1. So I open say the .stp, it opens an assembly with part files listed and when expanded those parts just list “Imported1” no option to detect features so I have to open the part.
2. The part opens with no features and then on the “imported1” right click and choose “Feature Works” “Recognize Features” then it generates the features –sometimes. Set on “automatic” or “interactive” and with all the “automatice features” to detect options clicked eg extrudes, drafts, etc.
3. It will crash and stops generating features and your stuck with just the “imported1” with no other options or rebuild errors which at least all the features are there to edit so they can be fixed.
4. But then there are now for some reason 2 solidworks parts generated –one I guess when the assembly was first opened and another when you do the “Feature Works”
5. So now the part with the features (if it got through the Feature Works) is not named and just called say “Part4” and so now the assembly is not pointed to this one and if I try to save it with the same name to trick it to use this wanted part, the assembly will not recognize it and so all the mates are gone and whatever other info part of the assembly to the part.

So any pointers on the best way to open non solidworks files? And how to recombine the new part with the assembly without losing the mates and such?

Oh I’m using Solidworks 2011 SP0.0