this is my setup i-- took a rockwell lathe built the 4th axis and with a lot of experimenting it works just fine
http://www.youtube.com/watch?v=EKzGCAM_QyM rockwell lathe mockup
http://www.youtube.com/watch?v=wra5FjQmG8I first setups
http://www.youtube.com/watch?v=nS8JY3f7UfM rounding a 4x4
http://www.youtube.com/watch?v=Q-AbyzF-kvQ rapeberry wrap
http://www.youtube.com/watch?v=dl_fldo0lew