Chapter 2 Sketching, Constraining & Dimensioning

1. Chapter 2Sketching, Constraining & Dimensioning

2. Chapter 2 - Objectives • After completing this chapter, you will be able to do the following: • Change the part and sketch options as needed • Sketch an outline of a part • Create geometric constraints • Use construction geometry to help constrain sketches • Dimension a sketch • Create dimensions using the automatic dimensioning command • Change a dimension’s value in a sketch • Open and insert AutoCAD DWG data

3. Sketch & Part - Application Options • Options • Customized your preferences • Settings are global • Affects all open & new Inventor documents

4. Part - Application Options • Sketch on new part creation • Construction • Auto-hide in-line work features • Auto-consume work features and surface features • 3D grips • Edit Base Solids Using

5. Sketch - Application Options • 2D Sketch • Display • Overconstrained dimensions • Spline fit method • Heads-Up Display • Snap to Grid • Edit dimensions when created • Autoproject edges during curve creation • Autoproject edges for sketch creation and edit • Autoproject part origin on sketch create • Point alignment • 3D Sketch

6. Units • Units • Default unit of measurement • Part, Assembly & Drawing files • Template file • Changing - Overridden • Edit dimension

7. Templates • Templates • New files created from a template • Add or Modify templates • Template directory • Subdirectory • New Tab

8. Creating a Part • From the Open dialog box click the Standard.ipt icon in the Open dialog box • From the New file drop list on the Standard toolbar

9. Creating a Part • Sketches & Default Planes • Sketch plane • 2D objects are sketched • Active sketch • Three planes • XY,YZ, and XZ • Three Axes • X, Y, and Z • Center • Origin - point at the intersection • Browser • New Sketch • Create 2D Sketch • Active sketch

10. Sketch the Outline of the Part • Step 1 - Sketches Overview • Sketching strategies, tools, & techniques • Outline • Draw to finished size/shape • Visual Guide – distance & angle • No overlaps & gaps • Keep shape simple • Closed vs. Open shape • Sketch Tools • Sketching tools • Expert mode on/off

11. Dynamic Input • Polar or Cartesian Coordinates • Persistent Dimensions • Heads-Up Display Settings • Dimension Input

12. Sketch the Outline of the Part • Using the Sketch Tools • Visual feedback • Dynamic Input • Line Tool • Powerful tool • Endpoint - Arc • Object Tracking - Inferred Points • Dashed lines • Endpoints • horizontal • vertical • perpendicular

13. Sketch the Outline of the Part • Automatic Constraints • Constraint symbols • Scrubbing • different constraint applied • move the cursor so it touches

14. Constraint Persistence & Inference • Persistence • Turns sketch constraints on/off • When on, sketch constraints are applied while sketching • When off, the constraint icon will appear on the screen, but it will not be applied to the sketch • Inference • Turns the preview of the constraint on/off • When off, Constraint Persistence is also turned off • When off, sketch constraints are not applied

15. Constraint Options • With Constraint Inference on you can control which sketch constraints can be inferred and which geometry they should be inferred from

16. Select Objects • Selecting Objects • individually objects • multiple objects • color change • Deleting Objects • right-click Delete

17. Measure Tools • Measure • Distances • Points • Edges • Faces • Parts • Angles • Loops • Area • Region Properties

18. Measure Tools • Measure • Additional Options • Click the arrow in the Measure dialog box

19. Exercise 2-1 • Creating A Sketch with Lines Exercise 2-2 • Creating a Sketch with Tangencies

20. Constraining the Sketch • Step 2 - Geometric Constraints • Apply behavior • Create relationships • Status Bar • Fully constrain • Use projected origin point • Constraint Types • 12 geometric constraints

21. Constraining the Sketch • Geometric Constraints • Dragging a Sketch • Constrained or Not • Geometry stretches • Showing Constraints • Show all & Hide all F8 and F9 • To see applied constraints • Objects change color • Deleting Constraints • Right-click or Delete key

22. Construction Geometry • Sketch tab > Format panel • Add dimensions and constraints • Not visible when a feature is created • Always available in the sketch

23. Sketch Degrees of Freedom • To see the open degrees of freedom in a sketch • Right-click and click Show All Degrees of Freedom

24. Exercise 2-3 • Adding and Displaying Constraints

25. Adding Dimensions Manually • Step 3 – Adding Dimensions • All dimensions created are parametric • Control & change size of geometry • General Dimensioning • Create linear, angle, radial, or diameter • Automatically snap • Extension lines • Preview image • Dimensioning Lines • Endpoints - two • Length • Dimensioning an Angle • Two lines • Arc

26. Adding Dimensions • Dimensioning Arcs and Circles • Default: Arc = radius • Default: Circle = diameter • Linear Diameter Dimensions • Revolved part • Represent a quarter outline • Axis of rotation • Dimensioning to a Tangency • Arc or circle • Constraint symbol changes • Two quadrants

27. Adding Dimensions • Entering and Editing a Dimension’s Value • Automatically appear • Change the value • Edit Dimension option • Default value • To change double-click • Enter exact value • Accurate to six decimal places • Smallest dimensions first • Fractions

28. Adding Dimensions • Entering and Editing a Dimension’s Value • Repositioning a Dimension • New location • Origin points cannot be moved • Over-Constrained Sketches • Inventor will not allow • over-constrain • duplicate constraints • conflict with another constraint • Driven dimension • Reference dimension • Parentheses • Over-constrained dimensions option

29. Adding Dimensions • Auto Dimension • Automatically apply • Dimensions • Constraints • State number of dimensions or constraints required to fully constrain the sketch • First apply critical constraints and dimensions • Will not override or replace existing constraints or dimensions

30. Exercise 2-4 • Dimensioning a Sketch

31. Move and Scale Tools • Move sketch objects to another location • Move or make copy • Scale a sketch • Enter scale factor • Pick two points • Relax dimensions • Relax constraints

32. Opening/Importing AutoCAD Files • Copy to clipboard within Inventor or AutoCAD and Paste in Inventor • Open/Import AutoCAD & AutoCAD Mechanical Files • New Drawing • New Part • Title Block • Border • Symbol • 2D and 3D • Import 2D geometry to an active sketch (part or drawing)

33. Importing Other File Types • DXF • Alias • IDF Board File • IGES • JT • Parasolids Binary Files • Parasolids Text Files • PRO/Engineer Files • SAT • STEP • SolidWorks Files • UGS NX Files

34. Exercise 2-5 • Inserting AutoCAD Data

35. Applying Your Skills • Skill Exercise 2-1 Skill Exercise 2-2

36. Checking Your Skills • True__ False__ When you sketch, constraints are not applied to the sketch by default. • True__ False__ When you sketch and a point is inferred, a constraint is applied to represent that relationship. • True__ False__ A sketch does not need to be fully constrained. • True__ False__ When working on an mm part, you cannot use English (inch) units. • True__ False__ After a sketch is constrained fully, you cannot change a dimension’s value. • True__ False__ A driven dimension is another name for a parametric dimension. • True__ False__ Dimensions placed dynamically are not parametric. • True__ False__ You can import only 2D AutoCAD data into Autodesk Inventor. • Explain how to draw an arc while in the Line command. • Explain how to remove a geometric constraint from a sketch. • Explain how to change a vertical dimension to an aligned dimension while you create it. • Explain how to create a dimension between two quadrants of two arcs.