Both older Logan and Atlas lathes have a lot of problems with cut off. I have a 1931 South Bend 11 which is better than my Logan. On both the Atlas and Logan the primary problem is the cross slide. Other lathes could be different. Another spot on these lathes is the screw on chuck, if you have a new after market chuck the over hang is usually too much and the back plate moves on the spindle. I'm sure other areas are moving as well. Probably the spindle flexing but the biggest weak spot is the threads. Thanks for the comment.