I am unable to offset the surface (Surface-Trim1) so I deleted some faces and trimmed some part of the surface to create a relatvely smooth surface with not many curves. Now, I am trying to offset the surface (Surface-Trim12) by 1 mm, however I get this error "Unable to offset selected surface". My understanding is that when I have complicated curves that is less than 1mm apart, then I can't offset the surface. However, I don't see any curve that complicated and don't understand as to why I am unable to offset. Any work around sugestions? I need a 1mm offset of this surface to work with.
Part available here.