125

In This Chapter

9

Working with 2D Hide and
2D Steel Shapes

In this tutorial, you learn about the new features in

AutoCAD

®

Mechanical 6 for defining the 2D hide

situations, and how to work with 2D steel shapes.

■

Defining a 2D hide situation

■

Inserting a 2D steel shape

■

Modifying steel shapes using
power commands

■

Editing a 2D hide situation

■

Copying and moving a 2D hide
situation

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Key Terms

Term

Definition

background

A contour that is covered by another contour or by objects that are lying behind
another contour, in the 3D sense. A background may be a foreground for an
additional contour.

foreground

Objects which are lying in front of another contour in the 3D sense. A foreground
may also be a background for an additional contour.

hidden line

Line that is not visible in a specified view. For example, in a front view, lines
behind the front plane would not be visible.

steel shapes

Steel shapes are standardized steel geometries and profiles, which are used for
steel- and plant construction.

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Working with 2D Hide and 2D Steel Shapes

Open the initial drawing.

To open a drawing

1

Open the file tut_ex09 in the acadm\tutorial folder.

Menu

File ➤ Open

Command

OPEN

2

Zoom in to the chain drive on the right.

Menu

View ➤ Zoom ➤ Window

Command

ZOOM

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Defining a 2D Hide Situation

Now you define a 2D hide situation. You can define foreground and back-
ground contours as well as the settings for the representation of the hidden
objects.

To define a 2D hide situation

1

Start the Hide Invisible Edges command.

Menu

Modify ➤ 2D Hide ➤ Hide Invisible Edges

Command

AM2DHIDE

2

Respond to the prompts as follows:

Select objects for foreground:

Select the chain

Select objects for foreground:

Press

ENTER

3

In the Create Hide Situation dialog, specify:

Representation of Hidden Objects:

Dashed

4

In the Select a Steel Shape dialog, choose Preview <.

NOTE

As you can see, the parts of the sprockets, which should be visible, are

dashed, too. This shows that the complete area inside the outer chain contour is
defined as foreground.

Now, define the 2D hide situation in a way that the chain has an inner con-
tour.

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5

Continue to respond to the prompts as follows:

Accept preview and exit command [Yes/No] <Yes>:

Enter N

6

In the Create Hide Situation dialog, activate the Foreground tab and choose
Select Inner Contours <.

7

Respond to the prompts as follows:

Select point inside a hole or select a loop to remove:

Select a point inside the

chain

The inner contour of the chain is displayed green.

8

Continue to respond to the prompts as follows:

Select point inside a hole or select a loop to remove:

Press

ENTER

9

In the Select a Steel Shape dialog, choose Preview <.

Now, the chain drive is displayed correctly.

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10

Respond to the prompts as follows:

Accept preview and exit command [Yes/No] <Yes>:

Press

ENTER

Your 2D hide situation is defined correctly and you can proceed with your
drawing.

Save the file.

Inserting a 2D Steel Shape

Steel Shapes can easily be inserted through a selection dialog, where you can
define the standard, profile, size and length of the steel shape.

Now, insert a steel shape with a square hollow section on the left edge of the
I-shaped girder.

To insert a 2D steel shape

1

Start the Zoom All command.

Menu

View ➤ Zoom ➤ All

Command

ZOOM

2

Start the Steel Shape command.

Menu

Content ➤ Steel Shapes

Command

AMSTLSHAP2D

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3

In the Select a Steel Shape dialog select Square / Rectangular hollow section.

4

Select IS 7630 and Top View.

5

Respond to the prompts as follows:

Specify insertion point:

Select point P1

Specify rotation angle <0>:

Press

ENTER

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6

In the ISO 657/14 - 1982 (Rectangular) - Size Selection dialog, specify:

Select a Size:

90x90x4.0

7

Choose Finish.

8

Respond to the prompts as follows:

Drag Size:

Select point P2

The steel shape is inserted. Your drawing looks like this:

Save the file.

Now, modify the steel shapes using the Power Commands.

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Modifying Steel Shapes using Power Commands

With the Power Commands, you can create different views of the steel shapes
as well as you are able to copy, multiply or edit the steel shapes.

Now, insert the steel shapes in the top view of the assembly using Power View
and Power Copy.

To modify a steel shape using Power Commands

1

Start the Power View command.

Menu

Modify ➤ Power Commands ➤ Power View

Command

AMPOWERVIEW

2

Select the previously inserted steel shape.

3

In the Select new view dialog select the Front View.

4

Respond to the prompts as follows:

Specify insertion point:

Select point P3

Specify rotation angle <0>:

180

The steel shape is inserted in the top view of the assembly. Your drawing
looks like this:

NOTE

A 2D hide situation will be generated automatically when inserting the

steel shape.

Now, copy the previously inserted view to the other edge of the girder.

5

Start the Power Copy command.

Menu

Modify ➤ Power Commands ➤ Power Copy

Command

AMPOWERCOPY

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6

Respond to the prompts as follows:

Select object:

Select the previously inserted steel shape at point P3

Specify insertion point:

Select point P4

Specify rotation angle <0>:

180

The steel shape is copied. Your drawing looks like this:

Save your file.

Editing a 2D Hide Situation

The insertion of the steel shapes in the top view of the assembly has created
a 2D hide situation automatically. As you can see, this 2D hide situation is
not correct.

Now, edit the 2D hide situation.

To edit a 2D hide situation

1

Start the Edit Hidden Edges command.

Menu

Modify ➤ 2D Hide ➤ Edit Hidden Edges

Command

AM2DHIDEDIT

2

Respond to the prompts as follows:

Edit the behind situation [modifY/Move/Restore/Genius12] <Update>:

Y

Select objects:

Select the square hollow section on the left

Select objects:

Press

ENTER

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3

In the Modify Hide Situation dialog, choose Select View.

4

Respond to the prompts as follows:

Select objects for foreground:

Select the I-shaped girder

Select objects for foreground:

Deselect the square hollow section on the left

Select objects for foreground:

Press

ENTER

NOTE

You can deselect a selected part by holding the

SHIFT

key while clicking

the part.

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5

In the Modify Hide Situation dialog, activate the Background tab, and choose
Select View < .

6

Respond to the prompts as follows:

Select objects for background:

Select the square hollow section on the left

Select objects for background:

Press

ENTER

7

In the Modify Hide Situation dialog, choose Preview < .

Now, the 2D hide situation is correct. Your drawing looks like this:

Select objects for foreground:

Press

ENTER

8

Respond to the prompts as follows:

Accept preview and exit command [Yes/No] <Yes>:

Press

ENTER

Now, edit the 2D hide situation of the right edge of the girder. The Edit Hidden
Edges command is still active.

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9

Respond to the prompts as follows:

Edit the behind situation [modifY/Move/Restore/Genius12] <Update>:

Y

Select objects:

Select the square hollow section on the right

Select objects:

Press

ENTER

10

In the Modify Hide Situation dialog, choose Select View < .

11

Respond to the prompts as follows:

Select objects for foreground:

Select the I-shaped girder

Select objects for foreground:

Deselect the square hollow section on the right

Select objects for foreground:

Press

ENTER

12

In the Modify Hide Situation dialog, activate the Background tab, and choose
Select View < .

13

Respond to the prompts as follows:

Select objects for background:

Select the square hollow section on the right

Select objects for background:

Press

ENTER

14

In the Modify Hide Situation dialog, choose Preview < .

The 2D hide situation on the right is now correct, too.

15

Respond to the prompts as follows:

Accept preview and exit command [Yes/No] <Yes>:

Press

ENTER

16

Press

ESC

to leave the command.

Your drawing looks like this:

Save your file.

Copying and Moving a 2D Hide Situation

If you copy or move assemblies which contain 2D hide situations, the 2D
hide information will not be lost.

Now, copy the girder assembly.

To copy a 2D hide situation

1

Select the I-shaped girder and the two square hollow sections.

2

Right-click and choose Copy with Base Point from the context menu.

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3

Respond to the prompts as follows:

Specify base point:

Select point P3

4

Right-click and choose Paste from the context menu.

5

Respond to the prompts as follows:

Specify insertion point:

Select point P5

The girder assembly is copied to the new location. Your drawing looks like
this:

Save your file.

Now, move the chain drive from the beginning of the chapter to the top view
of the assembly.

To move a 2D hide situation

1

Start the Move command.

Menu

Modify ➤ Move

Command

MOVE

2

Respond to the prompts as follows:

Select objects:

Select the complete chain drive using a window

Select objects:

Press

ENTER

Specify base point or displacement:

Select point P6

Specify second point of displacement or <use first point as displacement>:

Select point P7

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The complete chain drive is moved to the top view of the assembly. Your
drawing looks like this:

Finally, you have to define the 2D hide situation for the girder assembly and
the chain drive.

To define a 2D hide situation

1

Start the Hide Invisible Edges command.

Menu

Modify ➤ 2D Hide ➤ Hide Invisible Edges

Command

AM2DHIDE

2

Respond to the prompts as follows:

Select objects for foreground:

Select the complete chain drive

Select objects for foreground:

Press

ENTER

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3

In the Create Hide Situation dialog, choose OK.

Now, the girder assembly is hidden by the chain drive. Your drawing looks
like this:

This is the end of this exercise.

Save your file.