Hidden lines problem

[mischka]

So - just to recap - there is no way of successfully exporting a dwg that has removed the hidden lines - unless you do it manually in SU before ?

[TIG]

If the hidden lines are Coplanar and are not therefore required for face retention you can remove them using a tool like tt's CleanUp.
Then they don't export as they don't exist.
BUT if a hidden line is needed by the faces then moving them onto their own layer [ON/OFF] in the SKP lets you see them in the CAD version on a separate ON/OFF layer... BUT if they are needed by faces they'll be replicated in the faces' layer too ?

So if your SKP contains unneeded hidden lines you can remove them in the SKP and export to CAD.
BUT if your SKP's faces need those hidden lines, then even moving them onto their own OFF layer in the SKP will not prevent them from getting duplicated on the face's layer in the CAD version !
Just because a line is hidden it doesn't mean it is not needed !

If you give a clear outline of your workflow, intentions, hopes and aspirations we might advise further...