To Set Up a Retract Sphere
1. Select Sphere from the Type list on the Clearance tab of the Operation tab, or on the tab of any NC step you are creating.
2. Select the coordinate system in the graphics window. The coordinate system for the sphere center appears in the Reference collector.
By default, the sphere center is either the Machine or the NC Sequence coordinate system (depending on whether you define retract at the operation or the NC sequence level respectively).
3. To change the reference coordinate system, select the required coordinate system from the model tree or graphics window. The reference coordinate system should have its Z axis in the same direction as the Z axis of the NC sequence coordinate system. Alternatively, select a datum point that represents the origin of the reference coordinate system. The selected coordinate system will appear in the Reference collector.
4. To revert to the default reference coordinate system, right-click the coordinate system in the Reference collector and click Default Reference.
5. To copy the retract definition from another NC Sequence, select the NC Sequence from the model tree or by searching for features using the Search Tool dialog box that appears when you click > from the Creo Parametric main window. The retract definition is copied and from the selected sequence and its reference is highlighted in the graphics window and model tree.
6. In the Value box, select or type the radius for the retract sphere. The value can be:
◦ A number. For example 20.
OR
◦ A relation that can include other cutting and tool parameters. For example, STEP_DEPTH * 2.
OR
◦ A value or relation appears in the Value box if you have already defined the relation for the RETRACT_REF_OFFSET identifier. Define the relation in the Relations dialog box that you can open by clicking 
in the Edit Parameters dialog. For example, if you have specified RETRACT_REF_OFFSET = CLEAR_DIST in the Relations dialog box, the value CLEAR_DIST appears in the Value box.
in the Edit Parameters dialog. For example, if you have specified RETRACT_REF_OFFSET = CLEAR_DIST in the Relations dialog box, the value CLEAR_DIST appears in the Value box.Alternatively, click and drag the radius handle in the graphics window to create a retract sphere of the required radius. You can also double-click the radius handle in the graphics window to modify the value.
7. Click OK to set up the retract sphere.