IOT

POLY ENGINEERING2-8

1. What are the three rules for drawing?1) Always PULL your pencil; do not push it.

2) ALL lines begin as light construction lines.

3) Use appropriate line weights and types for final lines.

2. Get out your orthographic projections assignment.

1 Nov 10

DRILL

• Cover the 3 main technical drawing types and their ~12 variations

• Establish class standards for technical drawing• Further develop and apply skills in drafting• Develop and apply skills in Google Sketchup

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POLY ENGINEERING2-9

Objectives

Tech

nica

l Gra

phic

Com

mun

icati

onThe remainder of Unit 2:

Technical Graphic Communication

• One of many drafting techniques• Quick way to show an idea that would be difficult

to describe with words alone• Used mainly in Engineering Design Process Step 2:

Brainstorm, Research, and Generate Ideas

• NO DRAWING TOOLS (not even a straightedge)• Rules of drawing STILL APPLY

– Pull, don’t push– LIGHT construction lines– Use appropriate line weight and type

IOT

POLY ENGINEERING2-9

SKETCHESTY

PE 1

: SKE

TCH

ES

• Orthographic Projections:– Ortho: straight or at right angles– Graphic: written down– Pro: forward– Jacere: to throw“To throw straight forward and write down”

• The method of representing the exact form of an object in 2 or more views on planes (usually at right angles to each other)

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POLY ENGINEERING2-9

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

• There are 6 standard views:

• Which views to use?– The different features of an object will suggest which

views to draw. – Standard is:

IOT

POLY ENGINEERING2-9

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

IOT

POLY ENGINEERING2-9How are orthographic projections drawn?

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

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POLY ENGINEERING2-9

• Reference Planes:–Frontal Reference Plane

»Front View–Horizontal Reference Plane

»Top View–Profile Reference Plane

»Side View

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

IOT

POLY ENGINEERING2-9

– Frontal Reference Plane» Front View

– Horizontal Reference Plane» Top View

– Profile Reference Plane» Side View

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

Which Reference Plane?HRP

Which Reference Plane?PRP

Which View?FRONT

Which Reference Plane?HRP

FRP

Which View?RIGHT

Which Reference Plane?

Now, sketch the Horizontal Reference Plane and label the view and other planes.

IOT

POLY ENGINEERING2-9

• Reference Planes:– Frontal Reference Plane

» Front View– Horizontal Reference Plane

» Top View– Profile Reference Plane

» Side View

MULTI-VIEWTY

PE 2

: MU

LTI-V

IEW

Which Reference Plane?FRP

Which Reference Plane?PRP

Which View?TOP

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POLY ENGINEERING2-9

• Reference Planes:– You can also have multiple positions of the same

reference planes

MULTI-VIEW

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POLY ENGINEERING2-9

• Sectional Views– How an object looks if a cut were made through it

perpendicular to the direction of sight.– For example, if we cut the shape below at PRP 2 and

drew the shape (including its “insides”) we would have a sectional view:

SECTIONAL VIEWSTY

PE 2

: MU

LTI-V

IEW

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POLY ENGINEERING2-9

• Sectional Views– Different materials have different sectional views

SECTIONAL VIEWSTY

PE 2

: MU

LTI-V

IEW