Draft CircularArray

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

This tool can be used on any object that has a Part TopoShape, meaning 2D shapes created with the Draft Workbench, but also 3D solids created with other workbenches, for example, Part, PartDesign, or Arch. It can also create App Links instead of simple copies.


 * To create orthogonal or polar arrays, use the corresponding and  tools.
 * To position copies along a path use or.
 * To position copies at specified points use or.
 * To create copies and manually place them use or.
 * To create exact copies and manually place or scale them, use or.



Usage

 * 1) Select the object from which you wish to array.
 * 2) Press the  button. If no object is selected, you will be invited to select one before proceeding.
 * 3) The task panel is launched where you can select the radial distance, the tangential distance, the number of circular layers, the symmetry parameter, and the center of the axis of rotation.
 * 4) You can click on the 3D view to simultaneously set the position of the center of rotation, and complete the command. Otherwise, just press  or the  button to complete the operation.

Options
These are the options displayed in the task panel.


 * : the distance from the center of the array to the next circular layer, and between subsequent circular layers.
 * : 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.
 * : the original object is considered one layer by itself. There must be minimum 2, maximum 99.
 * : determines how the objects will be distributed in the array.
 * With symmetry 1 the first element needs to be rotated a full circle to reach the same position, with 2 a rotation of half a circle (180°) is sufficient, with 3 a one third rotation of a circle (120°) is enough. This means that the symmetry parameter determines a rotation of 360°/n. For large values of symmetry the number of objects in the circular layers decreases, that eventually no object will be placed in the inner circle at all. In most cases you want a number between 1 and 6.


 * : the coordinates through which the axis of rotation goes through.
 * : it resets the center of rotation to the origin.
 * : if it is checked, the resulting objects in the array will fuse together if they touch each other. This only works if is unchecked.
 * : if it is checked, the resulting array will be a "Link array". This array internally uses App Link objects, so it is more efficient when handling many copies of complex shapes. However, in this case, the objects cannot be fused together.
 * Press or the  button to abort the current command.

if a Link array is created, this object cannot be converted to a regular array. And similarly, a regular array cannot be converted to a Link array. Therefore, you must choose the type of array that you want at creation time.

Properties
A CircularArray object internally is the same object produced with the tool. It is based on Part Feature ( class), and thus shares all properties of the latter.

See the tool for the complete description of the properties. All properties apply, except for those under the and  groups.


 * For circular arrays, the specifies an offset from the  of the  object. That is, to keep the circular array centered on the  object, keep  to the default value.

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 object from the.
 * The values of and  correspond to the radial and tangential distances of the elements in the array.
 * 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. Usual values are from 1 to 6; higher values are not recommended and will make the copies in the inner layers to disappear.
 * The values of and  are vectors that describe the direction of the axis of rotation, and a point through which that axis goes.
 * If is  the created copies will be App Links and not regular copies.

Example: