ES1050 – Introductory Engineering
Design and Innovation Studio
Graphics I
Sketching
October 3, 2012
Prof. Paul Kurowski
Sketching in Engineering
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Objectives
 Demonstrate
the Importance of Sketching.
 Introduce Sketching Techniques

Drawing simple lines and curves, using construction
lines, bounding lines, etc.
The Importance of Sketching




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Sketching quickly communicates design ideas.
It’s a necessary skill for any technical person.
Often part of the creative process – Generation
of Design Concepts.
Helps to visualize 3D objects from 2D images.
Used extensively in Engineering.
Sketches from Leonardo da Vinci’s
Design Notebook
Thomas Edison's Sketches
A sketch showing the basic
circuit for energizing a
discharge tube.
First sketch of the phonograph, 1877
The Importance of Sketching
Not Just for Design - Engineering Inspections
The Importance of Sketching
Not Just for Design - Engineering Inspections
Sketching is used throughout the design
process to communicate information
The Role of Sketching

Talking sketches
 Informal

Thinking sketches
 To

communication
help you think creatively
Prescriptive sketches
 Document
design ideas
Example in Design
Problem Definition:
Sketch shows crosssection of a Hong
Kong skyscraper
tested in the wind
tunnel.
Tuned mass damper
required to prevent
excessive vibrations.
Example in Design
Preliminary Idea
Generation:
After considering other
alternatives, a
pendulum damper was
selected as the best
option.
The design progressed
with this basic shape.
Example in Design
Constraints:
After some detailed
engineering calculations,
the final requirements
were determined and
details could be worked
out with sketches.
The final unit has to meet
all of the constraints.
Example in Design
The Importance of Sketching
Plan good
for Layout
and Cost.
 But how
will it look?

The Importance of Sketching
Evaluate Options/Different Concepts
 Helps to visualize in 3-D.

The Importance of Sketching

To help
sort out
the
details.
Sketching is based on the interactive process of
seeing, imagining and representing
Interesting
optical illusion,
but not a good
engineering
sketch!
Interesting
optical illusion,
but not good
engineering
sketches!
What do you need…

Sketching tools - pencils, paper and a
big eraser – note: no ruler necessary.

patience and practice – with these you
can be good at making quick, clear, wellproportioned sketches regardless of
your experience or natural ability
Contour Sketching – a Practice
Technique
Contour Sketching
Fundamental Techniques

Straight Lines

Curved Lines

Construction Lines and Proportions

Lettering
Straight Lines

Begin using grid paper, or the clear side
of graph paper.

Mark the endpoints of the line to be
drawn
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Lines should be straight, continuous and
dark with uniform thickness
Straight Lines
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Long lines are difficult. Use grid paper as a
guide or reduce the size of the sketch.
Do not fix paper to the table, and rotate it to
find an easier angle for drawing lines.
Draw away from yourself or at a slight angle.
Relax your hand.
Straight Lines
Mechanical
MARK END-POINTS
Sketched
MARK END-POINTS
Good
No!
No!
No!
Line Types
Line Precedence
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Visible lines have top priority
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Hidden lines do not cross or have priority
over visible lines
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Centre lines do not cross or have priority
over visible or hidden lines
Construction Lines

The first step is drawing construction lines
that form the backbone the sketch.

These very light thin lines roughly layout
some of the details

Do not erase them!
Curved Lines

Curved lines are essentially
interpolations between 2 or more points.
These points are typically marked as
intersecting lines or tangents

Control the degree of curvature - not too
flat, not too curved
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Circles and ellipses require construction
lines.
Curved Lines
Circles and Ellipses
Small circles
Large circles
Use center lines
Use scrap paper with
radius marked on it as a
guide
Circles and Ellipses
Use diagonals to proportion
Locating the center of squares and rectangles
Use construction lines to draw diagonals. Diagonals can be used to
construct new rectangles
Creating a
Proportioned
Sketch
Creating a proportioned sketch
Use multiple steps to create lightly sketched rectangles and squares
then used them as guides for final sketch
Lettering
Suggested sequence of strokes
This can be a guide for hand lettering of technical drawings
Sketching in Engineering

Review
 Demonstrate
the Importance of Sketching.
 Introduce Sketching Techniques


Drawing simple lines and curves, using construction
lines, bounding lines, etc.
Next Class
 Types
of Engineering Drawings
 Projections
 Views