Computer Aided Design Basic Course

Transcription

1 Kon Computer Aided Design Basic Course 23 th September 2016

2 Agenda Practical Arrangements Parametric Modeling Software 2

3 Practical Arrangements

4 Course Staff Responsible Teacher Jarkko Säynäväjärvi Exercises You can find us in Room K238a (K1, Otakaari 4) 4

5 About the 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 Weekly Exercises Held in U344 (Otakaari 1, U-wing, 3 rd floor) on Fridays 9 exercises 7 is obligatory Individual Mid-term exam in your own exercise group On week 43 (28 th October) Grading pass/not pass 11

12 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! 12

13 Exercise Schedule Week Topic 39 Basic features 40 Basic features II 41 Family table 42 Assemblies 43 Mid-term exam in your exercise group 44 Parameters & relations 45 Engineering drawings 46 Sheet metal 47 Optimization & visualization 48 No topic 13

14 Course Material Exercise material will be distributed through MyCourses Available in the beginning of the exercise week Weekly publishing schedule 14

15 Final work Will be announced on the mid-term week Configurable assembly Design automate Report Grading 0-5 Parameters 15

16 Parametric Modeling

17 The Curse of the CAD Computer Aided Drawing 17

18 The Curse of the CAD Computer Aided Design 18

19 2D Drawing Is Just a Different View 19

20 A Simplified Example 1/2 Flange Traditional method is to sketch the artifact 20

21 A Simplified Example 2/2 Flange Then insert the dimensions 21

22 This is Closer to What We Do 1/2 Flange We have a set of requirements in place when we begin 22

23 This is Closer to What We Do 2/2 Flange Then we add a geometry that fulfills the requirements 23

24 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 24

25 What is CAD? CAD is not a documentation tool, it is an engineering tool! Use it to help your design process 25

26 What is Parametric Modeling? The Microsoft Word example Word is a parametric word processor i.e. computer-aided software 26

27 Two Different Word Documents 27

28 Looking beneath the Surface 28

29 Two Different Word Documents? 29

30 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 30

31 Real Differences (2) No Styles Text just highlighted and changed font size and color Imagine how easily it can be changed Poor reusability 31

32 Knowing Your Tools (1) The Google example The WolframAlpha example 32

33 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 33

34 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? 34

35 Dimensioning Matters Is this your design? Or does it look more like this? 35

36 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 36

37 Handling Sketches

38 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? 38

39 Degrees of Freedom in Sketches Two lines in 2D 6 dimensions Distances and angles Quadrilateral Four lines 8 dimensions - Because closed loop 39

40 Minimizing the Degrees of Freedoms Geometrical constrains Perpendicular constrains - -3 dimensions Coincident constrains - -2 dimensions 40

41 Finalizing Chose dimensions 3 dimensions Angle and lengths 41

42 Sketching Workflow References Geometry Constraints Dimensions 42

43 Design Intent

44 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 44

45 Many Ways to Model a Box 45

46 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 46

47 Making Design Intent Clear (2) One feature per function If part is symmetric, use symmetry If you need many holes, pattern them 47

48 One Function per Feature Makes understanding and changing the model easier Raw material Hole for the axel Cut for the belt Belt Wheel 48

49 Right Tool for the Task One tool can do the trick But how about flexibility? 49

50 Ultimate Goal Increase speed of delivery Reduce cost Increase your value Speed up the iteration cycle Communicate better Make your life easier 50

51 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 51

52 Software

53 Main CAD program Current version PTC Creo Parametric 3.0 M050 Can be found Otakari 1 - U257, U344, U351, U-wing - A046/a, A-wing, basement Maari - All Windows classes in Maarintalo 53

54 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 54

55 How not to Make a Sphere Round and chamfer are not industrial design tools! Rounds 55