1. Chapter 5 – Editing Objects
ENGT 122 – CAD I
Chapter 5 – Editing Objects

2. Selection Sets Last Previous WPolygon CPolygon ALL Fence Undo
Most editing commands require objects to be selected in order to perform an operation.
Previously we used mouse picks & bounding box selection (window and crossing).
Several other key word options are available for selection. These are the most useful ones:
Last
Previous
WPolygon
CPolygon
ALL
Fence
Undo

3. Selection Sets Last Previous WPolygon CPolygon ALL Fence Undo
All selection options can be activated on-the-fly (in the middle of a command).
At selection prompt, type option name or enter first letters shown capitalized in yellow.
At selection prompt, enter ? to display selection options.
Last
Previous
WPolygon
CPolygon
ALL
Fence
Undo

4. Selection Sets Last Previous
Selects the most recently drawn object displayed on the screen.
Only a single object can be selected by this method.
Previous
Selects all objects from the most recent selection set.

5. DEMO 1 Open Demo1.dwg. Demonstrate selection
Last – create centered construction line to move bottom threaded hole. Use Last to erase construction line.
Previous – move bottom threaded hole to right edge of part. Use Previous to rotate hole into horizontal position.

6. Exercise 1 Open a new drawing file using Imperial Units .
Draw the 3 objects shown in A in the order specified (1 first).
Use MOVE with the Last option to rearrange circle 3 as shown in B.
Use MOVE with window selection to rearrange circle 3 and line 1 as shown in C.
Use MOVE with Previous option to rearrange circle 3 and line 1 as shown in D.
Save your drawing as Exerc1.dwg.

7. Selection Sets WPolygon (window polygon)
Works like window selection but uses an irregular polygon.
Only selects what’s completely enclosed in polygon.
CPolygon (crossing polygon)
Same as WPolygon, except also selects objects partially enclosed in polygon (similar to Crossing Window).

8. DEMO 2 Open Demo2.dwg. Demonstrate selection
WPolygon – copy entire front view without dimensions.
CPolygon – delete all dimensions in side view.

9. Exercise 2
If not already up, open Exerc1.dwg. It should look like A below.
Use MOVE with the CPolygon option to rearrange circle 3 and line 1 as shown in B.
Use multiple MOVEs with the WPolygon option to rearrange circle 3 and line 1 as shown in C.

10. Selection Sets ALL Selects all objects on “thawed” layers
Even objects on layers with visibility turned off will be selected. Only objects on “frozen” layers will not be selected.
Fence
Uses an open polyline to select objects.
All objects which the polyline contacts will be selected.

11. DEMO 3 Open Demo3.dwg. Demonstrate selection
Fence – select and delete all dimensions around front view.

12. Exercise 4
Create the pattern of rectangles and circle approximately as shown.
Use ERASE with the Fence option to delete only the rectangles.

13. Selection Sets
Undo
Removes the most recently selected object from the selection set.
You can also unselect an item by holding [Shift] and reselecting it using single pick, window option, or crossing option. ?
Displays the various selection options on the command line (just in case you forget).

14. End Lesson 19

15. Modify Commands
Modify commands are used to eidt objects. They include the following list.
MOVE
COPY
OFFSET
ROTATE
SCALE
FILLET
CHAMFER
TRIM
EXTEND
STRETCH
LENGTHEN
ARRAY
MIRROR
BREAK
MEASURE
DIVIDE
Modify commands can be entered in 3 ways;
Type the command or abbreviation.
Use the Modify drop down menu.
Use the Modify toolbar.

16. Editing Commands COPY Creates a copy of an object.
Identical to the MOVE command except the original object is retained.
In 2007, creating MULTIPLE copies is the default. Use [Esc] or [Enter] to end command.

17. DEMO 5
Open Edit Demo.dwg.
Show Copy command.

18. Exercise 5 Create the blue square as shown.
Then use the least number of COPY commands to add the red and green squares (use object snap for precise placement on corner points).

19. Editing Commands OFFSET
Offsets an object perpendicular to original object by a specified distance or through a specified point.
Result depends on object being offset (arc, line, rectangle etc).
Primary Options:
Distance (default) - offset distance specified by offset value or point selection.
Through - offsets through specified point.

20. Editing Commands OFFSET Additional Options:
Erase – Erase option allows original object to be maintained or erased.
Layer – determines whether new offset object is placed on current layer or same layer as original object.

21. Show OFFSET command with options
DEMO 6
Open Edit Demo.dwg.
Show OFFSET command with options

22. Exercise 6 Create the three object as shown in A.
Use OFFSET to create the image in B.
Estimate the proper offset distance for the concentric circles.
Note: the red line is offset through the center of the circle and the corner point of the rectangle.

23. Editing Commands ROTATE
Rotates objects through a specified angle about a specified base point (center of rotation).
Positive angle = ; Negative angle = 
Command: ROTATE
Select objects to rotate.
Select Base Point.
Specify rotation angle.
The REFERENCE option can be used to designate a reference line on object and rotate to an absolute angle.

24. DEMO 7 Open Edit Demo.dwg. Show ROTATE command.
Show ROTATE command with REFERENCE option.
Show ROTATE command with COPY option.

25. Exercise 7
Create a 5 sided polygon and a line as shown in A. Use object snap or other means for precise placement.
Rotate both the line and polygon 23º as shown in B.
Use the REFERENCE option to rotate just the line so it aligns with the edge of the polygon as shown in C.
Use the REFERENCE option to rotate both the line & polygon to the position shown in D.

26. Editing Commands SCALE
Scales the size of an object by a specified multiplying factor about a specified point.
Useful for scaling title block to fit drawing prior to plotting.
Command: SCALE
Select objects to scale.
Select Base Point.
Specify scale factor.
The REFERENCE option can be used to designate a reference line on object and reduce or enlarge it to a specified length.

27. Editing Commands SCALE - Example showing REFERENCE option.
After selecting base point, enter R for reference option.
Specify 2 points on object – you then specify the actual length you want these points to become.
Specify points
Specify length of 1 rather than scale factor

28. Editing Commands IMPORTANT:
All drawing objects must be created full size in AutoCAD!
Never use the SCALE command to reduce an object so it fits the plotted sheet!
Plot scaling is the correct method for fitting your full size object on an itsy-bitsy piece of paper!

29. DEMO 8 Open Edit Demo.dwg. Show SCALE command.
Show SCALE command with REFERENCE option.

30. Exercise 7.5
Use polar tracking and the RECTANGLE command to create a square with a 3” diagonal as shown in red.
Then use object tracking and osnaps to create the inscribed circle shown in blue.
Use the SCALE command to double the size of both objects.
Then, use the SCALE command with the REFERENCE option to rescale only the square so the square has 2 inch sides and remains centered in the circle.
3” diagonal
Finally, use the SCALE command with the REFERENCE option to rescale the circle so that it is inscribed within the square.
Use the DIST command to verify the height of the square.

31. End Lesson 20

32. Editing Commands FILLET
Creates a tangent arc between 2 objects. Called a Fillet (interior corner) or a Round (exterior corner).
Command: FILLET
Select 1st object.
Select 2nd object.
Options:
Radius – specify fillet radius (value retained until modified).
Trim – determines whether original objects are modified (trim/extend) or left intact.
Polyline – fillets a polyline.
Multiple – allows multiple fillets
Notice the lines extend

33. Editing Commands FILLET
TRIM option controls whether filleted objects remain intact or are trimmed and extended to form the fillet.
NO TRIM - selected objects remain unaltered and a fillet is added.
TRIM – selected objects are cut or extended to form fillet.

34. Editing Commands FILLET
Works for arcs and circles as well as straight lines.
Point selection is also important for these cases.
If a circle is included it remains untrimmed.

35. Editing Commands FILLET
Also useful for capping parallel lines. Radius is automatically calculated based on line separation and overrides the set radius value.
Can also be used to clean up intersecting lines and create sharp corners by specifying a radius of zero.
A zero radius fillet can be made (regardless of radius setting) by depressing [Shift] during object selection.
Before
Radius = 0
After

36. DEMO 9 Open Edit Demo.dwg. Show FILLET command.
Show following options:
Radius
Trim
Radius = 0 using [Shift]
Cap parallel lines
Show Polyline option

37. Exercise 8
Create 4 sets of lines as shown in A. Use ortho, polar, or other means to assure they are parallel or perpenducular.
Then use FILLET to modify the line sets as shown in B.

38. Editing Commands CHAMFER
Similar to Fillet but creates a Chamfer - an angled corner or bevel between 2 objects.
Does not work on circles, arcs, curves or parallel lines.
May be specified by distance along each edge or distance along one edge and chamfer angle.

39. Editing Commands CHAMFER Command: CHAMFER Select 1st object.
Select 2nd object.
Options:
Distances- specify chamfer distance from corner along 1st edge. Specify chamfer distance from corner along 2nd edge.
Angle- specify chamfer distance from corner along 1st line. Then specify chamfer angle with respect to first edge.
Polyline- chamfers a polyline.
Trim- determines whether objects are trimmed or left intact.
Method – Determines default method (Distance or Angle).

40. DEMO 10 Open Edit Demo.dwg. Show CHAMFER command.
Show the following option:
Distances
Angle

41. Exercise 9 Draw the red object shown in A.
Then use CHAMFER to modify the object as shown in B.

42. Exercise 9 - Alt
Create 2 sets of lines as shown in A. Use ortho or other means to assure they are perpendicular.
Then use CHAMFER to modify the line sets as shown in B.

43. Editing Commands
TRIM
Cuts & removes (Trims) portion of an object that extends beyond intersection with another object (trim boundary).
More than one cutting edge (trim boundary) can be selected.
More than one object can be trimmed at a time.
Command: TRIM
Select trim boundaries.
Select objects to trim.
1) Select trim boundary
2) Select object to trim
Result
Remove

44. Editing Commands TRIM Additional options:
Fence – selects objects to trim using selection Fence.
Crossing – selects objects to trim using selection crossing box. This is the default, so no need for this option.
Project – only used for 3D.
Edge – activates & deactivates implied intersections.
Erase – erases selected objects in the middle of the trim command.
Undo – removes effect of most recent trim.

45. Editing Commands
TRIM
Edge option defaults to Extend which allows implied intersection. If deactivated with NOextend, only true intersections are considered.
Selection point determines which portion is trimmed.
More than one trim boundary or trim object may be selected.
An object may be a trim boundary and a trimmed object simultaneously.
1st pick cutting edge
2nd pick
trim edge
result
1st pick cutting edge
1st pick
2 cutting edges
2 trim edges

46. Editing Commands
TRIM
Depressing [Shift] while selecting the trim object extends the object to the trim boundary rather than trimming it. Discussed further during next command EXTEND.
1) Select trim boundary
2) Hold [Shift] & Select object to extend
Result

47. DEMO 11
Create some objects.
Show TRIM command.
Show the following option:
Multiple trim objects and trim boundaries.
Show use of ALL objects as trim boundaries.
Use of [Shift] to extend line.

48. Exercise 10 Create a circle, rectangle, and line as shown in A.
Then use TRIM to create the image as shown in B.
Then use TRIM again to create the image as shown in C.
Finally, use TRIM with [Shift] to reconnect the red line.

49. Editing Commands EXTEND
Opposite of TRIM. Extends or lengthens object to a specified object (extend boundary).
Operates in same manner as TRIM.
Depressing [Shift] while selecting the extend object trims the object rather than extending it.
Command: EXTEND
Select extend boundaries.
Select objects to extend.

50. Editing Commands EXTEND Additional options:
Fence – selects objects to trim using selection Fence.
Crossing – selects objects to trim using selection crossing box. This is the default, so no need for option.
Project – only used for 3D.
Edge – activates & deactivates implied intersections.
Undo – removes effect of most recent trim.

51. Editing Commands STRETCH
Used to stretch, lengthen, shorten, or modify an object’s boundaries.
Requires selection by Crossing Window or Crossing Polygon (CP).
Command: STRETCH
Select objects.
Specify basepoint.
Specify second point of displacement by pick or coordinates.

52. DEMO 12 Open Edit Demo.dwg. Show STRETCH command.
Show STRETCH to lengthen centerlines.

53. Exercise 11 Create 2 rectangles as shown in A.
Then use STRETCH to create the image as shown in B.
Then use STRETCH again to create the image as shown in C.

54. End Lesson 21

55. Editing Commands LENGTHEN
Lengthens or shortens an open object by a specified amount.
Object selection point determines which end changes size.
Does not operate on closed loops.
Command: LENGTHEN
Select object or specify method for lengthening.
If object is selected first, ACAD returns the length and prompts for lengthening method.

56. Editing Commands Lengthen Options:
DElta- used to specify length change in any open object or change in included angle (+/-) of arcs.
Percent- specify % change based on original size of 100%.
Total- specify new total length of any open object or total angle for arcs. Total can be specified by value or point selection.
DYnamic- change length by dragging.

57. DEMO 13 Create some objects. Show LENGTHEN command. Options: DElta
Percent
Total
DYnamic

58. Editing Commands ARRAY
Creates multiple duplicate objects in a rectangular or circular pattern.
Command: ARRAY
Brings up array dialog box.
Circular Array
Rectangular Array

59. Editing Commands ARRAY - RECTANGULAR Select items for array
Specify # of row and columns.
Specify the row offset.
Specify the column offset.
Specify array angle.

60. Editing Commands ARRAY - POLAR Select items for array
Specify array center point.
Specify method:
Total items & total fill 
Total items &  between items
Total fill  &  between items
Specify whether items rotate.
Specify base point or default.

61. DEMO 14 Create a rectangle. Show ARRAY command. Options: Rectangular
Polar (first create circle for guide)

62. Exercise 12
Create the following two array patterns.

63. Editing Commands MIRROR Creates a mirrored image of selected object.
Original object may be erased or retained.
Command: MIRROR
Specify mirror object.
Specify mirror line by end point picks or coordinate input.
Specify whether original is deleted.

64. DEMO 15
Create some objects.
Show MIRROR command.

65. Exercise 13 Create the arc and lines as in A.
Then using only the MIRROR command, create the image in B.
Figure A
Figure B

66. Editing Commands BREAK
Cuts an object into two parts or removes portion of object.
Command: BREAK
Specify object to break.
Specify break method.
Break Methods:
2 Point – Breaks object between 2 points and removes section between them.
1 Point – Breaks object at a single point and retains both pieces.

67. Editing Commands Approx. Break Methods:
*Note – osnap not available during object selection.
Object select point is 1st break point.
2nd break point.
Approx. 2 Point - object selection point is 1st break point, then select 2nd break point (portion between points removed).
Command: Break
Select object: select object
Specify second break point or [First point]: pick point
Command: Break
Select object: select object
Specify second break point or [First
Approx. 1 Point – object selection point is break point.
Object select point is break point.

68. Editing Commands Precise Break Methods:
2nd break point.
1st break point.
Object select point.
2 Point Break: select object, then select 1st and 2nd break points (portion between points removed).
Command: Break
Select object: select object
Specify second break point or [First point]: F
Specify first break point: pick point
Specify second break point: pick point
Command: Break
Select object: select object
Specify second break point or [First point]: F
Specify first break point: pick point
Specify second break
1 Point Break: select object, then select break point.
Object select point.
1st & 2nd break points.

69. Editing Commands BREAK
For circles, the break removal will be counter clockwise  from first to second selection point.
A circle cannot be broken at a single point (would form 360˚ arc which is illegal).

70. DEMO 16 Create some lines and circles. Show BREAK command. 1 Point
1 Point Select
2 Point
2 Point Select
Circle

71. Exercise 14 Create the rectangle, circle, and lines as in A.
Use only the BREAK command to create the image in B. Use layer colors to keep track of the breaks as shown.
Break at midpoint
Break at quadrants
Figure A
Figure B

72. Editing Commands MEASURE
Places point entities at specified distances along an object.
Command: MEASURE
Specify object.
Specify length between points by value or point selection.
Point shape and size determined by Format > Point Style
Object selection point

73. Editing Commands MEASURE For open objects, points start
closest to end where object was selected.
For closed polylines, points start at polyline start point.
Object selection point
For circles, points start at snap rotation angle (typically 0) and precede counter clockwise. To reset snap rotation use SNAP command from command line with Rotate option. Warning: the R option won’t appear in command at 2007!)

74. Editing Commands MEASURE
MEASURE is not available from a toolbar, but can be initiated from the Draw Drop Down Menu.
DDMenu: Draw > Point > Measure

75. DEMO 17 Create a line and circle. Show MEASURE command. Line Circle
Point Style

76. End Lesson 22

77. Editing Commands DIVIDE
Divides an object into specified number of equal segments without breaking. Point entities indicate divisions.
Command: DIVIDE
Specify object.
Specify number of segments.
Point shape and size determined by Format > Point Style

78. Editing Commands DIVIDE For open objects, points start
closest to end where object was selected.
For closed polylines, points start at polyline start point.
For circles, points start at snap rotation angle (typically 0) and precede counter clockwise. To reset snap rotation use SNAP command from command line with Rotate option. Warning: the R option won’t appear in command at 2007!)

79. Editing Commands DIVIDE
DIVIDE is not available from a toolbar, but can be initiated from the Draw Drop Down Menu.
DDMenu: Draw > Point > Divide

80. DEMO 18
Create a line and circle.
Show DIVIDE command.
Line
Circle

81. Exercise 15 Use POLYGON to create the yellow  in A.
Use DIVIDE to divide the yellow  into 9 equal lengths.
Use POLYGON with Edge option to create the blue  in A.
Move the blue  to location shown in B.
Use COPY to create image C.
All locations should be exact! Use OSNAP!

82. Chapter 5 – The End!

83. RETIRED MATERIAL

84. Selection Sets
Remove
Allows objects to be removed from the selected set.
Activates selection Remove Mode.
Once activated, objects can be selected for removal from the set by any selection method.
Remove Mode remains active until the Add option is activated to add objects back to the selected set.
Alternate remove method –hold
[Shift] during object selection.
Add
Toggles back to default Add
Mode so objects can be added to
selected set.

85. DEMO 3 Open Demo3.dwg. Demonstrate selection
Remove – select all objects surrounding hole in side view. Use Remove to remove all object lines from selection and then erase hole.
Add – show use of Add to add to selection set.

86. Exercise 3
Draw two concentric circles and a circumscribed square as shown in (1).
Select all objects for erasure, but don’t execute yet.
Use Remove option to remove the square and outer circle from the selected set.
Use the Add option to add the outer circle back to the selected set.
Execute the erase command to delete both circles (3).

87. Editing Commands Copy Using Shortcut Menu:
Select objects, then right click mouse to show shortcut menu.
Allows copy & paste options similar to MS Windows.
Select Copy to place copy of object in buffer.
Select Paste to paste object from buffer.
Copy with Base Point allows insertion point to be selected for better control.

88. DEMO 5 Open Edit Demo.dwg. Show Copy command access from menus.
Demonstrate COPY command.
Demonstrate COPY WITH BASE shortcut menu.

89. Exercise 5 Create the blue square as shown.
Use COPY to add the red squares using the blue square as the original (use object snap for precise placement on corner points).
Use Copy with Base Point (from shortcut menu) to create the remaining green squares.

90. Editing Commands
TRIM
Edge option defaults to Extend which allows implied intersection. If deactivated with NOextend, only true intersections are considered.
Selection point determines which portion is trimmed.
More than one trim boundary or trim object may be selected.
An object may be a trim boundary and a trimmed object simultaneously.

91. Other Editing Commands
Properties Command
Allows properties of an object to be modified.
Command: PROPERTIES
Brings up Properties Dialog box.
Other Methods:
Select object and right click for shortcut menu. Select properties.
Toolbar menu (toggles on/off).

92. DEMO 20
Show PROPERTIES command

93. Other Editing Commands
Matching Properties
Properties of objects can be transferred from object to object.
Such properties include;
Color Layer Linetype Linetype scale Line weight
Command: MATCHPROP
Specify source object.
Specify destination object or select Settings option to determine which properties get transferred.

94. DEMO 19 Show MATCHPROP command To match layer properties
To match linetype scale

95. Exercise 16 Set up the following layers:
Layer 1 - White - Continuous lines
Layer 2 - Red - Hidden lines
Layer 3 - Yellow - Centerlines
Use Layer 1 to create the objects in A. Then use any form of the PROPERTIES command to individually change the properties for each object as shown in B. Finally, use the MATCHPROP command to create the image in C.
Figure A
Figure B
Figure C