ME 142 Engineering Drawing and Graphics. Instructor Details. Col ( R ) Mumtaz Yousafi MSC ( Machine design ) NUST Rawalpindi B.E. ( Mechanical Engineering) NED Engineering University Karachi. Pre Requisites. Drawing Instruments Basic Knowledge of Geometry
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Instructor Details Col ( R ) Mumtaz Yousafi • MSC ( Machine design ) NUST Rawalpindi • B.E. ( Mechanical Engineering) NED Engineering University Karachi
Pre Requisites • Drawing Instruments • Basic Knowledge of Geometry • Basic Knowledge of units & conversion • Basic Knowledge of computers
COURSE OUTLINE • Pre requisites & Introduction • Dimension, sheet planning & use of dwg instruments • Orthographic projections • Engineering Geometry WEEK 1 to 7 • Fits and tolerances • Geometrical dimensioning & tolerances • Manual Drawing practice • 1 st Sessional WEEK 8 • Introduction to AUTOCAD • 2 D Modeling & practice WEEK 9 to 18 • 2 nd Sessional • Introduction to 3 D Modeling & practice • Course Review WEEK 19 • Final Examination WEEK 20
Details of Course Outline Part-I • Introduction. Types of lines, lettering, dimensioning, use of pencil and drawing instruments, planning of drawing sheet. • Projections. Types of projections, orthographic projections, plane of projections, four quadrants, projection of points, projection of straight lines, examples with different quadrants, traces of a line, true length of a line, inclination to both the planes, projection of oblique and auxiliary planes. • Use of instruments and letter writing practice • Engineering Geometry • Allowances and Tolerances • Geometric Dimensioning as per ANSI 14.5 • First angle and third angle projection engineering drawing practice. • Geometrical construction engineering drawing practice. Part - II • Introduction to computer aided engineering drawing and use of software/package (AUTOCAD). • 2 D & 3 D drawing including solid modeling
TEXT BOOKS FOR REFERENCE • Engineering Drawing by A W Boundy • Machine Drawing by Ajeet Singh • Engineering Graphics with AUTOCAD by James D Bethune
Overview of an Engineering Drawing (WEEK 1)
Graphics language Traditional Drawing Tools Drawing scales Drawing Symbols Engineering drawing Drawing standards LECTURE OBJECTIVES
Effectiveness of Graphics Language 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. You can easily understand that … The word languages are inadequate for describing the size, shape and featurescompletely as well as concisely.
The language is known as “drawing” or “drafting” . A drawing can be done using freehand, instrumentsor computermethods. Composition of Graphic Language Graphic languagein “engineering application” use linesto represent the surfaces, edges and contoursof objects.
Example Freehand drawing The lines are sketched without using instruments other than pencils and erasers.
Example Instrument drawing Instruments are used to draw straight lines, circles, and curves concisely and accurately. Thus, the drawings are usually made to scale.
Examples Computer drawing The drawings are usually made by commercial software such as AutoCAD, solid works , PRO – E, etc.
Simple CAD/CAE/CAM Product Lifecycle Design CAD Analysis CAE Manufacturing CAM C D
Graphics language Describe a shape(mainly). Word language Describe size, location andspecification of the object. Elements of Engineering Drawing Engineering drawing are made up of graphics language and word language.
Geometric construction Line types Projection method Lettering Basic Knowledge for Drafting Word language Graphics language
DRAWING TOOLS 1. T-Square 2. Triangles
DRAWING TOOLS 2H or HB for thick line 4H for thin line 3. Adhesive Tape 4. Pencils
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 standards are used so that drawings convey the same meaning to everyone who reads them. Introduction Standards are set of rules that govern how technicaldrawings are represented.
Full name Country Code USA American National Standard Institute ANSI Japanese Industrial Standard Japan JIS British Standard UK BS Australian Standard Australia AS Deutsches Institut fürNormung Germany DIN International Standards Organization ISO Standard Code
Drawing Sheet A4 Trimmed paper of a size A0 ~ A4. A3 Standard sheet size(JIS) A4 210 x 297 A3 297 x 420 A2 420 x 594 A1 594 x 841 A0 841 x 1189 A2 A1 (Dimensions in millimeters) A0
Orientation of drawing sheet c d d c c Sheet size c (mm) d (mm) A4 10 25 A3 10 25 A2 10 25 A1 20 25 A0 20 25 1. Type X (A0~A4) 2. Type Y (A4 only) Drawing space Drawing space Border lines Title block Title block
Drawing layout All engineering drawings should feature a title block. The title block should include: Title:- title of the drawing Name:- name of the person who produced the drawing Checked:- before manufacture, drawings are usually checked Version:- many drawings are amended, each revision must be noted Date:- the date the drawing was produced or last amended Notes:- any note relevant to the drawing Scale:- the scale of the drawing Company name:- name of the company Projection:- the projection system used to create the drawing
: Drawing Scales Length, size Scaleis 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
Designation of a scale consists of the word “SCALE” followed by the indication of its ratio, as follow 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. Drawing Scales SCALE 1:1 for full size SCALE X:1 for enlargement scales (X > 1) SCALE 1:X for reduction scales (X > 1)