The only fix I've seen so far is upgrading to "Pro" simulation. I've worked a week solid on the same problem. It is not user error, you're going to have to deal with it.

The best semi-solution I've seen was in the thread "4 axis simulates in 5 and posts junk" or something like that. The Engine Guy has a post there which works the best for simulating 4axis. It works so-so for me (it does eliminate the Y-flip) but I still don't get a good simulation.

Attachment 206558

http://www.cnczone.com/forums/bobcad...ml#post1315588