Mirroring a spline over midplane

If you mean Mirror a sketch no you cannot use plane draw in a center line and mirror about that or you can draw one seqment of the spline and copy that using circular pattern. If you want to copy one segment you have already cut use circular pattern.

Hi marko,
will post that disc to you tomorrow in the meantime a did a tutorial in word format may help you see attached

Hi marko,
Made an error on spline as it should be straight sided, attached amended solideorks file.
john