Basic info on Isometric and orthographic

1. Isometric and
Orthographic
Drawing
KIERAN SULLIVAN

2. Orthographic Drawing
 An orthographic drawing or orthographic projection is a
representation of a three-dimensional-object using
several two-dimensional drawings.
 You can use an orthographic drawing to better see
objects in 3D
 Think of it like a blueprint for the object you’re drawing!

3. 6 Views of Orthographic Projection
 Top View (plan)
 Bottom View
 Back View
 Front View
 Rights side View
 Left Side View
 Typically only 3 views
are used as long as
they are symmetrical.

4. Orthographic Drawing And Isometric
Drawing Differences
 Even though an orthographic drawing and an isometric drawing are
very correlated, there are a few major differences between them.
 In fact, the major difference is that an orthographic drawing is
a two-dimensional representation of an object, with all the views
represented in it.
 And an isometric drawing is a three-dimensional representation of
that same object. Now, since we’re drawing on paper we can’t quite
make it 3D, so we call it an isometric drawing.
 Isometric views are important because unlike perspective drawings
they can be used to accurately take dimensions from

5. Isometric Example
 The isometric view is on the left
and the orthographic view is the
2D planes broken down into
separate pieces, on the right and
below.
 As you can see with the image
above, there’s quite a difference
between an isometric view and an
orthographic view, but you can
create one from the other!

6. How to Draw an Isometric Drawing
 The 3 main rules to isometric drawing are
1. Horizontal edges are drawn at 30 degrees
2. Vertical edges are drawn as vertical lines
3. Parallel edges appear as parallel lines

7. Setting up a Drawing Board
 Paper should be set up parallel to your board this will make
sure your drawings are square with the paper
 Use the top edge of the board to align the paper
 Use tape to fix 4 corners of your paper this will help to stop
the paper moving when moving the sliding ruler
 All squares should rest against the sliding ruler this will make
sure all lines are at the correct angle and keep lines parallel

8. Drawing Terminology
 Drafting – a method of drawing used by technical fields to convey a design
 Annotate – to add notes or label drawings/components
 Guidelines – lightly drawn lines used for lettering
 Construction lines – temporary lines drawn lightly used for guides
 Object lines – heavier lines used to outline the object
 Hidden lines – thin dashed lines to show edges of a hidden surface
 Dimensions - Linear, radial, angular, ordinate and arc length generally the
most relevant sizes would be added to your drawing

9. Task 1
 On the left side of your paper draw a cube 120mm x
120mm
 Begin by drawing a vertical construction line followed by
2 / 30 degree construction lines
 Measure the required length
 After the required length has been marked form parallel
lines on each axis
 Use object lines to outline a cube

10. Scale
 Scale drawings are used to illustrate items that it is not useful or
convenient to draw at their actual size
 The scale of drawings is described as a ratio using the notation:
A distance at full size : The distance at the scale used that would be the same
length.
For example:
A full size drawing would be 1:1 (or
sometimes 1/1 or ‘one to one’).
A half size drawing would be 1:2.
A tenth size drawing would be 1:10.
A double size drawing would be 2:1.
In the construction industry a range of scales are
generally used depending on the nature of the
drawing. For example:
A location plan at 1:1000.
A site plan at 1:200.
A floor plan at 1:100.
A room plan at 1:50.
A component drawing at 1:5.
An assembly drawing at 1:2.

11. Task 2
 To the right hand side of your cube leave enough space and draw a cube
at a scale of 1:2 of the original
 Use construction lines to begin and adjust position to suit your space
before using object lines
 Next create a cut out on your larger cube using your own dimensions and
any design you think of the isometric principles

12. Hope this helps