2 - lecture two mech2305
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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
Last Comment