Communication
skills
PurPose of graPhics…
As part of the design process you are required to illustrate your ideas.
This is known as a universal language, meaning that people who don't
always speak the same language as you, find it easier to understand
what you mean through pictures.
And since it is considered as a universal language there has to be
certain conventions or rules which need to be followed for all 2D and
3D drawings.
Convention Line Types
Line type
Example
Construction lines are feint lines (light
line), used to start a drawing and then
are later erased.
Construction lines;
Outlines are dark thin / thick lines
used to show the edges of the product.
They are also known as object, visible
or final lines.
Outline;
Dashed lines;
Chained lines
Function
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Dashed lines are used to show the
important details that we cannot see
(the inside or back of the drawing)
Chained Lines are known as Centre
lines. They show symmetry (the
middle of the object) on a sketch.
DIMENSIONS
Dimensioning is the convention we use to indicate measurement on our drawings. They are thin feint lines
that show us how long, high or deep a drawing is. Unless stated otherwise, dimensions are given in mm
SCALE DRAWINGS
A scale is a tool used to create a
relationship between measurements on a
drawing and measurements on the real
object. It is the size to which the sketch is
drawn. For example;
If a scale is 1:100 It means that everything
in the sketch is 100 times smaller than in
reality.
and
If the scale is 5:1 It means that everything
in the sketch is 5 times larger in reality.
Isometric drawing
There is a difference between a 3D oblique
drawing and a 3D isometric drawing
➢ 3D – Oblique: starts at a 45° angle (flat
with depth) and shows the true length
of B and C but not A and B.
➢ 3D – Isometric: starts at a 30° angle
(slanted with depth) and shows the true
length of B and C, A and B and C and D
ISOMETRIC DRAWING
This is a 3D representation or view of an
object. It must always show THREE sides of the
object at the same time and is always drawn at
a 30̊ angle.
Isometric drawings are very useful for
designers – particularly architects, industrial
and interior designers and engineers, as they
are ideal for visualising rooms, products, and
infrastructure.
First angle orthographic
projection
Orthographic Projection is a way of drawing an 3D object from different directions. Usually a front, side
and top view are drawn so that a person looking at the drawing can see all the important sides.
Orthographic drawings are useful especially when a design has been developed to a stage whereby it is
almost ready to manufacture.