I have done some rotary stuff several years ago.
I can not help you much, but if it was me I would
start with a very simple like turning square to round
by some length.
Then go to something a little more complex like cutting
your name in the turned piece.
That way you can maybe identify what the problem is.
I think I had to modify Vetric's post processor when
I done mine.
Maybe Ger with chime in and give you some help.
He seems to be quite knowledgeable on this.
olf20 / Bob