2012 test midterm notes

7/23/2019 2012 Test Midterm Notes

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TD1-DDP Mr. Fung [MIDTERM NOTES]

Website: http://ddp2012.awardspace.us/home.shtml 1

[001] Technology and Science

Portfolio A set of creative work intended to demonstrate a persons ability

Technology Technology deals with human-made world and development of our surroundings Engineer A person who is trained in and uses technological and scientific knowledge to solve

practical problems Innovation An improvement of an existing technological product, system, or method

Product A tangible artifact produced by means of either human or mechanical work, or by

biological or chemical process. Solution A method or process for solving a problem

Technology can have negative impacts, such as pollution, medical problems, usage of resources

and unemployment Trade-off An exchange of one thing in return for another: especially the relinquishment of one

benefit or advantage for another regarded as more desirable Evolution A gradual development; in engineering, technology evolves to minimize the negative

impacts of a particular design, i.e. improve trade-offs of a technology

Brainstorming A group technique for solving problems, generating ideas, stimulating creative

thinking Rules of Brainstorming 1) No criticism allowed, 2) Work for quantity, 3) Welcome piling-on, 4)

Allow free-for-all

Piling-On An idea that produces a similar idea or an enhanced idea. Time Line Chart A one-axis chart used to display past and/or future events, activities, etc. in the

order they occurred or are expected to occur for the purposes of analysis and communication

[002] Design Brief

Design An iterative decision-making process that produces plans by which resources are

converted or systems that meet human needs and wants or solves problems

Designer A person who designs any of a variety of things

Iterative Describing a procedure or process that repeatedly executes a series of operations until

some condition is satisfied Design Brief A written plan that identifies a problem to be solved, its criteria, and its constraints.

The design brief is used to encourage thinking of all aspects of a problem before attempting a

solution. Problem Identification The recognition of an unwelcome or harmful matter needing to be dealt

with

Design Statement A part of the design brief that challenges the designer, describes what design

solution should do without describing how to solve the problem, and identifies the degree to whichthe solution must be executed

Client A person using the services of a professional person or organization Target Consumer A person or group for which product or service design efforts are intended Product A tangible artifact produced by means of either human or mechanical work, or by

biological or chemical process

Constraint A limit to a design process. Constraints may be such things as appearance, funding,

space, materials and human capabilities. (A limitation or restriction) Numeric Constraint a number value or algebraic equation that is used to control the size or

location of a geometric figure


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Geometric Constraint Constant, non-numerical relationships between parts of a geometric figure.

Examples: parallelism, perpendicularity, concentricityo Parallel two or more straight lines that do not intersect

o Perpendicular intersecting lines which form right angles

o Concentric two or more circular features which share the same center pointo

Coincident having the same position in space (usually used for points)o Collinear passing through the same straight line

o Equal congruent shapes or lines of the same length / angles of same measureo Fixed maintaining a set position in spaceo Tangent A line or curve that meets another line or curve at one common point

Criteria Principles or standards by which something may be judged or decided Annotate To add explanatory notes to. Fillet A rounded interior blend between two surfaces.

Chamfer A small angled surface formed between two surfaces.

[003] Design Process

Model - A visual, mathematical, or three-dimensional representation in detail of an object or

design, often smaller than the original. A model is often used to test ideas, make changes to adesign, and to learn more about what would happen to a similar, real object.

Prototype - A full-scale working model used to test a design concept by making actual

observations and necessary adjustments Mockup - Also referred to as an Appearance Model. A model or replica of a machine or structure

for instructional or experimental purposes Process A systematic sequence of actions that combines resources to produce an output. Sequential Forming or following a logical order or sequence.

Ergonomic The study of workplace equipment design or how to arrange and design devices,

machines, or workspace so that people and things interact safely and most efficiently.

(Note from Mr. Fung: do not memorize all the subparts of each step; just understand what an engineer

would so in each step and the importance of the major part of each step that is listed in bold)

1. Define a Problem

o Identify a problem

o 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 (specifications) Criteria and constraints

o Project Proposal

2. Generate Concepts

o Brainstorm possible solutions

o Research


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o Apply STEM (Science, Technology, Engineering, Mathematics) principles.

o Select an approach with a Decision Matrix

o Design Proposal

3. Develop a Solution

o Consider design validity

i.

Functionii. Aesthetics

iii. Ergonomics

iv. Safety

v. Costvi. Environment

vii. Durability

viii. Ease of Maintenanceo Create detailed design solution

o Technical Drawings

4. Construct and Test a Prototype

o

Construct a testable prototypeo Plan prototype testing

i. Performance

ii. Usability

iii. Durabilityo Test prototype and collect data

o Analyze test data

o Test Report

5. Evaluate the Solutiono Reflect on design an recommend

improvementso Optimize or redesign the solution (Return to prior steps if necessary)o Revise design documents

o Project Recommendations

6. Present the Solution

o Document the project with a portfolioof work

o Communicate the project with a formal presentation

[004] Principles and Elements of Design

Aesthetic 1) Concerned with beauty or the appreciation of beauty, 2) Of pleasing appearance.

Elements of Design Components used in the creation of a design. [8 elements point, line,

shape, form, color, value (tone), space and texture] Gestalt - The principle that maintains that the human eye sees objects in their entirety before

perceiving their individual parts

Variety - A thing which differs in some way from others of the same general class Principles of Design The components that encompass a design [7 principles balance, rhythm,

emphasis, proportion, unity (harmony), economy, contrast]


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Balance - A condition in which different elements are equal or in the correct proportions. There

are three types of visual balance: symmetry (a.k.a. formal balance), asymmetry (a.k.a. informalbalance), and radial.

Horizontal Balance Left and right side of a design is in similar proportion Vertical Balance Top and bottom of a design is in similar proportion

Radial Balance Design is in similar proportion in a circular manner around an axis Contrast 1) The state of being noticeably different from something else when put or considered

together, 2) Enhancement of appearance provided by juxtaposing different colors or textures Rhythm - A regularly recurring sequence of events or actions, usually to represent movement

o Regular An element is repeated at the same interval

o Random the repetition of the element is random or situated at irregular intervals

o Gradated the repeated element is identical with the exception of one detail increasing ordecreasing gradually with each repetition

o Graduated the repeated element becomes closer or further apart Emphasis - Special importance, value, or prominence given to something Proportion (Scale) - The relationship of one thing to another in size, amount, etc.

Unity/Harmony - The state of being united or forming a whole

[005] Statistics and Design

Statistics - Collection of methods for planning experiments, obtaining data, organizing,

summarizing, presenting, analyzing, interpreting, and drawing conclusions based on data Assessment An evaluation technique for technology that requires analyzing benefits and risks,

understand the trade-offs and them determining the best action to that in order to ensure that the

desired positive outcomes outweigh the negative consequences. Research The systematic study of materials and sources in order to establish facts and reach new

conclusions. Data Facts and statistics used for reference or analysis

Data Set A group of individual values or bits of information that are related in some way or have

some common characteristic or attribute

Mean The average or central value of a set of quantities Median Referring to the middle term or mean of the middle two terms of a series of values

arranged in order of magnitude

Mode The value that occurs most frequently in a given data set Range The difference between the highest and lowest values in a data set Dot plot (Line plot) A method of visually displaying a distribution of data values where each

data value is shown as a dot or mark above a number line. Also known as a line plot. Histogram A graph of vertical bars representing the frequency distribution of a set of data Class Interval A group of values that is used to analyze the distribution of data

Frequency The rate at which something occurs over a particular period or in a given sample Normal Distribution - A function that represents the distribution of variables as a symmetrical

bell-shaped graph


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Technical Writing A type of expository writing that is used to convey information for technical

or business purposes. Technical Report A document that conveys the results of scientific and technical research, and

provides recommendations for action.

[006] Engineer Notebook

Engineers Notebook Also referred to as an Engineers Logbook. A record of design ideas

generated in the course of an engineers employment that others may not claim as their own. Standard Something considered by an authority or by general consent as a basis of comparison. American Nation Standards Institute (ANSI) - A private, non-profit organization that coordinates

the development and use of voluntary consensus standards in the United States International Organization for Standardization (ISO) - A non-governmental global organization

whose principal activity is the development of technical standards through consensus


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Variation A change or slight difference in condition, amount or level. Unit A standard quantity in terms of which other quantities may be expressed. English System The measuring system based on the inch/foot, seconds and pound as units of

length, time and weight or mass. Inch A unit of linear measure equal to 1/12 of a foot.

Metric System The decimal measuring system based on the meter, liter, and gram as units oflength, capacity and weight or mass.

Millimeter A metric unit of linear measure equal to 1/1000 of a meter. Conversion rate from English System to Metric System: 1 inch = 25.4 mm Engineers Notebook Standards

o Pages are sequentially numbered in ink on the top outside edge.

o All figures and calculations are clearly labeled.o Entries start at the top of the page, working left-to-right and top-to-bottom.

o Each page is signed and dated before the next page is begun.

o Inserted items are permanently attached.o Mistakes are crossed off, initialed, with correction. Never erase anything.

Annotate To add explanatory notes to.

[007] One Point Perspective

Perspective Drawing: A form of pictorial drawing in which vanishing points are used to provide

the depth and distortion that is seen with the human eye. Perspective drawings can be drawn usingone, two, and three vanishing points.

Vanishing Point: A vanishing point is a point in space, usually located on the horizon, where

parallel edges of an object appear to converge. In a one point perspective drawing, there are only 3 types of lines:

o Horizontal

o Verticalo

Diagonal to Vanishing Point

The purpose of these lines is as follows:

o Horizontal/Vertical lines represent width and heighto Diagonal lines represent the depth of the object (getting farther away from the viewer)


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[008] Computer Aided Design

Computer Aided Design (CAD) For design, the use of a computer to assist in the process of

designing a part, circuit, building, etc. or for drafting, the use of a computer to assist in the process

of communicating a technical drawing.

Solid modeling Solid Modeling is a type of 3D CAD process that represents the volume of anobject, not just its lines and surfaces.

Wireframe Modeling Wireframe Modeling is a 3D CAD process that represents the lines and

surfaces of a design.

Additive Modeling A method of modeling in which each component is created individually andsubsequent components are created as needed. This method is represented by construction

processes such as welding, gluing, mechanical fastening,joinery. Subtractive Modeling A method of modeling in which a design is created by removing different

geometric shapes from a solid block larger than the final design. This method is represented by

milling, drilling, turning, grinding, and other manufacturing processes.

[009] Isometric View

Pictorial Sketch: A sketch that shows an objects height, width, and depth in a single view, i.e.

shows a design in 3D Isometric Drawing: A form of pictorial drawing in which all three drawing axes form equal angles

of 120 degrees with the plane of projection.

In an isometric drawing, there are only 3 types of lines that are to be drawn on each of the 3different isometric axes:

o Line along the (30/-150 axis) to represent depth

o Line along the (150/-30 axis) to represent widtho Line along the (90/-90 axis) to represent height


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[010] Two Point Perspective

Two Point Perspective - A pictorial drawing in which receding lines converge at vanishing points

on the horizon; the most natural of all pictorial drawings. In a two point perspective drawing, there are only 2 types of lines:

o Vertical

o Diagonal to either left or right vanishing point The purpose of these lines is as follows:

o Vertical lines represent height

o Diagonal lines represent the width/depth of the object

[011] Orthographic Projection

Orthographic Projection/Multiview Drawing - A method of representing three-dimensional objects

on a plane having only length and breadth (ie. 2D) The most commonly used technical drawing for

production purposes Technical Working Drawing - A drawing that is used to show the material, size, and shape of a

product for manufacturing purposes Manufacture - To make something, especially on a large scale using machinery


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Projection Plane - An imaginary surface on which the view of the object is projected and drawn.

This surface is imagined to exist between the object and the observer.


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[012] Orthographic Projection II

Object Line: Represents outline of object (solid line)

Hidden Line: Represents an edge that is not directly visible (dotted line) Center Mark: Denotes center of circular shapes

Centerline Bisector: Denotes axis of cylindrical shapes Leader Line: Used to dimension radius/diameter of circles

Dimension Line: Lines with arrowheads used to show dimensions Extension Line: Used to identify the extent of a dimension Miter Line: 45-degree line from corner from front view used to project lines

Line Convention - Standardization of lines used on technical drawings by line weight and style Line Weight - Also called line width. The thickness of a line, characterized as thick or thin

[013] Oblique Projection

Oblique Pictorial - A type of drawing involving a combination of a flat, orthographic front withdepth lines receding at a selected angle, usually 45 degrees Cavalier Oblique - A form of oblique drawing in which the receding lines are drawn true size, and

usually at a 45 degree angle from horizontal

Cabinet Oblique - A form of oblique drawing in which the receding lines are drawn at half scale,

and usually at a 45 degree angle from horizontal General Oblique - A general oblique is a type of oblique pictorial that represents an objects width

and height, but the depth can be any size and drawn at any angle.


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Projection Plane - An imaginary surface on which the view of the object is projected and drawn.

This surface is imagined to exist between the object and the observer. Construction Line - Thin lines that serve as guides while sketching or drawing.

Tonal Shading A method of shading used to enhance the appearance of a pictorial drawing

014-Basic Assembly Constraints

Assembly - A group of machine or handmade parts that fit together to form a self-contained unit.

Mate An assembly process used to constrain a surface, line or point to another surface, line orpoint such that they remain in contract with one another.

Flush An assembly process used to align two surfaces at the same height/level.

Angle An assembly process used to set the angle between two surfaces.

Insert An assembly process used to place a cylindrical object into a cylindrical slot.


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Tangent An assembly process used to force a curved object to touch a flat surface at only one

point (spherical shapes) or on an edge (cylindrical objects). Can also be used constrain two curvedsurfaces together.

Base Component The first part placed into an assembly (this component is also grounded) Grounded Component A component that has 0 degrees of freedom (cannot move).

015-Degrees of Freedom

Degrees of Freedom - The variables by which an object can move. In assemblies, an object

floating free in space with no constraints to another object can be moved along three axes of

translation and around three axes of rotation. Such a body is said to have six degrees of freedom. Translational A movement that changes the position of an object without rotating.

Rotational A movement that occurs around an axis in a circular path.

The 6 DOF are categorized by 3 rotational and 3 translational movements around the X, Y and Z

axes An ungrounded part in an assembly has all 6 degrees of freedom

A grounded part in an assembly has 0 degrees of freedom

After a mate constraint, there are 3 degrees of freedom remaining After a flush constraint, there are 3 degrees of freedom remaining

After an insert constraint, there is only 1

degree of freedom (rotational) remaining

Default axes orientation when analyzing degrees

of freedom in an isometric view.

Height Y-Axis

Width X-Axis

Depth Z-Axis


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016A-Dial Caliper Measurement Reading

016B-Standard Deviation

Standard Deviation A measure of variation in a set of data. Used to describe the distance of a

each value in a population (or sample) from the mean value of the population (or sample).


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Example: If you are asked to measure the height of each student in your class, and then are asked

to find the standard deviation of those heights, you would use the POPULATION standarddeviation. You would have a data value for every member of the population the students in your

class. We call it POPULATION standard deviation because the value is based on the entire

population.

However, if you are asked to estimate the height of all of the high school students in your county

(and you believed that your class provides a good representation on which to base that estimate)

you would use the SAMPLE standard deviation. In this case, you would have only a sample(subset) of the heights of the entire population since your class is a subset of the county high

school population. We call this the SAMPLE standard deviation because the value is based on a

sample of the entire population.

Notice that the main difference in the two formulas is the denominator. The population uses N,

the population size. The sample standard deviation uses n 1 which is one less than the size ofthe sample used in the calculation.

Calculation Example

017-Dimensioning Rules

American National Standards Institute (ANSI) - A private, non-profit organization that coordinates

the development and use of voluntary consensus standards in the United States.


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American Society of Mechanical Engineers (ASME) - A professional engineering organization

that is known for setting codes and standards for mechanical devices in the United States. ASMEdrawing standards are found in the Y-14M publications.

The front view of an orthographic projection should be the view of the object that has the least

amount of hidden lines, largest width and shows the shape of the object most clearly.

Location Dimension A dimension that shows the distance between features Size Dimension- A dimension that shows the length of a feature

Baseline/Datum Dimensioning A method of dimensioning in which all dimensions originatefrom a common point (called the baseline or datum)

Chain Dimensioning A method of dimensioning in where each dimension starts from the end of

the previous dimension


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Rules of Dimensioning A set of standards which must be followed in a technical working drawing forspecifying the dimensions of a design.

1) Dimensions should reflect the actual size of the object, not the scaled size.2) Include overall dimensions in the three principle directions depth, width, and height.

o Overall dimensions should be placed the greatest distance away from the object so that

intermediate dimensions can nest closer to the object to avoid crossing extension lines.

3)

Include all dimensions necessary to produce or inspect the part.o Dimensions should be placed so that it is not necessary for the observer to calculate, scale

or assume any measurement.

4) Do not include unnecessary dimensions.o Dimensions should NOT be duplicated, nor should the same information be given in two

ways.

o Do not include chain dimensions that add up to a given overall dimension.5) Dimensions should be attached to the view that best shows the contour of the feature to be

dimensioned.

6) A dimension should be attached to only one view (i.e., extension lines should not connect two

views).

7)

Place dimensions between adjacent views whenever possible.8) Avoid dimensioning to hidden lines.

9) Do not place dimensions on the object unless it is absolutely necessary.10)Do not cross a dimension line with another dimension line or with an extension line.

11)Avoid crossing dimension or extension lines with leader lines.

12)Leader lines point toward the center of the feature at an angle and should never be placedhorizontally or vertically.

13)Dimension numbers should be centered between arrowheads, except when using stacked

dimensions where the numbers should be staggered.

14)In general, a circle is dimensioned by its diameter; an arc is dimensioned by its radius.15)Holes should be located in the view that shows the feature as a circle.

16)

Holes should be located by their center lines which may be extended and used as extension lines.

018-Title Block (Parts List/Balloons) and Exploded Assembly

Balloons - A circled number identifying each part shown in an assembly drawing. Also called aball tag or bubble number.


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Documentation - 1. The documents that are required for something, or that give evidence or proof

of something. 2. Drawings or printed information that contains instructions for assembling,installing, operating, and servicing.

Exploded Assembly - An assembly drawing in which parts are moved out of position along an

axis so that each individual part is visible.

Parts List - A list of materials or parts specified for a project. Also referred to as a bill of materialsor BOM.

Title Block - A table located in the bottom right-hand corner of an engineering drawing that

identifies, in an organized way, all of the necessary information (designer, title, date, scale,company, logo) that is not given on the drawing itself. Also referred to as a title strip.

Local Note (Annotation) - Connected to specific features on the views of the drawing. Also known

as annotations. General Note - Notes placed separate from the views; relate to the entire drawing.

019-Tolerance

Limit Dimensions - The largest and smallest possible boundaries to which a feature may be made

as related to the tolerance of the dimension. Bilateral Tolerance - A tolerance in which variation is permitted in both directions from the

specified dimension

Unilateral Tolerance - A tolerance in which variation is permitted in only one direction from the

specified dimension Tolerance The total permissible variation in a size or location dimension

Total Tolerance A value which specifies the range of tolerance on a part Least Material Condition (LMC) - The smallest size limit of an external feature and the largest

size limit of an internal feature

Assembly Drawing

A drawing that shows parts of an

item when assembled.

(The view that shows the

assembled design itself is

referred to as the assembly view)


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Allowance Example in a clearance fit

Allowance Example in an interference fit


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021-Engineering Design Teams / Decision Matrix

Arbitration - The hearing and determination of a dispute or the settling of differences between

parties by a person or persons chosen or agreed to by them. Consensus A general agreement

Critique - A detailed analysis and assessment. Decision Matrix - A tool for systematically ranking alternatives according to a set of criteria.

Evaluate - To form an idea of the amount or value of; assess. Gantt Chart - A time and activity bar chart that is used for planning, managing, and controlling

major programs that have a distinct beginning and end.

Mediation - The act or process of using an intermediary to effect an agreement or reconciliation. Negotiation - Mutual discussion and arrangement of the terms of a transaction or agreement. Norms - Principles of right action, binding upon the members of a group and serving to guide,

control, or regulate proper and acceptable behavior. Open-Ended - Not having fixed limits; unrestricted; broad. Protocol - The accepted code of behavior in a particular situation.

Storming - A phase of team development that is marked by conflict.

Synergy - When the unit or team becomes stronger than the sum of the individual members. Virtual Team - A group of people that rely primarily or exclusively on electronic forms of

communication to work together in accomplishing goals.

Decision Matrix Gantt Chart

2012 test midterm notes

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