Line of sight (LOS) is an imaginary line from the eye to the object. LOS for F.V. LOS for T.V. To...
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e of sight (LOS) is an imaginary line from the eye to the object. LOS for F.V. LOS for T.V. o see the true shape of a surface, S must be perpendicular to that surface.
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Transcript of Line of sight (LOS) is an imaginary line from the eye to the object. LOS for F.V. LOS for T.V. To...
Line of sight (LOS) is an imaginary line from the eye to the object.
LOS for
F.V.
LOS for
T.V.
To see the true shape of a surface,LOS must be perpendicular to that surface.
Take an object as follows :
LOS (L.S.V.)
LOS (F.V.)
LOS (T.V.)
4
35
6
A
8
1
2
7
The Front, Top and Side Views are called the Principal Views. (Orthographic Projection)
Auxiliary View (or Extra View) is any view which is not one of the principal views.
Auxiliary view can be drawn from other views.
If you want to draw the true shape of surface A ( an auxiliary view of surface A) . need to choose LOS that is perpendicular to surface A.
1,8 2,7
4,5 3,6
A
T.V.1
2
A
4 3
5,8 6,7 6,5F.V.
4,3
7,8
L.S.V.
A
2,1
LOSfor Aux. V.
of surface A
Procedure to draw auxiliary view from 2 given views:
1- Label all corners for the two given views.
2- Draw projection lines between the two given views.
3- Choose LOS for the Auxiliary view (from view 1)
12
A
4 3
5,8 6,7 6,5F.V.
4,3
7,8
L.S.V.
A
2,1
(View 2)
(View 1)
4
35
6
A
8
1
2
7
LOSfor Aux. V.
of surface A
LOS
4
35
6
A
8
1
2
7
LOSfor Aux. V.
of surface A
LOS
4
35
6
A
8
1
2
7
x
x
4 - Draw a reference line RL1 perpendicular to LOS (OFFSET and Extend))
5 - Draw a second reference line RL2 perpendicular to the projection lines between the two views (choose it close to view) (OFFSET and Extend)
6,5
43
7,8
2,1
L.S.V.
12
A
4 3
5,8 6,7
F.V.
(View 2) (View 1)
LOS
RL1
RL2
6 - Draw projection lines // LOS from Each Corner to the reference line RL1 using SNAP TO perpendicular
6,5
43
7,8
2,1
L.S.V.
12
A
4 3
5,8 6,7F.V.
(View 2) (View 1)
LOS
RL1
RL2
7 - From Toolbars add Inquiry then use DISTANCE to measure from view 2 (example d1, d2 )
8 - Transfer these distance using OFFSET // RL1 for each corner9- Extend the projection lines to the offset lines
6,5
4,3
7,8
2,1
L.S.V.5,8 6,7
F.V.
(View 2) (View 1)
LOS
RL1
RL2
12
A
4 3
d1
d2
1
24
3
d1
d28
7
6
5
9 - Label corners on transfer points.
6,5
4,3
7,8
2,1
L.S.V.5,8 6,7
F.V.
(View 2) (View 1)
LOS
RL1
RL2
12
A
4 3
d1
d2
1
24
3
d1
d28
7
6
5
LOSfor Aux. V.
of surface A
LOS
4
35
6
A
8
1
2
7
x
x
10- Join all points to auxiliary view. To ensure that no edges have been missed, count the number of surfaces; loop each surface in turn, checking that all points are connected. Use solid lines to showing lines and dashed lines for hidden lines.
6,5
4,3
7,8
2,1
L.S.V.5,8 6,7
F.V.
(View 2) (View 1)
LOS
RL1
RL2
12
A
4 3
d1
d2
1
24
3
d1
d28
7
6
5
4
35
6
A
8
1
2
7
To draw the True shape of surface A, choose LOS which is perpendicular A. and repeat steps 1-10. (you will get an auxiliary view of the true shape of surface A).
6,5
4,3
7,8
2,1
L.S.V.5,8 6,7
F.V.
(View 2) (View 1)
LOSto A
RL1
RL2
12
A
4 3
1
24
3
8
7
6
5Complete Auxiliary View
showing the true shape
of Surface AA
4
35
6
A
8
1
2
7
Partial Auxiliary Views
In the previous examples, we have drawn complete auxiliaryviews of the object.
• Some times it is not necessary to draw complete auxiliary view, but only an auxiliary view of only one surface in order to find its true shape. This auxiliary view which shows only part of the object and not the whole object is called “Partial Auxiliary View”.
Example : draw the true shape of surface A as partial auxiliary view: repeat steps 1-10 but only for the corners of surface A (corners 1,2,3 and 4).
6,5
4,3
7,8
2,1
L.S.V.5,8 6,7
F.V.
(View 2) (View 1)
RL1
RL2
12
A
3 4
1
23
4LOS
to SurfaceA
Partial Auxiliary View
showing the true shape
of Surface A A
Auxiliary Views (Curved Edges)
The same procedure (steps1-10) discussed before applies for curved edges.However, curved edges have no corners, so we take points on the curved edges and treat them like corners. The more points we take, the better the drawing of the Curved edges.
Take the following examples.
Draw a true shape of surface A ( i .e we need an auxiliary view where LOS is Perpendicular to surface A.
Surface A
E
LOS
Surface A
- choose points on curved edges
-connect projection lines between views
-Choose LOS ( in this case LOS is perpendicular to surface A to get true shape)
1
11
+ 1
9'
8
7'
6 5
4'
2'3'10'
9
8'
7
6' 5'
4
2310
1
9
6
43
8
2
5
7
1110
3
- Draw RL1 perpendicular to projection lines // LOS
- Draw RL2 perpendicular to projection lines between the two views.
11
+ 1
9'
8
7'
6 5
4'
2'3'10'
9
8'
7
6' 5'
4
2310
1
9
6
43
8
2
5
7
11
10
RL2
RL1
2
-
- Draw projection lines from chosen points on curved edges parallel to LOS.
11
+ 1
9'
8
7'
6 5
4'
2'3'10'
9
8'
7
6' 5'
4
2310
1
9
6
43
8
2
5
7
1110
4
- Measure distance from RL2
- Transfer distance to RL111
+ 1
1
9
6
43
8
2
5
7
1110
RL2
RL1
1
2
3
4
56
78
910
11
2’3’4’
5’6’
7’
8’
9’
10’
9'7'
4'
2'3'10'
8' 6' 5'
8 6 59
74
2310
5
- Connect points
11
+ 1
RL2
RL1
1
9
6
43
8
2
5
7
1110
9'7'
4'
2'3'10'
8' 6' 5'
8 6 59
74
2310
78
910
11
2’3’
4’5’
6’
7’
8’
9’
10’
1
3
4
56
2
OR
- Draw RL1
- Draw RL1
3' 11
+1
9'
8
7'
6 5
4'
2'3'10'
9
8'
7
6' 5'
4
2310
1
9
6
43
8
2
5
7
1110
RL2
RL1
OR
- Measure distance from RL2
- Transfer distance to RL1
4' 11
+1
9'
8
7'
6 5
4'
2'3'10'
9
8'
7
6' 5'
4
2310
RL2
RL1
1
3
4
5
67
89
10
11
2’3’
4’5’
6’
7’
8’
9’
10’
2
1
9
6
43
8
2
5
7
1110
OR
5'• Connect Point
11
+1
RL2
RL1
1
9
6
43
8
2
5
7
1110
9'7' 4'
2'3'10'
8' 6' 5'
78
910
11
2’3’
4’5’
6’
7’
8’
9’
10’
1
3
4
5
2
6
8 6 574
23
910
OR
5'• Connect Point
11
+1
RL2
RL1
1
9
6
43
8
2
5
7
1110
9'7' 4'
2'3'10'
8' 6' 5'
78
910
11
2’3’
4’5’
6’
7’
8’
9’
10’
1
3
4
5
2
6
8 6 574
23
910
Summary of Auxiliary View• http://faculty.kfupm.edu.sa/CE/ahmadi/• Run //CE-WSINST• Identify line of sight• Create layers (1) Choose color for projection.• Create layers (2) Choose another color for point numbers.•- Draw offset Through (any distance) and
choose point for RL 2 & RL 1 • Project lines from each view
- Choose layer for text Give the Same Number on all layer
- Go to Tool pull down drafting setting object snap perpendicular
- OR ONSAP setting perpendicular (SELECT)
- Go to Construction layer (1)
- Type DI (distance) or from the Tool bar add Inquiry bar & choose DI
- Go perpendicular Go offset same dist. up and draw
- Extent line to new point Give a point number as text.
- For curved line choose PL commands to draw lines- Type PEDIT Choose line (to show it smooth
curve) F- To change some lines to hidden .
Modify properties Line type hidden- Mirror
Choose line shift choose ….. specify 1st point
2nd point around the x-x line Enter
THE END
