AutoCAD R12 Tutorial 4


	FBE AutoCAD Page

Stephen Peter, S.Peter@unsw.edu.au

Introduction

In this fourth (and final) AutoCAD tutorial you will learn how to plot drawings. In doing this you will learn about paper space and viewports.

You will draw a form study of Robert Venturi's "Fire Station - Number 4" in Columbus Indiana (1966), from Clark and Pause's "Precedents in Architecture", page 122. The drawing is quite simple, to allow time at the end to cover the issues relating to plotting.

Set the drawing limits: 0,0 to 50000,35000; then set the units (set the number of decimal points to 0) and finally do a zoom-all.

Draw the Drawing "Construction" Lines

Create a CONST layer, set it's colour and make it current; and then:

    rectang [return]

pick a position near the bottom-left corner of the screen

    @18800,18800 [return]

    c [return]               CIRCLE command

using the MIDpoint snap mode, pick the bottom edge of the square,
using the ENDpoint snap mode, pick the top-right of the square.

Next you will draw a rectangle to complete the golden rectangle. To do this we can use the bottom-right corner of the square for one corner, but the other corner is more difficult: you will use AutoCAD's point filters to take the x value from the circle and the y value from the original square. Type:

    rectang [return]

using the ENDpoint snap mode, pick the bottom-right of the square

    .x [return]
    per [return]

pick the circle to the right of the bottom of the square,

    .y [return]
    end [return]

pick the top-right corner of the square,
and finally pick a pick anywhere (to enter the Z value).

    line [return]

using the ENDpoint snap mode, pick the top-left corner of the square.
using the MIDpoint snap mode, pick the right edge of the rectangle.
using the ENDpoint snap mode, pick the bottom-left of the square.

    [return]                 end the command

Now, to move the end of the lower line up 1800:

pick the last line drawn (near the bottom-left corner), then
pick the bottom-left corner (to move that endpoint),

    @0,1800 [return]

Now draw the entry, type:

    line [return]

using the ENDpoint snap mode, pick the bottom-left of the square.

    [return]                 end the command
    c [return]               circle
    @9800,1400 [return]      circle centre
    1400 [return]            radius

Finally, explode the original square and then offset the bottom of the square, up 600, and then offset that line 1500 up. Then offset the left of the square 10000 to the right.

These are the major construction lines that will be used to setout the plan. Your drawing should look like figure 1.

    qsave [return]           save it!

enter the drawing name (for example "tut4 [return]")

Figure 1 "construction" lines

Draw the Walls

Create a new layer called WALLS, set it's colour and make it current.

Use Zoom Window to enlarge view of the square.

The walls will be drawn using the PLINE (polyline) command so that you can set the thickness of the lines after drawing them.

    osnap [return]           automatically use the INTersection
    int [return]             snap mode

Figure 2 path of exterior walls

    pline [return]

Note that one of the options when drawing polylines is to set the line width, you won't use this, you will use PEDIT later, to change the width.

pick the points shown in figure 2, after the 5th point, type:

    arc [return]             to signify that you are drawing an arc,
    Second [return]          (or "s [return]") and then

using the NEArest snap mode, pick the 6th point, then
pick the 7th point

    line [return]            change back to drawing line segments

pick the 8th point

    [return]                 end the command.

    osnap [return]
    off [return]             turn the autosnapping OFF.

Turn the CONST layer OFF.

Now you will change the width of the external wall to make it a thick line.

    pedit [return]

pick the external wall polyline.

    width [return]           to change the width
    250 [return]             the new width,
    [return]                 end the command.

    r [return]               redraw

Turn the CONST layer ON.

Venturi's building is quite interesting, but we don't have time to draw the whole plan (and cover plotting).... so we'll stop there!

Paper Space

In these tutorials, you have been drawing in what's called MODEL SPACE. The significance of this is that you use real-world sizes. When plotting, you can either specify a scale factor to plot the drawing at a particular scale or you can use PAPER SPACE.

The advantage of paper space is that you can have numerous drawings (or views of the one drawing), each at a different scale; and you can draw text using "paper heights" rather than world heights.

    tilemode [return]
    0 [return]               your drawing SHOULD disappear.

This turns "tilemode" OFF, so that viewports can overlap and be edited as if they were graphics. It also puts you into paper space.

Now we setup the limits again! This time for the paper. We will be plotting onto A3 paper and our plotter has 17mm left and right margins and 5mm top and bottom margins, this leaves you with a "plotable area" of 386x287mm. For more information about this refer to Jim Plume's "Notes on using the HP DesignJet 200 Ink Jet Printer". Type:

    limits [return]
    0,0 [return]
    386,287 [return]

    zoom [return]
    all [return]

Create a layer called FRAME, set it's colour and make it current.

Now, you will draw a border 20mm in from the edge of the paper, type:

    rectang [return]
    3,15 [return]            remember that we started 17,5 in from
    383,272 [return]         the paper edge....

This shows you the "paper". The rectangle is used to position "viewports" and then it's layer can be turned OFF before plotting (if desired).

Create a Viewport

Once in paper space you can create a number of views of your drawing, with each a different scale! Type:

    mview [return]

pick a point towards the bottom-left of the drawing.
pick a point towards the top-right of the drawing.

AutoCAD should show a view of your drawing! This view is at no particular scale.

If you want to change to size of the viewport to make it cover more of the paper:

pick one of the corners of the viewport frame,
pick where you want to move that corner to!

You could use snap modes to "snap" the viewport to the drawing border.

Return to MODEL SPACE

To edit your drawing, type:

    mspace [return]

Move the cursor around inside the viewport and you will see the normal cross-hair cursor appear. Usually, you want to have the view at a particular scale but sometimes you simply want a particular part of the drawing to plot and you don't care what it's scale is. Type:

    zoom [return]
    w [return]

enclose the entry circle in a selection rectangle.

    regen [return]           to draw smooth circles.

If your drawing is like mine you will see that AutoCAD has made a mess of the line widths...

    zoom [return]
    p [return]               zoom previous

Setting the View Scale

To see the viewport at a particular scale, you need to express the scale, relative to the paper scale. If you want the view at 1:100 you use a scale factor of 1/100 or 0.01. Type:

    zoom [return]
    left [return]

pick a point below and to the left of the bottom-left of the building

    0.01xp [return]

This will produce a view at 1:100. You will probably need to use pan to re-position the building in the view.

Paper Space Revisited

Now you will probably need to return to paper space and re-size the viewport to get the building fitting comfortably on the page. Type:

    pspace [return]

pick the viewport rectangle,
pick a corner,
pick the new position of that corner!

Pick the other corners as needed....

Text

Create a TEXT layer, set it's colour and make it current.

Now you will add some text to the drawing! Make sure you're in Paper Space, then select:

    /Draw . Text/

Pick a position below the bottom-left corner of the building

    10 [return]              10mm high text
    [return]                 text at angle 0 (horizontal)

    Robert Venturi's Mother's Fire Station #4! [return]
    [return]

This text is obviously wrong :-)

    ddedit [return]          edit text or attribute data.

pick the text (a dialogue box should appear),
double click (left button) on "Mother"
press the "Delete" key (to remove "Mother")
delete the "'s" and extra space after "Venturi's".
click the "OK" button.

    [return]                 end the command.

Lastly, we want to move this text, so that it is approximately centred under the plan, select:

    /Modify . Move/

pick the text

    [return]                 end selection process

pick a point near the middle of the text
pick a point below the middle of the building.

The "DTEXT" command can also be used to add text in MODEL SPACE, but the height of the text must be the text height x the plot scale, for example: if you want the height 5mm high and the drawing at scale 1:100, the height must be 500.

Figure 3 Completed drawing

Creating the Plot File

Before plotting, turn OFF the FRAME layer, this is optional; but if your viewport and your 20mm border are not the same, then you'll have a mess!

Select:

    /File . Plot.../

The Plot Configuration dialogue box will be displayed. This complicated dialogue box has six areas:

Device and Default Information
Pen Parameters
Additional Parameters
Paper Size and Orientation
Scale, Rotation, and Origin
Plot Preview

In the "Additional Parameters" section, make sure "Limits" is pressed IN and "Plot to File" is ticked.

In the "Paper Size and Orientation" section make sure "MM is pressed IN, then press the "Size..." button. The Paper Size dialogue box should appear; on the left is a list of pre-configured page sizes, select "USER1 386.00 287.00", note that the other "USER.." options match the drawing limits we use (see Jim Plume's Plotting Notes), click on "OK", note that the "Plot Area" should change to 386x287.

Click on the "OK" button near the bottom of the Plot Configuration dialogue box. AutoCAD will then create the plot file (which should only take a moment because your drawing is very simple. The plot file will be "tut4.plt" or whatever your drawing is called, with the ".plt" extension.

That's all folks!

    end [return]             save the drawing and exit AutoCAD.

Plotting

Plotting this tutorial is strictly optional. But, hopefully at least one drawing will be plotted from each group. This will allow you the opportunity to see it done! In addition to this section, refer to Jim Plume's "Notes on using the HP DesignJet 200 Ink Jet Plotter".

Each plot costs $1.00, and must be given to Guna (the CAD Lab system administrator) before plotting.

Move to the old terminal in the far corner of the CAD Lab; the terminal has "digital VT101" on the front. If the terminal is not turned on then run your hand down the back-left edge, the switch is a small cylinder that sticks out a bit; flick the switch UP. The terminal will take a minute to warm up. Press the [return] key, once the terminal is OK it will display a login prompt, login as you normally would.

The dj200 plotter is located outside the CAD Lab System Administrator's office, the ON/OFF switch is on the bottom-left of the front. If the lights on the right are dark then turn the plotter ON.

Take the paper from the plan-drawers and carefully load the paper into the plotter: hold the sheet with it's short edge facing the front of the plotter, the right edge of the paper must be between the dotted lines and exactly straight. Carefully push the paper up into the plotter until the plotter "grabs" the sheet. If the paper is not exactly straight the "Error" and "Load Media" lights will blink, remove the sheet and try again. If the paper is loaded correctly the "Ready" light will come on.

Go back to the terminal and type:

    dj200 plotname [return]      replace "plotname" with your plot file name.

When the plot is complete, carefully remove the paper from the plotter and leave for one minute to dry. Switch the plotter OFF.

Return to the terminal to erase the plotfile (and logout), type:

    rm plotname [return]         use your plot file name
    logout [return]

Switch the terminal OFF.

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Last Update : 8 April 2000 Major Revision : 29 October 1997 SEARCH . FBE SITEMAP		Disclaimer . Webmasters Page Contact : Stephen Peter Email : s.peter@unsw.edu.au