I'm currently trying to design a 5 axis head-head system for my current 3 axis system. I see in rhinocam where I can edit an existing post processor, and I see where I can put the offsets for the rotational axis of the head in the machine setup. What I am still left wondering is how can I simulate a custom machine just to make sure there are no collisions. And I'm not sure if editing the post-processor would detect the geometry of the machine to do collision avoidance. I've seen this video:
5axis Simultaneous with machine tool simulation - YouTube
But don't see where you would actually create this mockup of the machine. Does that make sense?