First, been lurking around this forum for a while now, thanks to everyone for the help!

Now a question:  Within a part file, is it possible to mirror an axis about a plane?

I am trying all the ways I can think of, and when in the mirror command, after picking my mirror plane, it does not seem to allow selection of an axis...

It feels like I am missing something that should be obvious...any info is appreciated.  Thanks.