EGR 110 – Inventor Lecture #4
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Features in Inventor
Inventor includes two types of
• geometric features:
Sketched features
(including extrusions, revolutions, and sweeps)
Placed features
(including holes, fillets, chamfers, and shells)
Sketched features
required that 1 or
2 sketches be drawn first.
Placed features
do not require a sketch.
So far we have only used sketched features (extrusions) to create solid models.
The Model browser shows a series of sequential sketched and placed features (see example to the right).
Sketched feature
Placed feature
Placed feature
Sketched feature
Sketched feature
Placed feature
Sketched feature
Placed feature
Placed feature
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EGR 110 – Inventor Lecture #4
Holes
We can create holes using extrusions, but an easier way is to use
Hole
from the 3D
Model menu.
Example:
Create a simple solid block (extrude a rectangle) and switch to an isometric view.
Select
Hole
from the
3D Model
menu (or press H on the keyboard).
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EGR 110 – Inventor Lecture #4
Holes
(continued)
On the Hole menu, select
Linear
1) Face
under
Placement
. Then select three items:
– Pick the face where you want the hole (pick the approximate location)
2)
3)
Reference 1
Reference 2
– Pick an edge for a distance measurement to the center of the hole
– Pick another edge for a second distance measurement
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EGR 110 – Inventor Lecture #4
Holes
(continued)
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Experiment by creating various types of holes, including:
Through holes
Holes with a specified depth
Tapped (threaded) holes
Countersink holes
Counterbore holes
Holes that intersect holes
Also try editing various holes to change their type, size, location, etc.
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EGR 110 – Inventor Lecture #4
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Threads
Note that threads placed inside holes are
bit-map images
added for appearance only (although the thread sizes used can be referred to when dimensioning). Threads do not appear on isometrics in drawing files; however, the threads are properly represented in other views.
Dashed lines represents threads
EGR 110 – Inventor Lecture #4
External threads
– Internal threads are typically added with the
Hole
command. External threads can be applied to the
3D model using the
Thread
command.
Example:
Try creating the following object. Discuss the sequence of operations used as shown in the browser.
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EGR 110 – Inventor Lecture #4
Fillets, Rounds, and Chamfers
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Sharp edges on objects are often rounded off using curved edges or beveled edges.
Fillet
Round
- rounded inside corner
– rounded outside corner
Chamfer
– beveled edge connecting two surfaces
•
•
Notes:
Both fillets and rounds are created in Inventor using the
Fillet
command
Chamfers and fillets can be added to both 2D sketches and to existing solid features.
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Original object with sharp corners:
Round
Chamfer
Fillet
EGR 110 – Inventor Lecture #4
Adding a Fillet to a 2D Sketch
Enter radius
Pick two edges and fillet (round) will appear
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EGR 110 – Inventor Lecture #4
Adding a Fillet to a 3D Model
Pick edge
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EGR 110 – Inventor Lecture #4
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Example with several fillets and chamfers
Try building this solid in class. Discuss the series of operations that might be used.
Which fillets and chamfers could be added to 2D sketches?
Which should be added later to the 3D model?
Chamfer
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Fillet
Chamfer
Round
Fillet
Note:
If possible, add chamfers and fillets to a 2D sketch before extrusion. If they are added later to a solid
(as a placed feature), they are often added as late as possible in the sequence of operations so that they do not interfere with other operations. Note that a machinist creating a part would be likely to add chamfers and fillets after creating other key features. It is often useful to think of creating parts in Inventor using a sequence of operations that might be logically used in building the part in a machine shop.
EGR 110 – Inventor Lecture #4
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Revolution
Another type of sketched feature in Inventor is a
revolution
. Revolutions are useful for features that are symmetrical about an axis. A revolved feature is formed by revolving a
2D sketch about a specified axis.
Example
: Creating a wheel using revolution
2D Sketch: Profile and axis of revolution
(axis of revolution does not have to be a centerline)
3D Model: Select Revolve and the window above appears.
Select the Profile and Axis
Revolved feature
EGR 110 – Inventor Lecture #4
Quick Test
The profile shown could be revolved around lines A, B, C, D, E, or F.
Can you determine which line was used for each solid shown below?
Circle the correct letter in each case.
C
A
B
E
F
D
A B C D E F
A B C D E F A B C D E F
A B C D E F
A B C D E F
A B C D E F
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EGR 110 – Inventor Lecture #4
Additional Revolution Examples
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EGR 110 – Inventor Lecture #4
Symmetrical Features
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Symmetrical Features can be added in Inventor using:
Circular Pattern
Rectangular Pattern
Mirror Pattern
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The patterns above can be added to the following:
2D Sketch
3D Model
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EGR 110 – Inventor Lecture #4
Examples of Rectangular Patterns
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Create the solid box using an extrusion
Add one countersink hole
Use rectangular pattern on 3D model
Quick Test
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Draw box and one circle in 2D Sketch
Use rectangular pattern on 2D sketch
Extrude
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Would you use a rectangular pattern on the 2D sketch or on the 3D model? Circle the answer.
Would you use a rectangular pattern on the 2D sketch or on the 3D model? Circle the answer.
EGR 110 – Inventor Lecture #4
Examples of Circular Patterns
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Create circular plate using an extrusion
Add one stud with a second extrusion
Use circular pattern on 3D model
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Draw 2D Sketch with one circle
Use circular pattern on 2D sketch
Extrude
Useful note: If you try to perform operations (such as trim or fillet) on a pattern, you may find that it will not work. To correct this problem:
1) Select Edit Pattern (box appears such as the one below)
2) Select the More button (>>)
3) Remove the check from Associative
More complex example
More
Remove Check
EGR 110 – Inventor Lecture #4
Example of Mirror Pattern
Mirror
Line
1. Draw half of object. Include mirror line (construction line may be useful)
3. Extrude to create solid model
2. Select sketch features to mirror and the mirror line
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EGR 110 – Inventor Lecture #4
Detailed Example: Rectangular Pattern in a 2D Sketch
1) Draw sketch, including one hexagon (use
Polygon
tool)
2) Select
Rectangular
pattern, select
Geometry
, and select the hexagon
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EGR 110 – Inventor Lecture #4
Detailed Example: Rectangular Pattern in a 2D Sketch (continued)
3) Select
Direction 1
and pick a line in the direction the pattern should go (a
4) horizontal line in this case). An arrow appears showing the direction selected. If the arrow is in the opposite direction, select the
Flip
button.
Enter the number of pattern elements and spacing for Direction 1
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Direction arrow and Flip button
Number of elements
Spacing between elements
Arrow appears in the direction selected for Direction 1
EGR 110 – Inventor Lecture #4
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Detailed Example: Rectangular Pattern in a 2D Sketch (continued)
5) Select
Direction 2
and pick a line in the second direction the pattern should go
6)
(vertical line). An arrow appears showing the direction selected. If the arrow is in the opposite direction, select the
Flip
button.
Enter the number of pattern elements and spacing for Direction 2
Arrow appears in the direction selected for Direction 1
Final result after extrusion
EGR 110 – Inventor Lecture #4
Detailed Example: Circular Pattern in a 3D Model
Create a wheel with 6 equally space threaded holes shown below.
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1. Create the basic wheel using a revolution
EGR 110 – Inventor Lecture #4
Detailed Example: Circular Pattern in a 3D Model
(continued)
2.
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Add another sketch plane to the face of the wheel where the holes will be added.
Add a line and a dimension for the
bolt circle
– the circular path on which the holes will lie.
Finish the sketch.
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EGR 110 – Inventor Lecture #4
Detailed Example: Circular Pattern in a 3D Model
(continued)
3. Select
Hole
• from the 3D Model menu. Use the following options:
Placement: From Sketch
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Pick the center point where the hole is to be placed
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Termination: Through All
Diameter: 0.75 in (or your choice)
Select Threaded Hole and then select OK
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EGR 110 – Inventor Lecture #4
Detailed Example: Circular Pattern in a 3D Model
(continued)
4. Select
Circular Pattern
• from the 3D Model menu. Use the following options:
Features: Select the threaded hole just created
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Rotational Axis: Pick any circle on the wheel that has the correct center
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Placement: Pick 6 holes spread over 360 degrees
Select OK
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Final result
EGR 110 – Inventor Lecture #4
Centerlines and Linear Diametric Dimensions
For revolved features it is common to use
linear diametric dimensions
instead of
radial dimensions
. An example of the difference is shown below.
25 f
25 f
15 f
5 f
15 f
25 f
5
Front
Example using
radial dimensions
Right
Front
Example using
linear diametric dimensions
EGR 110 – Inventor Lecture #4
Revolved Features with Linear Diametric Dimensions
An example is shown below to illustrate the procedure for creating a revolved feature using a centerline and linear diametric dimensions.
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1.
Create a new (metric) part and draw the profile to be revolved.
Use a
centerline
for the axis of revolution (required).
EGR 110 – Inventor Lecture #4
Revolved Features with Linear Diametric Dimensions
(continued)
2.
3.
Add dimensions by selecting: a) The centerline (not its endpoint) b) A line on the profile
Finish the sketch and revolve the sketch
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EGR 110 – Inventor Lecture #4
Revolved Features with Diametric Dimensions
(continued)
4. Create a metric drawing file using the part (ANSI(mm).idw with A-size, portrait).
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Add front, top, and isometric views. Change the scale if necessary.
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Retrieve dimensions for the front view – note that they are linear diametric dimensions
Change the number of digits to whole mm using:
Manage – Styles Editor – Dimension – Default: mm (ANSI) – Precision - 0
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Linear diametric dimensions