Civil Engineering Drawing / Auto Cad CE-01 Ammara Mubeen

SLTopics 1. Introduction 2. Lettering, Numbering and Dimensioning 3. Conic Section 4. Orthographic Projection 5. Section Views and Auxiliary Views 6. Isometric, Pictorial and Oblique Drawing 7. Development of Surfaces 8. Auto Cad Application

Importance of Engineering Drawing as graphic communication. Link between engineering drawing and other subjects of study. I. S.O (International standards organization) specification for preparation of drawings. Use of drawing instruments and materials. Basic Tools- classification and brief description. Special Tools: Mini-drafter. Drafting Machine. Scales, Recommended, reduced and enlarged scale. Lines, Types of lines, Selection of line thickness. Selection of Pencils. Drawing sheets, different sheet sizes and standard layouts. Care and maintenance of drawing material. INTRODUCTION

What is Engineering Drawing A fully developed language in its own right: A graphical language that Engineers understand all over the world irrespective native tongue. Communication between “DESIGNER and MANUFRACTURER”. BSI, ISO, BIS (Bureau of Indian Standards) set rules are followed. Engineering Drawing Requirements Unambiguous and Clear Complete Suitable for duplication Language Independent Conforms to standards

INTRODUCTION BASIC LIST OF EQUIPMENT The following list contains the selection of equipment necessary for making instrument drawings. 1. Case of drawing instruments 2. Drawing surface (board or table) 3. Drafting edge (T-square, parallel edge, drafting machine) 4. Triangles (30o, 45o or adjustable) 5. Scales 6. Drawing Pencils 7. Drafting Tape 8. Eraser 9. Dry cleaning pad 10. Erasing Shield 11. Drawing Paper 12. Tracing Paper or drafting film

Instruments

LINE TYPES

Types of Lines

Line Conventions Visible Lines – solid thick lines that represent visible edges or contours Hidden Lines – short evenly spaced dashes that depict hidden features Section Lines – solid thin lines that indicate cut surfaces Center Lines – alternating long and short dashes Dimensioning Dimension Lines - solid thin lines showing dimension extent/direction Extension Lines - solid thin lines showing point or line to which dimension applies Leaders – direct notes, dimensions, symbols, part numbers, etc. to features on drawing Cutting-Plane and Viewing-Plane Lines – indicate location of cutting planes for sectional views and the viewing position for removed partial views Break Lines – indicate only portion of object is drawn. May be random “squiggled” line or thin dashes joined by zigzags. Phantom Lines – long thin dashes separated by pairs of short dashes indicate alternate positions of moving parts, adjacent position of related parts and repeated detail Chain Line – Lines or surfaces with special requirements

Source: Viewing-plane line Extension line Dimension Line Center Line Hidden Line Break Line Cutting-plane Line Visible Line Center Line (of motion) Leader VIEW B-B SECTION A-A Section Line Phantom Line

Lettering Plain Gothic Italics are OK ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz

Sketching Drawings made without mechanical drawing tools Free-Hand Ruler Simple drawing program Should follow standards and conventions From Course Text

Pictorial 3-dimensional representations One-point one vanishing point lines that are not vertical or horizontal converge to single point in distance Two-point or Three-point two or three vanishing points With two points, vertical or horizontal lines parallel, but not both With three-point, no lines are parallel Isometric Drawing shows corner of object, but parallel lines on object are parallel in drawing Shows three dimensions, but no vanishing point(s) Source: “Introduction to Engineering”, by Paul Wright

One-point Two-Point

Isometric

Orthographic / Multiview Draw object from two / three perpendicular views / Orthographic What it looks like pictorially

Section Views If three views are not enough, draw sections needed to completely describe the object. Section A-AView B-B

ISOUSA Sizes Letter WidthLength Letterinches mminchesmminches F28.0 x 40.0 A E34.0 x 44.0 A D22.0 x 34.0 A C17.0 x 22.0 A B11.0 x 17.0 A A8.5 x 11.0 ISO Drawing Sheets Sizes

Recommended Books 1. Descriptive GeometryAbbot 2.Elementary Engineering DrawingN. D. Bhatt 5.I.S.I. Specification on drawing- S. C. Sharma 6.Engineering DrawingR. K. Dhawan 7.Fundamentals of Engineering DrawingWarren J. Luzadder 8.Engineering DrawingBasant Agrawal 9.I.S.M. & S.S.M. on Technical DrawingT.T.T.I., Madras

Title Block It should contain the following information The title of drawing The drawing and sheet number The Scale The angle of projection used Other information if required “The scale is the ratio of the linear dimension of an element of an object as represented in the original drawing to the real linear dimension of the same element of the object itself” All drawings should be drawn to the scale for which the selected scale should be large enough to permit easy and clear interpretation.

Title Block