That covered the most basic information you need to understand the workings of AutoCAD. Now you will put this knowledge to work In this architectural tutorial, which begins here and continues through, you will draw an apartment building composed of studios. The tutorial illustrates how to use AutoCAD commands and gives you a solid understanding of the basic AutoCAD package. With these fundamentals, you can use AutoCAD to its fullest potential, regardless of the kinds of drawings you intend to create or the enhancement products you may use in the future.
In this chapter you will start drawing an apartment’s bathroom fixtures. In the process, you will learn how to use AutoCAD’s basic tools.
Setting Up a Work Area
Before beginning most drawings, you should set up your work area. To do this, determine the measurement system, the drawing sheet size, and the scale you want to use. The default work area is roughly 9″x 16″ at full scale, given a decimal measurement system where’l unit equals 1 inch. Metric users will find that the default area is roughly 550 mm by 300 mm, where 1 unit equals 1 mm. If these are appropriate settings for your drawing, then you don’t have to do any setting up. It is more likely, however, you will be making drawings of various sizes and scales. For example, you may want to create a drawing in a measurement system where you can specify feet, inches, and fractions of inches at 1″=1′ scale, and print the drawing on an 81/2″ x 11″ sheet of paper.
you used the Create New Drawing wizard to set up a drawing file. The Create New Drawing wizard is a great tool, but it hides many of the drawing setup tools you’ll need to know to work with AutoCAD. In this section, you will learn how to set up a drawing exactly the way you want.
Start by creating a new file called Bath.
1. Start up AutoCAD. Choose File >- New .
2. In the Create New Drawing dialog box, click the Start from Scratch button and select English from the Select Default Setting list. Metric users can select Metric.
3.Click OK to open the new file.
4.Choose File >- Save As.
5.In the Save Drawing As dialog box, enter Bath for the filename.
6.Check to make sure you are saving the drawing in the Samples subdirectory, or the directory you have chosen to store your exercise files, and then click Save.
The first thing you want to tell AutoCAD is the unit style you intend to use. So far, you’ve been using the default. which is decimal inches. In this unit style. whole units represent inches, and decimal units are decimal Inches. If you want, to be able to enter distances in feet, then you must change the unit style to a style that accepts feet as input. This is done through the Drawing Units dialog box .
1. Choose Formats> Units, or type Un.↵, The Drawing Units dialog box appears. Let’s look at a few of the options available,
2. Click the Type drop-down list l! the Length button group. Notice the unit styles shown in the list. ,
3. Click Architectural in the list. Once you’ve selected Architectural. the Sample Output section of the dialog box shows you what the architectural style looks like in AutoCAD. users should keep this setting as Decimal.
4. Click the Precision drop-down list just below the Type list. Notice the options available. You can set the smallest unit AutoCAD will display in this drawing. For now, leave this setting at its default value of 1/16″. Metric users will keep the setting to 0.0000.
5. Close the drop-down list by pressing the Esc key and then click the Direction button at the bottom of the dialog box. The Direction Control dialog box appears. This dialog box lets you set the direction for the 00 angle and the direction for positive degrees. For now, don’t change these settings. you’ll read more about them in a moment.
6. Click the Cancel button .
7. Now click the drop-down list in the Drawing Units for Design Center Blocks group. The list shows various units.
8. Click Inches, or if you are a metric us-er, l choose Centimeters. This option allows you to control how AutoCAD translates drawing scales when you import drawings from outside the current drawing. You’ll learn more about this feature.
9. Click OK in the Drawing dialog box to return to the drawing.
If you use the English system of measurement, you selected Architectural measurement units for this tutorial but Your own work may require a different unit style. You saw the unit styles available in the Drawing Units dialog box. this shows examples of how the distance is entered in each of these styles.
In the previous exercise, you needed to change only two settings. Let’s take a look at the other Drawing Units settings in more detail. As you read, you may want to refer to the illustration of the Drawing Units dialog box.
Fine-Tuning the Measurement System
Most of the time, you will be concerned only with the units and angles settings of the Drawing Units dialog box. Bet as you saw from the last exercise, you can control many other settings related to the input and display of units.
The Precision drop-down list in the Length group lets you specify the smallest unit value that you want AutoCAD to display in the status line and in the prompts. If you choose a measurement system that uses fractions, the Precision list includes fractional units. This setting can also be controlled with Luprec system variables.
The Angle group lets you set the style for displaying angles. You have a choice of five angle styles: decimal degrees, degrees/minutes/seconds, grads, radians , and surveyor’s units. In the Angle group’s Precision drop-down list, you can determine the degree of accuracy you want AutoCAD to display for angles. These settings can also be controlled with the Aunits and Auprec system variables.
The Direction Control dialog box lets you set the direction of the 0° base angle. The default base angle (and the one used throughout this book) is a direction from left to right. However, there may be times when you will want to designate another direction as the 0° base angle. You can also tell AutoCAD which direction is positive, either clockwise or counterclockwise. This book uses the default, which is counterclockwise. These settings can also be controlled with the Angbase and Angdir system variables.
The Drawing Units for DesignCenter Blocks setting in the Drawing Units dialog box lets you control how external files are scaled as they are imported into your current drawing. For example, in older versions of AutoCAD, engineers often used one foot as their unit of measure so that they could enter values in decimal feet. In prior versions of AutoCAD, importing such a file into your architectural drawing would show an engineering drawing that is 1/12 the size that it should be. To fix this, you would have to scale the inserted engineering drawing by a factor of 12 to get it to match your architectural drawing.
The Drawing Units for DesignCenter Blocks setting lets you compensate for drawings of different scale by offering’ an automatic scale translation when files are imported. If you know that you will be importing engineering drawings that use decimal feet as the unit of measure, you can set the Drawing Units for DesignCenter Blocks value to feet, then the imported engineering drawing will be imported at a scale that matches your architectural drawing. The In units system variable also controls the Drawing Units for DesignCenter Blocks setting.
Setting Up the Drawing Limits
One of the big advantages in using AutoCAD is that you can draw at full scale; you aren’t limited to the edges of a piece of paper the way you are in manual drawing. But you still have to consider what will happen when you want a printout of your drawing. If you’re not careful, you may create a drawing that won’t fit on the paper size you want at the scale you want. When you start a new drawing, it helps to limit your drawing area to one that can be scaled down to fit on a standard sheet size. While this is not absolutely necessary with AutoCAD, the limits give you a frame of reference between your work in AutoCAD and the final printed output.
In order to set up the drawing work area, you need to understand how standard sheet sizes translate into full-scale drawing sizes. Table 3.2 lists widths and heights of drawing areas in inches, according to scales and final printout sizes. The scales are listed in the far-l~ft column; the output select Sizes are listed across the top.
Let’s take an example: To find the area needed in AutoCAD for your bathroom drawing, look across from the scale 1″=1′ to the column that reads 8 f/2″ x 11″ at the top. You’ll find the value 102×132. This means the drawing area needs to fit within an area 102″ x 132″ (8.5 feet by 11 feet) in AutoCAD in order to fit a printout of a 1″=1′-0″ scale drawing on;11181/2″ x 11″ sheet of paper. You may want the drawing area to be oriented horizontally, so that the 11 feet will be in the x-axis and the 8.5 feet will be in the y-axis.
If you’re a metric user, you’ll be drawing the bathroom at a scale of) to 10. This is a scale that is close to the 1″ = 1′-0″ scale used for the English measurements in the exercises. So for an A-l sheet. your work area should be 297cl11x 21Oem. This b the equivalent of an A4 sheet (Zl Omm x 297mm) enlarged by a factor of 10.
Now that you know the area you need, you can use the Limits command-to set up the area.
1. Choose Format > Drawing Limits.
2. At the Specify lower left corner or [ON/OFF}.<0′-0· ,0′-0″): prompt.
specify the lower-left comer of your work area. Press .J to accept the default.
3. At the Specify upper right corner <1’0· ,0’9″): prompt, specify the upper-right comer of your work area. (The default is shown in brackets.) Enter 132,102. Or if you prefer, you can enter 11′,8’6, since you’ve set up your drawing for architectural units. Metric users should enter 297,210.
4. Next, choose View> Zoom> All. You can also select the Zoom All tool from the Zoom Window fly out on the Standard toolbar, or type Z↵ A↵. Although it appears that nothing has changed, your drawing area is now set to a size that will allow you to draw Your bathroom at full scale.
5. Move the cursor to the upper-right comer of the drawing area and watch the coordinate readout. Notice that now the upper-right comer has a y-coordinate of approximately 8′-6″ or 300 for metric users. The x-coordinate will vary depending on the proportion of your AutoCAD window. The coordinate readout also displays distances in feet and inches.
In step 5 above, the coordinate readout shows you that your drawing area is larger than before, but there are no visual clues to tell you where you are or what distances you are dealing with. To help you get your bearings, you can use the Grid mode, which you will learn about shortly. But first, let’s take a closer look at scale factors and how they work.
Understanding Scale Factors
When you draft manually, you work on the final drawing directly with pen and ink or pencil. With a CAD program, you are a few steps removed from the actual finished product. Because of this, you need to have a deeper understanding of your drawing scale and how it is derived. In particular, you need to understand scale factors.
For example, one of the more common uses of scale factors is in translating text size in your CAD drawing to the final plotted text size. When you draw manual. you simply draw your notes at the size you want. In a CAD drawing, you need to translate the desired final text size to the drawing scale .
When you start adding text to your drawing, you have to specify a text height. The scale factor helps you determine the appropriate text height for a particular drawing scale. For example, you may want your text to appear 1/8″ high in your final plot. But if you drew your text to 1/8″ in your drawing, it would appear as a dot when plotted. The text has to be scaled up to a size that, when scaled back down at plot time, appears l/S” high. So, for a 1/4″ scale drawing you multiply the 1/S” text height by a scale factor of 48 to get 6″. Your text should be 6″ high ill the CAD drawing in order to appear 1/8″ high in the final plot.
All the drawing sizes were derived by using scale factors. It shows scale factors they relate to standard drawing scales. These scale factors are the values by which you multiply the desired final printout size to get the equivalent full-scale size. For example, if you have a sheet size of 11″x 17″, and you want to know the equivalent full-scale size for a 1/4″-scale drawing, you multiply the sheet measurements by 48. In this way, 11″becomes 528″ (48″x 11″)and 17″becomes 816″ (48″x 17″),Your work area must be 52S”x 816″if you intend to have a final output of 11″x 17″at 1/4″=1′. You can divide these inch measurements by 12″ to get 44′ x 68′.
You will be using scale factors to specify text height and dimension settings, so getting to understand them now will payoff later.