Inclined and oblique surfaces do not show true size in the standard views'

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Auxiliary Views

• Inclined and oblique surfaces do not show true
  size in the standard views.
• Auxiliary views are often used to show inclined
  and oblique surfaces true size.
• Auxiliary views are orthographic views taken from
  a direction of sight other than top, front, right
  side, left side, bottom, or rear.

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Auxiliary views
(Straight Edges)

• Line of sight (LOS) is an imaginary line from
  the eye to the object.

• To see the true shape of a surface,
• LOS must be perpendicular to that surface.

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• Take an object as follows

LOS (L.S.V.)
LOS (F.V.)
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• 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.

LOS for Aux. V. of surface A
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• 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)
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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)
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RL1
RL2
6 - Draw projection lines // LOS from Each Corner
to the reference line RL1 using SNAP TO
perpendicular
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1
d1
d2
8
2
4
RL1
5
7
4
2,1
LOS
6
4,3
7,8
5,8
6,7
6,5
L.S.V.
F.V.
RL2
(View 2)
(View 1)
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 corner 9- Extend the projection lines
to the offset lines
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1
d1
d2
8
2
4
RL1
d1
5
d2
7
4
2,1
1
2
LOS
6
A
4,3
3
4
7,8
5,8
6,7
6,5
L.S.V.
F.V.
RL2
(View 2)
(View 1)
9 - Label corners on transfer points.
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1
d1
d2
8
2
4
RL1
5
7
3
2,1
LOS
6
4,3
7,8
5,8
6,7
6,5
L.S.V.
F.V.
RL2
(View 2)
(View 1)
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.
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1
8
2
4
RL1
5
7
Complete Auxiliary View showing the true shape of
Surface A
3
2,1
1
LOS to A
2
6
A
A
4,3
3
4
7,8
5,8
6,7
6,5
L.S.V.
F.V.
RL2
(View 2)
(View 1)

• 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).

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• Partial Auxiliary Views

In the previous examples, we have drawn complete
auxiliary views 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.

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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.
Surface A
Draw a true shape of surface A ( i .e we need an
auxiliary view where LOS is Perpendicular to
surface A.
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1
- 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)

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7'
6'
8'
5'
4'
3
9'
3'
10'
2'
- Draw RL1 perpendicular to projection lines //
LOS
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1

• Draw RL2 perpendicular to projection lines
• between the two views.

2
10
3
9
4
8
5
6
7
RL2
1
2
3
4
5
6
7
8
RL1
9
10
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2

• Draw projection lines from chosen points
• on curved edges parallel to LOS.

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4
- Measure distance from RL2
- Transfer distance to RL1
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5
- Connect points using PLOly LINE
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OR
3'
- Draw RL1

• Draw RL1

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OR
4'
- Measure distance from RL2

• Transfer distance to RL1

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OR
5'
Connect Point For curved line choose PL commands
to draw lines
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OR
5'
Connect Point For curved line choose PL commands
to draw lines
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• 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

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• - 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

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• - 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

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THE END