Study Lesson 1 Introduction

Contents Engineering drawing Drawing standards Drawing sheet Scale Lettering Line types

Engineering Drawing --Albert Einstein The words of the language, as they are written or spoken, do not seem to play any role in my mechanism of thought. The psychical entities which seem to serve as elements in thought are certain signs and more or less clear images which can be “voluntarily” reproduced and combined--this combinatory play seems to be the essential feature in productive thought before there is any connection with logical construction in words or other kinds of signs which are communicated to others --Albert Einstein Contents

Effectiveness of Graphic Language 1. Try to write a description of this object. 2. Test your written description by having someone attempt to make a sketch or visualize from your description. You can easily understand that … The word language is inadequate for describing the size, shape and features completely as well as concisely.

Graphic Language in Engineering Drawing “Engineering drawing” or “blueprint” uses lines to represent the features of an object. Features of an object are surface (include plane) and edge. Surface Edge

Ways to Create an Engineering Drawing A drawing can be created in 3 ways Freehand sketch Using typical drawing instruments Using a computer

Create a Drawing : Freehand sketch The lines are drawn using only pencil and erasers on a blank or grid paper. Example Pictorial sketch Orthographic sketch

Create a Drawing : Using instruments Drawing instruments are used to draw straight lines, circles, and curves concisely and accurately. Drawings are usually made to scale. Example

Create a Drawing : Using a computer Computer aided drafting (CAD) software is used. Example 2D drawing Solid modeling

Elements of a Drawing A clear and precise engineering drawing requires both graphics and word languages. Graphics language Describe a shape (mainly). Word language Describe an exact size, location and specification of the object.

Text on drawings : Example Dimensions & Notes General notes Title block

Knowledge and Skills Require Engineering Drawing Graphics language Word language Using line types Geometric construction Visualization Projection method Dimensions & Notes Visualization is the ability to mentally picture things that do not exists. Contents

Drawing Standard Drawing sheet Scale Lettering Line types Contents

Definition and Necessity Drawing 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.

Standard Code Country Code Full name ANSI American National Standard Institute USA JIS Japanese Industrial Standard Japan BS British Standard UK AS Australian Standard Australia Deutsches Institut für Normung DIN Germany ISO International Standards Organization

Drawing Standard Drawing Sheet Contents

Drawing Sheet : Standard size Trimmed paper of a size A0 ~ A4. 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 A0 (Dimensions in millimeters)

Drawing Sheet : Orientation & Margin 1. Type X (A0~A4) c Sheet size c (min) d (min) A4 10 25 A3 10 25 A2 10 25 A1 20 25 A0 20 25 d c Border lines Drawing space c Title block 2. Type Y (A4 only) d Drawing space Title block

Drawing Standard Drawing Scale Contents

Drawing Scales : Definition Length, size Scale is a ratio between the linear dimension of a drawn representation of an object and the actual object. : 1 2 Drawing Actual

Drawing Scales : Designation Designation of a scale consists of the word “SCALE” followed by the indication of its ratio, as follows SCALE 1:1 for full size SCALE X:1 (X > 1) for an enlargement scales SCALE 1:X (X > 1) for a reduction scales Drawing scale is commonly found in a title block.

Drawing Scales : Notes Dimension numbers shown in the drawing represent the “true size” of an object and they are independent of the drawing scale used.

Drawing Scales : Standard scale Standard reducing scales are 1:2, 1:5, 1:10, 1:20, 1:50, 1:100 Standard enlarging scales are 2:1, 5:1, 10:1, 20:1, 50:1, 100:1

Drawing Standard Lettering Contents

Recommendation Text’s style on the drawing Examples must have the following 2 properties Examples GOOD Not uniform in style. Legibility - Shape Space between letters Space between words Not uniform in height. Not uniformly vertical. Uniformity Not uniform in thickness of stroke. - Size (or text height) - line thickness Inappropriate space between letters

Style (this course) Gothic vertical style. Begin the sentence, phrase or word with a capital letter. Text height 2~3 mm. Space between lines of text is about of text height. Height of the lower-case letter is about 2/3 of that of a capital letter.

Basic Strokes Straight Slanted Horizontal Curved Examples “I” letter “A” letter “B” letter 4 5 1 1 1 2 6 3 3 2

Suggested Strokes Sequence Upper-case Letters & Numerals Straight line letters Curved line letters & Numerals

Lower-case Letters

Stroke Sequence : Upper-case I L T F E H Skip section

Stroke Sequence : Upper-case V X W Skip section

Stroke Sequence : Upper-case M K Z Y A 4 Skip section

Stroke Sequence : Upper-case G Skip section

Stroke Sequence : Upper-case D U P B R J Skip section

Stroke Sequence : Upper-case 1 2 5 7 Skip section

Stroke Sequence : Upper-case 3 6 8 9 Skip section

Stroke Sequence : Lower-case i Skip section

Stroke Sequence : Lower-case v w x k z Skip section

Stroke Sequence : Lower-case j y f t r Skip section

Stroke Sequence : Lower-case b d p q e Skip section

Stroke Sequence : Lower-case g n m h u s Skip section

DRAWING D R A W I N G Word Composition Space between the letters depends on the adjacent contour of the letters. DRAWING Non-uniform spacing D R A W I N G Uniform spacing Word having non-uniform spacing is more readable.

DRAWING Word Composition Contour Contour can be denoted as “straight”, “slant” and “curve”. Adjacent contour can be 1. straight-straight : II, IN, IM, IP etc. 2. straight-curve (or curve-straight) : IO, QR etc. 3. straight-slant (or slant-straight) : IV, IW etc. 4. curve-curve : OO, OG etc. 5. slant-curve (or curve-slant) : VO, WG, VC etc. 6. slant-slant : VW, VX etc. Spacing

Sentence Composition ALL O DIMENSIONS O ARE O IN MILLIMETERS O UNLESS Leave the space between words equal to the space requires for writing a letter “O”. Example ALL O DIMENSIONS O ARE O IN MILLIMETERS O UNLESS OTHERWISE O SPECIFIED.

Drawing Standard Line Types Contents

Name according to application Basic Line Types & Name according to application Thickness 1. Dimension line 2. Extension line 3. Leader line Thick Thin Visible line Style Continuous Hidden line Dash Chain Center line 1. Visible line represent features that can be seen in the current view. 2. Dimension line Extension line Leader line indicate the sizes and location of features. 3. Hidden line represent features that can not be seen in the current view. 4. Center line represents symmetry, path of motion, centers of circles, axis of axisymmetrical parts

Example Contents