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1
ES050 – Introductory Engineering Design and Innovation Studio
Features
Prof. Paul Kurowski
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Feature-Based Solid Modeling
Parts modeled by adding features to a base part Features “represent” manufacturing “operations”
holes, ribs, fillets, chamfers, slots, pockets, etc.
Material can be added or subtracted Features can be created by extrusion, sweeping,
revolving, etc.
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Feature-based Modeling Process Create base part Add features until final shape is achieved
Extruded Base Extruded Cut Extruded CutES1050 part 01.SLDPRT
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Examples
Extruded Base Extruded CutRib
ES050 part 03.SLDPRT
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Extruded Base Extruded Cut Extruded Cut
Fillet Extruded Boss
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Tools for Creating Features
Geometry is defined by sketching a 2D profile on a plane, and “extending” it into 3D
These profiles can be extended to 3D by: Extruding Revolving Sweeping Lofting
These operations can add material or cut it away
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Tools for Creating Features
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Extrusion
Sweep
Hole
Revolution
Loft
Extruded cut
Sample of features
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Extruded Part
Profile
Extrude
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Revolved Part
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Swept Part
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Lofted Part
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Other Features
Fillets, chamfers and rounds Shelling Holes Ribs
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Example
Rib Round
Fillet
HoleShell
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Alternative Modeling Approaches There are usually many ways to model an object A good approach requires few steps, and is easy
to modify if necessary The modeling steps do not necessarily
correspond to manufacturing steps Think the steps through before you
start!
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Modeling a Bracket
ES050 part 04.SLDPRT
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One Method
Step 1 Step 2 Step 3
ES050 part 04.SLDPRT
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Alternative method
Step 1 Step 2 Step 3
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Exercise Alternative sequence of modeling operations
Extruded Base Extruded CutRib
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ExerciseAlternative sequence of modeling operations
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ExerciseAlternative sequence of modeling operations
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ExerciseAlternative sequence of modeling operations
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ES050 – Introductory Engineering Design and Innovation Studio
Parameters and Sketching
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Outline
Design intent and parametric modelling Constraint types “Smart sketching” Examples
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Parametric modeling
Also know as Constraint-based User constrains geometry based on
Design Intent Design variations can be generated by
changing a few key dimensions Geometry is automatically regenerated
based on constraints
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Example
D1
D2=D1/2
D4=D3/2
D3=2*D1
•The part should be twice as long as it is wide•The hole should be centered in both directions•The hole diameter should be 50mm
D5=50
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Sketch parameters
(dimensions) constrained
by equations
Feature created with that
sketch + Cut extrude added
ES050 part 02.SLDPRT
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Smart Sketching
Most CAD systems use “smart” sketching tools Design intent is inferred, and constraints added
automatically as you draw For example, two lines that are nearly
perpendicular “snap” perpendicular, with a constraint
SolidWorks calls this “Automatic Relations”
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SolidWorks Automatic Relations (Geometric Constraints)
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Before adding constraints
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After adding geometric constraints
Tangent
Concentric
Perpendicular
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After adding dimensional constraints
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Constraint Types
Geometric constraints Dimensional constraints
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Boolean operations
Geometric constraints Dimensional constraints
boolean.SLDPRT
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Summary
Parametric modeling captures design intent
Easy to modify part geometry by changing parameters
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Home work