Surface edges

Surface edges is useful for extracting trimming loops from 3D surface data, and projecting that curve onto the XY plane of the current UCS. You can use these curves to create 2.5D features.

IGES files often contain complete solid models of a part. Features such as pockets and holes are subtracted from part surfaces resulting in a collection of trimmed surfaces. In this model, the seven pockets have been subtracted from the surrounding surfaces.

Rather than manufacturing all of these surfaces using 3D surface manufacturing techniques, you should use 2.5D Pocket features for each pocket.

Surface edges enables you to extract trimming curves from a collection of surfaces, join them into a curve and then project the curve onto the XY plane of your current UCS. You can then use this curve to create features.

To extract curves from 3D data:

1. Select Construct tab > Curves panel > From Surfaces > Surface Edges to open the Surface Edges dialog.
2. Optionally enter a curve name in the Name field, or leave the default name.
3. Select the edge you want to use from the Edges menu, or use the Pick curve on surface button to select it in the graphics window. The edge is added to the table.
Note: Applies to solids only (not a random collection of surfaces).
Tip: Ctrl+click two edges to select all edges that make up the shortest path between them.
Tip: Double-click an edge to select all tangential edges.
4. The location of the pick is used to select a surface and extract a trimming edge. Click the Use next edge of surface button if you picked the correct surface, but the wrong edge.
5. Continue selecting edges in order until you have selected all edges.

   Use the Move item up and Move item down buttons to reorder the edges if necessary.

6. If the edges are in the correct order, but the endpoints are matched up incorrectly, select the surface name in the table and click the Reverse button.
7. Select Connect start and end if you want the curve to be closed automatically.
8. Select from the Project to UCS menu to have the curve automatically projected to the 2D XY plane of the UCS.
9. If a hollow blue square is displayed at the intersection of two edges, then the edges have not quite matched up. You can correct this by either selecting the missing edge that will connect the endpoints, or if it is just an issue of floating point error, increase the Tolerance parameter.
10. Click OK.