I have a part that created in Solidworks then imported. I manage to figure out the program (coming from something much simplier rhinocam) and setup my tool list, machine setup and set up the various cuts etc.
In rhinocam i could set the stock to whatever the size and it would only mill a pocket with the part inside but with FC it wants to remove all the waste stock that i had set. If i make the "virtual stock" smaller than my physical stock i get gouging and tool breakage as it wants to mill past the "virtual stock".
I found a post where they said to use the "total stock" in the milling tab, when i use this all my flats are the height of the stock and doesn't get touch by the tool.
In rhinoCam when i set the stock size this is what it cuts and when i set up my machine i can place all my clamps on the outside of this box and not worry about gouging into the remaining stock that my hold down clamps are on.
I've played with GibbsCam at my friends shop and they a have a feature called "stay in stock" in the process tabs that does it much like rhinocam.
Sorry long post for probably a quick and easy answer but i'm newbie to CNC.
Check out using a "curve as boundary" and the action will stay inside of it.