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Understanding Constraint Theory

Constraints determine how a part is located in an assembly.
• Most constraints are applied between parts within an assembly.
– Select component reference.
– Select assembly reference.
• Constraints are added one at a time.
• The box of the active constraint is highlighted.
• Double-click a constraint’s tag to modify it.

Understanding Constraint Theory 2
Figure 2 – Viewing the Active
Understanding Constraint Theory

Understanding Constraint Theory 1
Figure 1 – Selecting Placement
Figure 3 – Modifying a Constraint

Understanding Constraint Theory 3
You can assemble components using constraints. Constraints determine how a part is located within an assembly. There are many different types of constraints that you can use to assemble components.
Most constraints are applied between parts within an assembly. They specify the relative position of a pair of references. The system adds constraints one at a time. Use placement constraints in combinations to specify both placement and orientation. It is important to select your constraints based on the design intent of your assembly, so that when you edit a dimension on a part, the assembly reacts as predicted.
When you create a constraint, its references highlight on the models and the Constraint Type displays. For most constraints, it is necessary that you select two references, a component reference on the component being placed, and an assembly reference from an item in the assembly. When the first reference has been selected, a green, dashed line connects the first selected reference to your cursor until you select the second reference, as shown in Figure 1.
When multiple constraints are created, a box surrounding the active constraint highlights. For example, in Figure 2, the Oriented constraint is the active constraint. To activate a different constraint, simply select the displayed name or select it from the Placement tab in the dashboard. You can then right-click to perform a desired action.
You can also double-click a constraint’s tag in the graphics window to edit the constraint, as shown in Figure 3. Editing options include switching the constraint type, changing the constraint orientation, and viewing as well as deleting the constraint’s placement references.
You can toggle Constraints To Connections existing connections to constraints within an assembly.

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