Question Orthographic Projection - Colorado Mesa...

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Orthographic Projection

Question

What is the name of the feature indicated? A. Countersink B.  Counterbore C.  Spotface D. Hole E.  Stepped hole

2 CAD/Fab Assemblies & Mobility

Question

What is the name of the feature indicated? A. Countersink B.  Counterbore C.  Spotface D. Hole E.  Stepped hole

3 CAD/Fab Assemblies & Mobility CAD/Fab Orthographic Projection 4

Product Features The Vocabulary of Design

Download from web site

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CAD/Fab Orthographic Projection 5

Product Features (cont’d)


The Alphabet of Lines Line style communicates different information:

Visible object line (heavier than others)

Hidden line

Center line

Implies

Implies

Section line


Imagine an object inside a glass box

Orthographic Projection


Parallel visual rays project from the object to the projection plane.

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The object’s image is formed on the projection plane by the pierce points of the visual rays.


Similarly, the top view is projected to the horizontal plane


For many three-dimensional objects, two to three orthographic views are sufficient to describe their geometry.


The box can be unfolded to show the

multiple views in a single x-y plane

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FRONT

TOP

RIGHT SIDE

The views are oriented orthogonally in relationship to each other.


FRONT

TOP

RIGHT SIDE

Typical Three-View Placement

DEPTH

DEPTH

WIDTH

HEIGHT

Projection Lines


The “Glass Box” Concept Top View

Right View

Left View

Back View

Bottom View CAD/Fab Orthographic Projection 16

View Selection

Poor view orientation

Good view orientation

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View Selection in SolidWorks

•  Think first about what makes most sense

•  To change views in SolidWorks:

Note: This does NOT change the original reference planes used to create the model!


One View May be Adequate Centerline indicates circular feature

1.00 Φ

Φ symbol means

“diameter”


Two Views May be Adequate

CAD/Fab Assemblies & Mobility 20

Workshop

•  Sketch as many ways as you can to model a 2” diameter cylinder 3” tall in SolidWorks.

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Question

How many methods did you come up with? A) One B) Two C) Three D) Four E)  Five or more

21 CAD/Fab Assemblies & Mobility

Extrude a circle

Revolve a rectangle Extrude cut a square with a circular cutout

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Revolve cut a cutout shape

Sweep a circle along a straight line

Loft two circles

Be careful how you pick profiles!


∞

Line of Sight

Viewing Station at Infinity

Projection Plane (Picture Plane Viewing Plane)

First-Angle Projection

Object

Object is placed between the observer and viewing plane

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Front View

First-Angle Projection

The image of the front view is projected to the projection

plane behind the object.

Line of sight


Front View

Horizontal or Top View

The top (horizontal) view is projected from above the object but is created on the plane below.


Profile or Right Side View

Front View


As with the previous two projections, the right side view is projected to the opposite side of the glass box.


The reference frame can be unfolded to show the multiple views in a single X-Y plane


Front View


In first-angle projection the box unfolds away from the observer rather than towards the observer

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The reference frame can be unfolded to show the multiple views in a single X-Y plane


Front View


The views are reversed in their order from third-angle projection; the top view is below the front view and the right side view is to the left of the front view.


Question

What type of projection is this drawing: A. First-angle B.  Second-angle C.  Third-angle D. Fourth-angle


Question

What type of projection is this drawing: A. First-angle B.  Second-angle C.  Third-angle D. Fourth-angle


Front Right

•  The US and Canada use third-angle projection •  The rest of the world uses first-angle projection •  Symbols on drawing identify which is used

ISO Standard US Standard First-angle Third-angle

First-Angle vs. Third-Angle Projection

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First-Angle vs. Third-Angle Projection


First-Angle (Europe) Third-Angle (U.S. & Canada)

Assignment/Due Date

Sketch the appropriate views of problems (3), (6), and (19) from the ebook, Cad & Fabrication http://www.mcgrawhillcreate.com/shop. At this point you should have downloaded and read the preceding chapters. The problems are given in Figure 5.122, pages 294-5, printed page 140 & 141(when viewed online). Complete P1.6 from Howard and Musto, Introduction to Solid Modeling Using SolidWorks 2011. Sketches due at the beginning of class and SolidWorks problem due by the end of class Wednesday 2-1-12.


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