Chapter 1 Introduction

1. Chapter 1 Introduction

2. Engineering drawing Drawing standards Drawing sheet Scale Lettering Line types Contents

3. Contents EngineeringDrawing 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

4. 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 featurescompletely as well as concisely.

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

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

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

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

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

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

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

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

13. Drawing sheet Scale Lettering Line types Contents Drawing Standard

14. Drawing standards are set of rules that govern how technical drawings are represented. Drawing standards are used so that drawings convey the same meaningto everyone who reads them. Definition and Necessity

15. Full name Country Code มอก./TIS สำนักงานมาตรฐานผลิตภัณฑ์อุตสาหกรรม Thailand American National Standard Institute ANSI USA Japanese Industrial Standard JIS Japan British Standard BS UK Australian Standard AS Australia Deutsches Institut fürNormung DIN Germany ISO International Standards Organization Standard Code

16. Contents Code number Examples of TIS Standard มอก. 210 2520 วิธีเขียนแบบทั่วไป : ทางเครื่องกล มอก. 440 ล.1 2541การเขียนแบบก่อสร้างเล่ม 1 ทั่วไป มอก. 446 ล.4 2532 ข้อแนะนำสำหรับการเขียนแผนภาพวงจรไฟฟ้า มอก. 1473 2540การเขียนแบบเทคนิค การติดตั้ง สัญลักษณ์สำหรับระบบท่อของเหลว ระบบทำความร้อน การระบายอากาศ และระบบท่ออากาศ ที่มา : http://library.tisi.go.th/data/lib_resources/pdf/catalog-online49/tis/02_ICS.pdf

17. Contents Code number Examples of JIS Standard JIS Z 8311 Sizes and Format of Drawings JIS Z 8314 Scales JIS Z 8312 Line Conventions JIS Z 8313 Lettering JIS Z 8315 Projection methods JIS Z 8316 Presentation of Views and Sections JIS Z 8317 Dimensioning

18. Drawing standard Contents Drawing StandardDrawing Sheet

19. Drawing Sheet : Standard size 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 A0 (Dimensions in millimeters)

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

21. Drawing standard Contents Drawing StandardDrawing Scale

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

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

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

25. 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 Scales : Standard scale

26. Drawing standard Contents Drawing StandardLettering

27. Text’s style on the drawing must have the following 2 properties Recommendation 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

28. 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. Style (this course)

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

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

31. Lower-case Letters

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

33. Skip section Stroke Sequence : Upper-case V X W

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

35. Skip section Stroke Sequence : Upper-case G Q C O

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

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

38. Skip section Stroke Sequence : Upper-case 6 0 3 S 8 9

39. Skip section Stroke Sequence : Lower-case i l

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

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

42. Skip section Stroke Sequence : Lower-case o a b c d p q e

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

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

45. Contour can be denoted as “straight”, “slant” and “curve”. Word Composition DRAWING Contour 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

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

47. Contents Drawing StandardLine Types Drawing standard

48. 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

49. Contents Example