Engineering 22
©
AutoCAD
Advanced Cmds-2
Bruce Mayer, PE
Registered Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Learning Goals
 Use the ACAD “Osap” tools to facilitate
point selection
 Use ACAD “Grips” to facilitate entity
modification
 Create and Use ACAD “Blocks”
 Create & Modify ACAD “Layers”
 Use Geometric Construction to Bisect a
Line or an Angle
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layers
 Probably the most important object
property to understand well is the
LAYER property.
 Experienced AutoCAD users use layers
all the time
• that is why the Object Properties toolbar
contains so many layer functions.
Layers ToolBar
Engineering 22 – Engineering Design Graphics
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Properties ToolBar
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layers Concept
 Basically, layers are the computer
equivalent of TRACING OVERLAYS on
a drawing board
 A Drawing can Have MANY Layers
• Could be up to one for EACH Part
 You can control the Visibility, Color
and Linetype of layers independently
• These Three Properties form a
ShortHand for line meaning
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layer Utility
 Layers are effectively a way of ordering
a CAD drawing
• e.g.; You could create a layer called
"Construction" and use this for your
construction lines. When the drawing is
complete, you could simply TURN OFF this
layer off so that it can't be seen
 Good & Consistent use of layers is
the MOST Important aspect of good
CAD drawing practice
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layer Management
 Layers are Typically Defined Based on
Some Combination of these Criteria
• By Line-Type or Line-Usage
• By Part or Component
• By Material or Form; e.g.
– On a Construction dwg Layers might be defined
by Materials: Steel, Wood, Concrete
– On a Piping Design Dwg Layers Defined by
Fluid: ColdWater, HotWater, NatGas, Sewer
– On Landscape Design by main elements:
Trees, Scrubs, Grass, FlowerBeds
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Visible line
Hidden line
Hatching
Centerline
Dimension
Extension
Leader
Cutting Plane
Viewing Plane
Short break
Long break
Phantom
Stitch
Chain
Engineering 22 – Engineering Design Graphics
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Standard Lines
 Line Patterns
Communicate What
The Line Represents
In The Drawing
 Line Patterns Tell You
Information Such As
Whether The Line Is
Hidden, Visible, Or A
Centerline
 Line Precedence:
• Visible → Hidden
→ Center
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layers By Line-Type
One FUNCTIONAL Layer
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layers by Function
Several LineType Layers
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Layers by Part or Component
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Make A Layer

Let’s Make a New
Layer for HIDDEN
LINES
•
•
•
2. Activate Format
Layer Dialog Box
Color → Red
LineType → Hidden
(Evenly Spaced
Dashes)
LineWidth → ACAD
default
1. Start at new
acad.dwt Drawing
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Make A Layer cont
3. Click on the New
Layer icon
5. Select Color
6. Pick Red from DB
4. Name the Layer as
“Hidden”
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Make A Layer cont
7. Select Linetype
•
8. Don’t See the
“Hidden” type so
click Load → DB
Activates the
Loaded Linetypes
Dialog Box (DB)
•
Engineering 22 – Engineering Design Graphics
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Find HIDDEN;
click OK
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Make A Layer cont
9. With Hidden
Loaded, Pick it
from Select
Linetype DB
•
Click OK
Engineering 22 – Engineering Design Graphics
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10. Rt-Click on Status
Column and Select
Current
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Make A Layer cont
11. Click OK on Last dialog Box

Draw a Pentagon with the Hidden Layer
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Draw with Hidden Layer
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Draw on Different Layer
 Start with “OBJ”
layer
• Draw a Nice Circle
 Click on the “DIM”
Layer to make it the
“Current” Layer
 Activate Layer
PullDown on the
Layers ToolBar
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Draw on Different Layer CONT
 Layer-Status
Window on Layers
ToolBar Now shows
“DIM” as current
 The Heptagon will
then Reside on the
Current Layer “DIM
 Draw a Nice
Heptagon Next to
the “OBJ” Layered
Circle
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Entities on Different Layers
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Move Entity to Different Layer
 Lets Move the Circle
to the “PHANTOM”
Layer
 With the Handles
Active PullDown the
Layer-Status Menu
 Click to Circle to
activate the Grips
 Click on “PHANTOM”
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Move Entity to Different Layer
 Deactivate the Grips by Hitting Esc key
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
LineType Scale
 The distance
between Line
Dashes does NOT
change with the
Drawing Scale
 Pick the TOP one,
and Rt-Click to Turn
on Properties Menu
 Hidden lines?
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
LineType Scale cont
 Properties Menu
Active
Engineering 22 – Engineering Design Graphics
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 Change Linetype
scale to 4.000 and
close Prop Menu
 Can Change
GLOBALLY with
LTSCALE comand
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Match Properties Tool
 MATCHPROP is a
 Click the MatchProp
quite convenient tool
Tool
 Example – Want the
Ellipse to be on
Same Layer as
Heptagon
 Click the SOURCE
Object
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Match Properties Tool cont
 Mouse Pointer takes
PaintBrush Form
 The Result
 Click Target Object
 MatchProp Invocation
 Hit the Esc Key to
Deactivate the
format Painter
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
More Editing Commands
 Polyline
Edit
• Can Turn an Object INTO a PLine
 Spline
Edit
 Text
Edit
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Geometric Construction
 Geometric Elements
• Point
– Specifies An Exact
Location In Space
– Dimensionless
• Line
– Has Length And
Direction But No
Width
– Straight Line 
Shortest Distance
Between 2 Points
Engineering 22 – Engineering Design Graphics
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• Curve
– Locus Of Connected
Pts That are Not
Straight-Collinear
 Direction Changes
Constantly
• Plane
– A Two Dimensional
Slice Of Space
– No Thickness (2-D
Characteristic)
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Geometric Construction
 Geometric Elements
• Closed 2-D elements
– Edges May be
• Solids
– 3D Forms with Mass
& Volume
 Straight Lines →
Polygons
 Curved Lines → e.g.,
Circles, Ellipses
• Surfaces
– Do Not Have
Thickness
– Two Dimensional At
Every Point
 No mass or volume
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Construction: Math vs. Engrng
 Mathematical Geometric Construction
“Allows” Only Two Instruments
• Straight Edge; i.e., NOT a Ruler/Scale
• Compass
 No MEASUREMENTS Are Made
 Engineering Starts with Geometry and
Builds for Practical Application
• Triangles, Circle Templates, Scales, Etc.
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Line Perpendicular Bisection
 By Compass
Engineering 22 – Engineering Design Graphics
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 By CAD
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Angle Bisection
 By Compass
 By CAD
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
All Done for Today
The
Venerable
Drawing
Compass
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Engr/Math/Physics 25
Appendix
f x   2 x  7 x 
9x  6
3
2
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Engineering 20
Geometric
Construction
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
BMayer@ChabotCollege.edu
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Geometric Elements







A Point
A Line
A Curve
A Plane
Closed 2-D elements
Surfaces
Solids
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Point
 Specifies An Exact Location In Space
• Dimensionless
– No Height
– No Width
– No Depth
 Always Show With Crossed Lines
• Do Not Use a “Dot” •
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Line
 Has Length And Direction But No Width
 Straight Line  Shortest Distance
Between 2 Points
• The Common Definition of a Line
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Line cont.1
 May Be Infinite
• At Least One Point Must Be Specified
• Direction May Be Specified With A Second
Point Or With An Angle
• A “RAY” is Semi-Infinite (End-Pt & Direction)
 May be finite
• Defined By Two End Points
• Defined By One End Point, A Length, And
Direction
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Lines – Special Cases
 Two Intersecting Lines Form an ANGLE
• Symbol = 
• Measured in
– Degrees; 0-360, 36.87°
– Radians; 0-2, 0.6435rad or 0.6435
 Perpendicular Lines Intersect at Equal s
• 4, 90° Intersections; Symbol = 
 Parallel Lines  Lines in a Plane That do
Not Intersect
• Symbol = 
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Curve
 Locus Of Pts Along A Curve That are Not
Collinear
 Direction Changes Constantly
 Single Curved Lines
• All Pts On The Curve Lie in A Single Plane
 Regular Curve
• The Distance From A Fixed Point To Any
Point On The Curve Is A Constant
– e.g., Circle, Arc
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Plane
 A Two Dimensional Slice Of Space
 No Thickness (2-D Characteristic)
 Any Orientation Defined By:
• 3 Points
• 2 Parallel Lines
• Line And A Point
• 2 Intersecting Lines
 Appears As A Line When The Direction
Of View Is Parallel To The Plane
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Closed 2-D Elements (Planar)
 Edges May be
• Straight Lines → Polygons
• Curved Lines → e.g., Circles, Ellipses
 Triangles
• St-Lines on 3-Sides
• Part of the
Polygon Class
• Basis of
Trigonometry
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
4-Sides Polygons
 Quadrilateral  Straight-Line Bounded
on Four Sides
• Important Special Cases
– Rectangle
– Square
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Regular Polygons
 Regular Polygons Have Equal Angles
And Equal Sides
 Often Created And Described By
• Inscribing Them In A Circle
• Circumscribing Them About A Circle
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Circle
 A Circle Is A Closed
Curve, All Points Of
Which Are Equally
Distant From The
Center
Engineering 22 – Engineering Design Graphics
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 Primary Descriptors
• Radius, R
• Diameter, D = 2R
• Circumference,
C = 2R = D
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Most Important Closed Elements
 Circle
• Nature’s Favorite Shape
– Minimum Energy Geometry
 Sharp Angles Exist in Nature (e.g. Crystal Structures),
but Not many
• Easy to Fabricate by “Spinning”
– e.g., Drill, Lathe, Pottery Wheel, etc
 Rectangle
• Simplest “Human-Made” Form
– Fabricate With Rectilinear motion (XY-Table)
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Surface
 Does Not Have Thickness
 Two Dimensional At Every Point
• No mass
• No volume
 Generally 3-Dimensional
• May Be Planar
 May Be Used To Define The Boundary
Of A 3-D Object
• Defines the “Skin” of the Object
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Solids
 3D Forms with Mass & Volume
Engineering 22 – Engineering Design Graphics
48
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Construction: Math vs. Engrng
 Mathematical Geometric Construction
“Allows” Only Two Instruments
• Straight Edge; i.e., NOT a Ruler/Scale
• Compass
 No MEASUREMENTS Are Made
 Engineering Starts with Geometry and
Builds for Practical Application
• Triangles, Circle Templates, Scales, Etc.
Engineering 22 – Engineering Design Graphics
49
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Instrumental Drawing Tips
 GEOMETRIC-CONSTRUCTION And
PROJECTIONS Form the Heart of
Instrumental and CAD Drawing
 Accuracy is Critical
• Suggest Making “GuideLines” with 4H-6H
Lead
– Draw Construction/Guide Lines Very Lightly
 Later Fill-in “Drawing Lines” at Standard Darkness
• 2X-Check Measurements
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Line Bisection
 Preferred Methods → More Accurate
• Compass or Triangle
 Scaling OK → Quick; Less Accurate
HORIZONTAL & VERTICAL Lines
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Angles – Bisect, Transfer
 Protractors Can Be Cumbersome for
These Tasks
• Use the Compass-Based Techniques
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Parallel Lines (||)
 Compass Techniques Are Accurate But
Cumbersome → Use Sliding Triangles
 ||-Line Thru a Given Pt
Engineering 22 – Engineering Design Graphics
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 Line || to Given Line
@ Distance CD
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Divide Line into Equal Parts
 Division by the Higher Prime Numbers
(e.g., 7, 13) Results in Irrational Values
• Very Difficult To Scale Accurately
 Use “Tilted Scale” With Integral Values
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Proportional Division
 Again, Scaling Can Be Inaccurate
 Since Drawing Vertical & Horizontal
Lines Is Most Convenient, Method (a) is
Preferred (Others are Fine)
Engineering 22 – Engineering Design Graphics
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Ratio: 2:3:4
Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Drawing Perpendiculars ()
 Compass Methods Most Accurate
 Sliding Triangles Preferred Due to
Speed with Acceptable Accuracy
• 3-4-5 Rt-Triangle is Useful In Construction
– Most Convenient for Tape-Measures
Pt-P Off line
Pt-P
On line
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt
Triangles
 It’s Very Difficult to Close a Triangle
WithOUT Using the Compass
 Swing-Arcs Ensures a Nicely Closed 
Engineering 22 – Engineering Design Graphics
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Bruce Mayer, PE
BMayer@ChabotCollege.edu • ENGR-22_Lec-06_AdvanCmd-2.ppt