Chapter 2
Sketching, Constraining &
Dimensioning
Chapter 2 - Objectives
• After completing this chapter, you will be
able to
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Change the sketch and part options as needed
Sketch an outline of a part
Create geometric constraints
Dimension a sketch
Create dimensions using the automatic
dimensioning tool
– Change a dimension’s value in a sketch
– Import AutoCAD DWG data
Sketch & Part - Application
Options
• Options
– Customized your
preferences
– Settings are global
– Affects all open &
new Inventor
documents
Sketch - Application Options
• Constraint Placement
Priority
• Display
• Overconstrained
Dimensions
• Snap to Grid
• Edit dimensions when
created
• Autoproject edges during
curve creation
• Autoproject edges for
sketch creation and edit
• 3D Sketch
Part - Application Options
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Sketch on New Part Creation
Parallel view on sketch creation
Auto-hide in-line work features
Construction
Units
• Units
– Default unit of
measurement
– Part, Assembly &
Drawing files
– Template file
– Changing Overridden
– Edit dimension
Templates
• Templates
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New files created from a template
Add or Modify templates
Template directory
Subdirectory
• New Tab
Creating a Part
• Creating a Part
– Standard.ipt icon
– File menu
– Shortcut key
– New icon
– Part environment
Creating a Part
•Sketches & Default Planes
–Sketch plane
• 2D objects are sketched
• Active sketch
• Three planes
– XY,YZ, and XZ
• Three Axes
– X, Y, and Z
• Center
– Origin - point at the intersection
• Browser
•New Sketch
–Active sketch
Sketch the Outline of the Part
• Step 1 - Sketches Overview
– Sketching strategies, tools, & techniques
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Outline
Draw to finished size/shape
Visual Guide – distance & angle
No overlaps & gaps
Keep it simple
Closed vs. Open shape
– Sketch Tools
• Sketching tools
• Expert mode on/off
Sketch the Outline of the Part
• Using the Sketch Tools
– Visual feedback
• Line Tool
– Powerful tool
– Endpoint - Arc
• Inferred Points
– Dashed lines
– Endpoints
• horizontal
• vertical
• perpendicular
Sketch the Outline of the Part
• Automatic Constraints
– Constraint symbols
• Scrubbing
– different constraint applied
– move the cursor so it touches
• Precise Input
– specified length or angle
• Selecting Objects
– individually objects
– multiple objects
– color change
• Deleting Objects
– right-click
Measure Tools
• Analyze
– Sketch
– Part
– Assembly models
• Measure
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Distances
Angles
Loops
Area
Analysis Tools
• Measure
– Additional Options
• Click the arrow in the
Measure dialog box
Reset
Clears the contents of the measurement box
Add to Accumulate
Adds the measurement in the measurement box to the
accumulate
Clear Accumulate
Clears all measurements from the accumulate sum
Display Accumulate
Displays the sum of all measurements added to the
accumulate
All Decimals
Changes the decimal display between all decimals and
the number of decimal places specified in the document
settings
Exercise 2-1
• Creating A Sketch With Lines
Exercise 2-2
• Creating a Sketch With Tangencies
Constraining the Sketch
• Step 2 - Geometric Constraints
– Apply behavior
– Create relationships
• fully constrain
• fix constrain
– Constraint Types
• 11 geometric constraints
Constraining the Sketch
• Geometric Constraints
– Adding Constraints
• Applying
• Over-constrain
• Duplicate
“Adding this constraint will over-constrain the sketch”
– Snap
• Midpoint, center & intersection
• Coincident constraint
Constraining the Sketch
• Geometric Constraints
– Dragging a Sketch
• Constrained or Not
• Geometry stretches
– Showing Constraints
• To see applied constraints
• Objects change color
– Deleting Constraints
• Right-click
• Show all & Hide all
Exercise 2-3
• Adding and Displaying Constraints
Adding Dimensions
•Step 3 – Adding Dimensions
–All dimensions created are parametric
–Control & change size of geometry
–General Dimensioning
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Create linear, angle, radial, or diameter
Automatically snap
Extension lines
Preview image
–Dimensioning Lines
• Endpoints - two
• Length
–Dimensioning an Angle
• Two lines
Adding Dimensions
–Dimensioning Arcs and
Circles
• Circumference
• Arc = radius
• Circle = diameter
–Diametric Dimensions
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Revolved part
Represent a quarter outline
Linear diameter
Axis of rotation
–Dimensioning to a Tangency
• Arc or circle
• Constraint symbol changes
• Two quadrants
Adding Dimensions
• Entering and Editing a Dimension’s Value
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Automatically appear
Change the value
Edit Dimension option
Default value
To change double-click
Enter exact value
Accurate to six decimal places
Smallest dimensions first
Adding Dimensions
•Entering and Editing a Dimension’s Value
–Repositioning a Dimension
• New location
• Origin points cannot be moved
–Over-Constrained Sketches
• Inventor will not allow
– over-constrain
– duplicate constraints
– conflict with another constraint
–Driven dimension
• Reference dimension
• Parentheses
• Over-constrained dimensions option
Adding Dimensions
•Auto Dimension
–Automatically apply
• Dimensions
• Constraints
–State number of dimensions or constraints
required to fully constrain the sketch
–First apply critical constraints and dimensions
–Will not override or replace existing constraints or
dimensions
Exercise 2-4
• Dimensioning A Sketch
Opening/Importing AutoCAD Files
• Opening/Importing AutoCAD Files Import
AutoCAD & AutoCAD Mechanical Files
–New Drawing
–New Part
–Title Block
–Border
–Symbol
–2D and 3D
• Import 2D geometry to an active sketch (part
or drawing)
Summary
To
Do This
Modify the Sketch options of
Autodesk Inventor
Click Tools > Application Options and click
on the Sketch tab.
Modify the Part options of
Autodesk Inventor
Click Tools > Application Options and click
the Part tab.
Create a new part file
Click the New icon in What To Do and then
click the Standard.ipt icon on the Default
tab, or click Standard (unit).ipt on one of
the other tabs.
Make a planar face, a work
plane, or a nonactive sketch in
the active part the active sketch
Click the Sketch tool on the standard
toolbar and click a face, a work plane, or
an existing sketch in the Browser. You
can also click a face, a work plane, or an
existing sketch in the Browser and then
click the Sketch tool from the standard
toolbar or press S.
Summary
To
Do This
Sketch the outline of the part
Use the 2D Sketch tools on either the Panel
Bar or the Sketch toolbar.
Add geometric constraints to a
sketch
Click a constraint from the constraint popup menu on the Sketch Panel Bar or Sketch
toolbar, or right-click in the graphics area,
select Create Constraint from the menu, and
select the specific constraint.
Add parametric dimensions to a
sketch
Click the General Dimension tool on the
Sketch toolbar, or right-click in the graphics
area and select Create Dimension from the
menu or press d.
Import AutoCAD data
Either open the file using the Open tool or
click the Insert AutoCAD file tool on the
2D Sketch Panel Bar or Drawing Sketch
Panel
Applying Your Skills
• Skill Exercise 2-1
• Skill Exercise 2-2