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2D modeling in AutoCad - tutorial (ang)


2D Modelling in AutoCAD - tutorial exercise
The screen
The graphics area

This is the part of the screen in which the drawing will be created.

The command prompt area This area at the bottom of the screen gives you clues about your next action:Command: means that AutoCAD is expecting a new command e.g. line, arc, erase The status line Located at the very bottom of the screen, indicating current information about your drawing. The function keys can toggle between the settings. Screen Menu

This can be made to run down the right hand side of the screen, echoing the commands or options of commands chosen from the icons. It also provides the entire range of commands available. Highly recommended for beginners. An example of a parked toolbar. Snaps help you to find exact points on the drawing.

Function keys
F1 F2 F3 F7 F8 F9 F10 F11

Object Snaps

Properties Menu All elements of the drawing have properties which may be edited at any time from this menu

The Keyboard

To Cancel Press ESCAPE Escape will also remove the GRIPS (the blue squares which appear for simple editing)

Help Text screen Object snap on and off Grid on and off Ortho on and off Snap to grid on and off Polar snaps on and off Object Snap tracking on and off

To Undo Press U followed by the Return (or Enter ¿ ) key or Space The Enter key ¿ is used to:
finish off commands (e.g. Line) accept “selection sets” for Editing commands or <contents> in <> repeat the last command


Draw real sizes - scale will matter when putting your model onto paper. Think in metres or millimetres depending on what sort of object you are designing. AutoCAD measures angles (and draws arcs) anticlockwise.

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The Brief

Draw an accurate coloured plan of a St. Andrew’s Cross using the commands LINE, TRIM, MIRROR, HATCH and Layer Control. Setting up the drawing: Drawing Limits, Zoom All How big is your site or object? Always consider the real sizes in metres (or mm or whatever) of the overall site, in plan, measuring width then height. (x,y dimensions). We are going to make a coloured flag, we will be thinking in millimetres, so it should fit into an area of 3000mmx2000mm Pick: Format, Drawing Limits Accept the lower-left limit <0.0000, 0.0000> (Press Enter ¿ ) then type in 3000,2000¿ to define a new upper-right limit Pick: View, Zoom, All to stretch the graphics area to the new limits. This has provided you with a drawing area suitable to your project, but it will not stop you extending beyond this area later Draw the outline We want to keep the lines straight, so click on the ORTHO button on the status line, or press F8

Offset the diagonals We want to make a broad stripe on the flag. Pick Offset Type 50¿ This sets the distance for the offset Point at a diagonal, then above it. Point at the same diagonal, then below. We will trim off the untidy bits Pick: Erase Point at the original diagonal, then press ¿ All editing commands expect you to pick the items, then confirm with the Enter key. Pick: Trim

Pick: Line then a point near the lower left part of the screen Move the mouse to the right Type 2500¿ (2500 is a distance in millimetres) 1600 ¿ 2500¿ c¿ Draw diagonals Press down on the OSNAP button in the Status line, and release the ORTHO button. ObjectSNAP makes the cursor jump to recognised points on the drawing, like Endpoints (of line or arcs), Midpoints (of lines), Centres (of circles). Pick: line then point to the top left and bottom right of your rectangle. Press ¿ to finish the line.

This command works by using existing lines or arcs to cut other lines or arcs. Point, in turn, to each of the lines of the outline; these are your cutting edges Press Enter ¿ Now point at the pieces of line you want to trim off. Note that EXTEND is similar to TRIM. It will shoot a line or arc towards some boundary. Like TRIM, you have to choose, and confirm the boundary, before picking the object to extend. Pick Mirror Point to the two diagonal lines Press Enter ¿ Pick Midpoint from the OSNAP toolbar Click onto the middle of the top line. You are now drawing the mirror line, or the axis of symmetry of your object. Put Ortho on. The mirror line will now have only two positions. Move the mouse till the figure looks right, then Click the mouse. Press Enter ¿ to confirm that you want to keep the original pair of lines.

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Trim the crossover Pick Trim Swipe across all four diagonals - click top right, then bottom left of a rectangle ® Press Enter ¿ All four lines are now able to cut. Point at the pieces you want to remove.

(N.B. If you happen to have poor colour vision, tell your CAD tutor, who has experience of the problems you are liable to encounter) Apply colours to layers

Pick form the Files Menu, Save. Pick: File, Save (or Save As if you wish to change the name or drive e.g. change to H: the network drive, from C: the local machine’s Hard Disc ) Point at the little arrow and scroll up or down to find the drive, then pick, or Create a new folder to save your drawing in. Change the name in the File name box if you wish. There is a timed automatic save, and backup files which may rescue you from disasters. Ask for help before panicking, if you think you have lost your drawing.

Save your drawing

From the column of boxes labelled Color, click on the one for the Blue fill, and choose a Blue from the menu, then OK. Note that the row of colours at the top of the colour chart, have standard colour names. The others are merely numbers. Some plotters and display screens will be easier to control if you make use of the Standard Colours. Colour the other new layers to red and yellow, and make Layer Zero Magenta.

Colour the flag

Leave “White cross” as White meanwhile. Note that White will appear black on a white screen, and black on a white screen. However, you cannot print white on white paper! Highlight the Blue fill line, Click on Current, Then OK.

We need to create coloured Layers. Layers are used to separate out information. They are coloured to give some visual feedback while editing, not really for aesthetic purposes. Make Layers Pick Layers to open up the Layers Properties box. Click the New button Type Blue fill into the name box. Press Enter ¿ twice. Type Red pattern into the box. Make two more layers called Yellow pattern and White cross.

Anything you now draw will appear on screen as blue, and will be on the blue layer. The outline of the flag will now be coloured Magenta.

Colour in the flag with Hatch

Pick Draw, Hatch to open the Hatch dialogue box. Choose the area to fill with hatching. Click on the Pick Points button. This will return you to your drawing. Point and click into each of the triangles which need to be blue. Press ¿

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If at any time you get the error message This may be because your drawing has gaps in the boundary. Check each intersection by zooming in.

You may get the message at the Command prompt:Hatch spacing too dense, or dash size too small. Press Enter ¿ and on the dialogue box, choose a new scale, say 10. Preview again, and if you like the result, pick OK. Use the drop-down layers menu to start to draw onto the Red layer

Pick Zoom Realtime, then move the mouse Up and Down to change the view. Note, you are not changing the Size of the objects, just how you see them on screen. Choose the pattern for the fill. Click on the Swatch, then pick Other Predefined. Pick Solid, OK Now Click the Preview Button. If it looks fine then press ¿ Pick OK to fix the hatching.

Hatch the four triangles using another pattern. Many of the patterns were originally drawn at different scales, so when used they will need a different scale from each other. SAVE your drawing

Display both versions on one sheet

A new Colourway
Freeze the Blue fill Click on the layers button again to open the layers dialogue box

This illustrates how an integrated design of a building with several floors can be plotted onto a single sheet. Note that keeping all information in this way, instead of spread across a drawing in the traditional way, helps improve the accuracy of drafting. If you move columns - it will show up in every floor. Change from Modelspace to a Paperspace layout Pick the Layout1 button Click on Plot Device. Choose the printer If you want to print in colour choose the Epson.

Highlight the Yellow pattern layer, then Click on the Current button, and OK. Freeze the Blue layer A frozen layer does not appear on the screen. This way of concealing a layer and its information is more efficient than switching OFF - you will be able to draw faster. Fill the cross with a yellow pattern Repeat the Hatch command as above, but this time choose a pattern, rather than SOLID, and pick a point inside the cross. Press Enter ¿ Pick a pattern; you may have to change the scale (or spacing) to fit the shape. Pick Preview

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Whatever printer you choose, you must choose a suitable paper size at this stage. A4 will be large enough for this exercise:Pick Layout Settings, then choose A4 paper size. Pick Portrait. Press OK. The Paperspace layout will appear with one image of your flag. Erase it by picking the frame of the Viewport. We are not erasing you precious drawing only that view of it. Now, open the Layers dialogue box, and make a new layer called Paper. Make it Current, then press OK. Pick View, Viewports, 2Viewports Type H ¿ Press Enter twice ¿ ¿ Two views appear, split horizontally. The frames have been drawn onto the Paper layer. Note the triangular Paperspace icon. In Paperspace, you can add annotations, and edit the viewports frames, but cannot change the model. Double click on any viewport to activate it in Modelspace. The usual icon will now appear in each viewport. Any drawing or editing will appear in all three viewports. Indeed you can start a line in one, and finish it in another. Layouts need not be regular. Single Viewports can be placed as required. Polygonal shaped Viewports can be created.

Display both colourways

Open the Layers dialogue box, and stretch it wide to see the Active VP F... column. Thaw the Blue fill using the Freeze (in all Vports) column Look at the Active VP.... column. This lets you freeze layers, just for one viewport.

Freeze the red and yellow layers for this viewport (Local Freeze).

Note that because we Thawed the Blue Fill Globally, we see it covering the Red pattern. (left above) Click the other Viewport to activate it. Now Freeze the Blue fill, and the layer 0 just for that viewport. (right above) Double click outside the frames to change to Paperspace.. Open the layer dialogue box. Because we are now in Paperspace, the Active VP column is only of use in making new layers. Freeze the Paper layer Globally. (You will have to make a new Current Layer first)

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By drawing the Viewports onto the Paper layer, which has no other information on it, we can choose whether to display the viewport frames.

Information on the wrong Layer

Point at the object(s) (Blue grips will appear) Pick the new layer from the Properties box If you cannot see the Properties box, then pick the Properties button. Move the menu box to the right to Park it.

To edit the text Point at it to light up the grips Use the Properties box to change the size, or Contents. The Contents button sends you back to the full text box. Highlight the text in the box, then change size etc. Note that with the grips active, you can use them to move the text position, and the shape of the text box. Press the Escape button twice to switch off the Grips. Note that Grips - the blue squares that light up when you touch an object, can e used to edit an object. Try “grabbing” a grip on the corner of the flag and moving it. The hatch pattern should adjust to suite the new shape. Pressing Escape twice will hide the grips.


Text should be put onto its own layer, whether it is going to appear in Modelspace or Paperspace. In this case, we are going to annotate the drawing in Paperspace. Click outside the frames. Pick the text tool Draw a window where you want to place text. The text dialogue box will appear.


You have learned to use the following commands and techniques Drawing limits to set up the drawing Zoom to enlarge the view The use of Object Snaps (OSNAP) Drawing commands Line Hatch to fill an area with a pattern Text Editing Commands Offset to draw parallel lines (or arcs) Erase Trim (and Extend) Mirror Modelspace & Paperspace Layouts ViewPorts to create several views of one object (model) on a layout how to freeze and thaw layers globally, or just for one ViewPort


Choose a new font. Change the size of the text to about 50 Type in some text

How to Change Properties of objects layering or text content, size etc.

© Alison Murison 2000

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