Determining the Width and Depths of Cut in Milling on the Basis of a Multi-Dexel Model

Authors: Jens Friedrich, Matthias A. Gebele, Armin Lechler, Alexander Verl

Abstract:

Chatter vibrations and process instabilities are the most important factors limiting the productivity of the milling process. Chatter can leads to damage of the tool, the part or the machine tool. Therefore, the estimation and prediction of the process stability is very important. The process stability depends on the spindle speed, the depth of cut and the width of cut. In milling, the process conditions are defined in the NC-program. While the spindle speed is directly coded in the NC-program, the depth and width of cut are unknown. This paper presents a new simulation based approach for the prediction of the depth and width of cut of a milling process. The prediction is based on a material removal simulation with an analytically represented tool shape and a multi-dexel approach for the workpiece. The new calculation method allows the direct estimation of the depth and width of cut, which are the influencing parameters of the process stability, instead of the removed volume as existing approaches do. The knowledge can be used to predict the stability of new, unknown parts. Moreover with an additional vibration sensor, the stability lobe diagram of a milling process can be estimated and improved based on the estimated depth and width of cut.

Keywords: Dexel, process stability, material removal, milling.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1109161

References:

[1] Flexible mini-factory for local and customized production in a container, www.CassaMobile.EU, 2013.
[2] J. Friedrich, S. Scheifele, A. Verl, and A. Lechler, “Flexible and Modular Control and Manufacturing System,” in Procedia CIRP: Elsevier, 2014.
[3] S. A. Tobias and W. Fishwick, “Theory of regenerative machine tool chatters,” The engineer, vol. 205, pp. 199–203, 1958.
[4] T. Insperger and G. Stépán, “Semi-discretization method for delayed systems,” International Journal for numerical methods in engineering, vol. 55, pp. 503–518, 2002.
[5] Y. Ding, L. Zhu, X. Zhang, and H. Ding, “A full-discretization method for prediction of milling stability,” International Journal of Machine Tools and Manufacture, vol. 50, pp. 502–509, 2010.
[6] Y. Altintaş and E. Budak, “Analytical prediction of stability lobes in milling,” CIRP Annals-Manufacturing Technology, vol. 44, pp. 357– 362, 1995.
[7] G. Quintana, J. Ciurana, and D. Teixidor, “A new experimental methodology for identification of stability lobes diagram in milling operations,” International Journal of Machine Tools and Manufacture, vol. 48, pp. 1637–1645, 2008.
[8] C. A. Suprock, B. K. Fussell, R. B. Jerard, and R. Z. Hassan, “A low cost wireless tool tip vibration sensor for milling,” ASME MSEC, 2008.
[9] E. Budak and A. Tekeli, “Maximizing chatter free material removal rate in milling through optimal selection of axial and radial depth of cut pairs,” CIRP Annals-Manufacturing Technology, vol. 54, pp. 353–356, 2005.
[10] M. Stautner, Simulation und Optimierung der mehrachsigen Fräsbearbeitung. Essen. Vulkan-Verl., 2006.
[11] T. Surmann, Geometrisch-physikalische Simulation der Prozessdynamik für das fünfachsige Fräsen von Freiformflächen. Essen. Vulkan-Verl., 2006.
[12] Z. Hou, Beitrag zur voxelbasierten Simulation des fünfachsigen NCFräsens. Stuttgart. Fraunhofer-IRB-Verl., 2003.
[13] D. Jang, K. Kim, and J. Jung, “Voxel-Based Virtual Multi-Axis Machining,” The International Journal of Advanced Manufacturing Technology, vol. 16, pp. 709–713, 2000.
[14] P. Brunet, “Solid representation and operation using extended octrees,” ACM Trans. Graph., vol. 9, pp. 170–197, 1990.
[15] T. van Hook, “Real-time shaded NC milling display,” in the 13th annual conference. D. C. Evans, R. J. Athay, Eds., pp. 15–20.
[16] M. O. Benouamer and D. Michelucci, “Bridging the gap between CSG and Brep via a triple ray representation,” in the fourth ACM symposium. C. Hoffmann, W. Bronsvoort, G. Allen, M. Pratt, D. Rosen, Eds., pp. 68–79.
[17] M. E. Martellotti, “An Analysis of the Milling Process,” in Transactions of the A.S.M.E., vol. 63, pp. 677–700.
[18] S. Engin and Y. Altintas, “Mechanics and dynamics of general milling cutters,” International Journal of Machine Tools and Manufacture, vol. 41, pp. 2195–2212, 2001.
[19] A. H. Konig and E. Groller, “Real time simulation and visualization of NC milling processes for inhomogeneous materials on low-end graphics hardware,” in Computer Graphics International, pp. 338–349.
[20] Qt Cross-platform application & UI development framework, http://www.qt.io/, 2015.