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AutoCAD 2D III Module 29: Hatching 33
HATCHING
MODULE
29
Sections
Why are Sectional Views Important?
An orthographic projection of a product will show the exterior surfaces. Interior details are hidden and are represented with the hidden-line. If the hidden
features are complex, these hidden lines do not show them clearly. In such
cases, a sectional view is drawn.
LEARNING OUTCOME
After the completion of this module, you will be able to:
• Explain sectional views, sections, and hatching in sectional views.
• Describe and apply the BHATCH, HATCHEDIT, and SNAPBASE
commands to insert and edit hatching pattern into drawing.
Arrows show the direction you look for section view.
Cutting plane line
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AutoCAD 2D III Module 29: Hatching 34
A sectional view frequently replaces one of the regular views. For example, a
regular front view is replaced by a front section (see below).
TOP VIEW
FRON T VIEW
SECTION VIEW
TOP VIEW
Arrows show direction
Cutting plane line
Crosshatching
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AutoCAD 2D III Module 29: Hatching 35
Hatching Patterns
Section lining, sometimes referred to as cross-hatching, is used to indicate
material in the sectioned part.
Most often, the general-purpose cross hatching symbol is used to represent
any material.
General-purpose
crosshatching symbol for any material
There are also several other types of crosshatching symbols used to represent
a wide variety of materials. A few are illustrated below.
Define the Boundaries of a Hatch
You can choose from several methods to specify the boundaries of a hatch.
• Specify a point in an area that is enclosed by objects.
• Select objects that enclose an area.
• Drag a hatch pattern into an enclosed area from a tool palette or
DesignCenter. (This will be discussed later in this course)
Using the BHATCH command
Steel Concrete Bricks Concrete
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AutoCAD 2D III Module 29: Hatching 36
The BHATCH command is used to insert hatch patterns inside a boundary.
You can start the command using one of the following methods.
Command Keyboard input / Alias Icon Menu
BHATCH Bhatch / Hatch / H
Draw > Hatch
The BHATCH command opens the Hatch and Gradient dialogue box.
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AutoCAD 2D III Module 29: Hatching 37
The Hatch Type
Defines the appearance of the hatch pattern to be applied.
Type and Pattern Type In this option, you can choose the type,
three options are available:
1- Predefined
2- User defined
3- Custom
We will use Predefined at this level. Pattern
Lists the available predefined patterns.
The Pattern option is available only if
you set Type to Predefined.
Pressing this button next to
Pattern the “Hatch Pattern Palette”
dialogue box will open.
Swatch
Displays a preview of the selected
hatch pattern. You can click the
swatch to display the Hatch Pattern Palette dialog box.
Use the tabs available in the Hatch Pattern Palette dialogue box to display the
different patterns available.
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AutoCAD 2D III Module 29: Hatching 38
Angle and scale
Angle
Specifies an angle for the hatch
pattern relative to the X-axis of the
current UCS.
Scale
Expands or contracts a predefined or
custom pattern. This option is available
only if you set Type to Predefined or Custom.
Exercise 1: Create a new file using acadiso.dwt template. Draw a rectangle of a suitable size (use the rectangle command) and hatch it using the Pattern ANSI31.
Command: H HATCH (Click this button to Pick points) Pick internal point or [Select objects/remove Boundaries]: Selecting everything... Selecting everything visible... Analyzing the selected data... Analyzing internal islands... Pick internal point or [Select objects/remove Boundaries]: P1 (Select any point inside the rectangle and click OK in the Hatch dialogue box)
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AutoCAD 2D III Module 29: Hatching 39
Exercise 2: Draw another rectangle and hatch it using the Select Objects option. Use the Pattern ANSI32. Command: Hatch (Click this button to select objects) (Select the rectangle) Select objects or [picK internal point/remove Boundaries]: P1 1 found (AutoCAD will tell you how many objects found) Select objects or [picK internal point/remove Boundaries]: (Click OK to accept the hatching) Exercise 3: Draw two circles of suitable sizes. Use the hatch pattern ISO04W100 to fill in the first circle. For the second circle use the same pattern but change the angle to 30º and the scale to 0.5.
ISO04W100 (angle 0, scale 1) ISO04W100 (angle 30, scale 0.5)
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AutoCAD 2D III Module 29: Hatching 40
Command: _bhatch (Select Pattern to be ISO04W100) (Keep the values of the Angle and Scale as shown) Pick internal point or [Select objects/remove Boundaries]: Selecting everything... Selecting everything visible... Analyzing the selected data... Analyzing internal islands... (Select the circle) Pick internal point or [Select objects/remove Boundaries]: (Click OK to accept the hatching) Command: BHATCH (Select Pattern to be ISO04W100) (Change the values of the Angle and Scale as shown) Pick internal point or [Select objects/remove Boundaries]: Selecting everything... Selecting everything visible... Analyzing the selected data... Analyzing internal islands... (Select the circle) Pick internal point or [Select objects/remove Boundaries]: (Click OK to accept the hatching)
Options Controls several commonly used hatch or fill options.
Associative
A hatch that is associative is updated when you
modify its boundaries.
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AutoCAD 2D III Module 29: Hatching 41
Exercise 4: Use the drawing in exercise 1 and stretch it as shown below.
Exercise 5: Use the same object from exercise 4 and change the properties of
the hatch to non-associative and stretch the
object.
Before stretching After stretching
As you realized, when you stretched the object the Hatch moved with the object boundary and filled the whole area. Remember that when we hatch this object the Associative option was chosen.
Change the properties to non-associative then stretch the object as shown below.
Because of the non-associative option, the hatched area stays as is.
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AutoCAD 2D III Module 29: Hatching 42
When the Create Separate Hatches option is checked,
Four separate hatches are created as
shown.
When the Create Separate Hatches option is not checked,
One hatch is created as shown.
Create Separate Hatches
Controls whether a single hatch object or multiple hatch objects are created
when several separate closed boundaries are specified.
Exercise 6: Draw an object similar to the one shown below and hatch it once
when the Create Separate Hatches option is checked and another when it is
not checked.
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AutoCAD 2D III Module 29: Hatching 43
Islands
Exercise 6: Draw an object similar to the one shown below and hatch it using
the three Island display styles.
The drawing you created should look like the drawings below.
Note that the text is considered as a island and it is hatched according to the island style you are using.
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AutoCAD 2D III Module 29: Hatching 44
Exercise 7: Copy the object from exercise 6 and use normal island style, then
use the Remove Boundary option in order not to hatch the circle.
Command: _bhatch Pick internal point or [Select objects/remove Boundaries]: P1 (Select an internal point)
Selecting everything... Selecting everything visible... Analyzing the selected data... Analyzing internal islands... Pick internal point or [Select objects/remove Boundaries]: B (Select B to remove boundary) Select objects or [Add boundaries]: P2 (Select the circle) Select objects or [Add boundaries/Undo]: (Press enter) Select objects or [Add boundaries/Undo]: (Click OK)
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AutoCAD 2D III Module 29: Hatching 45
Using the HATCHEDIT command
The Hatchedit command modifies an existing hatch or fill. To start the
command you can the following methods.
Exercise 8: Copy the object in exercise 7 and use the edit command to change
the pattern from ANSI31 to ANSI 37. Use the Preview option to see the change
before accepting it.
Command: HE
HATCHEDIT
Select hatch object:
(Select the hatch)
(Change the pattern to ANSI37)
Command Keyboard input Icon Menu
Hatchedit Hatchedit / HE
Modify>Object> Hatch
Before After
ANSI
stands for American National Standards
Institute
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AutoCAD 2D III Module 29: Hatching 46
(Click preview)
Pick or press Esc to return to dialog or <Right-click to accept hatch>:
(Press ESC if you want to go back to the Hatch Edit dialogue or Right-click to
accept hatch box to accept)
Exercise 8: Copy the object in exercise 7 and use the edit command to change
the pattern from ANSI31 to SOLID then change the color to yellow.
Command: _hatchedit
Select hatch object:
(Select the hatch object and change the Pattern
and the color)
Before After
FILL command can be used to
control the fill of the hatching
pattern
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AutoCAD 2D III Module 29: Hatching 47
Exercise 9: Draw an object similar to the one shown below. Hatch it using the
pattern AR B816. Copy your drawing and use HatchEdit to change the hatch
origin to have a hatch pattern similar to the one shown in figure 2.
As you can see, the hatch location in the object at left is not proper. To modify this, use the Hatchedit command to change the origin of the hatch to a new position. In the Hatch edit dialogue box click the button “Click to set new origin” and use the indicated point as the new origin.
Before changing the origin After changing the origin New origin
SNAPBASE system variable
The SNAPBASE system variable sets the snap and grid origin point for the current viewport relative to the current UCS. It is also used to change the origin point for hatching pattern.
Command line: SNAPBASE
EXPLODE command can be used to change
the hatch from one object to individual
objects
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AutoCAD 2D III Module 29: Hatching 48
TASK 1 DETAILS
Instructions:
1. Draw the top and front views of the object. 2. Draw a section view as shown by the cutting plane. 3. Use hatching pattern ANSI31.
Lab Exercise 29-1 Time Allotted: 50 min.
Drawing Specifications
Name Template Units Text Style Font
AutoCAD 2D Lab 29-1 Module Template A Inches N/A N/A
Layering Scheme
Objects on Layer Name Color Linetype Lineweight
Construction Objects Construction 253 Continuous N/A
All Objects Object Red Continuous N/A
Centerlines Center Green Continuous N/A
Hatch Patterns Hatch 200 Continuous N/A
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AutoCAD 2D III Module 29: Hatching 49
Module 29 Review Questions
1. Section lining or crosshatching is also known as a ______. a. section pattern
b. section-line pattern
c. phantom-line pattern
d. hatch pattern
2. When half of the object is cut and removed on a drawing, the result is a _________.
a. half section
b. quarter section
c. 3 full section
d. removed section
3. Sectional views are defined or located using a _________. a. cutting-plane line.
b. 4 phantom line
c. 3 visible line
d. 2 phantom plane
4. What system variable controls the origin of a hatch pattern? a. RECTANG
b. PEDIT
c. SNAPBASE
d. POLYLINE
5. What two commands are used to toggle the hatching pattern display on or off in a drawing?
a. FILL and PEDIT
b. FILL and EXPLODE
c. FILL and REGENERATE
d. FILL and REDRAW
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AutoCAD 2D III Module 29: Hatching 50
6. Which on of the following objects can be exploded? a. A circle
b. An Ellipse.
c. A hatch
d. A single line
7. ANSI stands for ____________. a. American National Standards Institute
b. American National Society Institute
c. American National Standards Internet
d. AutoCAD National Standards Institute
8. A(n) ________ hatch will automatically adjust when the boundary that was used when it was inserted is moved or changed.
a. non-associative
b. associative
c. snapbased
d. None of the above.
9. A non-associative hatch can be changed to associative hatch by using the _________ command.
a. PEDIT
b. PROPERTIES
c. EXPLODE
d. FILL
10. You hatched a boundary and you couldn’t see the hatching. Which hatching property you must change to make the hatching pattern visible?
a. The Scale
b. The Angle
c. The Origin
d. The width