External Sketches An External Sketch is simply a Sketch feature in the model tree that is selected to be used in a feature tool, such as the Extrude Tool.  The flexibility of using External Sketches allows you to quickly select and alternate sketch for a feature.

Task 1-14. Redefine an Extrude to use an alternate sketch on the CRANKSHAFT.

1. Select the Folder Browser , then click the Part_Modeling folder.
1. Select CRANKSHAFT.PRT from the browser to view its preview, and then click Open in Pro/E .
2. Select the ALT_LOBE_SKETCH from the model tree, right-click and select Unhide.
   1. Select EXTRUDE_2 from the model tree, right-click and select Rename.
   2. Type LOBE_EXTRUDE as the name, and press ENTER.
3. Select an alternate sketch for an extruded protrusion:
   1. With LOBE_EXTRUDE still selected, right-click and select Edit Definition.
   2. Orient the model as shown in the following figure.
   3. Select the ALT_LOBE_SKETCH from the model tree.
   4. Click the yellow arrow on the model to flip the direction of feature creation.
   5. Click Complete Feature .

Redefining an Extrude Feature

	The alternate sketch is automatically hidden once used by the extrude feature.