Draft CircularArray

Description
The tool creates an array from a selected object placing the copies along concentric circumferences. This is like using PolarArray with a polar angle of 360 degrees, and creating several such concentric arrays.

This tool can be used on 2D shapes created with the Draft Workbench but can also be used on many types of 3D objects such as those created with the Part Workbench or PartDesign Workbench.

To position copies in a rectangular grid use Array; to position in a polar pattern use PolarArray; to position copies along a path use PathArray; to position copies at specified points use PointArray; to create copies or clones, and manually place them use Move, Rotate, and Clone.



Usage
With symmetry = 1 you might have to rotate the array a full circle to match positions on itself, with symmetry = 2 a rotation of half a circle (180°) is always sufficient, with symmetry = 3 a rotation of ⅓ of a circle (120°), …, with symmetry = n a rotation of 360°/n. If symmetry gets higher the number of objects in some circles decreases, it even might not be possible to place objects in the inner circle(s) at all. In most cases you want a number between 1 and 6.
 * 1) Select an object from which you wish to make the circular array.
 * 2) Press the  button. If no object is selected, the task panel will open, but you still need to select an object to proceed.
 * 3) Choose the radial distance, which determines the distance from the center of the array to the next circular layer, and between subsequent circular layers.
 * 4) Choose the tangential distance, which determines the distance from one element in the array to the next element in the same circular layer. This distance determines how many elements will be in the array; if the number is small, there will be many tightly packed copies; if the number is large, there will only be a few copies. This distance cannot be zero.
 * 5) Choose the number of circular layers. The original object is considered one layer by itself. Minimum of 2, maximum of 99.
 * 6) Choose the symmetry, which determines how symmetric the objects will be distributed in the array.
 * 1) Choose the center of the axis of rotation. You can click on the 3D view, to simultaneously set the position of the center of rotation, and complete the command.
 * 2) Optionally, check the fuse or link options.
 * 3) Press  to complete the command.

Notes:
 * By default, the axis of rotation is the positive Z axis . This can be changed in the property editor after the object is created.
 * Each element in the array is an exact clone of the original object, but the entire array is considered a single unit in terms of properties and appearance.
 * This command creates the same object as the one created with the Array and PolarArray tools. Therefore, the array can be converted to orthogonal, polar, or circular just by changing its properties.

Options

 * Press to set the center of the circular patterns to the origin.
 * If the checkbox is ticked, the resulting objects in the array will be fused into a single shape, if they touch or intersect each other.
 * If the checkbox is ticked, the resulting objects in the array will be App Links instead of simple copies. This improves the memory usage of the array, as the App Link re-uses the shape of the original object, and does not create new shapes. If this option is used, the  checkbox has no effect.
 * Press or the  button to abort the current command.

Properties
An Array object is based on Part Feature ( class), and thus shares all properties of the latter. In addition to the properties listed in Part Feature, the Array object has additional properties.

See the Array tool for the complete information.

Scripting
Draft API and FreeCAD Scripting Basics.

The Array tool can be used in macros and from the Python console by using the following function.


 * Creates an array from the objects contained in, which can be a single object or a list of objects.
 * The values of and  correspond to the radial and tangential distances of the elements in the array.
 * The values of and  are vectors that describe the direction of the axis of rotation, and a point through which that axis goes.
 * The value of is the number of circular layers in the circular pattern; the original object counts as the first layer.
 * The value of is an integer that participates in some calculations that affect the way the copies are distributed around the circumferences. Try different values, from 1 to 10, to get different placements of the copies.
 * If is  the created copies will be App Links and not regular copies.
 * is returned with the new copies.
 * is either a single object or a list of objects, depending on the input.

Example: