In a recent blog I outlined a new method of creating a line based void opening for cutting through structural Beams and Columns within Revit Structure 2012. See link Below:
https://revitstructureblog.wordpress.com/2011/08/19/creating-structural-opening-families-for-walls/
After a few requests I have now created a tutorial video on YouTube to show the creation of the family file and useage within a steel project. See Link Below:
Hope this helps,
LawrenceH
Autodesk Revit Structure 