Presentation on theme: "ME 142 Engineering Drawing and Graphics. Instructor Details Col ( R ) Mumtaz Yousafi MSC ( Machine design ) NUST Rawalpindi B.E. ( Mechanical Engineering)"— Presentation transcript:
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 Basic Knowledge of units & conversion Basic Knowledge of computers
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 COURSE OUTLINE
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)
LECTURE OBJECTIVES Drawing standards Graphics language Engineering drawing Traditional Drawing Tools Drawing scales Drawing Symbols
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. Effectiveness of Graphics Language sizeshapefeatures The word languages are inadequate for describing the size, shape and features completely as well as concisely. You can easily understand that …
Graphic language in “engineering application” use lines surfacesedgescontours lines to represent the surfaces, edges and contours of objects. freehandinstruments computer A drawing can be done using freehand, instruments or computer methods. Composition of Graphic Language drawingdrafting The language is known as “drawing” or “drafting”.
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. Example
Computer drawing The drawings are usually made by commercial software such as AutoCAD, solid works, PRO – E, etc. Examples
Elements of Engineering Drawing graphics language Engineering drawing are made up of graphics language word language and word language. Graphics language Describe a shape (mainly). Word language Describe size, location and specification of the object.
Basic Knowledge for Drafting Graphics language Word language Line types Geometric construction Lettering Projection method
Traditional Drawing Tools
TECHNICAL DRAWING BOARD
1. T-Square2. Triangles DRAWING TOOLS
3. Adhesive Tape4. Pencils 2H or HB for thick line 4H for thin line DRAWING TOOLS
9. Circle Template10. Tissue paper DRAWING TOOLS
11. Sharpener12. Clean paper DRAWING TOOLS
Introduction Standards Standards are set of rules that govern how technical drawings are represented. Drawing standards are used so that drawings convey the same meaning to everyone who reads them.
ISO International Standards Organization Standard Code ANSI American National Standard Institute USA JIS Japanese Industrial Standard Japan BS British Standard UK AS Australian Standard Australia Deutsches Institut f ü r Normung DIN Germany Country Code Full name
Drawing Sheet Trimmed paper of a size A0 ~ A4. Standard sheet size (JIS) A4 210 x 297 A3 297 x 420 A2 420 x 594 A1 594 x 841 A0 841 x 1189 A4 A3 A2 A1 A0 (Dimensions in millimeters)
Drawing space Drawing space Title block d d c c c Border lines 1. Type X (A0~A4) 2. Type Y (A4 only) Orientation of drawing sheet Title block Sheet size c (mm) d (mm) A A A A A
SAMPLE OF DRAWING SHEET
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
SAMPLE OF ENGINEERING DRAWING
Drawing Scales Scale 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 :
Drawing Scales Designation of a scale consists of the word “SCALE” followed by the indication of its ratio, as follow SCALE 1:1for full size enlargement SCALE X:1for enlargement scales (X > 1) reduction SCALE 1:Xfor 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.