Instructor: Mr. Laitinen Page 1

AutoCAD Tutorial Illusions

Start AutoCAD. When the STARTUP MENU appears, click the mouse on the USE A TEMPLATE button.

Now, click on the BROWSE button. When the window below ap-pears, click on the Look in down arrow and find the Handout di-rectory

Now, click on the file named ILLUSIONS, and then click on open.

After the file has opened, save the file in your Drive D: folder for your block. Use the drop-down menu FILE, SAVE AS.

Your file name should always be written like this: Lastname Firstname Drawingname Date where Drawingname is whatever we call the drawing, in this case it would be ILLUSIONS. EXAMPLE: Doe John Illusions Sept 20

Instructor: Mr. Laitinen Page 2

Your screen should Look like this: GOOD WORK! Now you need to create your layers...

Select the drop down menu FORMAT then LAYER. Create 4 NEW layers titled, OBJECT, CENTRE, HIDDEN, and TEXT.

Assign the correct colours and line types to each layer.

Fill in the Title Block using the TEXT EDIT command from the Right Click menu, or your can type DDEDIT at the command line and select the text you want to edit. Make sure you move your text to the correct layer.

Instructor: Mr. Laitinen Page 3

Now we are going to draw a set of woven squares. AutoCAD recognizes drawing coordinates in 4 different ways.

1. ABSOLUTE (X,Y): the absolute x and y value of a point on the grid. Similar to graphing coordinates in math.

2. RELATIVE (@X,Y): this adds two values to the previous x and y values.

3. POLAR

(@DISTANCE<DEGREES): the distance at a specific angle accord-ing to the diagram on the left.

4. MOUSE

That’s right, you can just select the LINE command and start clicking on the coordinates you want.

RELATIVE: Command: LINE From point: 4,0.5 To point: @1.5,0 To point: @0,1.5 To point: @-1.5,0 To point @0,-1.5 POLAR: Command: LINE From point: 1,3.5 To point: @1.5<0 To point: @1.5<90 To point: @1.5<180 To point @1.5<270 (or type “C” for close)

Follow these directions to practice using each of the keyboard coordinate entry system listed above. ABSOLUTE: Command: LINE From point: 1,0.5 To Point: 2.5, 0.5 To Point: 2.5, 2 To Point: 1, 2 To Point: 1, 0.5

MOUSE Now, you can draw the last square free-hand, but first, turn on SNAP and adjust the settings to 0.25. Make sure the GRID is set the same. You need to do this to ensure accuracy. ZOOM in to get a better view. Try using the shortcut key: COMMAND: Z (shortcut for ZOOM) Then drag a window to get a view like the one on the right.

Instructor: Mr. Laitinen Page 4

Now it’s time to draw a smaller square inside each square. Command: OFFSET Offset distance of through <through>: 0.25 Select object to offset: (pick one side of the square) Point on side to offset: (pick in the center of the square) Repeat OFFSET until all lines are offset as below. HINT: PRESS ENTER TO REPEAT THE LAST COMMAND ;)

Apply the knowledge you have gained in the preceding sections to draw the large square. Offset lines inside at 0.25 units. When you are done your drawing should look like this one: Use TRIM to remove the hidden parts of the square to make it ap-pear to be woven. Command: TRIM Select cutting edges… Select objects: (drag a CROSSING BOX around all 5 squares) Select objects: <ENTER> Select object to trim: (pick only the line segments you want trimmed away).

Clean up the overlapping corners. Command: FILLET Polyline/Radius/Trim: R Enter fillet radius: <0.000>: 0 Command: FILLET Polyline/Radius/Trim: (pick any two overlapping lines) Repeat until all overlapping corners are cleaned up.

IMPORTANT NOTE: CROSSING and ENCLOSING are selected by the direction you move your mouse. CROSSING you need only touch an object. ENCLOSING you must completely enclose the object to select it. Your drawing is now complete and it should look something like this…. GOOD WORK!!!

Instructor: Mr. Laitinen Page 5

Back to the Big Picture! Command: Z All/Center/Dyn…../Previous/Window/: A

Draw the outside of the polygon: Command: POLYGON Number of sides: 8 Edge/<Center of polygon>: 3,8 Inscribed in circle / Circumscribed about the circle (I./C): C Radius of circle: 2.25 You should be able to construct the remaining polygons. The width of all the webs is 0.25 units. IMPORTANT HINT: Make sure to use OSNAP, set the settings to Midpoint. You will also have to use the ROTATE command as well.

POLYGONS You are now well acquainted with the LINE command. So let’s look at the POLYGON command. The drawing at right is what we are at-tempting to achieve.

COMPUTER USERS HEALTH TIP: Take a 5-minute break from your monitor every 75 minutes in order to rest you eyes. Now, on to the next illusion….

Instructor: Mr. Laitinen Page 6

WOVEN STARS Do your best to replicate the interlocking stars in the upper right quadrant. Enough dimensions are given below. Ask a friend for help if I am busy.

Hint: There are several ways to draw this object, but I start with a 4 sided polygon Circumscribed, radius 1.5 and offset sides in 0.5 for reference and draw a line from corner to midpoint of offset line. You will need Midpoint and Endpoint OSNAP set.

IMPOSSIBLE HEXAGON The final quadrant is for the impossible to make hexagon, but not impossible to draw. When you are finished your drawing will look like the one below:

These reference lines should be enough information to draw the hexagon. CONGRATUALATIONS!!! You’ve learned a lot!

Instructor: Mr. Laitinen Page 7