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LECTURE TWO

CAD Projections andSections

Projection

Used for

Translation of a 3Ditem into a 2Drepresentation.

Using

Projection Planes

ProjectionProjection Methods

Perspective Projection Perspective Projection

Perspective is not used normally in Engineeringdrawings due to the size of the items.

Perspective

View

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Oblique Projection Oblique Projection

Axonometric ProjectionIsometric

Dimetric Trimetric

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Axonometric Projection

Screen Shot of Solid Edgeshowing named views

Axonometric Projection

Identify each type

Axonometric Projection

Answer

dimetric trimetricisometric

Isometric Assembly

Axonometric Projection

Exploded Assembly

Axonometric Projection

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Orthogonal Projection Orthogonal Projection

Orthogonal Projection Orthogonal Projection

WHAT ORTHOGONAL

PROJECTION IS USED?

Orthogonal Projection

THIRD ANGLE

PROJECTION

Orthogonal Projection

Solid Edge

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Orthogonal Projection Orthogonal Projection

DRAWING PROJECTION

is always identified on a

drawing either symbol or

as above

Orthogonal Projection

Is this drawing correct?

Orthogonal Projection

Correct Layout

Partial Views Auxiliary Views

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Auxiliary Views Auxiliary Views

Removed Views Removed Views

Pictorial Drawing Pictorial Drawing

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Pictorial DrawingSections

Sometimes it is difficult toadequately define an object by usingonly external views.

Sections are used to exposethe internal details. Theobject is cut by a surface(cutting plane) and the part infront is removed to exposethe details of the cut object.

Sectional Shading

45o

Sectional Shading

Sectional Shading Sectional Shading

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Sectional Shading Sectional Shading

Sections Sections

Sections Sections

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Sections Sections

Sections Sections

How would you achieve this in Solid Edge?

Sections

Sectioning along this li ne would achieve the

preferred option

Thin webs

If the sectionplane is coincidentwith the centreplane of a thin webor similarattachment, doNOT section thethin web.

Why is Section B-B is different ?

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Standard representations forshafts and tubes

Drawing Information

AngularDimension

ArrowheadsAuxiliaryDimension

Boss (projectionfor extra support)

Centre LineThick Chain Line(SpecialTreatment)

ChamferCirclip Groove(locates acomponent)

Counterbore toaccommodate thenut. Counterboreis not tapered.

Countersink(similar functionbut tapered hole)

Section Plane

Enlarged View (togive betterdetails)

Round describes anexternal radius

Fillet an internalradius

Flange This is aprojecting rimused forstiffening or forfixing to anotherpart)

Leader Line- pointsto a note

Pitch CircleDiameter Thecircle for thecentres of a groupof holes

Surface Finish Indicates maximumroughness for a matisurface

Square Diagonallines indicate flatsurfaces

Internal Threadrepresentation

Exploded Views Last Comment

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