which is in correct first angle projection ? (180 sec)
a)
b)
c)
d)
0
45 90 135 180
4. Which is in correct third angle projection ? (180 sec)
a)
b)
c)
d)
0
45 90 135 180
5. Which is a wrong 3rd angle orthographic views ?
(180 sec)
a)
b)
c)
d)
0
45 90 135 180
VIEW SELECTION STEPS
1. Orient the object to the best position
relative to a glass box.
2. Select the front view.
3. Select adjacent views.
STEP 1 : Orient the Object
The object should be placed in its natural position.
The object should presents its features in actual
size and shape in orthographic views.
GOOD
NO !
STEP 2 : Select a Front View
The object’s longest dimension should be
presented as a width.
First choice
Second choice
Waste more space
Inappropriate
GOOD
STEP 2 : Select a Front View
The adjacent views that are projected from the
selected front view should appear in its natural
position.
Inappropriate
STEP 2 : Select a Front View
Choose the view that have the fewest number of
hidden lines.
GOOD
Inappropriate
STEP 3 : Select an Adjacent View
Choose the view that have the fewest number of
hidden lines.
GOOD
Inappropriate
GOOD
Inappropriate
STEP 3 : Select an Adjacent View
Choose the minimum number of views that can
represent the major features of the object.
Necessary
Hole’s location can be
specified on the same view.
Easy to understand
Difficult to interprete.
Necessary
STEP 3 : Select an Adjacent View
Choose the views that are suitable to a drawing
space.
POOR
Not enough space
for dimensioning.
STEP 3 : Select an Adjacent View
Choose the views that are suitable to a drawing
space.
GOOD
D
Example : View selection
H
mislead to…
W
F.V.
D
H
W
F.V. & T.V.
Size description
Shape description


Three views


F.V. & R.S.V.


ONE-VIEW DRAWING
Flat part having a uniform thickness.
1 Thick
Unnecessary These 2 views provide only information
about the part thickness !
ONE-VIEW DRAWING
Cylindrical-shaped part.
Unnecessary
Repeat !
Infer from CL
Unnecessary
TWO-VIEW DRAWING
There exists an identical view.
Repeat !
Unnecessary
TWO-VIEW DRAWING
The 3rd view has no significant contours of the object.
Unnecessary
TWO-VIEW DRAWING
The 3rd view has no significant contours of the object.
Unnecessary
Quick Quiz
1. Which should be the natural position of the light
bulb ? (20 sec)
a
b)
c)
d)
0
5
10 15 20
2. Which are the necessary views ? (60 sec)
a) A-C-E
E
D
b) E-B-D
B
c) E-A
d) E-C
A
0
15 30 45 60
C
F
Projection
Projection
Projection
Quick Quiz
Projection
B(FV)
B(SV)
A(TV)
D(FV)
C(SV)
A(FV)
C(FV)
D(SV)
Drawing Reading
Drawing Reading
Rear tool post is generally used on capstan lathes, mainly for parting-off operations. It is fixed
on the cross-slide in the slots, provided at the rear side of the lathe