Abstract: The paper presents the theoretical background for new approaches for achieving high accuracy in finish turning with slender tools. The approaches are developed especially for high-accuracy turning with vibrationsdamped boring bars with a length-to-diameter ratio up to 14. The approaches are based on established force models of turning operations and utilize a three-pass scheme where the deflection of the boring bar is calculated and compensated for in the final passes. Very good results are achieved in practical machining tests for a great variation of cutting conditions. Experiments show that the typical diameter error is 0.01 mm, even in situation where the tool deflection is 0.3 mm.

Key words: Turning, Precision, Boring bar