Exam 1 Review

what are the three steps to the design thinking process?

1. Needfinding
2. Brainstorming
3. Prototyping

needfinding

Figuring out what your user needs by living life with them

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Observe people beyond the point of boredom, take notes, interview them, figure out what they need (e.g. "a way to...")

brainstorming

generating lots of ideas in a limited amount of uninterrupted time with a group of about 6-10 people

7 rules of brainstorming

1. defer judgment
2. go for quantity
3. encourage wild ideas
4. write everything down - be visual, make sketches
5. one conversation at a time
6. stay on topic
7. build off of the ideas of others

prototyping

creating an early version of a product, service, or experience that is designed to TEST some part of the concept

looks-like prototype

useful for

* exploring material choices, finishes, colors
* refining the overall appearance
* assessing overall size
* trying out different different user interfaces/experiences

scale model prototype

a smaller scale of the full design of a large project

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used to try different layouts and assess the overall shape

works like prototype

test whether the device can function well enough to meet the design specification requirements; looks don't matter

tests like prototype

used to see if the functional prototype can be turned into a real product

isometric drawing

a 3D drawing with no perspective and no foreshortening; the scale of these drawings is the same along each axis and the angle between each axis is 120deg.

orthographic drawing

a way of showing a 3D object in 2D views where the axes are parallel to the projection plane; usually a front, side, and top view; measurements can be taken off any of these drawings

detail part

an engineering drawing that tells manufacturers how to produce the design of a single part

assembly drawing

an engineering drawing that tells a manufacturer how to put detail parts together to create a finished product

tape measure

caliper

micrometer

depth gauge

t-square

carpenter square

speed square

combination square

awl

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crosscut saw - designed to cut perpendicular to the grain of wood

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rip saw - cuts with the grain of wood

hack saw

pull saw

jig saw

table saw

circular saw

miter saw

scroll saw

angle grinder

mallet

claw hammer

dead blow hammer

sledgehammer

chain breaker

open ended wrench

box ended wrench

combination wrench

adjustable wrench

pipe wrench

channel lock wrench

alan wrench

socket wrench

torque wrench

tin snips

deburring tool

tap

die

quick grip bar clamp

c-clamp

vise

locking pliers

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needle nose pliers

slip joint pliers

groove joint pliers

ratchet strap

come-along

turnbuckle

file

plane

bolt

non-tapered, not threaded all the way

machine screw

non-tapered, threaded all the way

self tapping screw (aka screw)

tapered, threaded all the way

drill bit vs end mill

end mill can cut axially (up and down) and radially (side to side)

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MDF (Medium Density Fiberboard) - engineered composite made of wood fibers; no grain

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LDF (Low Density Fiberboard) / Particle Board - engineered composite made of wood chips

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Masonite - engineered wood made of steam-cooked and pressure-molded wood fibers

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veneer - thin sheet of wood used for cosmetic purposes

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plywood - made by taking layers of veneer and gluing them together in perpendicular orientations

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butt joint

lap joint

miter joint

mortise and tenon joint

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gusset

corner brace

splice

a method of joining two members end to end in woodworking; used when the material being joined is not available in the length required

definition of yield strength

amount of stress that causes a specific amount of plastic deformation

definition of ultimate tensile strength

the maximum amount of stress a material can withstand before it fractures

definition of toughness

the ability of a material to absorb energy and plastically deform without fracturing

definition of ductility

ability to be drawn and withstand tensile stress without fracturing

definition of fatigue

cracking due to cyclical loading

definition of stress

the measure of what the material feels from externally applied forces; equal to the ratio of the external forces to the cross sectional area

definition of strain

the ratio of the change in length to the original length; a measure of the deformation caused by stress

definition of elastic

temporary deformation; when stress is removed, the material returns to its original shape

definition of plastic

permanent deformation; even when the stress is removed, the material does not return to its original shape

definition of hardness

resistance to plastic deformation

the four main types of steel

1. carbon steel
2. stainless steel
3. alloy steel
4. tool steel

carbon steel

all steels contain carbon, but carbon steels don't contain other elements; easy to weld but welding weakens the metal near the weld

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mild/low-carbon steel: 0.05 to 0.15% carbon content

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medium-carbon steel: 0.3 to 0.5% carbon content

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high-carbon steel: 0.6 to 1.0% carbon content

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ultra-high-carbon steel: 1.25 to 2.0% carbon content

stainless steel

shiny, 10 to 20% chromium (main alloying element); difficult to weld

alloy steel

mixture of several different metals like nickel, copper, and aluminum

tool steel

made up of things like cobalt, molybdenum, and tungsten; very commonly used to make metal tools; hard and heat/scrape resistant

annealing

heat treatment to increase ductility, reduce hardness, and make it easy to work

case hardening

outside surface of low-carbon steel is hardened while the material underneath remains soft

precipitation hardening

increases the yield strength of ductile materials like aluminum

tempering

increases the toughness of iron-based alloys; usually performed after hardening to reduce the hardness

quenching

increases hardness

basic characteristics of aluminum

1/3 density of steel, more ductile, immediately oxidizes in air, forming a protective layer that prevents corrosion; visually resembles silver because it is very reflective; difficult to weld (TIG welding)

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not as strong as steel, but lower density makes it a good choice for applications like aircraft where weight is a major consideration

flange