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Title of script: Introduction to QCAD

Author: Leena Mulye

Keywords: CAD, Drawing, qcad

QCAD Introduction

Visual Cue
Show slide number 1


Hello and welcome to the tutorial Introduction to QCAD -2D drafting tool.

In this tutorial I will introduce you to the basics of QCAD tool and its interface.

Switch to slide number 2

(What is QCAD?)


Let's look at what is QCAD?

It is an application for computer aided drafting(CAD) in two dimensions.

With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schemas and diagrams.

Community edition of QCAD is available freely for download at: http://www.qcad.org/

Switch to slide number 3

(Lesson Plan)


For this tutorial, I am using GNU Linux operating system Ubuntu Version 10.04 LTS

and QCAD Community Edition Version

If you do not have it installed on your system,

you can do so by going to System->Administration->Synaptic Package Manager and

at the search box look for QCAD.

And install these applications

For more information on how to install software using synaptic,

please refer to spoken tutorial available on this website: www.spoken-tutorial.org

Switch to Desktop to Open QCAD

(1:10 -1.27)

Once installed to start QCAD in Ubuntu 10.04 go to Applications->Accessories->terminal

and at the prompt type “qcad” and hit 'Enter'

This will launch the application in 10.04 version.

For other Ubuntu versions it is available under Applications menu.

Slide 4

(Lesson Plan)


In this tutorial we will see

Menu items and tool bar

drawing objects

snapping options

and using layers

Switch to QCAD Applicationto explain the window


A typical QCAD window looks like this.

It has a standard menu bar on top.

Options like Draw, Dimension, Modify and Snap are QCAD specific.

On the left side is the tool bar, which is used to draw objects.

At the very bottom is the status bar which displays various information about the current drawing.

Notice as my mouse is moving in the drawing area.

Coordinate widget on the extreme left side is displaying absolute and relative position of my mouse cursor.

Just above the status bar is the command line for QCad.

Which is used to put in exact co-ordinates to draw objects.

At the right side is the layer list and the block list.

These list the layers and blocks related information for the current drawing.

We will look at these in detail in subsequent tutorials.

Right in the middle is the drawing area.

Black in colour with dots.

Dots signify the grid, at any time you can choose not to view grid by going on to top option and click on this 'grid' icon to not to show the grid.

Click it back again to make it visible.

Similarly all other windows as status bar, command line, block and lists can be enabled / disabled going to top menu View.->Views

and select check box in front of the window of your choice.

On QCAD Window View Drawing Objects


QCAD uses Cartesian and polar coordinates system to draw objects.

To draw objects we use tool bar from left or this can also be accessed from top menu → Draw option.

Let's start by drawing a line. From the tool bar click on the line icon.

There are numerous options to choose from

Let's click on line with two points. Notice the command prompt is asking to specify first point.

Move your mouse cursor on the drawing area.

There are two things happening now

1. mouse cursor has changed into white cross hair.

2.There is blue circle appearing right below the mouse cursor

It is basically hopping from grid to grid as I move my mouse, waiting for me to select.

I can click left mouse button to click for the start of the line

and click again to for the line to end. Line is drawn.

Notice if I keep clicking further it will start drawing line, as QCAD is still in line command.

For this I need to come out of that command

To come out of any command you press either 'Enter' or 'Esc' button on keyboard twice or double click right mouse button.

You will be out of any command

Similarly you can draw Parallel lines, horizontal lines, vertical lines, parallel lines with distance.

Let's see this option. When I choose this option I need to specify distance between the lines and number of lines.

let's say 10 here and no. of lines I want 3.

You will move mouse cursor closer to entity in relation to which you would want parallel lines to be drawn.

Once satisfied I can confirm selection by clicking on left mouse button, and lines will be drawn on the board.

Now let us see the arc tool. From the tool bar choose arc.

I am choosing arc with centre point and angles.

From snapping option let's choose 'snap to grid'

Notice command prompt is asking to specify centre, left click to specify centre.

Now it is asking to specify radius, I can enter say 30.

Now specify start angle and click again for end angle and arc is drawn.

Double click right mouse button to come out of that command.

Lets try and draw circle. Go to the circle icon from tool box, click on it. I am using circle with centre and radius.

Again from the snapping option choose 'snap to grid'.

Command line is asking to specify circle's centre.

Go on the grid and left click to specify centre. Circle is drawn.

It is drawn with previously specified radius. If I want to change I can change and draw new circle with different radius.

Unless you come out of that command, it will keep on drawing circles.

So double click right mouse button and you are out of that.

Use zoom option, drawing preferences and saving QCAD file.


Now that my drawing has become busier I can use zoom from top menu → view-> Zoom in to zoom in on the more details.

and view-> Zoom out to see the wider extent.

Zoom is very essential command because it is very useful when you draw details.

Similar effects can be achieved by rolling a middle mouse button to zoom in and out

Or I can also use View->(third option)Auto zoom to fit the drawing in the given area.

Let's try drawing a new file, Let me clear this area.

For this I click at one corner select and then from top menu->modify->Delete selected.

Every drawing QCAD starts at absolute 0,0 position it is marked by red cross hair on the drawing area.

Every other point is drawn in relation with this point.

Before starting any drawing it is important to set drawing preferences'

for QCAD to know which units you are using, what grid size you would want.

For this you go to Edit- and there are Application Preferences and Current drawing preferences.

Application preferences

Are the ones which apply to entire QCAD application, rather than just a single drawing

You can change background, grid colour, meta colour, language options and set the default Units that you want.

Lets say 'meter' here and click 'OK'.

Now let's go to Edit ->set Current Drawing preferences: These apply only to current drawing and once you close the drawing these needs to be set again.

Paper applies only when we want to print a drawing.

Units: You can set units for that particular drawing, let's say 'Inch' here. Decimal, precision can be 0.00.

Grid: You can either choose to show grid or not show grid. You can give grid size as .5x.5 specific size that you want.

Dimensions: Are useful when you want to start dimensioning on the drawing. Extension line, text height all these points matters when you want to show text.

If you think text height or the line or arrow is too small, you can always revisit this area later.

I am setting some things now, after you are done click 'OK'.

It is better to save the drawing

We go to File->save as and select the directory where you would want to save it.

I want to save it as qcad-dwg. Notice it is saving it as dxf format

Document Exchange Format, which is QCAD native.

Click on save, it saves the drawing.

QCAD Window

Using the Application and snap tool


let us start with our drawing.

We will draw rectangle and then cut it in half by drawing a line in the middle and draw circle exactly in the centre.

Draw rectangle:Go to tool bar-Line option. select rectangle.

From the snapping options, choose 'snap to grid'

Move cursor over the drawing area and left click for the first corner of rectangle and click away for second corner .

Rectangle is drawn.Double click right mouse button to come out of that command.

draw line going through middle:Now we want to draw line exactly in the middle, cutting it in two halves.

This is where snapping options will be useful.

Let's go click on line- Line with two points.

Now from grid options, since I want it exactly at middle. I choose 'snap to middle point'.

And I go on the top line, notice it is snapping exactly to the middle point of the top line, click there.

Go on the bottom line, click again. The line is drawn cutting the rectangle in two halves.

draw circle in the centre of rectangle: Now let's draw circle in the centre of the rectangle.

Click on circles icon and I am choosing centre and radius.

Go over here. If you want circle to occupy entire width.

I know my grid is .5x.5 and there are 6 divisions. So that means my rectangle is 30x40.

So I put radius 15 to cover entire width, and notice I need to click on the snap to 'centre point'.

And left click to confirm. Circle is drawn exactly in the centre of the rectangle.

QCAD Using Layers and adding dimensions


Now that our drawing is ready so let's add dimensions. We always add dimensions to new layer so that we can keep it separate.

Click on '+' sign to add new layer. Go to 'dimensions'

Give it a different colour, so that we can identify it separate from rest of the drawing.

You can use type 'dash' then you go to top menu 'Dimensions'

Horizontal first. From the snapping option click on 'end point'

Click on first point of the line, then second point.

Now to place dimensions away from the line, from snapping option I can choose 'snap to grid' or free positioning and place it away. Left click once.

Again to place vertical go to dimensions->vertical, from end point

Place it again away by using 'free positioning'

This way if I have it on different layer I can always, when drawing gets busier click on Eye icon to not to show that layer and see the drawing clearly.

When you want it back, click back on eye icon to make it visible.

QCAD changing drawing properties


Now if I want to change attributes of any object.

I click on that object and go to Modify->attributes

Now once the selection is made, click on the arrow.

go to modify → attributes

and once our selection is made click on the arrow.

Let's say I want to change, colour to 'Red'

Width: let's increase it

and the type: make it 'Dash and dot', click 'ok'

The attributes are changed. Let's save the drawing.

Switch to Slide 4



Now that you are familiar with the QCAD basic tool bar and drawing objects.

[[Image:]]I would like you to draw a rectangle as shown in the figure. of size 20x30.

with centre line of type dash and dot and red in colour.

Draw two parallel lines are 5 units apart.

Add dimensions on a new layer.

Switch to Slide 5



I would like to acknowledge the spoken tutorial project which is part of the talk to a teacher project.

It is supported by the National Mission on Education through ICT, MHRD government of India.

And you can see more information about this at this website.

Switch to Slide 6


Thank you.

I hope you enjoyed the tutorial and enjoy exploring QCAD.

This is Leena signing off.

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