PICTORAL AND WORKING DRAWINGS
ISOMETRIC DRAWING
ONE AND TWO POINT PERSPECTIVE
3RD ANGLE ORTHOGRAPHIC PROJECTION
BRITISH STANDARD CONVENTIONS
SECTIONAL AND EXPLODED DRAWINGS
3D CONTAINERS AND SURFACE DEVELOPMENTS
ISOMETRIC DRAWING
DRAWING IN 3D IS CALLED PICTORIAL DRAWING
• Isometric drawings is a
good way of presenting
a design in 3D
• Isometric means equal
measure because the
angles used are 30 to
the horizontal
• Isometric drawing is
also used to construct
round and more
complex objects.
ONE AND TWO POINT PERSPECTIVE
PERSPECTIVE DRAWING IS BASED ON THE FACT ALL LINES APPEAR TO CONVERGE AND MEET AT
A VANISHING POINT
ONE POINT PERSPECTIVE
• A form of 3D drawing created with a
single vanishing point.
• All horizontal lines converge and
meet at one common vanishing point
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•
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•
TWO POINT PERSPECTIVE
Produces more realistic views of an
object or product
There are two vanishing points sitting
on the horizon line
There are no horizontal lines
It is possible to draw shapes above,
below and on the horizon line
3RD ANGLE ORTHOGRPAHIC
PROJECTION
ORTHOGRAPHIC MEANS DRAWING AT RIGHT ANGLES AND IS A 2D METHOD OF DRAWING
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•
•
Used to show sizes and details
of a design
Requires 3 views (front, side
and plan) with dimensions in
mm
Drawings are used for
manufacturing purposes so
the drawing should have
enough detail to enable a third
party to make it
Front view – produced by looking
at the front of a product
Plan view – drawn directly above
the front view
End/side view – drawn by looking
at the end or the side of the
product
The above is a 3D
drawing and on
the right is how
the drawing has
been constructed
in 3rd angle
orthographic. The
symbol below is
used to indicate
when a drawing is
drawn in 3rd angle.
BRITISH STANDARD CONVENTIONS
BRITISH STANDARD CONVENTIONS ARE SET BY THE BRITISH STANDARDS INSITITUE (BSI)
British standard conventions are
used for working drawings and are
recognised
throughout
the
manufacturing industry
Using British Standard Conventions
• Dimensions should read from the front or from the
right
• The leader line should not touch the object
• The dimension should be in the middle of the line but
not touching
• Arrowheads should be solid and pointed
• Dimensions should be in mm
• Centre lines define the centre of a circle and are
usually presented by long dash, short dash lines
SECTIONAL AND EXPLODED DRAWINGS
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•
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SECTIONAL DRAWINGS
Show the inside of an object as if it was
cut in half
The areas where the object is cut are
shown as hatched lines
Different parts of an object are hatched
differently
EXPLODED
DRAWINGS
•
•
•
Exploded drawings
are 3D drawings
used to show how
an object has been
constructed
Sections of the
object are drawn
separately from
one another but
remain in line with
one another
Flat pack furniture
assembly
instructions used
exploded drawings
3D CONTAINERS AND SURFACE
DEVELOPMENTS
SURFACE DEVELOPMENTS ARE THE 2D OR FLAT VERSIONS OF AN ITEM THAT WILL EVENTUALLY
ASSEMBLE INTO A 3D OBJECT
SURFACE DEVELOPMENTS ARE;
• Flat shapes that are scored,
creased and sometimes glues,
before being folded into a 3D
shape
• Designed using CAD
• Printed in multiples on a sheet
of card when used for packaging
JOINING AND LOCKING CARD
•
Card can be glued or designed in a
way that it becomes self-locking
SURFACE DEVELOPMENTS MANUFACTURE
• Paper and card with straight edges are cut to shape and size on
large guillotines
• Irregular shapes such as packaging nets are made using a die
cutter
• Die cutting is inexpensive and used when a large number of things
are needed
DIE CUTTING
• Narrow blades are shaped to the outline of the surface
development and fixed to a board
• When this is pressed down onto the printed development it cuts
around the outline of the net (like a pastry cutter)
• Round edged steel strips called creasing bars are used to squash
the fibres of the card where a fold is needed
• To reduce waste the nets are usually
tessellated