By John Flanagan
Introduction
In AutoCAD we can add vertical and horizontal centrelines and also centre marks for circles. Click the Annotate tab on the ribbon to access the Centrelines panel. Select the Centrelines tool and in the drawing area follow the prompts on the command line – click the lines that you want to place the centre line between. In the illustrated example the two horizontal lines on the rectangle were selected. If the two vertical lines were selected the centreline would also be vertical. This could be very useful when marking out a boundary line equally between two properties.
A similar technique is used when placing centre marks. Select the Centre Marks tool and follow the prompt – Select a circle or arc to add centre mark. The illustration above shows the result. Notice that centrelines or centre marks automatically use the centre line dashed line type irrespective of what the active layer is set to.
The “Square Grip” controls the “Centerline” “Length”, and the “Triangular Grip” controls the “Centerline” “Overshoot”. The appearance of the “Centerlines” are controlled by a number of new system variables. “Centerexe” - sets the length of the “Overshoots” for “Centerlines”, or how far the “Centerline” extends passed the selected creation lines.