Why can't I trim surface?

I had mirrored (using Face) a surface along a plane and when i try to trim both of surfaces by one sketch i get nothing. Why is it so?

Answer
 
Comments 2

5 Answers

I think I might have an solution. What you got to do first is delete the mirror and than you can trim the surface with the sketch. And than you can mirror it.
I tried this and it works.

 
Comments 0

Probably because you didn't KNIT the surfaces.

 
Comments 1

I tried to solve this problem and it's not working. Tried projecting the sketch on the surface and trimming it and it doesn't work. Tried extruding the sketch and trying to use the common trim and still nothing. If you find out how to solve this let me know.

 
Comments 1

I got a workaround by thickening the surfaces, thickened cut, then deleting out the thickened faces. It works though it's not very elegant.
I haven't figured out why SW doesn't "see" those surfaces

 
Comments 3