Now it's time to learn a few more commands. Like all of the commands
learnt so far, these too will be ones that you will use regularly.
Here are the commands that you will be learning in this lesson.
Command |
Keystroke |
Icon |
Menu |
Result |
Rotate |
Rotate
/ RO |
|
Home > Modify > Rotate |
Rotates objects to a certain angle |
Fillet |
Fillet
/ F |
|
Home > Modify > Fillet |
Creates a round corner between two lines |
Chamfer |
Chamfer
/ CHA |
|
Home > Modify > Chamfer |
Creates an angled corner between two lines |
Array |
Array
/ AR |
|
Home > Modify > Array |
Creates a repeating pattern of the selected objects |
Once again you will recreate a drawing. This one is called Assignment #5.
Click here to see the GIF format file.
Click here for the DWG file.
Follow the steps shown carefully. As these commands require a little more input, make
sure that you keep an eye on the command line. You will be asked to provide
information throughout the commands.
Start
up AutoCAD and load the acad.dwt template like you have for the
other lessons.
Start
by drawing a horizontal 10" X 7" border with the bottom left
corner at 0,0
Draw a
rectangle 1" wide by 3" tall with the bottom left
corner at .75,.75
You are now going to rotate this rectangle 90° clockwise.
Start
the ROTATE command.
AutoCAD asks you to select objects. Select all parts of
the rectangle and press <ENTER>. Now you must indicate
a 'base point'. Think of this as a pivot point around which
the rectangle will rotate. In this example, you want to
select the bottom right corner (remember to use your Osnap).
Once you've selected the base point, the command line shows rotation angle or [Reference]: This means that 'Rotation
angle' is the default, so type in the angle you want to
rotate the object. Think about how AutoCAD
measures angles.
Looking at your rectangle and the one on the assignment
sheet, you'll see that you want to rotate the rectangle
clockwise or: -90 degrees. Enter that number and press <ENTER>.
Command: RO <ENTER>
Current positive angle in UCS: ANGDIR=counterclockwise ANGBASE=0
Select
objects: <Select
the Rectangle> 1
found
Select objects: <ENTER>
Specify base point:<PICK
BOTTOM RIGHT CORNER OF THE RECTANGLE>
Specify rotation angle or [Reference]:-90 <ENTER>
The rectangle is now been rotated -90 degrees from its original
position. Picking different base points will give you different results. Undo the
last command. Try a few different combinations of base points and angles
to see what results you get. When you are done practicing, get the rectangle
back to the position that it needs to be in.
Make
a COPY of
the rectangle 2" above the first one (remember your relative coordinates).
Now
you're going to modify the second rectangle so that it has rounded
corners. Start the FILLET command.
Look at the command line. It will look something like this:
Command: F <ENTER> FILLET
Current settings: Mode = TRIM, Radius = 0.0000
Select first object or [Undo/Polyline/Radius/Trim/Multiple]:
AutoCAD
first shows you what the current fillet radius is (0.0000).
This will be the last value that was used. Once it's changed,
it will keep the new value in memory. The next line shows you
what options you have in this command. Remember that the Capitol
of each option selects that particular option. What you want
to do is change the fillet radius to 3/8" (or .375). To do
this you have to type R <ENTER>.
When you type this AutoCAD will give the chance to enter a
new fillet radius. At this point enter .375 and
press <ENTER>.
The fillet radius is now .375 (which is what you want).
The default option is Select
first object. Select the left side of the top rectangle
(yes, the whole rectangle will highlight if you drew it as
a rectangle). AutoCAD now asks you to select second object.
Select the top line and AutoCAD will make a smooth round
corner with a radius of .375. AutoCAD automatically ends
the command at this point.
Restart the FILLET command and
do this to the remaining corners so that you have an object
similar to the example.
BREAK TIME : The Fillet command is commonly used with a Zero radius. This can sometimes be much quicker than trimming two lines that meet at endpoints. To practice this, fillet this lines you made with round corners using a Zero radius. |
Copy the
first rectangle to a point 4-1/2" above. Now
you will use the chamfer command to give this rectangle sharp, angled
corners.
Start the CHAMFER command.
This
is very similar to the fillet command. You have several options
available. Want you want is an even 45 degree angle 3/8" in
from the corner. Like the fillet command, you first have to
tell AutoCAD what distance you want. To do this, type D to
select the Distance option. The command line now looks like
this:
Specify
first chamfer distance <0.5000>: .375 <ENTER>as your first distance.) The command line now asks for the
second distance. AutoCAD will automatically change the default
of the second distance to match the distance you entered for
the first.
Specify
second chamfer distance <0.3750>: (Press <ENTER> to accept this)
You
will then be asked to Select
first line. The chamfer command works just like the fillet command. Select
the line on the left of the top rectangle. (Don't worry if
the entire rectangle highlights.) When prompted to Select
second line: select
the top line. You will now have a perfect sharp corner at a
45 degree angle 3/8" in from the corner. Do this to the rest
of the corners.
Look at the command line. It should look like this:
Command: CHA <ENTER> CHAMFER
(TRIM mode) Current chamfer Dist1 = 0.0000, Dist2 = 0.0000
Select first line or [Polyline/Distance/Angle/Trim/Method]: D <ENTER>
Specify
first chamfer distance <0.5000>: .375 <ENTER>
<0.3750>: <ENTER>
Select first line or [Undo/Polyline/Distance/Angle/Trim/mEthod/Multiple]: <select
one side of the rectangle>
Now look
at the assignment sheet and notice the group of six rectangles
on the bottom right. You could draw each one individually, but
AutoCAD has a command that will allow you to draw one, and it
will make the others.
Create a rectangle that is 1/2" square
with the bottom left corner at 6,1.5 (absolute
points).
Start
the ARRAY command. Look
at the dialog box shown below (if you are using AutoCAD 2012, please check these videos for the updated command):
When confronting a new
dialog box, I recommend that you look for what is needed from
the TOP DOWN to the bottom. This is a great example.
-
Choose the radio button for "Rectangular Array".
This will array the object in a row/column arrangement.
-
Next select the object you want to array, by picking on
the button in the top right corner. (Press enter when done)
-
Enter the number of rows (going across the page) and column
(running up and down the page).
-
Enter the Row offset. This is this from the bottom left
of the original rectangle, to the bottom left of where
the first copy will go.
-
Enter the Column offset
-
Pick the Preview button to see the array before committing.
Pick or press Esc to return to dialog or <Right-click to accept array>:
If the array is correct (check the sample drawing),
press right click.
If you need to change anything, press the ESC button,
make your changes in the dialog box and preview again.
Now you are going to use the ARRAY (polar) command to create the shape
in the top right corner of the assignment.
Start by making a CIRCLE with
a center point of 7.5,5.5 and
a diameter of 1.5 Next
make a LINE from
the center of the circle going 1" to the right (remember
your relative input and Osnaps).
Start
the ARRAY command.
When asked to select objects, pick the line you just drew.
Examine the dialog box
above. Remember to start from the TOP. In this case, you
have to select your objects and select a Center Point for
the array. (Select the center of the circle.)
NOTE: Sometimes the Array command can be quicker than the offset command. Think of creating lines for a ceiling grid. You 'could' offset 30 lines one at a time, or you 'should' use the array command to create all 30 lines at once.
Save
and print your drawing.
So far in seven lessons, you have learned many of the common commands in AutoCAD. It may not seem like a lot, but the idea is to become fluent in them. It should be second nature to run these commands, as these are the ones you will be using most often. With practice, you won't need the command line to help you along. Think of the first time you drove a car with a manual transmission. After time, it got smoother, didn't it. I can't stress enough how important practice is during these early lessons.
Extra Practice: Copy this drawing - extra_009.gif
Extra Practice: Copy this drawing - extra_010.gif
Extra Practice: Copy this drawing using 2 methods. First create the lines using the offset command, then create the lines using the Array command. Compare which method should be easier, and when you might use one over the other - extra_012.gif
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