lesson4 create sketchcad

Exercise: Visualize 3D ObjectsIn this exercise, you review 3D objects in Autodesk Inventor and interpret each of their six views by sketching. You:

� Open a part file.

� Create sketch views.

You use Autodesk Inventor visualization tools to improve your spatial understanding of the part. The ability to visualize a 3D part is an important skill for you to develop as a mechanical designer.

PreparationTo view objects in 3D, you will use Autodesk Inventor.

You also need a pencil, scale, and sketch paper. Sketch paper is supplied. Open mod04_01_grid.pdf from the Lesson4 folder, and then print the file.

Open a Part File

1. Start Autodesk Inventor.

Note: If you are already in Autodesk Inventor, close all files.

2. If the Open dialog box is displayed, click Projects. Otherwise, click File menu > Projects.

3. Browse to the folder where you installed the exercise files and open the project file Inv_Edu.ipj.

4. Open Lesson4\mod04_01.ipt.

5. Click Rotate.

6. Rotate the die in all directions to view its sides.

All 3D objects have sides. If you put any object into a clear plastic box, it would appear to have six sides just like the clear plastic box. These sides are called views. There are six views to any object: top, front, back, bottom, right-side, and left-side.

of 22Exercise 1: Visualize 3D Objects

20/01/2013file://C:\Users\Utama_eng\AppData\Local\Temp\~hhF0D4.htm

Tip: Use the ViewCube to display standard orthographic views of the die.

7. Close the file. Do not save changes.

Create Sketch Views

1. Use Autodesk Inventor to view the following objects, and then sketch the front, top, and right-side views.

2. Do not add hidden lines. These will be discussed in the next exercise.

3. Open mod04_01a.ipt.

4. Open mod04_01b.ipt.

5. Open mod04_01c.ipt.

6. Open mod04_01d.ipt.

7. Open mod04_01e.ipt.



8. Open mod04_01f.ipt.

9. Keep these sketches for the next exercise,

where you will add the other linetypes required to complete the sketch.

10. Close the files. Do not save changes.

Exercise: Add Hidden Lines to Sketches In this exercise, you add hidden and centerlines to complete the sketches from the Visualize 3D Objects exercise. You:

� Add hidden lines.

� Add centerlines.

Add Hidden and Centerlines

1. Review your sketches from the Visualize 3D Objects exercise.

2. Add hidden lines to represent hidden details.

3. Add centerlines to represent symmetry, and to show the center of circles and circular features.

Exercise: Add Dimensions to a SketchIn this exercise, you add dimensions to a sketch. This part of the process is known as annotating a drawing. Correctly dimensioning a sketch provides the manufacturing team with the information required to make the part. You:

� Review the part.

� Dimension the sketch.

� Review the solution.

The incomplete sketch is shown.



Note: Autodesk Design Review must be installed to complete this exercise. If it is not installed, it can be downloaded free from the Autodesk website.

Review the Part


2. Click Rotate.

3. Rotate the part in all directions to gain a better understanding of each face.

Dimension the Sketch

1. Open Lesson4\mod04_03_dimension.dwf. Print the file.

Note: To open a DWF file, locate the file in Windows Explorer, and then double-click the file. This opens the file in Autodesk Design Review.

2. Review the incomplete sketch you printed in Step 1.

3. On the sketch, add centerlines to represent holes and symmetry.

4. Add necessary dimensions to fully describe the part.

Review the Solution

1. Open Lesson4\mod04_03_solution.dwf. Print the file.

2. Review the solution and compare it to your sketch.

3. Make the necessary edits to your sketch.

4. Close all files.

Exercise: Create a Sketch with LinesIn this exercise, you create a new part file, and then you create sketch geometry using basic construction techniques. You:

� Start a new part file and sketch.

� Use the Design Support System to review the procedure.



� Complete the sketch.

You learn how to use the Autodesk Inventor Design Support System to assist in the design process.

The completed exercise

Part constructed from the sketch

Start a New Part File and Sketch

1. On the Standard toolbar, click New. Click the Metric tab, and then double-click Standard (mm).ipt.

A new part is created and listed in the browser. Sketch1 is active.

2. Click Line.

3. Click near the left side of the graphics window, move the cursor to the right approximately 100 units. Click to specify a second point.

Tip: If the entire line is not visible on the screen, use the Zoom tool or the wheel on your mouse to zoom out.

Note: The length, angle, and geometry of the line are dynamically displayed on the screen.



The length and angle are displayed in the lower right corner of the window, and symbols indicate the geometric constraint. In this example, the symbol indicates that the line is horizontal.

Use the Design Support System

1. On the Standard toolbar, click Visual Syllabus.

2. Click Sketch Lines > Lines > Perpendicular. Watch the animation.

Tip: Use the controls at the lower edge of the dialog box to reset and replay the animation.

3. Close the Show Me Animations window when you understand the concept.

Complete the Sketch

1. Move the cursor up approximately 40 units, and then click to create a perpendicular line.

2. Move the cursor to the left, and then create

a horizontal line of approximately 30 units. The parallel constraint symbol is displayed.

3. Move the cursor down and create a vertical

line of approximately 10 units.



4. Move the cursor left to create a horizontal

line of approximately 40 units.

5. Move the cursor up until the parallel

constraint symbol is displayed and a dotted line is displayed.

6. Click to specify a point.

7. Move the cursor left until the parallel

constraint symbol is displayed and a dotted line appears.

8. Click to specify a point.

9. Move the cursor down until it touches the

first point you specified at the beginning of the exercise. When the coincident constraint symbol is displayed, click to close the sketch.

10. Right-click in the graphics window, and then

click Done [Esc].




click Finish Sketch.


Exercise: Create Profiles with Tangencies In this exercise, you create a new part file, and then you create a simple profile using basic construction techniques. The profile consists of lines and tangential arcs.

This exercise illustrates how you can use the Autodesk Inventor Design Support System to assist in the design process.


Part constructed from the sketch

Start a New Part File

1. On the Standard toolbar, click New. Click the Metric tab, and then double-click Standard (mm).ipt.

2. On the Standard toolbar, click View > Toolbar > Inventor Precise Input.

3. Click Line.



4. Click in the center of the graphics window.

If the Precise Delta is off, click to turn it on. Select XY from the drop-down list.

5. Enter 65 in the X field of the Inventor Precise

Input toolbar.

6. When the horizontal constraint symbol is displayed, click to create a 65mm horizontal line.

Tip: If the entire line is not visible on the screen, use the Zoom tool or the wheel on your mouse to zoom out.

7. Click in the Y field, and then enter 15.

8. Click a second point when the perpendicular constraint symbol is displayed.

9. Move the cursor up and to the left, and then

click to create a sloping line.



Use the Design Support System

1. On the Standard toolbar, click Visual Syllabus.

2. Click Sketch Lines > Arcs > Tangent. Watch the animation.

Tip: Use the controls at the lower edge of the dialog box to reset and replay the animation.

3. Close the Show Me Animations window when you understand the concept.

Complete the Sketch

1. Click the end of the line, hold down the mouse button, and then drag the endpoint to create a tangent arc. Release the mouse button to place the endpoint of the arc.

Note: As the Show Me animation demonstrates, a tangent arc can be created by clicking and dragging the endpoint of the line just placed.

2. Move the cursor to the start point of the

profile and click when the coincident constraint symbol is displayed.




click Done [Esc].

4. Right-click in the graphics window, and then click Finish Sketch.

5. Close the Inventor Precise Input toolbar.

Note: The last line placed is not tangent to the arc. You will learn how to add geometric constraints in the next exercise.


Exercise: Add and Display Constraints In this exercise, you practice adding geometric constraints to an existing sketch containing three closed loops. In some cases, you see that you can greatly reduce the number of dimensional constraints required on a sketch.

This exercise involves geometry that does not meet design criteria and requires additional geometric constraints to comply with the design intent. You:

� Add constraints to the first sketch.

� Add constraints to the second sketch.

� Add constraints to the third sketch.

Starting sketches

Completed sketches

Add Constraints to the First Sketch




2. On the ViewCube, click Front.

3. In the browser, double-click Sketch1 to make it active.

4. Use the Zoom and Pan tools to view the sketch loop on the left.

5. Click Show Constraints.

6. Pause the cursor over the sloping line on the left side of the sketch.

The current constraints are displayed.

In this example, there are two coincident constraints. The sloping lines in the sketch should be vertical, so you now add a vertical constraint.

7. Click the arrow beside the Constraint tool.

8. Click Vertical.

9. Click the three sloping lines.



Your sketch should be as shown.

Note: The cursor displays the selected constraint type. In this step the vertical symbol is displayed.

10. Right-click in the graphics window. Click Done.

11. Right-click in the graphics window. Click Show All Constraints.

All constraints are displayed as shown.

12. Right-click in the graphics window. Click

Hide All Constraints.

Add Constraints to the Second Sketch

1. Click Pan, and then pan your view to center it on the second sketch loop.




Click Colinear.

3. Click the horizontal lines at the top of the sketch.


Done.

5. Drag the upper right horizontal line down and notice how the sketch changes. This action is known as a constrained drag.

6. Click the arrow beside the Constraint tool. Click Equal.

7. Click the horizontal line at the lower left of the sketch and then click the horizontal line at the upper left.

8. Make each of the horizontal lines on the right side equal to the line at the lower left.

Your sketch should look similar to the following illustration:

9. Press ESC to cancel the Constraint tool.

10. Drag the right vertical line and note how the sketch changes.

With the equal constraints applied, the sketch retains its symmetry as you drag the vertical lines.



Note: In some workflows, the Symmetric constraint can be used.

Add Constraints to the Third Sketch

1. Pan to center your view on the third sketch loop.

2. Click Show Constraints.

3. Pause the cursor over the vertical line at the left of the sketch.

The constraints are displayed. Your sketch should be as shown.


Click Tangent.

5. Apply a tangent constraint to the arc and line at the left side of the sketch.

6. Click the arrow beside the Constraint tool. Click Equal.

7. Apply equal constraints to the radii of the arc on the left and the center arc, and then the center arc and the right arc.

Your sketch should be as shown.



8. Right-click in the graphics window. Select

Done.

9. Right-click in the graphics window. Select Finish Sketch.


Exercise: Dimension a Profile In this exercise, you add dimensional constraints to a sketch. You:

� Dimension linear profiles.

� Use automatic dimensioning.


Part created using sketch

Dimension Linear Profiles


The sketch geometry requires dimensional constraints to maintain its overall size. Geometric constraints have already been applied to maintain the shape of the sketch.

2. In the browser, double-click Sketch1 to



make it the active sketch.

3. On the ViewCube, click Front.

4. Click General Dimension.

5. Click the top horizontal line of the sketch, and then place the dimension.

6. Click the dimension to display the Edit

Dimension edit box.

7. Enter 135, and then click the check mark.

In the previous example, you clicked the dimension to display the dialog box. If you are placing many dimensions, you can display the Edit Dimension edit box automatically.

8. With the General Dimension tool active, right-click in the graphics window. Select Edit Dimension to turn on edit dimension. A check mark is displayed next to the option.

Complete the dimensional constraints as follows.

9. Add a dimension of 10.




Done.

Use Automatic DimensioningNext, you remove the existing dimensions, and then use the Auto Dimension tool to quickly dimension the sketch.1. Press the SHIFT key and hold it down while

you select each of the dimensions on your sketch.

2. When all the dimensions are selected, press DELETE to remove them.

Tip: You can use a window to select all the dimensions.

3. On the 2D Sketch Panel, click Auto Dimension.

4. When the Auto Dimension dialog box is displayed, click Apply to accept the default settings and begin to dimension the sketch.

The dimensions are applied to the sketch.

The Auto Dimension dialog box indicates that two dimensions are required to fully constrain the sketch. This is due to a missing fix constraint.



Tip: This information is also available on the status bar throughout a design session.

5. Click Done in the Auto Dimension dialog box to close it.

6. In the sketch, select and reposition dimensions so that they are easier to read.

7. Add a fix constraint to the bottom left corner of the sketch, noting that the color of the sketch changes. It is now fully constrained.

Your dimensions should look similar to the following illustration:


Challenge ExerciseUsing the knowledge gained in this lesson, complete this Challenge Exercise section.

Create Sketch GeometryCreate and constrain the profiles as shown.1. Start a new part file for each profile using the

Standard (mm).ipt template.

2. Place lines and arcs using the techniques discussed in this lesson.

3. Add geometric and/or dimensional constraints.

Note: Assume symmetry for the V-block clamp and approximate missing dimensions.



Tip: Use the Three Point Arc tool to create the arcs. The sketch approximates the profile. Add tangent constraints to the arcs as required. Also, add a vertical constraint between the center points of the top and bottom arcs.

QuestionsUse these questions to test your knowledge of the material covered in this lesson.

Question 1

What constraint causes two lines or ellipse axes to lie along the same line?

nmlkj Coincident

nmlkj Equal

nmlkj Colinear

nmlkj Symmetric

Question 2

What is the purpose of "symbols" in the sketch environment?

nmlkj To allow you to switch tools while sketching

nmlkj To indicate inferred geometric constraints

nmlkj To create markers for placed features

nmlkj To allow you to precisely locate points



Question 3

To dynamically check how applied constraints are affecting the sketch, you can click and drag a curve. What is this process called?

nmlkj Constrained drag

nmlkj Curve drag

nmlkj Constraint display

nmlkj Drive constraint

Question 4

Autodesk Inventor denotes whether or not a sketch is fully constrained by displaying the sketch in a different color. For this to happen, what constraint must be applied to at least one curve in the sketch?

nmlkj Coincident

nmlkj Equal

nmlkj Fix

nmlkj Colinear

Question 5

Only numeric values can be entered in the Edit Dimension edit box.

nmlkj True

nmlkj False



lesson4 create sketchcad

Documents

d objects exercise

exercise files

d objects20012013file

sketch paper

open dialog box

d objectsin

hidden lines

sketch views1