LESSON 1-3
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| LESSON 1-1 | X-Y CO-ORDINATE SYSTEM, INPUTTING POINTS THE AUTOCAD SCREEN BASIC AUTOCAD TERMINOLOGY |
| LESSON 1-2 | ASSIGNMENT 1 - INTRO TO DRAWING / MODIFYING COMMANDS |
| LESSON 1-3 | ASSIGNMENT 2 - MORE MODIFYING COMMANDS |
| LESSON 1-4 | ASSIGNMENT 3 - ACCURATE INPUT |
| LESSON 1-5 | SELECTION SETS |
| LESSON 1-6 | ASSIGNMENT 4 - MODIFYING COMMANDS |
| LESSON 1-7 | ASSIGNMENT 5 - MODIFYING COMMANDS |
| LESSON 1-8 | ASSIGNMENT 6 - LAYERS / DIMENSIONING / TEXT |
| LESSON 1-9 | DIRECT DISTANCE ENTRY AND OBJECT TRACKING |
| LESSON 1-10 | CHANGING THE PROPERTIES OF OBJECTS |
BASIC DRAWING SKILLS
The previous lesson dealt with drawing commands. This lesson will introduce the common modifying commands. In AutoCAD, you may use modifying commands more often than drawing commands. Now that you know that basics, here's some more commands to add to your collection.
ASSIGNMENT #2 - MODIFYING COMMANDS
The purpose of this assignment is to use the commands learned in the previous lesson and learn some new ones.Once again, do not worry about title blocks, text or dimensions, draw only what is in yellow. Start AutoCAD and begin the the drawing by opening up the template file like you did in Lesson 1-2. Draw a LINE from 1,2 to 3,2 to 3,4 to 1,4 (*Remember to watch the command line as you do this.) For the last line, you can either type in 1,2 or C to close the line back to the first point you entered. These are absolute co-ordinates. Make sure you understand what the points your just entered represent. Draw the next square using the RECTANGLE command. A rectangle is created by specifying 2 points to represent the opposite corners. Enter the first point as 4.5,2 and then make the opposite corner 2 inches over and 2 inches up @2,2 using relative co-ordinates. This is much faster and also makes the square one object and not 4 separate lines. ERASE the rectangle. You will see that all of it is gone with one pick. Redraw it and continue. Draw the third box using the MULTILINE command. This box is 1-1/2" square. The following steps are what you will see on the command line. Before drawing the lines, you have to set the SCALE to 0.15"(distance between the lines) by typing 'S'. Then set the JUSTIFICATION (offset origin) by typing 'J'. Command: ml MLINE Current settings: Justification = Top, Scale = 1.00, Style = STANDARD Specify start point or [Justification/Scale/STyle]: s Enter mline scale <1.00>: .15 Current settings: Justification = Top, Scale = 0.15, Style = STANDARD Specify start point or [Justification/Scale/STyle]: 8,2 Specify next point: @1.5,0 Specify next point or [Undo]: @0,1.5 Specify next point or [Close/Undo]: @-1.5,0 Specify next point or [Close/Undo]: @0,-1.5 Specify next point or [Close/Undo]: To review what you just did, you started the command, then set the scale (distance between the lines) to .15 units. Then you just drew the rectangle using relative co-ordinates. Erase the multiline rectangle you just drew. Notice that when you hover over the rectangle, it will turn to a dotted line. This means that it is highlighted as the object that will be selected if you pick at that moment. In highly detailed drawings, this is very handy. Draw it again as shown below and note the subtle difference from the first one you drew. Command: ML MLINE Current settings: Justification = Top, Scale = 1.00, Style = STANDARD Specify start point or [Justification/Scale/STyle]: s Enter mline scale <1.00>: .15 Current settings: Justification = Top, Scale = 0.15, Style = STANDARD Specify start point or [Justification/Scale/STyle]: 8,2 Specify next point: @1.5,0 Specify next point or [Undo]: @0,1.5 Specify next point or [Close/Undo]: @-1.5,0 Specify next point or [Close/Undo]: C The difference is that instead of drawing to the last point, you used the C (close) option to complete the rectangle. The difference is shown in the drawing below.  Draw a line from 2,5 to 2,6.5 Draw another line from 1,6 to 3,6 You should now have two perpendicular lines. What you want to do is trim off the top of the vertical line and createa T. Start the TRIM command. It will first ask for a cutting edge. Select the horizontal line and press This is what you saw on the command line:
Command: TR
Current settings: Projection=UCS, Edge=None Select cutting edges ... Select objects: Select object to trim or shift-select to extend or [Project/Edge/Undo]:
Once again, it is important to keep your eye on the command line as it will guide through most commands.
Draw a LINE from 4,6.5 to 6,6.5 Draw another line from 5,5 to 5,6 What you want to do now is extend the vertical line up to the meet horizontal line. Start the EXTENDcommand. AutoCAD asks for a boundary edge; select the horizontal line press
Command: EX
Draw a CIRCLE with a center point of 7.5,5.5 with a radius of .5 Now you will use to offset command to make another circle 1/4" larger. Start the OFFSET command (watch the command line) and enter .125 as the offset distance. Now select the circle and pick anywhere outside the circle. Press Current settings: Projection=UCS, Edge=None Select boundary edges ... Select objects: Select object to extend or shift-select to trim or [Project/Edge/Undo]:
OBJECT SNAPS
Suppose you want to draw a line from the center of the circle to the middle of the vertical line you extended earlier. AutoCAD has a feature that makes this very easy. These are the Object Snaps (or Osnaps "Oh-Snaps"). Type OS 
You may also see a toolbar with these Osnaps as shown below.
Endpoint - snaps to either the beginning or the end of an object such as a line - END Midpoint - snaps to the exact middle of a line or an arc - MID Center - snaps to the center-point of a circle or arc - CEN Node - snaps to 'nodes' (not covered in this course) - NOD Quadrant - snaps to any of the four quadrants of a circle - QUA Intersection - snaps to the point where two object cross - INT Extension - Snaps to the phantom extension of an arc or line - EXT Insertion - snaps to the insertion point of an object (such as a block or text) - INS Perpendicular - will snap so that the result is perpendicular to line selected - PER Tangent - snaps to create a line tangent to a circle or arc - TAN Nearest - will find the closest point an object and snap to that point - NEA Parallel -Snaps parallel to a specified line - PAR None - temporarily turns off all Osnaps. (Pressing your F3 Key is quicker) - NON Osnap settings - opens the Osnap dialog box. Temporary Tracking - Creates a temporary tracking point (see Object Tracking). From - Allows you to select a point, then denote a new location 'from' that point using relative co-ordinates. This can save you the time of drawing (and erasing) construction lines. Note: Beside each checkbox is a symbol. That symbol will show up on the screen when you have found a valid snap point. (An endpoint will show a small square). If you select the "Options" button, you can change the aperture size and the color of the Osnaps. Depending upon the background you are drawing on, this may be needed.
1. Check off the boxes as shown in the dialog box above (Object Snaps On, Endpoint, Midpoint, Center) and press OK.
2. Begin the LINE command. Move your cursor around the screen and you'll see that as you get close to an object, it will 'snap' to one of the points that you had checked off in the dialog box. Place your cursor on the circle (not the middle of the circle) until you see a small purple circle appear at its center. Left-click to make this the start point of the line. Move the cursor towards the middle of the vertical line until you see a small triangle appear. (Remember this is the symbol for 'midpoint'). When you see it left-click to accept this as your endpoint. Press
3. Save your drawing.
4. Print your drawing with the same settings as in Assignment #1.
TIP: Before you select the Osnap you want, you can press the TAB key on your keyboard to cycle through the available Osnaps in the area of your cursor.When you have finished the assignment, continue practicing with the commands until they are mastered. These are common commands that you will use in everyday drafting. Extra Practice: Copy this drawing, using lines, mlines, offset, osnaps - extra_003.gif Extra Practice: Copy this drawing, it could a little to figure out, but still uses the commands you have learned so far. - extra_004.gif | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Draw > Rectangle
Modify >Trim
Modify > Extend
Modify > Offset
Endpoint
Perpendicular
Tangent
Center
Nearest
Node
Apparent Intersection
Quadrant
Parallel
Intersection
None
Extension
Osnap
Insertion Point
Temporary Tracking Point
Snap From
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