A circle track is a special form of a curved track that extends 360° and has no endpoints. The three methods (with their Shortcut keys) used to create a Circle Track are:
Control-8
) Use the Fixed Radius specified on the Circle Radius control displayed on the Status Bar (Section 3.1). Drag the Circle track into position.
Control-9
) Drag from tangent point (Edge) of the Circle track to the Center.
Control-0
) Drag from the Center of the Circle track to the edge.
A drop down menu, which allows selection of the Circle Track creation method, is invoked from the down arrow button () located on the right side the Circle track button. Dependent upon previous selection, the Circle Track button will look like
,
or
.
If Snap Grid (Section 2.12.1) is enabled then circle centers will be constrained to the grid.
Circle tracks are useful for fitting curves into corners and other tight places. They're also handy when establishing an initial layout and finding out "what will fit".
You can join to and from circles, after which they become curved tracks.