by Martin Phelps
This is a demonstration that I include in many of my AutoCAD courses. It incorporates “Importing a PDF” with the standard AutoCAD “Copy” and “Scale” commands.
Once the PDF file has been located and selected, the following “PDF Import” settings shown in Figure 1 are used, which should be the default.
Since the selected file in this case does not contain any “Raster” Images, there is no need to have the “Raster Images” box checked.
Figure 2 shows the sample PDF imported.
The PDF file courtesy of Travis Perkins.
This “Scaling” process will work for most drawn and imported objects, a simpler description is documented in one of my earlier blogs, “Scaling an Object to an Existing Line”. Follow the link below to view.
Since the original file has been greatly reduced to fit on to an A4 sheet, its components are no longer drawn to a standard recognised scale. So, taking data from the drawing like a dimension or calculating an area will not give the correct value.
Since all items in a CAD drawing are drawn full size, due to this reason all or part of the drawing requires an increased in size, in this case only part of the drawing will be rescaled.
It is probably best to make a “Copy” of the area that is required to be scaled and positioned within the drawing area, as shown in Figure 3.
Somewhere close to the “Copied” objects draw a horizontal line of a known size, since the drawing contains a door it makes sense to draw this “Line” the same size as the actual door, possibly 840 long as shown in Figure 4.
The small dot that is just about visible at the top left of the “Line” are the objects to be scaled.
Access the “Scale” command and select the objects that require scaling. Specify a suitable “Scale” base point close to the selected objects.
“Zoom” in to display the recognised object i.e. the door, window, dimension etc. from either the command line or the right click menu select the scale sub command “Reference”, select two points on the object to define the “Reference” line.
“Zoom” out to display the drawn “Line”, either from the command line or right click menu select the “Scale” sub command “Points”, select the endpoints of the drawn “Line”.
The selected objects are now scaled using a “Scale” factor based on the distance of the “Reference” line and the distance between to two selected “Points” on the drawn “Line”.
Once the selected objects have been scaled, check the distance between the known points to confirm the objects have scaled correctly, as per Figure 5.
Figure 6 shows the value enlarged for confirmation.