<ul><li>Engineering Drawing It is the graphical representation of complete details about shape and size of an object. </li...
<ul><li>Engineering Drawing It is the graphical representation of complete details about shape and size of an object. </li...
 
<ul><li>Types of Lettering </li></ul><ul><li>Roman </li></ul><ul><ul><li>Old  </li></ul></ul><ul><ul><li>Modern  A B C D E...
<ul><li>Width : Height Ratio </li></ul><ul><li>Alphabets  5:7 </li></ul><ul><li>Numerals 4:7 </li></ul><ul><li>Height </li...
<ul><li>Spacing  (No Specific instructions) </li></ul><ul><li>Between Words   1- 1/6 of word width </li></ul><ul><li>Betwe...
 
<ul><li>Polygons </li></ul>Exterior angle  =  360/N Interior angle  =  180- exterior angle No of Sides Name Interior angle...
<ul><li>Conic Sections </li></ul>
Cone A cone is formed when a right angled triangle  with an apex angle    is rotated about  its altitude as the axis. (ap...
Circle When cutting plane is perpendicular to the axis of the cone the curve of intersection obtained is called circle Rad...
Isosceles Triangle Cutting plane passes through apex and cuts the base of the cone the curve of intersection obtained is c...
Ellipse   Cutting plane is inclined to the axis(such that    >   ) and cuts all generators
Parabola  Cutting plane is inclined to the axis(such that    =   ) and is parallel to one of the generators of the cone
<ul><li>Hyperbola  Cutting plane is inclined to the axis(such that    <   )  </li></ul>
 
<ul><li>Inscribed Figures </li></ul><ul><li>Circumscribed Figures </li></ul>
 
Designation Shape Spec Pencil Line width Point Application Border Thick Very thick line H, HB 1-1.5 Hvy rd Border of sht V...
 
 
All chain lines should start and finish with a long dash Centre line should cross one another on long dash portions of the...
Long dashes should meet or cross at intersections of angle between chain lines Arcs should meet at tangent points Dashed l...
<ul><li>Order of Priority of coinciding lines </li></ul><ul><li>Visible outlines and edges  </li></ul><ul><li>Hidden outli...
<ul><li>Rules for Dimensioning </li></ul><ul><li>Dimensions should be clear and permit only one interpretation. Numerals a...
<ul><li>As far as possible intersection of dimensions lines should be avoided. If inevitable then lines should not be brok...
Correct Incorrect Dimension values should be placed preferably near the middle or if unavoidable then above  the extended ...
Correct Incorrect Correct Incorrect Dimensions should be placed at sufficient distance from the object and also from each ...
Correct Incorrect Dimensioning to a centre line should be avoided, except when the centre line passes through the centre o...
Correct Incorrect Dimensions should be marked with reference to the visible outlines rather than from the hidden lines. Di...
Intersection of dimension and projection line should be avoided. However if unavoidable then neither line should be broken...
If the space for the arrowhead termination is sufficient, it should be shown within the limit of dimension lines. If the s...
<ul><li>Liner space may be dimensioned as shown </li></ul><ul><li>Angular spacing of holes and other features may be dimen...
Dimensioning  Circles, Radii, Chords, Arcs and Angles
Dimensioning  Squares, Hexagons, Chamfers and Countersinks
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Enggdrg 11

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Enggdrg 11

  1. 1. <ul><li>Engineering Drawing It is the graphical representation of complete details about shape and size of an object. </li></ul><ul><li>To elaborate a mechanism </li></ul><ul><li>To communicate the concept and vision of designer/engineer to technicians </li></ul><ul><li>To explain parts and subparts of a complex machine/system </li></ul><ul><li>To provide details for the manufacture of a part/component </li></ul>
  2. 2. <ul><li>Engineering Drawing It is the graphical representation of complete details about shape and size of an object. </li></ul><ul><li>To elaborate a mechanism </li></ul><ul><li>To communicate the concept and vision of designer/engineer to technicians </li></ul><ul><li>To explain parts and subparts of a complex machine/system </li></ul><ul><li>To provide details for the manufacture of a part/component </li></ul>
  3. 4. <ul><li>Types of Lettering </li></ul><ul><li>Roman </li></ul><ul><ul><li>Old </li></ul></ul><ul><ul><li>Modern A B C D E F 1 2 3 4 5 6 </li></ul></ul><ul><li>Gothic Letters same thickness A B C D E F I 2 3 4 5 </li></ul><ul><li>Stroke Style Size Case </li></ul><ul><li>Single Vertical letters Normal Upper </li></ul><ul><li>Double Inclined letters Compressed Lower </li></ul><ul><li>Extended </li></ul>Waist Line Base Line Cap Line Drop Line Fractions (guide lines) Height of fraction is (2x/3) the whole number(x) lower case p UPPER CASE
  4. 5. <ul><li>Width : Height Ratio </li></ul><ul><li>Alphabets 5:7 </li></ul><ul><li>Numerals 4:7 </li></ul><ul><li>Height </li></ul>Revision Columns Process & Dimensional notes 0.120 1/8 Dimensions (Decimal/Fraction) Revision details Sub titles Instrumental Free Hand Example Part No 0.250- 0.350 1/4- 3/8 3546598 Section & Tabulation letters 0.240 1/4 A-A Part Name 0.140 5/32 Block
  5. 6. <ul><li>Spacing (No Specific instructions) </li></ul><ul><li>Between Words 1- 1/6 of word width </li></ul><ul><li>Between Sentences Word Width </li></ul><ul><li>Between Lines <= Word Height </li></ul><ul><li>Rules for Lettering </li></ul><ul><li>Alphabets should be written in capital </li></ul><ul><li>Alphabets and numerals should not touch each other or any lines </li></ul><ul><li>Letters should appear upright with reference to bottom edge </li></ul><ul><li>Spacing between letters should be equal </li></ul><ul><li>For ease and consistency, the letters can be so formed that lines cross or meet nearly at right angles </li></ul>
  6. 8. <ul><li>Polygons </li></ul>Exterior angle = 360/N Interior angle = 180- exterior angle No of Sides Name Interior angle Exterior angle 5 Pentagon 108 72 6 Hexagon 120 60 7 Heptagon 128.58 51.42 8 Octagon 135 45 9 Nonagon 140 40 10 Decagon 144 36 11 Undecagon 147.28 32.72 12 Dodecagon 150 30
  7. 9. <ul><li>Conic Sections </li></ul>
  8. 10. Cone A cone is formed when a right angled triangle with an apex angle  is rotated about its altitude as the axis. (apex angle of cone 2  and imaginary lines joining the apex to circumference of the base circle is called generators
  9. 11. Circle When cutting plane is perpendicular to the axis of the cone the curve of intersection obtained is called circle Radius/ Diameter /Circumference Arc Chord Sector Quarter Circle Segment Normal Tangent Concentric circles Eccentric circles Touching circles
  10. 12. Isosceles Triangle Cutting plane passes through apex and cuts the base of the cone the curve of intersection obtained is called
  11. 13. Ellipse Cutting plane is inclined to the axis(such that  >  ) and cuts all generators
  12. 14. Parabola Cutting plane is inclined to the axis(such that  =  ) and is parallel to one of the generators of the cone
  13. 15. <ul><li>Hyperbola Cutting plane is inclined to the axis(such that  <  ) </li></ul>
  14. 17. <ul><li>Inscribed Figures </li></ul><ul><li>Circumscribed Figures </li></ul>
  15. 19. Designation Shape Spec Pencil Line width Point Application Border Thick Very thick line H, HB 1-1.5 Hvy rd Border of sht Visible Thick H, HB 0.75-0.96 Hvy rd Extn, edges Hidden (dotted) Medium Dash 3 mm space 1 mm H, 2H Sharp point Hidden details, edges Centre Thin sharp Chain 1long 19-38 mm short dash 3 mm space 1mm 3H SP To indicate axis/ centre Extension & Dimension Thin sharp 3 mm outside dimnsn line 10-15 from obj ln 3H, 4H 0.38-0.55 mm SP Dimensional features Section Thin sharp 3 mm apart 45 o 3H SP sectioned Cutting plane Extra Thick 1 long, 2 small and a gap H, HB 0.96-1 SP To show cutting place Short Break Thick free hand irregular H, HB 0.75-0.96 Hvy rd Short breaks Long Break Thin sharp Instrumental line 2H, 3H 0.38-0.55 Hvy rd Long spans Detto/ phantom Thin sharp 1 long 2 small and a gap 2H, 3H 0.38-0.55 SP Outline of adjacent parts Construction Very Thin Very thin line H, HB 0.1-0.2 SP Drg layout Leader Thin Thin sharp circle 10 2H 0.38-0.55 SP Prts of assy Arrow head Dark 1:3 ratio H Dark Hvy rd Limit
  16. 22. All chain lines should start and finish with a long dash Centre line should cross one another on long dash portions of the line/circles etc Centre line should extend only a short distance beyond feature unless required for dimensioning A centre line should not extend through the spaces between views A centre line should not terminate at another line
  17. 23. Long dashes should meet or cross at intersections of angle between chain lines Arcs should meet at tangent points Dashed lines should start and end with dashes in contact with the hidden or visible outlines Dashed lines should meet or cross with dashes at the intersections If a dashed line meets a curved line tangentially, it should be with solid portions of the line
  18. 24. <ul><li>Order of Priority of coinciding lines </li></ul><ul><li>Visible outlines and edges </li></ul><ul><li>Hidden outlines and edges </li></ul><ul><li>Cutting planes </li></ul><ul><li>Centre/ symmetry lines </li></ul><ul><li>Projection lines </li></ul>
  19. 25. <ul><li>Rules for Dimensioning </li></ul><ul><li>Dimensions should be clear and permit only one interpretation. Numerals and letters should be large enough to ensure easy reading </li></ul><ul><li>The decimal point should be bold and should be placed in line with the bottom line of the figure. A zero should precede the decimal point in case the dimension is less than unity </li></ul><ul><li>Functional dimensions should be shown directly on the drawing where ever possible, while non functional dimensions should be placed in a way that is most convenient for production and inspection </li></ul><ul><li>Projection lines should be drawn perpendicular to the feature being dimensioned. However they may be drawn obliquely or parallel to each other, if necessary </li></ul><ul><li>Dimensions should be placed on the view that most clearly shows the corresponding features </li></ul>
  20. 26. <ul><li>As far as possible intersection of dimensions lines should be avoided. If inevitable then lines should not be broken </li></ul><ul><li>The dimensions should be staggered when number of parallel dimensions are more </li></ul><ul><li>As far as possible, all dimensions in one particular drawing should be expressed in one unit only( recommended unit is the mm). There is no necessity to add the symbol for the unit. Otherwise a footnote should be added in a prominent place on the drawing to state that “ALL DIMENSIONS ARE IN METERS/FEET/INCHES ETC” </li></ul>
  21. 27. Correct Incorrect Dimension values should be placed preferably near the middle or if unavoidable then above the extended portion of the dimension line beyond the arrowhead but preferably on the right side Dimensions should be placed outside the views. However they may be placed inside the view only if the drawing becomes clearer Correct Incorrect
  22. 28. Correct Incorrect Correct Incorrect Dimensions should be placed at sufficient distance from the object and also from each other Dimensions indicated in one view need not be repeated in another view except for the purpose of identification and clarity
  23. 29. Correct Incorrect Dimensioning to a centre line should be avoided, except when the centre line passes through the centre of a hole or a cylindrical part An axis or a contour line should never be used as a dimension line but may be used as a projection line
  24. 30. Correct Incorrect Dimensions should be marked with reference to the visible outlines rather than from the hidden lines. Dimensions should be marked from a base line of a hole or cylindrical part or finished surfaces
  25. 31. Intersection of dimension and projection line should be avoided. However if unavoidable then neither line should be broken Overall dimensions should be placed outside the intermediate dimensions. When ever an overall dimension is shown, one of the intermediate dimension is redundant and should not be dimensioned
  26. 32. If the space for the arrowhead termination is sufficient, it should be shown within the limit of dimension lines. If the space is limited, the arrowhead termination may be shown outside the intended limits of the dimension lines that are extended for that purpose. A dimensional line should be shown unbroken whenever the feature to which it refers is shown broken
  27. 33. <ul><li>Liner space may be dimensioned as shown </li></ul><ul><li>Angular spacing of holes and other features may be dimensioned as shown </li></ul><ul><li>When a dimension line cannot be completely drawn to its normal termination point, the free end should be terminated in a double arrowhead </li></ul>
  28. 34. Dimensioning Circles, Radii, Chords, Arcs and Angles
  29. 35. Dimensioning Squares, Hexagons, Chamfers and Countersinks

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