Graphics I Sketching October 3, 2012 Prof. Paul Kurowski ES1050 – Introductory Engineering Design...

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Graphics ISketching

October 3, 2012

Prof. Paul Kurowski

ES1050 – Introductory Engineering Design and Innovation Studio

Sketching in Engineering

Objectives Demonstrate the Importance of Sketching. Introduce Sketching Techniques

Drawing simple lines and curves, using construction lines, bounding lines, etc.

The Importance of Sketching

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

First sketch of the phonograph, 1877

A sketch showing the basic circuit for energizing a discharge tube.

The Importance of SketchingNot Just for Design - Engineering Inspections

The Importance of SketchingNot Just for Design - Engineering Inspections

Sketching is used throughout the design process to communicate information

The Role of Sketching

Talking sketches Informal communication

Thinking sketchesTo help you think creatively

Prescriptive sketchesDocument design ideas

Problem Definition:

Sketch shows cross-section 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

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, well-proportioned 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

Begin using grid paper, or the clear side of graph paper.

Mark the endpoints of the line to be drawn

Lines should be straight, continuous and dark with uniform thickness

Straight Lines

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

Sketched

Good

No!

No!

No!

Straight Lines

MARK END-POINTSMARK END-POINTS

Line Types

Line Precedence

Visible lines have top priority

Hidden lines do not cross or have priority over visible lines

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

Circles and ellipses require construction lines.

Curved Lines

Circles and Ellipses

Small circles

Use center lines

Large circles

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

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