Overview

Geometric constrains set the geometry between selected drawing objects. They allow the user to quickly and accurately set the properties between objects.

To apply constraints between drawing objects:

• select the objects

• either

  • from the Constraints menu select the appropriate constraint

• or

  • click the required object on the Constraints Toolbar

To view constraints between objects:

• select the objects

• select Constraints Inspector

To view all the constraints applied to objects on a sketch:

• select the sketch

• click on the Constraints tool in the Design Toolbar

If the constraints toolbar is not visible turn it on:

• from the View menu select Toolbars

• select Constraints

Constraints Inspector

The constraints inspector allows the user to see what constraints apply to a selected drawing object.

To see what constraints are applied to an object:

To remove a constraint simply remove the tick from the constraints list.

Toggle fixed

Toggle fixed as the name implies allows an object to be fixed in position and size. Before applying constraints it may be necessary to fix one of the two components so it does not move when constraints are applied. In most of the following examples, one of the lines or circles has been fixed.

The toggel fixed constraint symbol.

An example of toggle fixed constraint is shown below.

Parallel lines

Lines which must be parallel have this constraint applied.

The parallel lines constraint symbol.

An example of parallel lines constraint is shown below.

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Perpendicular

Perpendicular lines have an angle of ninety degrees between them. The lines need not touch or cross to have this constraint applied. If lines do not touch, a phantom line will be added to extend one line to the constraint symbol.

The perpendicular lines constraint symbol.

An example of perpendicularlines constraint is shown below.

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Colinear lines

Colinear lines share the same path.

The colinear lines constraint symbol. When the two lines do not touch, a phantom line is added to indicate that the lines are colinear.

An example of colinear lines constraint is shown below.

Equal length

The equal length constraint symbol.

An example of equal length constraint is shown below.

Concentric

Concentric circles share the same centre.

The concentric constraint symbol.

An example of concentric constraint is shown below.

Tangent

Tangent lines or circles, touch but do not cut the circumference of a circle.

The tangent constraint symbol

An example of tangent constraint is shown below.

Equal radius

The equal radius constraint symbol

An example of equal radius constraint is shown below.

Projected

Lines which are a projection from another line are constrained to be geometrically the same as the original lines. To make changes to a projected object, the projection constraint must be removed.

The projected constraint symbol

An example of projection constraint is shown below.

Mirrored Lines

When lines are mirrored, a mirror constraint is created. This constraint may be removed in the same manner as any other constraint.

The mirror constraint symbol

An example of mirror constraint is shown below.