Computer Aided Design Basic Course

Transcription

1 Kon Computer Aided Design Basic Course 9 th January 2016

2 Agenda Practical Arrangements Parametric Modeling Software 2

3 Practical Arrangements

4 Course Staff Responsible Teacher Niko Tapanainen Friday You can find us in Room K238a (K1, Otakaari 4) 4

5 About the Course This is not a basic course This is a basic course of parametric computer aided design Bottom-up solid 3D design 5

6 Learning Outcomes Modeling of basic features and extrusions Parametric modeling, features and history trees Assemblies and special applications like sheet metal and drafting Ability to create design automates 6

7 Model vs Reality 7

8 Model vs Reality 8

9 What isn t Taught Making standardized engineering drawings You should already know it Choosing tolerances & production methods Basic scripting/programming A = B + C vs. B + C = A Not mathematical notation 9

10 Needed to Pass This Course Weekly exercises Mid-term exam Final work Grading based on the final work, but other areas can lower it 10

11 Lectures Two lectures You are already in the first one Practical arrangements Parametric modeling Second on Week 6 or 7 (8 th 19 th February) Publication of the Final Work Design methods 11

12 Weekly Exercises Held in CAE class (K344, K1 building, 3 rd floor) on Fridays 10 exercises 80% is obligatory (8) Individual Mid-term exam in your own exercise group On week 7 (19 th February) Grading pass/not pass 12

13 Weekly Exercise Workflow I II III Demo by teacher about this week s topics May be something extra Time for doing the exercises Teacher is there for you, ask! Show results to teacher If made in the correct way end of exercise Remember to sign the attendance list! 13

14 Exercise Schedule Week Topic 2 Basic features 3 Basic features II 4 Family table 5 Assemblies 6 Parameters & relations 7 Mid-term exam in your exercise group 8 Engineering drawings 9 Sheet metal 10 Optimization & visualization 11 Catia: part & assemblies 12 No exercises (Eastern Holidays) 13 Final work with guidance 14

15 Course Material Exercise material will be distributed through MyCourses Available in the beginning of the exercise week Weekly publishing schedule 15

16 Courses in CAE class (K344) Period I Open Mon - Thur 8:00-19:50 and Fri 8:00-17: Mon Tue Wed Thur Fri Kon Kon Kon CAD Basic Course Kul Kul closed 16

17 Courses in CAE class (K344) Period II Open Mon - Thur 8:00-19:50 and Fri 8:00-17: Mon Tue Wed Thur Fri Kon Kon CAD Basic Course Kul Kul closed 17

18 Final work Will be announced on the second lecture Configurable assembly Design automate Report Grading 0-5 Parameters 18

19 Parametric Modeling

20 The Curse of the CAD Computer Aided Drawing 20

21 The Curse of the CAD Computer Aided Design 21

22 2D Drawing Is Just a Different View 22

23 A Simplified Example 1/2 Flange Traditional method is to sketch the artifact 23

24 A Simplified Example 2/2 Flange Then insert the dimensions 24

25 This is Closer to What We Do 1/2 Flange We have a set of requirements in place when we begin 25

26 This is Closer to What We Do 2/2 Flange Then we add a geometry that fulfills the requirements 26

27 Reality is Not As Simple More likely you know something like this The problem might be arbitrarily complex Unknown things Known things subject to change 27

28 What is CAD? CAD is not a documentation tool, it is an engineering tool! Use it to help your design process 28

29 What is Parametric Modeling? The Microsoft Word example Word is a parametric word processor i.e. computer-aided software 29

30 Two Different Word Documents 30

31 Looking beneath the Surface 31

32 Two Different Word Documents? 32

33 Real Differences (1) Smartly used Styles: Headings e.g.: - Main heading distance from top - Empty space before and after heading Basic text paragraph e.g.: - Empty space after paragraph 33

34 Real Differences (2) No Styles Text just highlighted and changed font size and color Imagine how easily it can be changed Poor reusability 34

35 Knowing Your Tools (1) The Google example The WolframAlpha example 35

36 Knowing Your Tools (2) CAD tools can make many things But you need to know that those things exists Learning to use one program in a effective way can help you to use another program more efficient Almost all CAD programs have similar idea Difference is what is allowed to user to do 36

37 What is Parametric Modeling? Models are designed to be changed Engineering is an iterative process Within reasonable limits Dimensioning is important Main design parameters Only the dimensions, not their values Showing your world view to others Design Intent Think before doing Does CAD designer know how the design process will change the model? 37

38 Dimensioning Matters Is this your design? Or does it look more like this? 38

39 Dimensioning Matters Choosing dimensions that is needed for design E.g. distance between bearings, main length Trying to avoid any unnecessary calculations E.g. when the main design dimension is not in the model Minimizing the work to change the model 4 times more dimensions changed = 4 times bigger error risk 39

40 Handling Sketches

41 Degrees of Freedom in Sketches Point on 2D plane Two dimensions X and Y coordinate Polar coordinate system can be also used Line on 2D plane Four dimensions Coordinates of the starting point (X,Y) and vector to the end point and other options? 41

42 Degrees of Freedom in Sketches Two lines in 2D 6 dimensions Distances and angles Quadrilateral Four lines 8 dimensions - Because closed loop 42

43 Minimizing the Degrees of Freedoms Geometrical constrains Perpendicular constrains - -3 dimensions Coincident constrains - -2 dimensions 43

44 Finalizing Chose dimensions 3 dimensions Angle and lengths 44

45 Sketching Workflow References Geometry Constraints Dimensions 45

46 Design Intent

47 Design Intent Also in CAD models HOW it is made is important Models may look the same, but how easily can you understand and change them? Even with same dimensioning modeling method matters 47

48 Many Ways to Model a Box 48

49 Making Design Intent Clear (1) Plan ahead Just doing it may be fast, but changing it not Unplanned models will slow down downstream engineering activities Use test models Test different approaches Destroy when not needed Models needs to have a purpose Model for showing ideas is not the model planed for design 49

50 Making Design Intent Clear (2) One feature per function If part is symmetric, use symmetry If you need many holes, pattern them 50

51 One Function per Feature Makes understanding and changing the model easier Raw material Hole for the axel Cut for the belt Belt Wheel 51

52 Right Tool for the Task One tool can do the trick But how about flexibility? 52

53 Ultimate Goal Increase speed of delivery Reduce cost Increase your value Speed up the iteration cycle Communicate better Make your life easier 53

54 The Hard Part There is no one right way to do things Your skill will increase, you will get better This is why we have exercises Take time to clean up your mistakes Do not be afraid to change a bad solution 54

55 Software

56 Main CAD program Current version PTC Creo Parametric 3.0 M050 Can be found CAE class (K344, K1, 3 rd floor) - Our teaching class CAD class (K345) - Next to CAE class Maari-B, -E and -K - Classes in Maarintalo 56

57 Creo Student Edition Possibility to install Creo 3.0 to your home computer Download link Deal between you and PTC - All support through them Customization files available at MyCourses - Use those to make your Creo behave like in our teaching classes Differences to University Edition - No Simulate - No Mankin - No Illustrate - No Schematics 57

58 How not to Make a Sphere Round and chamfer are not industrial design tools! Rounds 58