Introduction to Engineering Design Comprehensive Study Guide

Table of ContentsTable of Contents 2

Unit 1: Design Process 3

Brainstorming Solutions 3

Design Process 4

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Unit 1: Design Process

Brainstorming Solutions

Brainstorming: A group technique for solving problems, generating ideas, stimulating creative thinking, etc.

o Involves collecting ideas without regard to feasibility Rules for brainstorming

o No criticism allowedo Work for quantityo Welcome piling-ono Allow free-for allo Individual descriptions for each?

People must experience “brain-drain” before the innovative, creative ideas can surface. The more ideas, the more likely quality ideas for surface

Piling-on: When a member’s idea produces a similar idea or an enhanced idea. Types of free-form brainstorming

o Post-it noteso Free writingo “Blurting out”

Forced association: Ideas created by mentally forcing the association of two seemingly unrelated items

o Ex. Wine press + coin stamp = Moveable type press SCAMMPERR technique- start with a current solution that somehow addresses the problem you

are investigating, then try to generate new and different approacheso Substitute somethingo Combine it with something else o Adapt something to ito Magnify or add to ito Modify ito Put it to some other useo Eliminate somethingo Rearrange ito Reverse it

Mind mapping Brainstorming documentation

o Have a note takero Take photographso Compile ideas after the session

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What to do if you get stuck brainstormingo Combine promising partial solutions o Try a different brainstorming techniqueo Try both individual and group researcho Do some more research

Design Process

Design: A generic term that refers to anything that was made by a conscious human effort. Also a process that is used to systematically solve problems

Design Process: A systematic problem-solving strategy, with criteria and constraints, used to develop many possible solutions to solve or satisfy human needs or wants and to narrow down the possible solutions to one final solutions

12-Step design processo Define the problemo Brainstormo Research and generate ideaso Identify criteria and specific constraintso Explore possibilitieso Select an approacho Develop a design proposalo Make a model or prototypeo Test and evaluate the design using specificationso Refine the designo Create or make solutiono Communicate processes and results

IED design process

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Define the problemo Identify a problemo Validate the problem

Who says it is a problem? Needs and wants Prior solutions

o Justify the problem Is the problem worth solving?

o Create design requirements (criteria and constraints)o Project proposal

Generate conceptso Brainstorm possible solutionso Researcho Apply STEM principleso Select an approach (decision matrix)o Assess technology needso Design proposal

Develop a solutiono Consider design validity

Function, aesthetics, ergonomics, safety, cost, environment, durability, ease of maintenance, etc.

o Create detailed design solutionso Technical drawings

Construct and test a prototypeo Plan prototype testing- performance, usability, durabilityo Analyze test data

Evaluate the solutiono Reflect on design and recommend improvementso Optimize/redesign the solution

Revise design documentso Project recommendations

Present the solutiono Document the project- project portfolioo Communicate the project- formal presentation

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Introduction to Research

Research: The systematic study of materials and sources in order to establish facts and reach new conclusion

Primary researcho Original researcho Generates current informationo Includes observation, experiments, surveys, and interviewso Analyzes, synthesizes, and evaluates all information and data

Advantages of primary researcho Directly applicable to the needo Can result in extremely detailed, accurate, and relevant information or datao Can result in new information that cannot be found in secondary sourceso Expert knowledge

Disadvantages of primary researcho Time consumingo Requires extensive planningo Can be expensiveo May depend on the participation of unreliable sources for results

Secondary researcho Look to see what has been written/done before on a topico Published works: Books, journals, magazines, newspaperso Unpublished works: Business reports, operating manuals, web pageso Most common research

Advantages of secondary researcho Less time and little to no costo Helps focus or expand your scopeo Sense of credibility and authority in that it shows others the researcher has done their

homework Disadvantages of secondary research

o May have to go through a lot of informationo Unauthoritative or unreliable sources

Research librarieso Support researcheso Extensive collections of book and journals, theses, dissertations, and other unpublished

works Ways to tell the quality of a source

o Authority: Creator’s qualificationso Reliability: Can you trust it to have accurate information?o Bias: How creator’s interests influence the informationo Currency: How current the information is, and how important that is to the topic

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Unit 2: Technical Sketching

Isometric and Oblique Pictorials

Pictorial drawingo 2D illustration of a 3D objecto Shows three faces of an object in one viewo Three types: Isometric, oblique, perspective

Oblique pictorialso Starts with a straight-on view of one of the object’s faces (often the front face)o Angled, parallel lines drawn to represent the objects deptho Common oblique angles: 30°, 45°, 60°

Cavalier oblique: Represents the object with full depth. Tends to create the illusion that it is deeper than it actually is.

Cabinet oblique: Represents the object with half depth, but provides a more realistic, less distorted view

General oblique: represents an object’s true width and height, but the depth can be any size and drawn at any angle

Isometric pictorialo Three adjacent faces on a cube will share a single pointo Edges converge at one point will appear as 120° angles or 30° from the horizon lineo 3 edges represent height, width, and deptho Two different view orientations

Top, front, right side (used in IED) Top, left side, front

How to select the front viewo Most natural position or useo Shows best shape and characteristic contourso Longest dimensions o Fewest hidden lineso Most stable and natural positions

Good sketching requires a sense of proportion, and the ability to estimate size, distance, angles, and other spatial relationships

Sketching an Isometric Circle

1. Use points and construction lines to box the location of the circular face

2. Connect points with diagonal construction lines

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3. Place marks at the midpoints of the diagonal lines, and 2/3 the distance from the box center to each outside corner

4. Draw four individual construction line arc segments tangent to the marks that were created5. Draw an object line over the construction line ellipse6. Repeat for the other end of the cylinder7. Use construction lines to connect the two ellipses 8. Tonal shading

Multi-view Sketching

Multi-view drawingo Shows two or more 2D views of a 3D objecto Provides the shape description of an objecto When combined with dimensions, serves as the main form of communication between

designers and manufacturers Orthographic projection

o Technique used to create multi-view drawingso Any projection of the features of an object onto an imaginary plane of projection

Projection of the features of the object made by lines of sight that are perpendicular to the plane of the feature

Projection plane (also plane of projection or picture plane): An imaginary surface between the viewer and the object. The surface onto which a 2D view of a 3D object is projected and created.

Projection line: An imaginary line that is used to locate or project the corners, edges, and features of a 3D object onto an imaginary 2D surface

Number of orthographic projectionso One view

Uniform thickness or shape Two views would be identical All dimensions properly and easily shown on one view

o Two views Symmetrical part A third view would be identical to one other Second view is necessary for depth

Perspective Sketching

Perspective drawingso Offer the most realistic 3D view of all the pictorial methods, because they portray

objects in a manner that is most similar to how the human eye perceives the world One-point perspective

o Relatively simple to make, but somewhat awkward appearanceo Horizontal line represents the horizon

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o One vanishing point is identified on the horizon lineo Lines draw from distinctive points on the object to the vanishing point

Two-point perspective: Most common perspective drawing Three-point perspective: Gives worm’s eye or bird’s eye view of an object

Line Conventions

Construction line: Very lightly drawn lines to guide drawing other lines and shapes Object line: Thick and dark- defines the object Hidden line: Shows interior detail not visible from the

outside of the part Center line: Define the center of arcs, circles, or

symmetrical parts. Half as thick as an object line Section line: Defines where material is cut away Short-break line: Freehand drawn line. Shows where

part is broken to reveal detail behind the part or to shorten a long continuous part

Dimension line: Shows distance. Arrows drawn on ends to show where dimension line starts and ends

Extension line: Shows where a dimension starts and stops. 1/16” away from part to avoid confusion with object lines

Long break line: Shortens very long objects with uniform detail. Represented as a jagged cut or break

Leader line: Shows dimensions of arcs, circles, and detail Precedence of lines

o Object lines take precedence over hidden and center lineso Hidden lines take precedence over center lines o Cutting plane lines take precedence over all others

Unit 7: Documentation

Alternate Views

Section viewo Provides a view of an object as if it were cut by a sawo Location is indicated by a cutting plane line on another view

Cutting plane lineo Indicates location of the cut

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o Thick and broken lineo Arrows indicate direction of viewo Labeled with a letter for identification on drawing

Section lineso Hatch lines that indicate material that was “cut” at the cutting plane lineo Thin lines

Types of section viewso Full section

Cutting plane line passes fully through the part The part of the object behind the cutting plane line (away from arrows) is

removedo Half section

Used on symmetrical parts to show inside as well as outside details in one view One quarter of the part is cut away Cutting plane line goes halfway through the part

o Offset section Interior features not in line with each other can be

shown in an offset section view Cutting plane line changes direction and follows the

center of each feature Auxiliary views

o Orthographic projection of an inclined plane (angled surface) which appears foreshortened in a principle orthographic projection

o Used to show the true size and shape of an inclined plane and the features on ito Allows the viewer to look perpendicular to an angled surface to witness the true size

and shape of that surface and its features Foreshortened surfaces do not give a clear or accurate representation of the size or shape of the

surface or features and should not be dimensioned Detail views: An enlargement of a portion of another view to illustrate small features on a part

(different than a detail drawing, which is any drawing that contains all the information needed to manufacture a part)

Dimensioning Standards

ANSI: American National Standards Institute. Creates the engineering standards for North America

ISO: International Organization for Standardization. Worldwide organization that creates engineering standards with about 100 participating countries

US military organizations that develop standards- Department of Defense (DoD) and Military Standard (MIL)

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DIN: Deutsches Institut für Normung. The German Standards Institute created many standards used worldwide, including the standards for camera film.

JIS: Japanese Industrial Standard. Created after WWII for Japanese standards CEN: European Standards Organization If the dimension text will not fit between the extension lines, it may be placed outside them Dimension text is placed in the middle of the line both horizontally and vertically Two dimensioning systems

o Unidirectional: Dimensions place so they can be read from the bottom of the drawing sheet. Common in mechanical drafting

o Aligned: Dimensions placed so the horizontal dimensions can be read from the bottom of a drawing sheet and the vertical dimensions can be read from the right side. Common in architectural and structural drafting

Chain dimensioning: Dimensioning from feature to featureo Preferable method: Dimension from feature to feature except one feature, then

dimension overall length/width/height Datum dimensioning: Dimensioning from a single point of origin (datum). Reduces dimensional

deviations in manufactured parts because each size/location dimension is referenced to a single point

Coordinate method of dimensioning angles: Specify the two location distances of the angle Angular method of dimensioning angles: Specifying one location for distance and the angle Arrows can be inside or outside for small arcs. Small arcs do not need a center mark, but large

arcs do Fillet: An inside radius between two intersecting plane Round: An outside radius applied to corners Points are placed along the contour of splines and dimensioned from a datum

Documentation Working drawings are a complete set of drawings that document how an object will be

manufactured and assembled. Includes part drawings, assembly drawings, parts list, and specifications and instructions

Part drawingo Consists of dimensioned orthographic views, and if necessary, section, auxiliary, and

isometric Title block

o Person who created ito Person who checked ito Quality assuranceo Sheet #o Scale o Project name (instead of part) o Drawing number or specific part name

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o Zoningo Person who approves it for manufactureo How many times drawing has been revisedo Size of sheeto General notes and information

Assembly drawingso Show how parts of a multi-component design fit togethero Generally depict at least one orthographic projectiono Full section views often show necessary internal features

Types of assembly drawingso Design assembly: Shows relationships between components. Often based on

preliminary design process sketches before the product is modeledo General assembly: Most common type of assembly drawing. Displayed as a multi-view

drawing, sometimes with a section view. Not dimensionedo Detail assembly: Combines an assembly view with several parts as dimensioned multi-

view drawings on one sheet, which reduces the number of drawing sheets needed. More appropriate for designs with small numbers of components

o Erection assembly: Similar to general assemblies, except dimensions and fabrication specifications are included. Used for cabinetry, products made from steel, fabrication, and assembly

o Subassembly: Part of an assemblyo Pictorial assembly: Usually an isometric or perspective drawing that may be rendered to

imitate photographic quality. Uses include sales promotions, customer self-assembly, and maintenance procedures

Exploded pictorial drawings commonly show how individual components fit together

Balloon: A circle with a single number connected to an assembly component with a leader lineo Balloons on a drawing are the same sizeo Grouped in an easy-to-read patterno Correspond to item numbers in parts listo No horizontal or vertical leader lines

Parts list: A table with information about each part contained in the assembly Items on a parts list

o Item number from balloonso Quantity of a particular part needed for the assemblyo Part or drawing number as reference to the detail drawingo Descriptiono Material identification of parto Information about vendors

Most commonly located above the title block

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Holes

Through/Thru: Hole cuts through entire thickness Clearance: Hole large enough to allow screw head (and driver) to pass through Blind: Hole does NOT cut through entire thickness Countersink: Conical-shaped recess around hole at surface. Often used to accept tapered screw Counterbore: Cylindrical recess around hole at surface. Often used to receive a bold head or nut Tapped: Hole has internal threads

o ISO method M12-1.5 6H THRU [M for metric][Nominal diameter in mm]-[Pitch] [Grade of tolerance- whole # 3-

9][H for no allowance, G for tight allowance] [THRU] (LH for left hand may be before thru)

o Unified National Thread method 5/16-18 UNC [Major diameter]-[Thread per inch] UN[C for coarse, F for fine]

Technical Writing

Examples of technical writing include proposals, regulations, manuals, procedures, requests, technical reports, progress reports, emails, and memos

Technical writing: A type of expository writing that is used to convey information to a particular audience for a particular technical or business purpose.

o Not used to entertain, create suspense, or invite differing interpretations Technical reports: Communicate technical information and conclusions about projects to

customers, managers, legal authority figures, and other engineers o ANSI provides technical report layout and format specifics

3 parts of a technical reporto Front mattero Text o Back matter

Front matter: Used to help potential readers find the report and certain parts of ito Front cover: Label identifies report title and subtitle, author’s name, publisher, and date

of publicationo Title page: Provides descriptive information that is used by organizations that provide

access to information resources. Duplicates information on the front covero Abstract: A short summary that provides an overview of the purpose, scope, and

findings contained in the report Purpose: identifies the issue, need, or reason for the investigation Scope: Reviews the main points, extent, and limits of the investigation Findings: Includes condensed conclusions and recommendations

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Informative abstract: Identifies the issue or need that led to the report, reviews the main points and major findings, and includes condensed conclusions and recommendations.

Descriptive abstract: Provides a description of the report’s main topic and purpose, along with an overview of its contents. It presents the broadest view and offers no major fact. Often only a few sentences long and may be located at the bottom of the title page.

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