Lecture 1 Wednesday 12 April 2023 1

ENGINEERING GRAPHICS1E7

Lecture 1: Introduction

Lecturer: Dr. Bidisha Ghosh (bghosh@tcd.ie)

Course Structure

Assessment •  Examination: 65% of the overall mark

– 3 sections (A, B and C) – 2 questions per section– 3 questions to be answered, one from each

section• Dr B. Gosh : Sections A and B• Dr G. O’Donnell : Section C

• Labs 35% - assessed by coursework– 10 % AutoCAD– 10 % Pspice– 10% D.O. Tutorials Dr B. Gosh – 5 % D.O. Assignment Dr G. O’Donnell

Time Table

Lecture 1 Wednesday 12 April 2023 5

Syllabus – Hand Drawing 1

• Basic Construction

• Orthographic Projections

• Isometric Projections

• Auxiliary Views

• Perspective : One-Point

• Perspective : Two-Point

Lecture 1 Wednesday 12 April 2023 6

Aim of the Course

• Knowledge of engineering drawing instruments

• Understanding and interpretation of technical drawings

• Ability to develop projections of a 3D object

Lecture 1 Wednesday 12 April 2023 7

Evaluation

• Examination (Sections A & B)

(2/3 of the total examination marks)

• Continuous Assessment (10% of the total course marks)

– four drawing office tutorials

Lecture 1 Wednesday 12 April 2023 8

WaterfallM. C. Escher

Technical drawing is the language of engineers and designers

Lecture 1 Wednesday 12 April 2023 9

Topics of Interest

•Drawing Instruments

•Lines

•Dimensioning

Lecture 1 Wednesday 12 April 2023 10

1. Drawing Board

DRAWING INSTRUMENTS 1

Lecture 1 Wednesday 12 April 2023 11

DRAWING INSTRUMENTS 2

A Series Formats (mm)

A0 841 × 1189

A1 594 × 841

A2 420 × 594

A3 297 × 420

A4 210 × 297

A5 148 × 210

A6 105 × 148

A7 74 × 105

2. Drawing Sheets

Lecture 1 Wednesday 12 April 2023 12

DRAWING INSTRUMENTS 3

•Layout of a Drawing Sheet

Lecture 1 Wednesday 12 April 2023 13

• Tee square/ Drafting Machine

DRAWING INSTRUMENTS 4

Lecture 1 Wednesday 12 April 2023 14

• Set squares (a pair)

DRAWING INSTRUMENTS 5

Lecture 1 Wednesday 12 April 2023 15

• Irregular/ French curves

DRAWING INSTRUMENTS 6

Lecture 1 Wednesday 12 April 2023 16

• Compasses

• Divider

• Protractor

• Ruler/Scale

• Pencil, Eraser

DRAWING INSTRUMENTS 7

Lecture 1 Wednesday 12 April 2023 17

TYPES OF LINES

• 3 Main Types

DRAWING LINES 1

Lecture 1 Wednesday 12 April 2023 18

• Lines to aid understanding

DRAWING LINES 2

Lecture 1 Wednesday 12 April 2023 19

DIMENSIONING 1

Dimension Lines (DL)

Position of DL

Lecture 1 Wednesday 12 April 2023 20

DIMENSIONING 2

Alignment of DL DL of Small Features

Dimensioning Angles Dimensioning Circles

Lecture 1 Wednesday 12 April 2023 21

DIMENSIONING 3

Lecture 1 Wednesday 12 April 2023 22

DIMENSIONING 4

Correct Practice of Dimensioning

Drawing should only carry dimensions needed to manufacture

Lecture 1 Wednesday 12 April 2023 23

Reference Books• Technical DraughtsmanshipBy Eanna O’Broin

• Engineering Drawing with Worked Examples

By M.A. Parker & F. Pickup

• Technical DrawingBy F. E. Giesecke, A. Mitchell,

H. C. Spencer, I. L. Hill, J. T. Dygdon, J. E. Novak

Lecture 1 Wednesday 12 April 2023 24

Assignment for Thursday!

• Get your instruments sorted- buy them

or borrow them