A Beginner’s Guide to AutoCAD
Alice Fulton-Russell University of Salford
Contents Basics Viewing Geometry Precision Layers Properties Modifying Blocks Layouts Notes and Labels Dimensions Printing
Basics 1.
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When launching AutoCAD, click START DRAWING. This will give you a blank drawing canvass to work with The canvass will open and you will notice a bar running along the top of the screen. This is the command bar and is where you will find most of the commands you will need whilst creating your drawings. There is also the QUICK ACCESS toolbar which includes familiar commands such as NEW, OPEN and SAVE At the bottom of the canvass, you will find the COMMAND WINDOW which displays prompts, options and messages. When using typing shortcuts, this is where the suggested options appear for you to choose The mouse is a well used piece of kit for any computer software, but it has many uses in AutoCAD
- Left click = select objects/specify location - Right click = shortcut menus - Wheel = pan and zoom 5. When starting a new drawing, you can use drawing templates that comply to industry standards - For imperial drawings that assume your units are inches use acad.dwt or acadlt.dwt - For metric units that assume your units are millimeters, use acadiso.dwt or acadltiso.dwt 6. You can save any drawing as a drawing template to keep for future drawings by saving it as a .dwt file 7. When you start a drawing, you need to decide what one unit of length represents, e.g. a foot, a kilometre, an inch or a centimetre. This is when unit display settings can be applied. These controls include: - Format (type): e.g. a decimal such as 1.5 can be set to display as a fraction 1-1/2 - Precision: e.g. a decimal such as 1.5 can be set to display as 1.50, 1.500 or 1.5000 etc. 8. The term ‘model’ refers to the geometry of your design. A ‘drawing’ includes the model geometry, notes, dimensions and title block in the layout. You should always draw your models at full size 1:1 so it can be scaled in ‘Layout’ later
Viewing 1.
The easiest way to change a view is by using the wheel on your mouse - Zoom in and out by rolling the wheel - Pan a view in any direction by holding the wheel down and moving your mouse - Zoom to the extents of your model by clicking the wheel twice 2. If you create objects that overlap each other, you might want to change the order that they appear. This is when you’d use DRAWORDER. You can also send all text to the front, hatches to the back etc.
Geometry 1.
Lines are the most basic geometric component in AutoCAD. To draw a line use the ‘Line’ tool or you can type LINE in the command window and press ENTER
- To specify the starting point of the line, you can type coordinates 0,0 to create an origin or you can specify a starting point with your mouse - The line automatically repeats itself until you click ENTER or SPACEBAR 2. Whilst drawing, you have the option to work with a grid display or background or a blank background which can be toggled using F7. Even with the grid turned off you can use F9 to force your cursor to snap to grid increments 3. When drawing a circle, the default CIRCLE option command is to specify a centre point and a radius measurement however more options are available in the drop down menu - Circles can also be useful for reference geometry as you can see in the example below that the doors will intersect each other
4. A POLYLINE is a sequence of lines or arc segments that is created as a single object. You can type PLINE to to create polylines - Polylines can have different starting and end widths for each segment - A fast way to create closed rectangular polylines is to use the RECTANG command. Simply click two diagonal points 5. A HATCH is defined as a ‘single, compound object that covers a specified area with a pattern of lines, dots, shapes, a solid fill color, or a gradient fill’ - When you start the HATCH command, the hatch ribbon will appear from which you can choose from industry standard hatch patterns
- Once the hatch is created, you can remove bounding lines to create partially bound hatches and you can adjust its scale and spacing. You can also set a transparency to the hatch
Precision 1.
There are several precision options available including: - Polar tracking = snap to the closest preset angle and specify a distance along that angle - Locking angles = lock to a single, specified angle and specify a distance along that angle - Object snaps = snap to precise locations on existing objects, such as an endpoint of a polyline, the midpoint of a line, or the centre point of a circle - Grid snaps = snap to increments in a rectangular grid - Coordinate entry = specify a location by its Cartesian or polar coordinates, either absolute or relative - Of these, the 3 most commonly used features are polar tracking, locking angles and object snaps 2. Polar tracking can be used when you need to specify a certain point and guide the movement of your cursor in certain directions - By default, polar tracking guides your cursor in horizontal and vertical directions
3. If you need to draw a line at a specified angle, you can use the LOCKING ANGLES tool by typing for example, <45 for a 45 degree angle and then specifying a length along that angle
4. Object snaps are really important as they make drawings really easy
5. You can check the distance between two points by using the DIST function and clicking between the points you need the measure 6. The function keys all have their own uses and referencesâ&#x20AC;Ś Key
Feature
Description
F1
Help
Displays help for the active tooltip, command, palette or dialog box
F2
Expanded history
Displays an expanded history in the command window
F3
Object snap
Turns object snap on and off
F4
3D object snap
Turns on additional object snap for 3D objects
F5
Isoplane
Cycles through 2-1/2D isoplane settings
F6
Dynamic UCS
Turns on UCS alignment with planar surfaces
F7
Grid display
Turns the grid display on and off
F8
Ortho
Locks cursor movement to horizontal and vertical
F9
Grid snap
Restricts cursor movement to specified grid intervals
F10
Polar tracking
Guides cursor movement to specified angles
F11
Object snap tracking
Tracks the cursor horizontally or vertically from object snap locations
F12
Dynamic input
Displays distances and angles near the cursor and accepts input as you use TAB between the fields
Layers 1.
Your drawings can be easily organised using layers. These can be turned on and off to hide certain parts of a drawing when theyâ&#x20AC;&#x2122;re not needed. With layers you can: - Associate objects by their function or location - Display or hide all related objects in a single operation - Enforce linetype, colour and other property standards for each layer 2. You can view the organisation of your drawing by using the LAYER PROPERTIES button or by typing LAYER into the command window 3. There are a number of settings in the layer properties, the most important being: - Turn off layers to reduce the visual complexity of the drawing - Freeze layers that you don't need access to for a while. This is similar to turning the layers off but improves the performance in very large drawings - Lock layers to prevent accidental change to objects on those layers 4. To create a new layer click the CREATE LAYER button. You can also use the MAKE CURRENT button to make the selected layer, current
Properties 1.
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The PROPERTIES palette is an essential tool which can be opened by typing PROPERTIES into the command window. It opens the settings for any object such as linetype and colour A property that is set to BYLAYER means that it inherits its settings from the layer For a fast way to copy properties of an object to another object you can use MATCH PROPERTIES, select the source object and then select the
objects you want to modify
Modifying 1.
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To erase objects use the ERASE button or type E into the command window. Use the cursor to select the object you want to erase and then ENTER or SPACEBAR When selecting multiple objects, there are 2 options Dragging from left to right: WINDOW selection, only the objects completely contained within the selected area are picked up Dragging from right to left: CROSSING selection, any objects within or touching the selected area are picked up
3. There are a number of ways to MOVE and COPY items: - Distance method: type CP into the command window, click the object that needs copying and then moving the cursor in the direction you would like the copied object to be placed, type the distance - Two Points method: type CP into the command window, click the object that you want copying on a particular point and then click again where youâ&#x20AC;&#x2122;d like the copied object to go 4. For larger numbers of copies, you can use the ARRAY option within COPY to make a specified number of copies, a specified distance apart
3. The OFFSET tool can be useful to replicate a polyline by a specified offset distance. This can be done by typing O into the command window
4. You can also use the TRIM and EXTEND options. In the following example, you want to extend the lines that represent the decking stepsâ&#x20AC;Ś type EX in the command window, select the boundary and click ENTER. Next you select the objects that need to be extended then press ENTER or SPACEBAR to end the command
3. The TRIM command works in the same way except you select portions you want to trim away 4. The MIRROR command can be used to mirror any object in another plane by typing MI into the command window 5. You can also STRETCH your geometric model by typing S into the command window, using a CROSSING selection to select the geometry that needs to be stretched, click anywhere in the drawing area and move the cursor in the direction of the stretch along with a distance value 6. The FILLET command creates a rounded corner by creating an arc that is a tangent to the two selected objects. This can be done by typing F into the command window and specifying a radius value 7. The EXPLODE command or X in the command window, disassociates compound objects into its component parts 8. You can also edit polylines using the PEDIT command or PE in the command window. With this command you can: - Join two polylines into a single polyline if they share a common endpoint - Convert lines and arcs into polylines - Change the width of a polyline
Blocks 1.
A BLOCK is a collection of objects that are combined into a single named object. You can use the INSERT function or I in the command window to insert a new block 2. You can also create a new blockâ&#x20AC;Ś - Create the objects for the block - Start the BLOCK command - Enter a name for the block - Select the objects that you created for the block - Specify the block insertion point 3. You can then use the EXPLODE command to disassociate the objects of the block
Layouts 1. 2.
When creating a drawing, you do this in the MODEL space The PAPER space is specifically designed for layouts and scaling
3.
The simplest way to scale drawings is to create a VIEWPORT using V in the command window, double click this to get the viewport properties and then scale the space to your desires You can also rename your layouts and choose the paper sizes
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5. The viewport is an object created in the paper space to display a scaled view of the model space. You can quickly switch between the model and paper spaces by double clicking inside and outside of the viewport 6. You can create notes, titles and dimensions in the paper space as they automatically appear at the correct size without the need for scaling
Notes and Labels 1.
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You can create general notes using the MTEXT tool or MT in the command window which stands for Multiline text. This prompts you to create a textbox with two diagonal clicks You can change the font, colour, size etc with the Text Style controls Multileader lines are used to create text with leader lines such as general labels, reference labels, bubbles and callouts
4. To create a multileader use the MLEADER command window and modify it using the grips
Dimensions 1.
2. 3.
You can create horizontal, vertical, aligned and radial dimensions with the DIM command. These can be parallel to an object by dragging the dimension line away from the measured object You can modify the dimensions using the grips You can also modify the dimension style using the properties tool
Printing 1.
The easiest way to share CAD drawings are by converting to PDF. To do this, you plot to a PDF plotter choosing the paper size, plot area, plot offset and plot scale
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You can also print to any printer in the same way, selecting the printer and making sure the paper sizes and scales are correct