6/23/2009. AutoCAD Chapter 3 Objectives. Line Command. Coordinate Entry Methods. Rectangular Coordinate System

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1 Chapter 3 Objectives AutoCAD 2009 CHAPTER 3 JUNE 23, 2009 Use the correct entry format when entering numbers Demonstrate how to end or cancel commands Describe and use several point entry methods Draw given objects using the line tool Demonstrate tool access using dynamic input and command line Use direct distance entry with polar tracking and ortho mode Revise objects using Erase tool and its options Create selection sets using the various selection options Use the U, Undo Redo, and Oops tools appropriately Line Command Rectangular Coordinate System Command: Line Alias : L Requires coordinates to locate end point. Rectangular Coordinate System Origin (0,0) Coordinate Entry Methods Cartesian Coordinate System Absolute Relative Polar Absolute Coordinate: (1,2) Absolute Coordinate: (3,1) Grid: 1 by 1 1

2 Relative Coordinates Point 1 Point 2: (@2,-1) What s the Point? Polar Coordinates Specifying Coordinates Relative Polar <24 Polar Coordinate Polar Tracking Remember Angular measurement s will run counterclockwise Polar tracking is on by default F10 may be used to toggle it on and off Screen capture below show the result of having polar tracking on. Angular measurement and distance relative to the previous point are displayed

3 Ways to Toggle Ortho On or Off Undo Command Ortho may be toggled on and off by clicking on the icon shown below in the Auto cad. F8 Key [Ctrl] + [L] From time to time you will inadvertently click on a point while using the line command and create an unwanted line. To quickly remove a line created this way, use the undo command Typing Ortho at the Command prompt, and selecting on / off Undo Command Ortho Mode Type Undo at Command prompt or U Rick click and select undo from the shortcut menu. Undo may be used repeatedly to undo a series of steps Click on the menu browser button to expand the browser menu, select edit and then undo. When the Ortho mode is selected points are constrained so that they are located horizontally or vertically from the previous point. It may be temporarily disabled by pressing the shift key. Ortho may be used in conjunction with direct distance entry, by first moving the cross hairs in the desired direction and then typing the distance after a vertical or horizontal rubber band is displayed. Close Option Exercise 3-2 / Lab Activity Using Relative Coordinates When drawing a series of lines to create a polygon using the close option eliminates the need to locate the end point of the last segment of the polygon. Rather then pick the endpoint or enter coordinates type C or Close. Command: Line Specify first point: 2,2 Specify next point or [close/ Specify next point or Specify next point or 0,3 Specify next point or Specify next point or Specify next point or Specify next point or [close/undo]: c 3

4 Exercise 3-2 / Lab Activity Using Relative Coordinates Continue Function Command: Line Specify first point: 2,2 Specify next point or [close/ Specify next point or Specify next point or 3<90 Specify next point or Specify next point or Specify next point or Specify next point or [close/undo]: c Frequently after exiting the line command a cad user may find that they need to reselect the last point on a line they created after exiting the line command. The quickest way to reselect this point is to press Enter or right click once the line command is active. This function may also be used with arcs. Basic Editing Tools, (MVPs) Erase Erase Undo, (U) Oops Redo When you pick the Erase tool, you will be prompted to select the objects to be erased. The cross hairs are then replaced with a pick box which you will use to pick the objects to be erased. Objects that have been inadvertently erased may be restored with undo or oops Erase Command When an object has been selected with the Erase command active it will become thicker and dashed, allowing you to preview your selection and make sure you are erasing the correct object. More than one object may be selected at a time. Once all of the objects to be erased are selected press the enter button, or right click and select erase from the shortcut menu. Window and Window Crossing Windows allows the user to select multiple objects at one time by simply clicking and dragging to create a rectangular selection region that encompasses the objects to be selected. When the rectangular a window region is created by clicking and dragging to the right the object to be selected are within the bounds of the window. If the rectangular window region is created by clicking and dragging to the left it is considered to be Windows Crossing, and the object that the window crosses through are selected. 4

5 Windows and Windows Crossing Window Polygon Window used to select thru hole at top of part Windows Crossing used to select chamfers Windows and Windows crossing provide a rectangular selection area, which is not always suitable. Windows polygon, allows the Autocad user to create a polygon selection area. At select objects prompt type WPOLYGON or WP Windows Crossing Polygon Fence Selection The windows crossing polygon is similar to windows crossing in that only the objects that are crossed by the polygon are selected. The crossing polygon differs from the windows crossing in that it is not necessarily rectangular. At select objects prompt type CPOLYGON or CP Fence selection is another method of selecting multiple objects. Only the objects that are crossed by the fence are included in the selection. Objects that are entirely within the fence are not included in the selection set. At the Select objects prompt type FENCE or F Select All Objects Removing From or Adding to a Selection Set The Select All object function on the Utility tab, allows the user to select all of the objects. Often while selecting a series of objects the Autocad user will accidently select an object hat is not meant to be included. The easiest way to un-select it is to hold down the shift key and reselect it. If in the middle of selecting objects for a modify command and you need to un-select an object, type Remove or R at the select objects prompt. To switch back from the remove mode type Add or A to restore the select object mode. 5

6 Windows Selection Practice Dynamic Input From Student CD Practice Folder Open Wire Diagram. Dwg Use Windows crossing to select horizontal lines Use Windows selection to select TB6 Individually pick wires and then unselect last pick Activate Erase command, type wpolygon and select connector pins at top of TB 4. Dynamic Input may be toggled on or off by using the F12 key. Dynamic input places the command / input prompts in the work area immediately next to the cursor. This allows the Autocad user to keep their eyes on the work area rather than the command prompt at the bottom of the screen. Undo Tool Undo Command Options The undo tool is not limited to the last operation or two. It may be used to undo numerous operations in a step by step process or in one operation, where the number of steps to be undone is specifies. Command: Undo Enter number of operations to undo: # Undo Command Redo Begin option: Sets the place to which the U toll will undo if used in the future. Type B to set Beginning point End option: Sets the end of a sequence of operations. The U tool would treat t theoperationsti that occurred between the beginning and the end as one step. Mark option: Inserts a marker in the undo file. This would allow the back option to undo the operations that occured after the marker was inserted. The redo tool will reverse the Undo operation. It will only work if used immediately after the undo tool. 6

7 Oops Tool Shortcuts Will bring back the last object erased. It has no effect on other modifications. F7 = Toggles Grid On/ Off F8= Toggles Ortho On/ Off F9= Toggles Snap On/ Off F10= Toggles Polar Tracking On/ Off F12= Toggles Dynamic Input On/ Off Language of Lines for Technical Drawing Object Lines.7mm dark continuous line (Represents visible surfaces on part) Hidden Line.3mm light segmented line (Represents hidden edges on part) Section line.3mm light, (Used to show interior details) Centerlines.3mm light segmented line (Used to locate the center axis of features such as holes ) Line Types A variety of line types are available to work with in Autocad. Typically, the Autocad user will assign different line types to different layers. The layers will be built into the template from which all drawings are started. 7

8 Lab Assignments Drawing Problems on page , #3, 5 & 9A 8