ENGINEERING GRAPHICS By R Nathan Assistant Professor Department

ENGINEERING GRAPHICS By R. Nathan Assistant Professor Department of Mechanical Engineering I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 20. 09. 2012

Engineering Graphics Lecture Notes UNIT – 1 BASICS OF ENGINEERING GRAPHICS I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes PENCIL GRADES I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes Types of Lines I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes Types of Lines I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes Example for Lines I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes Pencil Holding Technique I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes ALPHABETS FOR TITLE BLOCK I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes ALPHABETS FOR TITLE BLOCK (FOR LEFT HAND USERS) I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes LIST OF DRAWING EQUIPMENTS & MATERIALS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. DRAWING BOARD MINI DRAFTER DRAWING SHEET PENCILS (HB, 2 H, 4 H, 2 B, 4 B etc…) NON DUST RUBBER SCALES (150 mm & 300 mm) INSTRUMENT BOX SET SQUARES (30°, 45°, 60° etc. . ) DRAWING BOARD CLIPS, CLAMPS, PINS, CELLO TAPE PROTECTOR or PROCIRCLE or CIRCLE MASTER PENCIL SHARPENER SMALL PAPER KNIFE or STITCHING THREAD to cut the sheet. S A HANDKERCHIEF or HAND TOWEL I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes DRAWING BOARD ERASER I - SEMESTER SCALES C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes COMPASS BOW COMPASS I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics DIVIDER Lecture Notes BOW DIVIDER SET SQUARES I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes DRAWING CLIPS, CLAMPS, PROTRACTOR I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes PAPER KNIFE or STITCHING THREAD CIRCLE MASTER or PRO-CIRCLE I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics ROLLER Lecture Notes MINI DRAFTER INSTRUMENT BOX I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes HOW TO KEEP DRAWING SHEET CLEAN 1. ALWAYS CLEAN YOUR HANDS & INSTRUMENTS BEFORE FIXING THE DRAWING SHEET 2. HANDS SHOULD BE FREQUENTLY WIPED WITH CLEAN HANDKERCHIEF 3. THE SET SQUARES MAY BE LIGHTLY MOVE WITH THE FINGER NAILS WHILE USING 4. CLEAN PENCIL SMULGE WITH A CLEAN CLOTH 5. THE RUBBER PPOWER OF PENCIL IS REMOVED AWAY FROM THE DRAWING SHEET 6. DRAWING SHEET SHOULD BE ERASED WITH A SOFT RUBBER ONLY 7. REMOVE RUBBER DUST WITH A CLEAN PIECE OF CLOTH or HANDKERCHIEF 8. DO NOT KEEP ANYTHING or ARTICLE ON THE DRAWING SHEET 9. AVOID UNNECCESARY RUBBING OF LINES 10. DO NOT TOUCH DRAWING SHEET WITH DIRECT HANDS I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes DIMENSIONING ARROWS SYMBOLS I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes TYPES OF DIMENSIONING 1. CHAIN DIMENSIONING 2. DIMENSIONING FROM A COMMON FEATURE 3. PARALLEL DIMENSIONING I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes TYPES OF DIMENSIONING 4. SUPER IMPOSED RUNNING DIMENSIONING 5. COMBINED DIMENSIONING I - SEMESTER 6. PROGRESSIVE DIMENSIONING C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes SYSTEM OF PLACING DIMENSION 1. ALIGNED SYSTEM 2. UNIDIRECTIONAL SYSTEM I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes TYPES OF DIMENSIONING IN THE HATCHING DIMENSIONING ANGLES DIMENSIONING CIRCLES I - SEMESTER DIMENSIONING ARCS C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CORRECT & INCORRECT METHODS OF DIMENSIONING CORRECT METHOD I - SEMESTER INCORRECT METHOD C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes TYPES OF TRIANGLES I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF TRIANGLES 1. Construct an equilateral triangle given the length of the side = 50 mm Solution: Method – 1 (using Compass) 1. Draw a line AB of 50 mm length 2. With centres A & B and radius equal to 50 mm draw arcs intersecting each other at C 3. Draw lines joining C with A and B. 4. Now, ABC is the required equilateral triangle I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF TRIANGLES 2. Construct an equilateral triangle given the length of the side = 50 mm Solution: Method – 2(using Set Squares) 1. Draw a line AB of 50 mm length 2. Draw a line through A, making 60° angle with AB 3. Similarly through B, draw a line making the same angle with AB 4. Intersecting point is C 5. Now, ABC is the required equilateral triangle I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF TRIANGLES 3. Construct a triangle given the altitude = 55 mm and two base angles = 40° and 65° Solution: Let ∟A and ∟B are the given base angles and CD be the altitude Steps Involved: - 1. 2. 3. 4. 5. 6. Draw a base line of any convenient length Draw a ┴ at a point D Make CD equal to the given altitude = 55 mm Through C, draw a line EF ║ to AB Make ∟ECA = 40°, ∟FCB = 65° Thus ABC is the required triangle I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF SQUARE 1. Construct a square ABCD with AB = 60 mm Solution: Steps Involved: - 1. Draw a line segment AB of 60 mm 2. At A, draw a perpendicular at B. 3. With A as centre, 60 mm as radius draw an arc and to intersect the ┴ to get the point D 4. With B as centre, 60 mm as radius draw an arc and to intersect the ┴ through B, to get the point C. 5. Now ABCD, is the perfect square I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF RECTANGLE 1. Construct a rectangle PQRS when PG = 70 mm, QR = 50 mm Solution: Steps Involved: - 1. Draw a line segment PQ of 70 mm long 2. At P and Q erect perpendiculars 3. With P as centre, 50 mm as radius draw an arc, to cut the ┴ at the point S 4. With Q as centre, 50 mm as radius draw an arc, to cut the ┴ at the point R 5. Join R with S 6. Now PQRS is the required rectangle I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF RHOMBUS 1. Construct a rhombus ABCD, having its side equal to 40 mm and base angle at B of 105° Solution: Let us use the properties of rhombus here. “All sides of a rhombus are equal” Steps Involved: 1. Draw a line segment AB of 40 mm length 2. At B, draw a line BX at an angle of 105° 3. B as centre 40 mm as radius draw an arc to cut the line BX. Intersection point is C 4. With A and C as centres, 40 mm as radius draw arcs, intersecting point is D 5. Join A with D and C with D 6. Thus ABCD is the required rhombus I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF RHOMBUS 1. Construct a rhombus PQRS with diagonals 46 mm and QS = 60 mm Solution: We know that, the diagonals of a rhombus bisect each other at right angles Steps Involved: 1. Draw a line segment QS of 60 mm length 2. Draw a bisector of QS which passes through the point O 3. With O as centre, ½ PR (23 mm) as radius draw arcs above and below to cut the ┴ bisector. Intersection points are P & R 4. Draw lines joining P with Q & S. 5. Thus PQRS is the required rhombus I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF QUADRILATERAL 1. Construct a Quadrilateral with AB = 45 mm, BC = 55 mm, CD = 40 mm, AD = 60 mm, AC = 70 mm. Solution: From our earlier classes, we learnt that, to draw a quadrilateral, minimum five dimensions are required. Let u now draw this quadrilateral. Steps Involved: 1. Draw AB of 45 mm length 2. With B as centre, 55 mm as radius draw an arc 3. With A as centre, 70 mm as radius draw an arc to cut the previous arc at the point C 4. With C as centre, 40 mm as radius draw an arc 5. With A as centre, 60 mm as radius cut the previous arc to get the intersection point D 6. Draw lines joining D with C and A 7. Thus ABCD is the required quadrilateral I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF TRAPEZIUM 1. Construct a trapezium ABCD, having its sides AD = 30 mm, DC = 25 mm, CB = 35 mm and the difference of parallel sides is 20 mm Solution: Steps Involved: 1. Draw a line segment AB of 45 mm, difference between parallel sides = 20 mm (20 + 25=45 mm) 2. With A as centre and 30 mm as radius draw an arc 3. With E as centre 35 mm as radius draw an arc to cut the previous arc (ie; ED║BC) 4. Intersecting point is D. D as centre 25 mm as radius draw an arc 5. With B as centre, 35 mm as radius cut the previous arc. Intersection point is C 6. Draw lines joining A with D, D with C and C with B 7. Thus ABCD is the required trapezium I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF POLYGONS HEPTAGON I - SEMESTER OCTAGON C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 NONAGON 18. 09. 2012

Engineering Graphics Lecture Notes CONSTRUCTION OF PENTAGON 1. Construct a regular pentagon given the lengh of its side as 40 mm Solution: 1. Draw a line segment AB of 40 mm length 2. At B, draw a perpendicular BL such that BK = AB, join A with K 3. With B as centre, AB as radius draw an arc (ie; arc AK) 4. Draw a perpendicular bisector of AB 5. Mark the point of intersection of perpendicular with line AK as 4 and arc AK as 6 6. Mark a point 5 which is the midpoint of 4 -6 obtained by bisecting it 7. With 5 as centre and 5 A as radius draw a circle 8. With B as centre and radius = AB, draw an arc to cut the circle at C 9. In a similar way, set off the measurement of side along the circle to get the points D and E 10. Draw lines joining B with C, C with D, D with E & E with A I - SEMESTER C. R. ENGINEERING COLLEGE Alagarkovil, Madurai - 625301 18. 09. 2012