LESSON 6 LEARNING OBJECTIVES. After completing this lesson, you will be able to:

Transcription

1 LEARNING OBJECTIVES After completing this lesson, you will be able to: 1. Use the 4 Break command options. 2. Trim an object to a cutting edge. 3. Extend an object to a boundary. 4. Move an object(s) to a new location. 5. Explode objects into their primitive entities. LESSON 6

2 BREAK The BREAK command allows you to break a space in an object, break the end off an object or split a line in two. I think of it as taking a bite out of an object. There are 4 break methods described below. You may select the BREAK command by using one of the following: TYPING = BR PULLDOWN = MODIFY / BREAK TOOLBAR = MODIFY METHOD 1 How to break one object into two separate objects with no visible space in between. (If you are not fussy about where the break point is) a. Select the BREAK command using one of the methods listed above b. _break Select object: pick the break location (P1) c. Specify second break point or [First point]: type symbol (this will duplicate the last point) Before Break After Break METHOD 2 This method is the same as method one with the exception that you are very specific where you want the break point. a. Select the BREAK command using one of the methods listed above b. _break Select objects: select the object to break (P1) c. Specify second break point or [First point]: type F <enter> d. Specify first break point: select break location (P2) accurately e. Specify second break point: <enter> Before Break After Break Method 2 can also be accomplished easily by selecting the Break at point icon. But I wanted you to understand how it works. 6-2

3 BREAK (continued) METHOD 3 Take a bite out of an object, but you are not fussy where the BREAK lies. (This is the Default option) a. Select the BREAK command b. _break Select object: pick the first break location (P1) c. Specify second break point or [First point]: pick the second break location (P2) Before Break After Break METHOD 4 Take a bite out of an object and you are very specific where the gap is located. a. Select the BREAK command b. _break Select objects: select the object to break (P1) anywhere on the object c. Specify second break point or [First point]: type F <enter> d. Specify first break point: select the first break location (P2) accurately e. Specify second break point: select the second break location (P3) accurately Before Break After Break 6-3

4 TRIM The TRIM command is used to trim an object to a cutting edge. You first select the Cutting Edge and then select the part of the object you want to trim. The object to be trimmed must actually intersect the cutting edge or could intersect if the objects were infinite in length. 1. Select the Trim command using one of the following: TYPE = TR PULLDOWN = MODIFY / TRIM TOOLBAR = MODIFY 2. The following will appear on the command line: Command: _trim Current settings: Projection = UCS Edge = Extend Select cutting edges... Select objects: select cutting edge(s) by clicking on the object (P1) Select objects: stop selecting cutting edges by pressing the <enter> key Select object to trim or shift-select to extend or [Project/Edge/Undo]: select the object that you want to trim. (P2) (Select the part of the object that you want to disappear, not the part you want to remain) Select object to trim or [Project/Edge/Undo]: press <enter> to stop Note: You may toggle between Trim and Extend (page 6-5). Hold down the shift key and the Extend command is activated. Release the shift key and you return to Trim. EDGE (Extend or No Extend) In the Extend mode, (default mode) the cutting edges and the Objects to be trimmed need only apparently intersect if the objects were infinite in length. In the No Extend mode the cutting edges and the objects to be trimmed must visibly intersect. PROJECTION Same as Edge except used only in 3D. 6-4

5 EXTEND The EXTEND command is used to extend an object to a boundary. The object to be extended must actually or theoretically intersect the boundary. 1. Select the EXTEND command using one of the following: TYPE = EX PULLDOWN = MODIFY / EXTEND TOOLBAR = MODIFY 2. The following will appear on the command line: Command: _extend Current settings: Projection = UCS Edge = Extend Select boundary edges... Select objects: select boundary (P1) by clicking on the object Select objects: stop selecting boundaries by selecting <enter> Select object to extend or shift-select to Trim or [Project/Edge/Undo]: select the object that you want to extend. (P2 and P3) (Select the end of the object that you want to extend.) Select object to extend or [Project/Edge/Undo]: stop selecting objects by selecting <enter> You may toggle between Extend and Trim (page 6-4). Hold down the shift key and the Trim command is activated. Release the shift key and you return to Extend. EDGE (Extend or No Extend) In the Extend mode, (default mode) the boundary and the Objects to be extended need only imaginarily intersect if the objects were infinite in length. In the No Extend mode the boundary and the objects to be extended must visibly intersect. PROJECTION Same as Edge except used only in 3D. 6-5

6 MOVE The MOVE command is used to move object(s) from their current location (basepoint) to a new location (second displacement point) 1. Select the Move command using one of the following: TYPE = M PULLDOWN = MODIFY / MOVE TOOLBAR = MODIFY 2. The following will appear on the command line: Command: _move Select objects: select the object(s) you want to move (P1) Select objects: stop selecting object(s) by selecting <enter> Specify base point or displacement: select a location (P2) (usually on the object) Specify second point of displacement or <use first point as displacement>: move the object to it s new location (P3) and left click. (Note: if you press <enter> instead of actually picking a new location, Autocad will send it into Outer Space. If this happens, press U <enter> and try again. BASE POINT (P2) P1 ORIGINAL LOCATION DRAG TO NEW LOCATION (P3) NEW LOCATION 6-6

7 EXPLODE The EXPLODE command changes (explodes) an object into its primitive objects. For example, a rectangle is originally one object, if you explode it, it changes into 4 lines. Visually you will not be able to see the change unless you select one of the lines. For example: Draw a rectangle and then click on it. The entire object highlights. Now explode the rectangle, then click on it again. Only the line you clicked on should be highlighted. Each line that forms the rectangular shape is now an individual object. 1. Select the Explode command by using one of the following: TYPE =X PULLDOWN = MODIFY / EXPLODE TOOLBAR = MODIFY 2. The following will appear on the command line: Command: _explode Select objects: select the object(s) you want to explode Select objects: select <enter> 6-7

8 INSTRUCTIONS: EXERCISE 6A 1. Start a New file. 2. Draw the objects below: Locate the center of the circles using object snap = Nearest Ortho and Snap = OFF Second Point (CCW) First Point 3. Modify the drawing above to look like the drawing below using: MODIFY / BREAK (Refer to 6-3, use Method 3) OBJECT SNAP = INTERSECTION and ENDPOINT 4. Remember the Circles break CCW. 5. Save this drawing as EX6A. 6-8

9 INSTRUCTIONS: EXERCISE 6B 1. Start a New file. 2. Draw the objects below: OBJECT SNAP = CENTER and NONE ORTHO and SNAP OFF CUTTING EDGES 3. Modify the drawing above to look like the drawing below using: MODIFY / TRIM 4. Save this drawing as EX6B. 6-9

10 INSTRUCTIONS: 1. Start a New file. EXERCISE 6C 2. Draw the LINES below exactly as shown. ORTHO and SNAP ON BOUNDARY 3. Modify the drawing above to look like the drawing below using: MODIFY / EXTEND 4. Save this drawing as EX6C. 6-10

11 INSTRUCTIONS: 1. Start a New file. EXERCISE 6D 2. Draw the drawing below using: RECTANGLE, CIRCLES and LINES (FOR THE X S) 3. Modify the drawing above to look like the drawing below using: MODIFY / EXPLODE and ERASE 4. Save this drawing as EX6D. 6-11

12 INSTRUCTIONS: 1. Start a New file. EXERCISE 6E 2. Draw the drawing below using: CIRCLES, POINT and LINES 3. Assemble the objects as shown below using: MODIFY / MOVE OBJECT SNAP = CENTER, INTERSECTION, NODE, ENDPT and QUADRANT 4. Save this drawing as EX6E. 6-12