Chapter 2 Sketching, Constraining & Dimensioning

1. Chapter 2Sketching, Constraining & Dimensioning

2. Chapter 2 - Objectives • After completing this chapter, you will be able to: • Change the part and sketch Application Options • Sketch an outline of a part • Create geometric constraints to a sketch to control design intent • Use construction geometry to help constrain a sketch • Dimension a sketch • Change a dimension’s value in a sketch • Insert AutoCAD DWG data into a part’s sketch

3. Part & Sketch - 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 • Configure Default Template • Template directory • Subdirectory • New Tab

8. Creating a New Part • Application Menu • Quick Access toolbar • New file drop list on the Quick Access 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 • 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 an edge

14. Common Sketch • Center-point Circle • Tangent Circle • Three-Point Arc • Tangent Arc • Center-Point Arc • Two-Point Rectangle • Three-Point Rectangle • Two-Point Center Rectangle • Three-Point Center Rectangle • Fillet • Chamfer • Polygon • Mirror • Rectangular Pattern • Circular Pattern • Offset • Trim • Extend

15. Select Objects • Selecting Objects • Individually objects • Window and Crossing • Color change • Deleting Objects • Right-click Delete • Delete on keyboard

16. Measure Commands • Measure • Distances • Points • Edges • Faces • Parts • Angles • Loops • Area • Region Properties

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

18. Exercise 2-1 • Creating A Sketch With Lines Exercise 2-2 • Creating a Sketch With Tangencies

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

20. Constraining the Sketch • Geometric Constraints • Dragging a Sketch • Constrained or Not • Showing Constraints • Status Bar • Show All = F8 • Hide All = F9 • Objects change color • Deleting Constraints • Select constraint icon and then right-click Delete or Delete key

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

22. Sketch Degrees of Freedom • To see open degrees of freedom in a sketch • Status Bar - Show All Degrees of Freedom

23. Exercise 2-3 • Adding and Displaying Constraints

24. 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

25. 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

26. 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

27. 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

28. 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

29. Exercise 2-4 • Constraining and Dimensioning a Sketch

30. Inserting 2D AutoCAD Data • Insert 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)

31. Importing Other File Types • DXF • Alias • Catia • IDF Board File • IGES • JT • NX Files • Parasolids Binary Files • Parasolids Text Files • PRO/Engineer Files • Rhino Files • SAT • STEP • STL • SolidWorks Files

32. Exercise 2-5 • Inserting AutoCAD Data

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

34. 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. Continued

35. Checking Your Skills - continued • Explain how to change a vertical dimension to an aligned dimension while you place the dimension. • Explain how to create a dimension between two quadrants of two arcs. • True__ False__ AutoCAD needs to be installed to insert AutoCAD geometry. • True__ False__ When a sketch is extruded that contains construction geometry, the construction geometry is deleted. • Explain how to change the unit type in a part file. • True ___ False ___ To scale the entire sketch when placing the first dimension you must right-click and check Scale from the menu. • True ___ False ___ When a Pushpin appears in the Sketch icon in the browser the sketch is fully constrained. • True ___ False ___ An arc length dimension can only be a driven dimension. • Explain how to draw a rectangle that is centered on the origin point. • True ___ False ___ When creating the first 2D sketch you must select an origin plane from the browser's Origin folder.