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

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 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 Thinking sketches Informal communication Thinking sketches To help you think creatively Prescriptive sketches Document design ideas

Example in Design 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

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

Straight Lines 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 Good No! No! No! Mechanical MARK END-POINTS Sketched

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 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 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