mechanical drawing (mdp 115) firstyear, mechanical engineering dept., faculty of engineering, fayoum...
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Mechanical Drawing(MDP 115)
FirstYear,Mechanical Engineering Dept.,
Faculty of Engineering,Fayoum University
Dr. Ahmed Salah Abou Taleb
Aims of the course
This module is designed to provide students with an analysis of mechanical drawings. Comprehensive study of fasteners. Methods of assembling various mechanical parts together with and without locking devices (working drawings, dimensional tolerance, fits, surface finishing).
Course Outlines
Review. Dimensions, Limits, Fits and Tolerance. Surface Roughness. Standard Machine Elements (threads, fasteners,
Keys, spline, gears, pulleys, bearing, …….). Welding and Riveting Conventions.
Part One:
Course Outlines (Cont.)
Introduction to Computer Graphics. Wire Frame. Applying solid modeling of mechanical components. Assembly drawing. Production Drawing.
Part Two:
Teaching and Learning Methods
Power Point Lectures. Computer Program (Auto CAD). Class Work Drawings. Home Work Assignments. Quizzes.
Weighting of Assessment
Final Exam 80
Mid Term Exam 20
Class Work Drawing 20
Home Work Assignment 20
Oral 10
Total Marks 150
Review - Instruments
The following is the list of drawing instruments and other drawing materials required for preparation of drawing work:
1. Drawing board2. T-Square3. Set- Triangles – (30o – 60o and 45o)4. Instrument box consists of compasses and dividers5. Mechanical Pencil6. Rubber or eraser7. Erasing shield8. Scotch-tape9. Duster or handkerchief10.Drawing sheet
Review - Basic Line Types
Types of Lines AppearanceName 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.
Review - 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
:
Review - 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.
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FOR T.V.
FOR S.V. FOR F.V.
FIRST ANGLE PROJECTION
IN THIS METHOD, THE OBJECT IS ASSUMED TO BE SITUATED IN FIRST QUADRANT
MEANS ABOVE HP & INFRONT OF VP.
OBJECT IS INBETWEENOBSERVER & PLANE.
ACTUAL PATTERN OF PLANES & VIEWS
IN FIRST ANGLE METHOD
OF PROJECTIONS
X Y
VP
HP
PP
FV LSV
TV
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FRONT
FRONT
13
FRONT
TOP
TOP
FRONT
14
FRONT
TOP
SIDE VIEW
SIDE VIEW
TOP
FRONT
15
FRONT
TOP
SIDE VIEW SIDE VIEW
SIDE VIEW
TOP
FRONT
SIDE VIEW
First angle orthographic projection
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FOR T.V.
FOR F.V.FOR S.V.
PICTORIAL PRESENTATION IS GIVENDRAW THREE VIEWS OF THIS OBJECT
BY FIRST ANGLE PROJECTION METHOD
ORTHOGRAPHIC PROJECTIONS
FRONT VIEW
TOP VIEW
L.H.SIDE VIEW
X Y
Object
GRAPHICS COMMUNICATION WITH ENGINEERING DRAWING
Workingdrawing
Clear ?
Orthographicprojection
(convention)
Section viewsconvention
Section Views
Orthographic Projection
Finish
Yes
No
Dimensioning
PURPOSES OF SECTION VIEWS
Clarify the views by
Facilitate the dimensioning.
reducing or eliminating the hidden lines.
revealing the cross sectional’s shape.
Let See the example
EXAMPLE : Advantage of using a section view.
SECTION LININGSection lines or cross-hatch lines are used to
indicate the surfaces that are cut by the cutting
plane.
Sectionlines
Drawn with 4H pencil.
FULL SECTION VIEWThe view is made by passing the straight cutting plane
completely through the part.
TREATMENT OF HIDDEN LINES
Hidden lines are normally omitted from section
views.