MD 121 Machine Construction

1
MD 121 Machine Construction
Saturdays, 1000 am 1200 am _at_ Room 420
Instructors Dr. Khaled Ahmed, Assistant
Professor Dr. Wael Khair, Assistant
Professor Office Hours Saturdays 2-3
Tel 1058 e-mail
dr.kh.ahmed_at_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

2

• Intended Learning Outcomes (ILOs)
• 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.

3
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

4
Course Assessment and Evaluation
We shouldnt learn to get marks We shouldnt
learn to get certificates We shouldnt 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 L
ecture Quizzes .. 5 Mid Term
(November 27th 2010) 10 Final Exam
(Sit in Exam) 65
5
Revision
6
How to Keep Your Drawing Clean
Do
Dont
7
Drawing Sheet Size
Assembly Drawing
Working Drawing
8
Types of lines and their applications
9
Types of lines and their applications
10
Types of lines and their applications
11
PROJECTION SYSTEMS
12
PROJECTION SYSTEMS
1. First angle system
- European country- ISO standard
First Quadrant
2. Third angle system
- Canada, USA, Japan, Thailand
Third Quadrant
13
ORTHOGRAPHIC PROJECTION
3rd angle system
1st angle system
14
ORTHOGRAPHIC VIEWS
3rd angle system
1st angle system
Folding line
?
Folding line
Folding line
?
Folding line
15
ORTHOGRAPHIC VIEWS
3rd angle system
1st angle system
Top View
Front View
Right Side View
Front View
Right Side View
Top View
16
PROJECTION SYMBOLS
First angle system
Third angle system
17
Quick Quiz
18
3. Which is in correct first angle projection ?
(180 sec)
b)
a)
c)
d)
45
90
135
180
0
19
4. Which is in correct third angle projection ?
(180 sec)
b)
a)
c)
d)
45
90
135
180
0
20
5. Which is a wrong 3rd angle orthographic views
? (180 sec)
b)
a)
c)
d)
45
90
135
180
0
21
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.
22
STEP 1 Orient the Object
GOOD
NO !
23
STEP 2 Select a Front View
First choice
Second choice
Waste more space
Inappropriate
GOOD
24
STEP 2 Select a Front View
Inappropriate
25
STEP 2 Select a Front View
GOOD
Inappropriate
26
STEP 3 Select an Adjacent View
GOOD
Inappropriate
GOOD
Inappropriate
27
STEP 3 Select an Adjacent View
Necessary
Holes location can be specified on the same view.
Easy to understand
Difficult to interprete.
Necessary
28
STEP 3 Select an Adjacent View
POOR
Not enough space for dimensioning.
29
STEP 3 Select an Adjacent View
GOOD
30
Example View selection
mislead to
F.V.
Three views
F.V. T.V.
F.V. R.S.V.
?
?
?
Size description
?
?
?
Shape description
31
ONE-VIEW DRAWING
1 Thick
Unnecessary
These 2 views provide only informationabout the
part thickness !
32
ONE-VIEW DRAWING
Unnecessary
Repeat !
Infer from CL
Unnecessary
33
TWO-VIEW DRAWING
Repeat !
Unnecessary
34
TWO-VIEW DRAWING
Unnecessary
35
TWO-VIEW DRAWING
Unnecessary
36
Quick Quiz
37
1. Which should be the natural position of the
light bulb ? (20 sec)
b)
a
c)
d)
5
10
15
20
0
38
2. Which are the necessary views ? (60 sec)

1. A-C-E
2. E-B-D
3. E-A
4. E-C

15
30
45
60
0
39
Projection
40
Projection
41
Projection
42
Quick Quiz
43
Projection
44
Drawing Reading
45
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