You can constrain an individual axis with the Scale constraint. For example, you can scale only an object’s Y-axis.
To constrain a single axis:
- Double-click the Scale constraint in the Scene browser to select it.
- Open the Properties window. The Scale constraint settings display.
- Expand Constraint Axes and disable the X, Y, or Z axis for the desired translation effect you want to inhibit.
- To reactivate the unconstrained axes, activate the option.