chapter 1 introduction to engineering drawing and design

Chapter 1

Introduction to Engineering Drawing and Design

History of Drafting – the Renaissance

– History has not documented the history of inventors and engineers, much less drafting, very well.

– DaVinci’s drawings, more artistic than engineering-oriented, served as schematics for one-of-a-kind machines.

• No dimensions were included• No interchangeable parts

•[Insert Figure 1.1]

History of Drafting – the 19th Century

• The development of the micrometer in the late 1800s made interchangeability of parts achievable, though difficult.– Interchangeability forced inventors, engineers,

and builders to produce accurate and dimensioned drawings.

– Most designs were accomplished by • Developing a pattern from a wood model produced

from hand sketches

History of Drafting – the early 20th Century

• Henry Ford– Famous “blackboards” were actually drafting

tables– Would sketch cars and parts in 3D

• Patternmakers would construct full-size models in wood

History of Drafting - Schools

• 1824– Philadelphia

• Founded to advance the general interests of mechanics and entrepreneurs by extending a knowledge of mechanical science.

– Abandoned due to conflicts between classical learning experts and science & practical learning academics

– Upstate New York• Rensselaer Polytechnic Institute founded

– Founded by Amos Eaton “for the purpose of instructing persons … in the application of science to the common purposes of life.”

History of Drafting - Schools

• 1862– Morrill Act

• Federal government assistance• Helped the emergence of more technical schools

Myth Debunked

• There is a common thought that “it” (the Great Pyramids, steam engine, and other mechanical marvels) all started with a drawing.– Cartoons, freehand sketches, and graphic

models did exist, however,• It is accurate to say that before most things were

built, they were tested with a 3D model.

Drafting Technology

• Theoretical and practical occupational areas, including– Architecture– Engineering– Math and Physical Sciences– Social Sciences

• Support occupational areas

Definition

• Drafter– Translate data and sketches into detailed

drawings• Used in manufacturing and construction

– Duties may include• Interpreting directions• Making sketches• Preparing scaled drawings• Specifying details

Definition

• Drafter– Translate data and sketches into detailed drawings

• Used in manufacturing and construction

– Duties may include• Interpreting directions• Making sketches• Preparing scaled drawings• Specifying details• Calculating stresses and strains• Developing cost information

– Use instruments, computers, and engineering theory and practice to generate and complete drawings.

Occupations

• Architectural Drafter– Draws architectural

and structural features

– Confirms code compliance

– Plans architectural details

[Insert Figure 1.3(a) here]

Occupations

• Landscape Drafter– Prepares detailed

drawings from sketches provided by Landscape Architect

• Site plan• Drainage plan• Lighting plan• Paving plan• Irrigation plan

– Generate models – Prepared presentation

drawings

[Insert Figure 1.4 here]

Occupations

• Electrical Drafter– Prepares electrical

equipment working drawings and wiring diagrams

• Electronics Drafter– Drafts layout and detail

drawings of racks, panels, and enclosures.

– Conducts service and interference studies

– Prepares maps and charts

Occupations

• Civil Drafter– Prepares detailed

construction drawings, topographic profiles, and related maps and specifications for

• Highway construction• River and harbor

improvements• Flood control • Drainage

[Insert Figure 1.7 here]

Occupations

• Structural Drafter– Draws plans and

details for structures

• Wood• Masonry• Reinforced steel

– Produces foundation and framing plans

[Insert Figure 1.8 here]

Professional Organization

• ADDA– American Design Drafting Association

• Founded in 1948• Non-profit• Dedicated to advancement of design and drafting• Based in Tennessee• Website

– http://www.adda.org

Computers in Drafting and Design

• CAD– Computer-aided drafting

• CADD– Computer-aided design and drafting

• Parametric modelingChange geometries by changing dimensions and

features

Computers in Drafting and Design

• VR– Virtual reality

• Demonstrates products or displays materials on the Web• Walk-through

– A camera in a program that simulates a person walking through a structure

• Fly-through– A camera in a program that simulates a helicopter flying about a

structure

• Internet– Worldwide network of computers

• Intranet– Links computers within an organization

Computers in Drafting and Design

• Rapid Prototyping (RP)– Manufacturing process– Solid, physical part is made directly from a 3D model– No special tooling– Two types

• Stereolithography• Fused deposition modeling

Computers in Drafting and Design

• Advantages of CADD– More accuracy– Greater efficiency– Allows for greater creativity and innovation– Produces accurate, legible, and uniform drawings– Enables companies to achieve more consistency in

standards

CADD Standards• NACFAM

– National Council for Advanced Manufacturing– Provides publications for beginning CADD users– Website

• http://www.nacfam.org• United States National CAD Standards

– Created by • CADD/GIS Center• AIA• CSI• SMACNA• GSA• NIBS

– Website• http://www.nationalcadstandard.org

Becoming a Drafter

• Should be– Mechanically minded and able to visualize all types of

entities– Willing to work in cross-functional teams– Detail-oriented– Committed to accurate work

• Training– Specialized

• Includes computer-aided drafting and design (CADD)

Becoming a Drafter

• Where to Train– Community and Junior Colleges– Technical Institutes– Vocational Schools

Opportunities

• Levels of drafting– Entry-level: close supervision– Intermediate-level: more complex

responsibilities and less supervision• Exercise more judgment• Perform calculations

– Supervisory-level: oversee other drafters– Designer-level: generate concepts

Opportunities

• Advancement opportunities are excellent– Based on

• Specific employer’s needs• Location supply and demand• Individual’s

– Initiative– Ability– Product knowledge– Willingness to continue education

» “Professional development”

Opportunities

• Drafting is an excellent stepping-stone to– Design– Engineering– Management

Searching for a Drafting Position

• Internet

• College or University Placement Office

• Personal network of friends, relatives, employers, and teachers

Successfully Seeking Employment

• Get your resume in order– Must be a quality and professional

representation of you

• Write an application or cover letter

• Prepare a portfolio– Tailor to needs of prospective employer

Copyrights, Patents, and Trademarks

• Copyright– Legal rights given to authors of “original works of authorship”– Exists from time the work is created in fixed form

• Patent– Grant of property right to the inventor– Invention must have useful purpose and operate– Term: 20 years from date of application

• Trademark– Word, phrase, symbol, design, or combination thereof that

distinguishes a good or service of one party from a good or service from another party

Summary

• Drafting started as sketching and evolved when interchangeable parts became the norm in manufacturing.

• Drafters are employed in many types of industries and companies and can become supervisors and designers with experience and added education.

• Computers have made drafting more accurate, more efficient, and more consistent.