I did 2 setups today and got the first part dialed in and then I put the new program in the control. The second part used the same tools and same projection the od was big by .004 and the Id was small. Is it incorrect to assume that the lathe leveling is off? Or is it a bed twist?
Have you checked the leveling? You do not have to have a master level to see if it is close. Be sure to check your level itself by turning it 180 dg and reading it again.
It is unlikely that lathe level would cause that much error (assuming we are working in inches here). The lathe should be level, but if one part is OK and the other is out of spec, then I would look at cutter comp.
This is not unusual condition. Many times I have to adjust cutter comp when changing jobs, even if using the same tools.
What kind of lathe?
And other thought question would be did you change materials like from aluminum to steel we’re still to bronze or 4140 to 1018
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Same material. It’s an old Mori sekei sl3 vintage 1983. Rigged it up to rs 232 for programs.
OK, it is very unlikely that twist is even possible with that lathe. At least as long as there is about the same tension on each of the leveling feet. Twist is something I might expect on a conventional bed lathe, not a short and very stiff slant bed.
Adjusting the cutter comp or re-zeroing the tools is the correct answer here.