Comment créer l'"axe" d'un trou coudé ?

Bronek Bednarz from L-3 Wescam showed me a sheet metal model (similar to the one shown in fig. 1) and asked a very interesting question:

I need to place bolts in these bent holes, but – since the holes are no longer cylindrical – I cannot use their faces for Concentric Mates and they do not have axes to be used for a Coincident Mates. Any suggestions?

Figure 1 : Trous appliqués à une pièce en tôle

Very often after drilling or punching holes in sheet metal, the material is bent exactly in that area and, as a result, the holes are no longer cylindrical. When a bolt or a pin has to be mated “concentric” to one of those holes, there is no face or axis that can be use as a mating reference.

This video (no audio provided) shows the steps taken in order to create the axis of the bent hole. The same technique can be applied to any shape of a cut-out.

1. Create a fill surface first, using the edge of the hole as boundaries. Select Curvature for the Edge settings.
2. Find the center of this surface by using a Reference Geometry Point
3. Create a Reference Geometry Axis coincident to the point and normal on the filled surface
4. Once the axis is created, the surface can be hidden or deleted.