Have 2 romis 1 sd one older trying 2 cut 3/4 6 acme . Did a test piece couple of weeks ago worked great . Started making my parts with same prog as before no luck like the lead is getting off starts good the deeper i go the more it cuts off the back of my threads. went 2 my other lathe cut 1 good one thought it must be encoder or something with the other.Today same on the 2nd lathe, not slipping in chuck or be pushed back first thing i checked.Turned some M30x1.5 on 1st lathe mins ago .Take all the help i can get thanks.