Constraints > Concentric

Command call:

This constraint can be applied to circles, arcs and ellipses, including arcs are obtained as a result of Fillet and Offset Curve commands. This constraint moves the points of the centers so that they coincide.

 

If positions of both objects are not fixated by other constrains, then, upon applying a concentric constraint, the object selected second will be moved, while the first object keeps its position. If position of the second object is fixated, then the first one will be moved. If positions of both objects are fixated, then the new constraint will throw an error.

 

If the object to be moved doesn't have fixated points, then it keeps its initial geometry upon moving. Otherwise, instead of moving the whole object, only the central point gets moved, which results in changes in object's geometry.

 

The constraint allows to select multiple second objects.

 

Icon of constraint is displayed near center of constrained objects.

Examples

Concentricity of Two Circles

Select the first line of the circle with the help of , then the second, and end the input or <Ctrl>+<Enter>. The second circle has moved, so that the centers of the two circles coincide. In the drawing, the constraint is indicated by an icon similar to the one that indicates this constraint in the Ribbon. Now, if you move one circle, the another one moves, so that the centers of the circles coincide.

 

Concentricity of Arc and Ellipse

Select the arc line and the ellipse line, and then end input using or <Ctrl>+<Enter>. The object selected second will move so that their centers coincide.

Concentricity of Several Lines

Concentricity can be created for several elements at once.

First, select the line, which other lines should be concentric with, then sequentially select other lines with in any order, and end input using or <Ctrl>+<Enter>. The parameters window will indicate, that several second objects have been selected (in this case, three). All second objects will move, so that their centers coincide with the center of the first object. As a result, three constraints will be created for the four lines: each object 2 will be concentric with the object 1.

When moving any of the four lines, or when editing a line, so that its center changes position, all elements are rearranged in such a way, that their centers coincide.