SECTIONAL VIEWS

1
SECTIONAL VIEWS
In the Graphic Communication exam you may well
need to draw a Sectional View. A Sectional View
shows what is going on inside an object. The
object is sliced along an imaginary line and part
of it is removed revealing the inside of the
object. Hatching lines (not shown here) are drawn
at 450 to show exactly where the cutting plane
came into contact with the solid parts of the
object.
2
1
ENGINEERING
Q1
SUPPORT BLOCK
Drawing a SECTIONAL View to show information more
clearly can be very helpful. Sometimes the
ELEVATION, END ELEVATION and PLAN combined still
do not tell the whole story of what is going on
with an object. Perhaps the most interesting
detail is happening inside the object.
In this situation, a SECTIONAL drawing is used.
In a SECTION, we imagine what would happen if we
sliced the object along an imaginary line and
removed part of the object. When we draw what is
left, the finished drawing often gives a much
clearer picture of what is going on. There are
lots of rules to remember when SECTIONING and we
will learn them gradually.
X
Here are a couple of PICTORIAL views of a simple
engineering block. The cutting plane is clearly
marked X-X.
X
X
PICTORIAL VIEWS
X
CUTTING PLANE
Look at the two ORTHOGRAPHIC views of the block.
You are asked to complete the SECTIONAL view X-X.
HERE ARE SOME IMPORTANT RULES . . .

• the cutting plane X-X defines where the object
  is to be split
• surfaces touched by the cutting plane should
  be hatched with 450 lines
• certain types of items are NEVER hatched. (you
  will find out which)
• the arrows point at the bit that is left
• DO NOT include hidden detail in a sectional
  drawing

PLAN
X
HATCHING LINES
PLAN
CUTTING PLANE LINE
X
X
ELEVATION
SECTION X-X
X
ELEVATION
SECTION X-X
3
2
Q2B
SUPPORT BLOCK
Q2A
SUPPORT BLOCK
Here are a couple of PICTORIAL views of a simple
engineering block. In the first view the block
has been halved and in the second view the block
is complete. The cutting plane is clearly marked
X-X.
Here are a couple of PICTORIAL views of a simple
engineering block. In the first view the block
has been halved and in the second view the block
is complete. The cutting plane is clearly marked
X-X.
X
X
This block would be used to support the weight of
a square bar. The largest flat square face would
be secured to a surface and the square bar would
fit in the square hole, thus giving it support.
Here are two PICTORIAL views of a simple block
which would be used to support the weight of a
round bar. The flat square face would be secured
to a surface and the round bar would fit in the
round hole, thus giving it support.
Take a look at the two ORTHOGRAPHIC views of the
block. You are asked to complete the SECTIONAL
view X-X.
Take a look at the two ORTHOGRAPHIC views of the
block. You are asked to complete the SECTIONAL
view X-X.
PLAN
X
PLAN
X
X
X
ELEVATION
SECTION X-X
ELEVATION
SECTION X-X
4
3
Q3A
Q3B
SUPPORT BLOCK
METAL TUBING
Metal tubing is used for all sorts of purposes in
engineering. Most commonly it is used as pipework
to carry a wide range of liquids and gases. It
can also be used to construct frameworks to
support all kinds of furniture etc. and in the
making of bicycles.
This small block has been manufactured to
strengthen a larger framework. It was found that
the large framework was much too flimsy and
required to be made more rigid. Small support
pieces like the one shown here were fitted to all
of the joints to add rigidity. One of the
blocks is shown here sectioned.
Take a look at the two ORTHOGRAPHIC views of the
tube shown below. You are asked to complete the
SECTIONAL view Z-Z.
Take a look at the two ORTHOGRAPHIC views of the
block shown below. You are asked to complete the
SECTIONAL view A-A.
PLAN
PLAN
Z
A
A
Z
ELEVATION
SECTION A-A
ELEVATION
SECTION Z-Z
5
4
Q4B
PULLEY WHEEL
Q4A
ROLLER
This plastic roller is used to allow heavy
objects to be moved around. Four of these rollers
placed at the corner of a flat board making an
ideal transportation device for bulky items. The
rollers become wheels when a rod is placed
through a hole in the centre allowing the roller
to spin around it.
This pulley wheel is used as part of a lifting
device to handle heavy objects. The lifting rope
runs in the groove in the middle of the wheel and
the wheel spins around a rod which runs through
the hole in the centre.
Take a look at the two ORTHOGRAPHIC views of the
pulley wheel shown below. You are asked to
complete the SECTIONAL view D-D.
Take a look at the two ORTHOGRAPHIC views of the
roller shown below. You are asked to complete the
SECTIONAL view P-P.
PLAN
PLAN
P
D
D
P
ELEVATION
SECTION D-D
ELEVATION
SECTION P-P
6
5
Here are a couple of PICTORIAL views of the wall
bracket. The first view shows the complete
bracket and the second shows the sectioned
bracket.
Q5
WALL BRACKET
The general name for a device which is used to
hang things on a wall is a BRACKET. Brackets come
in all shapes and sizes. The one shown here is
fixed to the wall by a screw which runs through
the hole in the back of the bracket. Two prongs
then stick out from the wall to support whatever
is required.
Take a look at the two ORTHOGRAPHIC views of the
bracket shown below. You are asked to complete
the SECTIONAL view X-X and then Y-Y.
SECTION Y-Y
X
Y
Y
ELEVATION
END ELEVATION
SECTION X-X
X
7
6
Here are a couple of PICTORIAL views of the wall
bracket. The first view shows the complete
bracket and the second shows the sectioned
bracket.
Q6
WOODEN TOY
The general name for a device which is used to
hang things on a wall is a BRACKET. Brackets come
in all shapes and sizes. The one shown here is
fixed to the wall by a screw which runs through
the hole in the back of the bracket. Two prongs
then stick out from the wall to support whatever
is required.
Take a look at the two ORTHOGRAPHIC views of the
bracket shown below. You are asked to complete
the SECTIONAL view X-X and then Y-Y.
SECTION X-X
8
7
EXPLODED ASSEMBLED VIEWS
An exploded view of a salt dish is shown. You are
also shown an ELEVATION and a PLAN of the salt
dish with the lid in place.
Q7
The weather vane shown here is an assembly of
three parts the pointer, the swivel housing and
the pivot pin. The PICTORIAL view shows how they
all fit together.
Take a look at how the weather vane fits
together. Below is an exploded view of the swivel
housing and the pivot pin. Use all of this
information to complete the ASSEMBLED SECTION Y-Y.
PLAN
X
X
ASSEMBLED SECTION Y-Y
ELEVATION
SECTION X-X
9
8
A car heater control switch is shown here in
various ways Photograph, PICTORIAL views and
SECTIONS. The switch is an assembly of two parts.
Exactly how they fit together is detailed in the
SECTIONS.
Q8
DASHBOARD HEATER CONTROL
You are asked to complete the ELEVATION and then
SECTION B-B.
SECTION B-B
Audi TT Dashboard
A
B
A
18
B
B
B
A
SECTION A-A
ELEVATION
A
10
9
Q9
SPARKPLUG
CONNECTOR
Most garden lawn mowers are powered by
electricity. Larger machines, designed for use in
larger areas such as sports fields, parks etc.
are more often powered by petrol engines. A
petrol engine works by creating a series of small
explosions, ignited by a device called a
sparkplug. Here is how a sparkplug is put
together . . .
You are asked to complete the ASSEMBLED VIEW of
the sparkplug.
ELECTRODE
CERAMIC INSULATOR
SCREW ADAPTOR