A good understanding of the Model and Paper spaces in Autocad's 2D interface is essential when creating working drawings in Autocad.
Most of our drafting work takes place in the Model Space environment, which is open by default but can be accessed via the Model tab on the bottom left of the interface (PC). In the Apple Macintosh version of Autocad, however, this is accessed via a small pop-up list at the middle bottom of the screen.
Model Space is where we create the vast majority of our geometry and annotations. Strictly speaking, the space is three-dimensional and is unlimited, but generally we would utilize only the X and Y axes. The Z axis is pointing straight towards us and we would generally ignore unless working on a 3D model. We can think of this as if we are looking downwards onto a drawing placed on the floor.
When we click on the Model tab at the bottom left of the screen we enter Autocad's Model Space. We can also note the difference between the two User Coordinate System (UCS) icons on the bottom left of our screen. In Model Space it appears as an X-Y axis, whereas in Paper Space it would appear as drafter's set square. In Model Space we generally draw to real-world (1:1) scale, where one unit usually represents 1mm. We may check these units and their precision via the top left Application button (PC), and choosing Drawing Utilities then Units, or by typing UN into the bottom Command line. Round off the Precision value to zero, and leave the rest of the fields at their default values.
Drawing layers, dimensions and annotations are also usually created within Model space, as well as any modifications to drawn or imported objects like Blocks.
In contrast to Model space is Autocad's Paper space. By default we are given two Layout tabs (PC) - when clicked these take us to virtual drawing sheets which represent previews of how the drawing will look when exported for print. Again for Macintosh users these are included in the centre pop-up list. These Layout environments are called Paper Space, the sizes of which can be modified for A3, A2, A1 sheets, etc. Various view-ports can be drawn onto the sheets - these are like windows into our Model Space, and it's these windows that are scaled 1:50, 1:100, etc. (Remember that everything is drawn 1:1 scale in Model Space.)
In addition to clicking on the bottom icons to switch from Model to Paper Spaces, we can also modify elements in Model Space whilst in a paper layout. This is done by either double-clicking inside the view-port window, by typing MS into the Command line, then hitting the Enter key, or by clicking on the Model button in the middle of the bottom Control panel. To return to Paper Space we can likewise double-click outside the View-port window, type PS into the Command Line, or click the Paper button in the middle of the bottom Control panel.
Our main drawn elements are thus created in Model Space, whilst some text and annotations like Title blocks and Legends are usually created in Paper Space.
Tom Gillan has been training Autocad 2D to corporate clients in Sydney for over seven years. Visit our website for more information at Design Workshop Sydney.