Reference Section > Shape Library > Round Shapes

The Cut Ring is a full ring – an outer circle and an inner circle centred on the insert point – built as one closed path, with a straight radial cut joining the outer circle to the inner circle. Because the radial cut is part of the path, cutting the shape severs the ring at that point: the finished part is a split ring, not a closed washer, and the outside and the hole are cut as one profile. Use the Ring shape when you want a closed washer with a separate hole.

It appears in the shapes library under Round Shapes.

Insert point and direction

The centre of both circles is the insert point (Base X, Base Y). The radial cut lies on the line straight up from the centre (12 o’clock, before any Rotation). The path starts at the top of the outer circle and runs:

1.once round the outer circle, anticlockwise, back to the top;

2.straight down the radial line to the top of the inner circle;

3.once round the inner circle, clockwise, back to the top;

4.straight back up the same radial line to the start point, closing the path.

The radial line is therefore travelled twice, once in each direction. To put the cut somewhere else on the ring, use Rotation.

IR is dimensioned as a radius on the inner circle and OR as a radius on the outer circle. Swept Angle is not dimensioned on the shape.

Properties

Property	Description	Default
IR	Inside radius – the radius of the hole. Length units. Minimum 0. With an IR of 0 there is no hole: the shape is a disk with a radial line from the centre out to the top of the circle, cut in and back out along the same line.	25 mm (1 in)
OR	Outside radius – the radius of the outer circle. Length units.	50 mm (2 in)
Swept Angle	Shown on the property page, but has no effect on the shape. The Cut Ring is always a full 360° ring: each time the shape is built the value is set back to 360°, whatever was entered. The field is inherited from the Partial Ring (Radius), which the Cut Ring is built on.	360° (set on every build)

Limits

Apart from IR, which the property page does not let go below 0, the Cut Ring has no checks of its own: it does not compare IR with OR, and OR has no minimum. The warning Warning: Cannot build shape from these parameters appears only if the geometry itself cannot be created, so check the values yourself:

•IR must be smaller than OR. An IR equal to OR gives two coincident circles joined by a zero-length radial line. An IR larger than OR is not checked, and the two circles swap roles, so the result is not a ring with its hole inside the outside edge. Neither is a usable ring.

•OR must be greater than 0. The shape does not check for this, and an OR of 0 is not a usable ring.

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.