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Civil Engineering Drawing / Auto Cad CE-01 Ammara Mubeen. INTRODUCTION. INTRODUCTION. What is Engineering Drawing
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Civil Engineering Drawing / Auto Cad CE-01 Ammara Mubeen
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. • Case of drawing instruments • Drawing surface (board or table) • Drafting edge (T-square, parallel edge, drafting machine) • Triangles (30o, 45o or adjustable) • Scales • Drawing Pencils • Drafting Tape • Eraser • Dry cleaning pad • Erasing Shield • Drawing Paper • Tracing Paper or drafting film
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
Viewing-plane line 1 Dimension Line 4 Center Line 3 Extension line 2 Hidden Line 5 6 Break Line Cutting-plane Line 7 8 Visible Line Center Line (of motion) 9 10 Leader Phantom Line 14 13 Section Line 11 VIEW B-B 12 SECTION A-A Source: http://www.genium.com/pdf/dmpc.pdf
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 orhorizontal 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
Orthographic / Multiview • Draw object from two / three perpendicular views What it looks like pictorially / Orthographic
Section A-A View B-B Section Views • If three views are not enough, draw sections needed to completely describe the object.
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.