Reference Section > Shape Library > Primitives

The Nipple Bridge is two open cut paths that face each other. Each path is a half slot: a quarter arc, a straight line and a second quarter arc, bulging sideways by one Radius. The second path is the first turned through 180°, and the two are placed so that their bulges cross by the Overlap distance. The shape has no closed outline; it is a pair of separate open cuts.

It appears in the shapes library under Basic Shapes and Primitives.

Insert point and build direction

The insert point is the start of the left-hand path, at the bottom left of the shape. The two paths are built as follows:

•Left path – starts at the insert point and runs anticlockwise round a quarter arc of the given Radius to the point (Radius, Radius), straight up to (Radius, Length – Radius), then round a second quarter arc to finish at (0, Length), directly above the insert point. It bulges to the right, out to X = Radius.

•Right path – the same profile turned through 180°. It starts at the top, at (2 × Radius – Overlap, Length), and finishes at the bottom, at (2 × Radius – Overlap, 0). It bulges to the left, out to X = Radius – Overlap.

While Overlap is between 0 and Radius, the overall size is 2 × Radius – Overlap wide by Length high. Along the straight part of the two paths the bulges cross each other by the Overlap distance.

Properties

Property	Description	Default
Length	The height of each path, from its start point to its finish point, measured along Y. Length units.	15 mm (0.591 in when working in inches)
Radius	The radius of the four quarter arcs, and so how far each path bulges sideways from its start and finish points. Length units.	5 mm (0.197 in when working in inches)
Overlap	How far the bulges of the two paths cross each other, measured along X. The straight line of the right path sits Overlap to the left of the straight line of the left path. At 0 the two straight lines coincide. A negative value leaves a gap of that size between them. Length units.	2 mm (0.079 in when working in inches)

The dimensions drawn on the shape are Radius (on the bottom arc of the left path), Length (along the start and finish points of the right path) and Overlap (across the crossing of the two straight lines).

Limits

The shape does not validate its values, and its geometry code has no error handling of its own. Check the values against these limits before cutting:

•Length should be at least 2 × Radius. If it is shorter, the straight line between the two arcs runs backwards (downwards) and each path doubles back on itself.

•Radius must be greater than 0. At 0 both arcs have zero chord (degenerate) and the shape may fail to build.

•An Overlap larger than Radius puts the straight line of the right path to the left of the start and finish points of the left path (X < 0). An Overlap larger than 2 × Radius puts the start and finish points of the right path to the left of those of the left path.

The defaults are 15 mm, 5 mm and 2 mm. When working in inches the property page shows them converted: 0.591 in, 0.197 in and 0.079 in.

Every 2D shape also has the Transform properties (Base X, Base Y, Rotation, Scale, Mirroring X) and the Polar Array properties, listed after the shape's own properties.