Читать книгу Beginning AutoCAD 2018 - Cheryl R. Shrock - Страница 11
ОглавлениеLEARNING OBJECTIVES
After completing this lesson, you will be able to:
1. Create a Circle using 6 different methods.
2. Create Rectangles with Chamfers, Fillets, Width and Rotation.
3. Set Grids and Increment Snap.
4. Draw using Layers.
5. Control Layers.
6. Create Layers.
There are options to create a circle.
The default option is “Center, radius”. (Probably because that is the most common method of creating a circle.)
We will try the “Center, radius” option first.
1. Start the Circle command by using one of the following:
Ribbon = Home Tab / Draw Panel /
or
Keyboard = C <enter>
2. The following will appear on the command line: Command: _circle Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:
3. Locate the center point for the circle by moving the cursor to the desired location in the drawing area (P1) and press the left mouse button.
4. Now move the cursor away from the center point and you should see a circle forming.
5. When the circle is the size desired (P2), press the left mouse button, or type the radius and then press <enter>.
Note: To use one of the other methods described below, first select the Circle command, then select one of the other Circle options.
Center, Radius: (Default option)
1. Specify the center (P1) location.
2. Specify the Radius (P2).
(Define the Radius by moving the cursor or typing radius.)
Center, Diameter:
1. Specify the center (P1) location.
2. Specify the Diameter (P2). (Define the Diameter by moving the cursor or typing Diameter.)
2 Points:
1. Select the 2 point option
2. Specify the 2 points (P1 and P2) that will determine the Diameter.
3 Points:
1. Select the 3 Point option.
2. Specify the 3 points (P1, P2 and P3) on the circumference. The Circle will pass through all three point.
Tangent, Tangent, Radius:
1. Select the Tangent, Tangent, Radius option.
2. Select two objects (P1 and P2) for the Circle to be tangent to by placing the cursor on the object and pressing the left mouse button.
3. Specify the radius.
Tangent, Tangent, Tangent:
1. Select the Tangent, Tangent, Tangent option.
2. Specify three objects (P1, P2 and P3) for the Circle to be tangent to by placing the cursor on each of the objects and pressing the left mouse button. (AutoCAD will calculate the diameter.)
A Rectangle is a closed rectangular shape. It is one object not 4 lines.
You can specify the length, width, area, and rotation options.
You can also control the type of corners on the rectangle—fillet, chamfer, or square and the width of the Line.
First, let’s start with a simple Rectangle using the cursor to select the corners.
1. Start the Rectangle command by using one of the following:
Ribbon = Home Tab / Draw Panel /
or
Keyboard = C <enter>
2. The following will appear on the command line:
Command: _RECTANG Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]:
3. Specify the location of the first corner by moving the cursor to a location (P1) and then press the left mouse button.
The following will appear on the command line:
Specify other corner point or [Area / Dimensions / Rotation]:
4. Specify the location of the diagonal corner (P2) by moving the cursor diagonally away from the first corner (P1) and pressing the left mouse button.
OR
4. Type D <enter> (or click on the blue letter “D”)
Specify length for rectangles <0.000>: Type the desired length <enter>.
Specify width for rectangles <0.000>: Type the desired width <enter>.
Specify other corner point or [Dimension]: move the cursor up, down, right or left to specify where you want the second corner relative to the first corner and then press <enter> or press left mouse button.
Options: Chamfer, Fillet and Width
Note: The following options are only available before you place the first corner of the Rectangle.
Note: Sizes shown in brackets [...] are for metric users. Enter the numbers without the brackets. Example: [12.7] just enter 12.7
Chamfer
A chamfer is an angled corner. The Chamfer option automatically draws all 4 corners with chamfers simultaneously and all the same size. You must specify the distance for each side of the corner as distance and distance 2.
Example: A Rectangle with dist1 = 0.50” [12.7 mm] and dist2 = 0.25” [6.35 mm]
1. Select the Rectangle command.
2. Type C <enter> (or click on the blue letter “C”).
3. Enter 0.50 [12.7] for the first distance.
4. Enter 0.25 [6.35] for the second distance.
5. Place the first corner (P1).
. Place the diagonal corner (P2).
Fillet
A fillet is a rounded corner. The fillet option automatically draws all 4 corners with fillets (all the same size). You must specify the radius for the rounded corners.
Example: A Rectangle with 0.50” [12.7 mm] radius corners.
1. Select the Rectangle command.
2. Type F <enter> ( or click on the blue letter “F”).
3. Enter 0.50 [12.7] for the radius.
4. Place the first corner (P1).
5. Place the diagonal corner (P2).
Note: You must set Chamfer and Fillet back to “0” before defining the width. Unless you want fat lines and Chamfered or Filleted corners.
Width
Defines the width of the rectangle lines.
Note: Do not confuse this with the “Dimensions” Length and Width.
Width makes the lines appear fatter. .
Example: A Rectangle with a width of 0.50” [12.7 mm]
1. Select the Rectangle command. Width-
2. Type W <enter> (or click on the blue letter “W’).
3. Enter 0.50 [12.7] for the width.
4. Place the first corner (P1 ).
5. Place the diagonal corner (P2).
Options: Area and Rotation
Note: The following options are available after you place the first corner of the Rectangle.
Area
Creates a Rectangle using the area and either a length or a width. If the Chamfer or Fillet option is active, the area includes the effect of the chamfers or fillets on the corners of the rectangle.
Example: A Rectangle with an Area of ” [152.4 mm] and a Length of 2” [50.8 mm]
1. Select the Rectangle command.
2. Place the first corner (P1).
3. Type A <enter> for Area. (or click on blue “A”).
4. Enter [152.4] <enter> for the Area.
5. Select L <enter> for length option (or click on blue “L”).
6. Enter 2 [50.8] <enter> for the length. (The width will automatically be calculated.)
Rotation
You may select the desired rotation angle after you place the first corner and place the first corner and you place the second corner. The base point (pivot point) is the first corner.
Note: All new rectangles within the drawing will also be rotated unless you reset the rotation to 0. This option will not effect rectangles already in the drawing.
Example: A Rectangle with a rotation angle of 45 degrees.
1. Select the Rectangle command.
2. Place the first corner (P1).
3. Type R <enter> for rotation. (or click on blue “R”).
4. Enter 45 <enter>.
5. Place the diagonal corner (P2).
Grid is the criss-cross lines in the drawing area. The grid is only a drawing aid to assist you in aligning objects and visualizing the distances between them.
The Grid will not plot. (Refer to page 1-13.)
Increment Snap controls the movement of the cursor. If it is off the cursor will move smoothly. If it is on, the cursor will jump in an incremental movement.
(Refer to page 1-13.)
The Drafting Settings dialog box allows you to set Increment Snap and Grid spacing. You may change the Grid Spacing and Increment Snap at anytime while creating a drawing. The settings are only drawing aids to help you visualize the size of the drawing and control the movement of the cursor.
1. Select Drafting Settings by using one of the following:
Keyboard = DS <enter>
Status Bar = Right Click on Snap or Grid button and select Settings.
2. The dialog box shown below will appear showing inch or metric units depending on whether you selected an inch or metric template.
3. Select the “Snap and Grid” tab.
4. Make your changes and select the OK button to save them. If you select the Cancel button, your changes will not be saved.
A Layer is like a transparency. Have you ever used an overhead light projector? Remember those transparencies that are laid on top of the light projector? You could stack multiple sheets but the projected image would have the appearance of one document. Layers are basically the same. Multiple layers can be used within one drawing.
The example, on the right, shows 3 layers.
One for annotations (text), one for dimensions and one for objects.
How to use Layers
First you select the layer and then you draw the objects.
Always select the layer first and then draw the objects.
It is good “drawing management” to draw related objects on the same layer.
For example, in an architectural drawing, you would select layer “walls” and then draw the floor plan.
Then you would select the layer “Electrical” and draw the electrical objects.
Then you would select the layer “Plumbing” and draw the plumbing objects.
Each layer can then be controlled independently.
If a layer is Frozen, it is not visible. When you Thaw the layer it becomes visible again. (Refer to the following pages for detailed instructions for controlling layers.)
How to select a Layer
1. Go to Ribbon = Home tab / Layers panel.
2. Select the drop-down arrow
3. Highlight the desired layer and press the left mouse button.
The selected layer becomes the “Current” layer. All objects will be located on this layer until you select a different layer.
Controlling Layers
The following controls can be accessed using the Layer drop-down arrow .
On or Off
If a layer is on it is visible. If a layer is off it is not visible.
Only layers that are on can be edited or plotted.
Freeze or Thaw
Freeze and Thaw are very similar to on and off. A Frozen layer is not visible and a Thawed layer is visible. Only thawed layers can be edited or plotted.
Additionally:
a. Objects on a Frozen layer cannot be accidentally erased.
b. When working with large and complex drawings, freezing saves time because frozen layers are not regenerated when you zoom in and out.
Lock or Unlock
Locked layers are visible but cannot be edited.
They are visible so they will be plotted.
To access the following options you must use the Layer Properties Manager.
You may also access the options listed on the previous page within this dialog box.
To open the Layer Properties Manager use one of the following.
How to delete an existing layer
1. Highlight the layer name to be deleted.
2. Select the Delete Layer tool.
or
1. Highlight the layer name to be deleted.
2. Right click and select Delete Layer.
Plot or Not Plottable
This tool prevents a layer from plotting even though it is visible within the Drawing Area. A Not Plottable layer will not be displayed when using Plot Preview. If the Plot tool has a slash the layer will not plot.
Layer Color
Color is not merely to make a pretty display on the screen. Layer colors can help define objects. For example, you may assign color Green for all doors. Then, at a glance, you could identify the door and the layer by their color.
Here are some additional things to consider when selecting the colors for your layers.
Consider how the colors will appear on the paper. (Pastels do not display well on white paper.)
Consider how the colors will appear on the screen. (Yellow appears well on a black background but not on white.)
How to change the color of a layer.
A Lineweight means “how heavy or thin is the object line”.
It is “good drawing management” to establish a contrast in the lineweights of entities.
In the example below the rectangle has a heavier lineweight than the dimensions. The contrast in lineweights makes it easier to distinguish between entities.
Lineweight Settings
Lineweights are plotted with the exact width of the lineweight assigned.
But you may adjust how they are displayed on the screen. (Refer to #4 below)
Important: Before assigning lineweights you should first select the Units for Listing and Adjust Display Scale as shown below.
1. Select the Lineweight Settings box using one of the following:
Keyboard = lw <enter>
or
Status Bar = Right click on the Lineweight button.
and then left click on Lineweight Settings.
Note: These settings will be saved to the computer not the drawing and will remain until you change them. You may have to shut down AutoCAD then restart for the changes to take effect.
Assigning Lineweights
Note: Before assigning Lineweights to Layers make sure your Lineweight settings (Units for Listing and Adjust Display Scale) are correct. Refer to the previous page.
Assigning Lineweights to Layers
1. Select the Layer Properties Manager using one of the following:
2. Highlight a Layer (Click on the name).
3. Click on the Lineweight for that layer.
4. Scroll and select a Lineweight from the list.
5. Select the OK button.
Note:
Lineweight selections will be saved within the current drawing and will not effect any other drawing. The images above show lineweight sizes for the inch-helper.dwt. Metric sizes will appear if you are using the metric-helper.dwt.
Each layer may be assigned a transparency percentage from 0 to 90 percent. 0 would not be transparent at all and 90 would be 90% transparent.
Assigning Transparency to Layers
1. Select the Layer Properties Manager using one of the following:
2. Highlight a Layer (Click on the name).
3. Click on Transparency for that layer.
4. Select a Transparency from the list.
5. Select the OK button.
Note: Transparency selections will be saved within the current drawing and will not effect any other drawing.
Plotting Transparent Objects
Plotting transparency is disabled by default. To plot transparent objects, check the Plot transparency option in either the Plot dialog box or the Page Setup dialog box.
This will be discussed in Lesson 26.
Using layers is an important part of managing and controlling your drawing. It is better to have too many layers than too few. You should draw like objects on the same layer. For example, place all doors on the layer “door” or centerlines on the layer “centerline”.
When you create a new layer you will assign a name, color, linetype, lineweight, transparency and whether or not it should plot.
1. Select the Layer command using one of the following:
2. Select the New Layer tool and a new layer will appear.
3. Type the new layer name and press <enter>.
4. Select any of the features and a dialog box will appear.
Features:
Refer to the previous pages for controlling and selecting Layer colors, lineweights and transparency.
Refer to the next page for loading and selecting Layer linetypes.
Loading and Selecting Layer Linetypes
In an effort to conserve data within a drawing file, AutoCAD automatically loads only one linetype called “continuous”. If you would like to use other linetypes, such as “dashed” or “fenceline”, you must Load them into the drawing as follows:
Instructions:
1. Start a New file using either the inch-helper.dwt or the metric-helper.dwt
2. Draw the Lines below using:
A. Line command
B. Ortho (F) on.
C. Turn Increment Snap (F9) on
3. Select the appropriate layer, then select the Line command, then draw a line.
4. Select the appropriate layer, then select the Line command, then draw a line.
5. Select the appropriate layer, then select the Line command, then draw a line.
Are you noticing a pattern here?
6. Save the drawing as: Ex-3A
Exercise 3B
Instructions:
1. Start a New file using either the inch-helper.dwt or the metric-helper.dwt
2. Change the Increment Snap to 0.20” [5.08 mm] and Grid spacing to 0.40” [10.16 mm]. If you have the Snap and Grids set correctly it will be easy.
3. Make sure Snap and Grid status bar buttons are on.
4. Draw the objects below using layer Object Line.
Review pages 3-2 through 3-6 for Circle and Rectangle options.
5. Do not dimension, you will learn dimensioning soon.
6. Save the drawing as: Ex-3B
Exercise 3C
Instructions:
1. Start a New file using either the inch-helper.dwt or the metric-helper.dwt
2. Draw the Rectangles below using the options:
Dimension, Chamfer, Fillet, Width and Rotation
3. Use layer Object Line.
4. Save the drawing as: Ex-3C
Rectangle Dimensions:
Length = 3” [76.2 mm]
Width = 2” [50.8 mm]
Chamfer = Dist1 = 0.50” [12.7 mm] Dist2 = 0.50” [12.7 mm]
Rectangle Dimensions:
Length = 3” [76.2 mm]
Width = 2” [50.8 mm]
Fillet = 0.50” [12.7 mm]
Rectangle Dimensions:
Length = 3” [76.2 mm]
Width = 2” [50.8 mm]
Rotation = 45°
Chamfer = 0
Fillet = 0
Rectangle Dimensions:
Length = 3” [76.2 mm]
Width = 2” [50.8 mm]
Line Width = 0.200” [5.08 mm]
Rotation = 0°
Chamfer = 0
Fillet = 0
Exercise 3D
Instructions:
1. Start a New file using either the inch-helper.dwt or the metric-helper.dwt
2. Important: Draw the objects below using the following Layers:
Roof, Wall, Window, Door and Plants
3. You can change Snap and Grid settings to whatever you like.
4. You decide when to turn Ortho and Snap on or off.
5. All objects must be placed accurately. All lines must intersect exactly.
6. Save the drawing as: Ex-3D
Exercise 3E
Instructions:
1. Open Ex-3D. (Use Open not New to open an existing drawing)
2. Make layer Object “current”
(I am having you do that because you can’t Freeze or Lock a layer that is current and I want to make sure that none of the layers that you used in the drawing is current.)
3. Freeze the following layers: Window and Plants (Do not use erase)
4. Lock layer Roof
5. Try to erase any of the roof lines.
You can’t because the Roof layer is Locked.
6. Save the drawing as: Ex-3E
Exercise 3F
Instructions:
1. Start a new file using template: acad.dwt (inch) or acadiso.dwt (metric).
2. Load Linetypes Zigzag, Gas_Line and Dashed (Refer to page 3-16).
3. Create 3 layers named Fence, Gas and Invisible. (Refer to page 3-15.) Assign the Name, Color, Linetype and Lineweight as shown above.
Note: Lineweights for metric users are: Zigzag = 0.5 mm, Gas-Line = 1.2 mm, Dashed = 0.25 mm.
4. Draw the Lines below using the new layers:
A. Select the layer
B. Select the Line command
C. Draw the lines approximately 5 inches [127 mm] long.
D. Ortho (F) on.
5. Save the drawing as: Ex-3F
Exercise 3G
Instructions:
1. Open Ex-3B
2. Open the Layer Properties Manager (Refer to page 3-10).
3. Change Transparency of the Object Line layer to 70 (Refer to page 3-14).
4. Select the Transparency status button to show or hide Transparency.
5. Save the drawing as: Ex-3G
Notes:
