ENGT 122 – CAD I

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

2. Modify Commands • Modify commands are used to edit objects. They include the following list. • MOVE • COPY • OFFSET • ROTATE • SCALE • FILLET • CHAMFER • TRIM • EXTEND • STRETCH • LENGTHEN • ARRAY • MIRROR • BREAK • MEASURE • DIVIDE

3. Selection Sets • 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

4. Selection Sets • 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

5. Selection Sets • Last • 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.

6. DEMO 1 • Open Demo1.dwg. • Demonstrate selection • Last – create construction line .5” from right side 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.

7. 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 (center to end). • 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.

8. 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).

9. DEMO 2 • Open Demo2.dwg. • Demonstrate selection • WPolygon – copy entire front view without dimensions. • CPolygon – erase all items inside primary object lines of front view.

10. Exercise 2 • If not already up, open Exerc1.dwg. It should look like A below. • Use MOVE with the CPolygonoption to rearrange circle 3 and line 1 as shown in B (intersection to endpoint). • Use MOVE with the WPolygonoption to rearrange circle 3 and line 1 as shown in C (quadrant to midpoint).

11. 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.

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

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

14. 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).

15. End Lecture 16

16. Modify Commands • Modify commands are used to edit 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 Modifypanel on the ribbon. • Use the Modify toolbar.

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

18. DEMO 5 • Open Edit Demo.dwg. • Show Copy command.

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

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

21. 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. • Multiple – repeatedly offsets selected object.

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

23. 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.

24. 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.

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

26. 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.

27. 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.

28. Editing Commands • SCALE -Example showing REFERENCEoption. • 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. Base Point Before Scale After Scale Base Point • Specify points on edge • Specify new length of edge = 1.4

29. 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!

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

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

32. End Lecture 17

33. 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

34. 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.

35. 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.

36. 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

37. DEMO 9 • Open Edit Demo.dwg. • Show FILLET command. • Show following options: • Radius • Trim • Radius = 0 using [Shift] • Cap parallel lines • Fillet a rectangle with Polyline option

38. 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.

39. Editing Commands • CHAMFER • Similar to Fillet but creates a Chamfer - an angled corner or bevel between 2 lines. • 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.

40. Editing Commands • CHAMFER • Command:CHAMFER • Select 1st line. • Select 2nd line. Options: • Distance- 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).

41. DEMO 10 • Open Edit Demo.dwg. • Show CHAMFER command. • Show the following option: • Distances • Angle • Chamfer a rectangle using Polyline option

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

43. 2) Select object to trim Remove 1) Select trim boundary Result 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.

44. Editing Commands TRIM Additional options: • Edge – activates & deactivates extended intersections. • Undo – removes effect of most recent trim. • 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. • Erase – erases selected objects in the middle of the trim command.

45. 1st pick cutting edge 2nd pick trim edge result 1st pick cutting edge 2nd pick trim edge result 2nd pick 2 trim edges result 1st pick 2 cutting edges 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.

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 lines.

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: • Edge – activates & deactivates implied intersections. • Undo – removes effect of most recent trim. • 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.