Engineering Drawing - BE Mechanical Engineering - Notes - Mechanical Engineering

 Page 1


Engineering Drawing 
MECHANICAL ENGINEERING DEPARTMENT 
L.J. POLYTECHNIC 
Missamraza 
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Engineering Drawing 
MECHANICAL ENGINEERING DEPARTMENT 
L.J. POLYTECHNIC 
Missamraza 
TO DRAW PROJECTIONS OF ANY OBJECT,  
ONE MUST HAVE FOLLOWING INFORMATION 
A) OBJECT  
 { WITH IT’S DESCRIPTION, WELL DEFINED.} 
B) OBSERVER  
 { ALWAYS OBSERVING PERPENDICULAR TO RESP. REF.PLANE}. 
C) LOCATION OF OBJECT,  
 { MEANS IT’S POSITION WITH REFFERENCE TO H.P. & V.P.} 
TERMS ‘ABOVE’ & ‘BELOW’ WITH RESPECTIVE TO H.P.  
AND TERMS ‘INFRONT’ & ‘BEHIND’ WITH RESPECTIVE TO V.P  
FORM 4 QUADRANTS.  
OBJECTS CAN BE PLACED IN ANY ONE OF THESE 4 QUADRANTS. 
 
IT IS INTERESTING TO LEARN THE EFFECT ON THE POSITIONS OF VIEWS ( FV, TV )  
OF THE OBJECT WITH RESP. TO X-Y LINE, WHEN PLACED IN DIFFERENT QUADRANTS. 
ORTHOGRAPHIC PROJECTIONS 
OF POINTS, LINES, PLANES, AND SOLIDS. 
STUDY ILLUSTRATIONS GIVEN ON HEXT PAGES AND NOTE THE RESULTS.TO MAKE IT EASY  
HERE A POINT   A   IS TAKEN AS AN OBJECT. BECAUSE IT’S ALL VIEWS ARE JUST POINTS. 
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Engineering Drawing 
MECHANICAL ENGINEERING DEPARTMENT 
L.J. POLYTECHNIC 
Missamraza 
TO DRAW PROJECTIONS OF ANY OBJECT,  
ONE MUST HAVE FOLLOWING INFORMATION 
A) OBJECT  
 { WITH IT’S DESCRIPTION, WELL DEFINED.} 
B) OBSERVER  
 { ALWAYS OBSERVING PERPENDICULAR TO RESP. REF.PLANE}. 
C) LOCATION OF OBJECT,  
 { MEANS IT’S POSITION WITH REFFERENCE TO H.P. & V.P.} 
TERMS ‘ABOVE’ & ‘BELOW’ WITH RESPECTIVE TO H.P.  
AND TERMS ‘INFRONT’ & ‘BEHIND’ WITH RESPECTIVE TO V.P  
FORM 4 QUADRANTS.  
OBJECTS CAN BE PLACED IN ANY ONE OF THESE 4 QUADRANTS. 
 
IT IS INTERESTING TO LEARN THE EFFECT ON THE POSITIONS OF VIEWS ( FV, TV )  
OF THE OBJECT WITH RESP. TO X-Y LINE, WHEN PLACED IN DIFFERENT QUADRANTS. 
ORTHOGRAPHIC PROJECTIONS 
OF POINTS, LINES, PLANES, AND SOLIDS. 
STUDY ILLUSTRATIONS GIVEN ON HEXT PAGES AND NOTE THE RESULTS.TO MAKE IT EASY  
HERE A POINT   A   IS TAKEN AS AN OBJECT. BECAUSE IT’S ALL VIEWS ARE JUST POINTS. 
NOTATIONS  
 
FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING 
DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. 
IT’S FRONT VIEW        a’                              a’ b’ 
SAME SYSTEM OF NOTATIONS SHOULD BE FOLLOWED   
                                                     INCASE NUMBERS, LIKE 1, 2, 3 – ARE USED. 
OBJECT               POINT  A                    LINE  AB 
IT’S TOP VIEW             a                               a b 
IT’S SIDE VIEW            a”                             a” b” 
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Engineering Drawing 
MECHANICAL ENGINEERING DEPARTMENT 
L.J. POLYTECHNIC 
Missamraza 
TO DRAW PROJECTIONS OF ANY OBJECT,  
ONE MUST HAVE FOLLOWING INFORMATION 
A) OBJECT  
 { WITH IT’S DESCRIPTION, WELL DEFINED.} 
B) OBSERVER  
 { ALWAYS OBSERVING PERPENDICULAR TO RESP. REF.PLANE}. 
C) LOCATION OF OBJECT,  
 { MEANS IT’S POSITION WITH REFFERENCE TO H.P. & V.P.} 
TERMS ‘ABOVE’ & ‘BELOW’ WITH RESPECTIVE TO H.P.  
AND TERMS ‘INFRONT’ & ‘BEHIND’ WITH RESPECTIVE TO V.P  
FORM 4 QUADRANTS.  
OBJECTS CAN BE PLACED IN ANY ONE OF THESE 4 QUADRANTS. 
 
IT IS INTERESTING TO LEARN THE EFFECT ON THE POSITIONS OF VIEWS ( FV, TV )  
OF THE OBJECT WITH RESP. TO X-Y LINE, WHEN PLACED IN DIFFERENT QUADRANTS. 
ORTHOGRAPHIC PROJECTIONS 
OF POINTS, LINES, PLANES, AND SOLIDS. 
STUDY ILLUSTRATIONS GIVEN ON HEXT PAGES AND NOTE THE RESULTS.TO MAKE IT EASY  
HERE A POINT   A   IS TAKEN AS AN OBJECT. BECAUSE IT’S ALL VIEWS ARE JUST POINTS. 
NOTATIONS  
 
FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING 
DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. 
IT’S FRONT VIEW        a’                              a’ b’ 
SAME SYSTEM OF NOTATIONS SHOULD BE FOLLOWED   
                                                     INCASE NUMBERS, LIKE 1, 2, 3 – ARE USED. 
OBJECT               POINT  A                    LINE  AB 
IT’S TOP VIEW             a                               a b 
IT’S SIDE VIEW            a”                             a” b” 
X 
Y 
1
ST
 Quad. 
2
nd
  Quad. 
3
rd
  Quad. 
4
th
 Quad. 
X  Y 
VP 
HP 
Observer 
THIS QUADRANT PATTERN,  
IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION) 
WILL EXACTLY APPEAR AS SHOWN ON RIGHT SIDE AND HENCE, 
IT IS FURTHER USED TO UNDERSTAND ILLUSTRATION PROPERLLY. 
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Engineering Drawing 
MECHANICAL ENGINEERING DEPARTMENT 
L.J. POLYTECHNIC 
Missamraza 
TO DRAW PROJECTIONS OF ANY OBJECT,  
ONE MUST HAVE FOLLOWING INFORMATION 
A) OBJECT  
 { WITH IT’S DESCRIPTION, WELL DEFINED.} 
B) OBSERVER  
 { ALWAYS OBSERVING PERPENDICULAR TO RESP. REF.PLANE}. 
C) LOCATION OF OBJECT,  
 { MEANS IT’S POSITION WITH REFFERENCE TO H.P. & V.P.} 
TERMS ‘ABOVE’ & ‘BELOW’ WITH RESPECTIVE TO H.P.  
AND TERMS ‘INFRONT’ & ‘BEHIND’ WITH RESPECTIVE TO V.P  
FORM 4 QUADRANTS.  
OBJECTS CAN BE PLACED IN ANY ONE OF THESE 4 QUADRANTS. 
 
IT IS INTERESTING TO LEARN THE EFFECT ON THE POSITIONS OF VIEWS ( FV, TV )  
OF THE OBJECT WITH RESP. TO X-Y LINE, WHEN PLACED IN DIFFERENT QUADRANTS. 
ORTHOGRAPHIC PROJECTIONS 
OF POINTS, LINES, PLANES, AND SOLIDS. 
STUDY ILLUSTRATIONS GIVEN ON HEXT PAGES AND NOTE THE RESULTS.TO MAKE IT EASY  
HERE A POINT   A   IS TAKEN AS AN OBJECT. BECAUSE IT’S ALL VIEWS ARE JUST POINTS. 
NOTATIONS  
 
FOLLOWING NOTATIONS SHOULD BE FOLLOWED WHILE NAMEING 
DIFFERENT VIEWS IN ORTHOGRAPHIC PROJECTIONS. 
IT’S FRONT VIEW        a’                              a’ b’ 
SAME SYSTEM OF NOTATIONS SHOULD BE FOLLOWED   
                                                     INCASE NUMBERS, LIKE 1, 2, 3 – ARE USED. 
OBJECT               POINT  A                    LINE  AB 
IT’S TOP VIEW             a                               a b 
IT’S SIDE VIEW            a”                             a” b” 
X 
Y 
1
ST
 Quad. 
2
nd
  Quad. 
3
rd
  Quad. 
4
th
 Quad. 
X  Y 
VP 
HP 
Observer 
THIS QUADRANT PATTERN,  
IF OBSERVED ALONG X-Y LINE ( IN RED ARROW DIRECTION) 
WILL EXACTLY APPEAR AS SHOWN ON RIGHT SIDE AND HENCE, 
IT IS FURTHER USED TO UNDERSTAND ILLUSTRATION PROPERLLY. 
HP 
VP 
a’ 
a 
A 
POINT A IN 
1
ST
 QUADRANT 
OBSERVER 
VP 
HP 
POINT A IN 
2
ND
 QUADRANT 
OBSERVER 
a’ 
a 
A 
OBSERVER 
a 
a’ 
POINT A IN 
3
RD
  QUADRANT 
HP 
VP 
A 
OBSERVER 
a 
a’ 
POINT A IN 
4
TH
  QUADRANT 
HP 
VP 
A 
Point A is  
Placed In  
different  
quadrants 
and it’s Fv & Tv  
are brought in  
same plane for  
Observer to see  
clearly.  
Fv is visible as 
it is a view on  
VP. But as Tv is 
 is a view on Hp,  
it is rotated 
downward 90
0
,  
In clockwise  
direction.The  
In front part of 
 Hp comes below  
xy line and the  
part behind Vp  
comes above. 
 
Observe and  
note the  
process.