High-accuracy turning with slender boring bars

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 vibrations-damped 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.

Keywords

Turning / Precision / Boring bar

References

[1] Polini W, Prisco U. The estimation of the diameter error in bar turning: a comparison among three cutting force models. Int J Adv Manuf Technol, 2003, 22: 465-474.

[2] Mayer JRR, Phan A-V, Cloutier G. Prediction of diameter errors in bar turning: a computationally effective model. Appl Math Model, 2000, 24: 943-956.

[3] Asao T, Mizugaki Y, Sakamoto M, Sato H. Precision turning by means of a simplified predictive function of machining error. CIRP Ann—Manuf Technol, 1992, 41: 447-450.

[4] Yih-fong T. Parameter design optimisation of computerised numerical control turning tool steels for high dimensional precision and accuracy. Mater Des, 2006, 27: 665-675.

[5] Benardos PG, Mosialos S, Vosniakos G-C. Prediction of workpiece elastic deflections under cutting forces in turning. Robot Comput-Integr Manuf, 2006, 22: 505-514.

[6] Chiu WM, Chan KW. Design and testing of piezoelectric actuator-controlled boring bar for active compensation of cutting force induced errors. Int J Prod Econ, 1997, 51: 135-148.

[7] van Luttervelt CA, et al. Present situation and future trends in modelling of machining operations. Progress report of the CIRP working group ‘Modelling of machining operations’. CIRP Ann, 1998, 47(2): 587-626.

[8] Armarego EJA, Samaranayake P. Performance prediction models for turning with rounded corner plane faced lathe tools. II. Verification of models. Mach Sci Technol, 1999, 3(2): 173-200.

[9] Armarego EJA. The unified-generalized mechanics of cutting approach—a step towards a house of predictive performance models for machining operations. Mach Sci Technol, 2000, 4(3): 319-362.

[10] Altintas Y. Manufacturing automation, 2012, Cambridge: Cambridge University Press

Funding

Norges Forskningsråd http://dx.doi.org/10.13039/501100005416