ES050 – Introductory Engineering Design and Innovation Studio 1 Features Prof. Paul Kurowski
2 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.
3 Feature-based Modeling Process Create base part Add features until final shape is achieved Extruded BaseExtruded Cut ES1050 part 01.SLDPRT
4 Examples Extruded BaseExtruded CutRib ES050 part 03.SLDPRT
5 Extruded Base Extruded Cut Fillet Extruded Boss
6 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
7 Tools for Creating Features
8 Extrusion Sweep Hole Revolution Loft Extruded cut Sample of features
9 Extruded Part Profile Extrude
10 Revolved Part
11 Swept Part
12 Lofted Part
13 Other Features Fillets, chamfers and rounds Shelling Holes Ribs
14 Example Rib Round Fillet Hole Shell
15 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!
16 Modeling a Bracket ES050 part 04.SLDPRT
17 One Method Step 1Step 2Step 3 ES050 part 04.SLDPRT
18 Alternative method Step 1Step 2Step 3
19 Exercise Alternative sequence of modeling operations Extruded BaseExtruded CutRib
20 Exercise Alternative sequence of modeling operations
21 Exercise Alternative sequence of modeling operations
22 Exercise Alternative sequence of modeling operations
ES050 – Introductory Engineering Design and Innovation Studio 23 Parameters and Sketching
24 Outline Design intent and parametric modelling Constraint types “Smart sketching” Examples
25 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
26 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
27 Sketch parameters (dimensions) constrained by equations Feature created with that sketch + Cut extrude added ES050 part 02.SLDPRT
28 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”
29 SolidWorks Automatic Relations (Geometric Constraints)
30 Before adding constraints
31 After adding geometric constraints Tangent Concentric Perpendicular
32 After adding dimensional constraints
33 Constraint Types Geometric constraints Dimensional constraints
34 Boolean operations Geometric constraints Dimensional constraints boolean.SLDPRT
35 Summary Parametric modeling captures design intent Easy to modify part geometry by changing parameters
36 Home work