Chapter 2 Sketching Constraining Dimensioning Chapter 2 Objectives

Chapter 2 Sketching, Constraining & Dimensioning

Chapter 2 - Objectives • After completing this chapter, you will be able to – Change the sketch and part options as needed – Sketch an outline of a part – Create geometric constraints – Dimension a sketch – Create dimensions using the automatic dimensioning tool – Change a dimension’s value in a sketch – Import Auto. CAD DWG data

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

Sketch - Application Options • Constraint Placement Priority • Display • Overconstrained Dimensions • Snap to Grid • Edit dimensions when created • Autoproject edges during curve creation • Autoproject edges for sketch creation and edit • 3 D Sketch

Part - Application Options • • Sketch on New Part Creation Parallel view on sketch creation Auto-hide in-line work features Construction

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

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

Creating a Part • Creating a Part – Standard. ipt icon – File menu – Shortcut key – New icon – Part environment

Creating a Part • Sketches & Default Planes – Sketch plane • 2 D 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 – Active sketch

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 it simple Closed vs. Open shape – Sketch Tools • Sketching tools • Expert mode on/off

Sketch the Outline of the Part • Using the Sketch Tools – Visual feedback • Line Tool – Powerful tool – Endpoint - Arc • Inferred Points – Dashed lines – Endpoints • horizontal • vertical • perpendicular

Sketch the Outline of the Part • Automatic Constraints – Constraint symbols • Scrubbing – different constraint applied – move the cursor so it touches • Precise Input – specified length or angle • Selecting Objects – individually objects – multiple objects – color change • Deleting Objects – right-click

Measure Tools • Analyze – Sketch – Part – Assembly models • Measure – Distances – Angles – Loops – Area

Analysis Tools • Measure – Additional Options • Click the arrow in the Measure dialog box Reset Clears the contents of the measurement box Add to Accumulate Adds the measurement in the measurement box to the accumulate Clear Accumulate Clears all measurements from the accumulate sum Display Accumulate Displays the sum of all measurements added to the accumulate All Decimals Changes the decimal display between all decimals and the number of decimal places specified in the document settings

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

Constraining the Sketch • Step 2 - Geometric Constraints – Apply behavior – Create relationships • fully constrain • fix constrain – Constraint Types • 11 geometric constraints

Constraining the Sketch • Geometric Constraints – Adding Constraints • Applying • Over-constrain • Duplicate “Adding this constraint will over-constrain the sketch” – Snap • Midpoint, center & intersection • Coincident constraint

Constraining the Sketch • Geometric Constraints – Dragging a Sketch • Constrained or Not • Geometry stretches – Showing Constraints • To see applied constraints • Objects change color – Deleting Constraints • Right-click • Show all & Hide all

Exercise 2 -3 • Adding and Displaying Constraints

Adding Dimensions • 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

Adding Dimensions – Dimensioning Arcs and Circles • Circumference • Arc = radius • Circle = diameter – Diametric Dimensions • • Revolved part Represent a quarter outline Linear diameter Axis of rotation – Dimensioning to a Tangency • Arc or circle • Constraint symbol changes • Two quadrants

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

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

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

Exercise 2 -4 • Dimensioning A Sketch

Opening/Importing Auto. CAD Files • Opening/Importing Auto. CAD Files Import Auto. CAD & Auto. CAD Mechanical Files – New Drawing – New Part – Title Block – Border – Symbol – 2 D and 3 D • Import 2 D geometry to an active sketch (part or drawing)

Summary To Do This Modify the Sketch options of Autodesk Inventor Click Tools > Application Options and click on the Sketch tab. Modify the Part options of Autodesk Inventor Click Tools > Application Options and click the Part tab. Create a new part file Click the New icon in What To Do and then click the Standard. ipt icon on the Default tab, or click Standard (unit). ipt on one of the other tabs. Make a planar face, a work plane, or a nonactive sketch in the active part the active sketch Click the Sketch tool on the standard toolbar and click a face, a work plane, or an existing sketch in the Browser. You can also click a face, a work plane, or an existing sketch in the Browser and then click the Sketch tool from the standard toolbar or press S.

Summary To Do This Sketch the outline of the part Use the 2 D Sketch tools on either the Panel Bar or the Sketch toolbar. Add geometric constraints to a sketch Click a constraint from the constraint popup menu on the Sketch Panel Bar or Sketch toolbar, or right-click in the graphics area, select Create Constraint from the menu, and select the specific constraint. Add parametric dimensions to a sketch Click the General Dimension tool on the Sketch toolbar, or right-click in the graphics area and select Create Dimension from the menu or press d. Import Auto. CAD data Either open the file using the Open tool or click the Insert Auto. CAD file tool on the 2 D Sketch Panel Bar or Drawing Sketch Panel

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