Gipuzkoako Ingeniaritza Eskola (EHU). CFAA Fabrikazio Aeronautiko Aurreratuko Zentroa (EHU).
Institute of Advanced Materials for Sustainable Manufacturing, Tecnológico de Monterrey.
Mechanical manufacturing, especially mechanization, faces a great challenge: vibrations limit productivity and lead to a bad surface finish. The University of the Basque Country and the Tecnológico de Monterrey have developed the Mill+ application to evaluate the stability and surface quality of the milling in order to help decision-making with reliability and effectiveness.
Milling is common in mechanical manufacturing and is one of the most valuable processes for the piece. But it's very sensitive to vibrations, especially the so-called chatter, which are very dangerous for parts. This problem is due to the fact that the shear system does not have sufficient stiffness or damping when the shear is made under certain conditions. This phenomenon, in addition to producing noise, worsens the quality of the piece and reduces the service life of the herramienta.Cuando occurs the Chatter phenomenon, the vibrations of the cutting tool exacerbate the working surface or produce irregularities; on the other hand, the tool is eroded faster and, therefore, reduces productivity and increases the costs of the process [1-3].
Although the problem of vibrations is old, it currently poses new challenges, since higher standards must be ensured in machining processes. When the cutting system cannot be changed or does not want to change, the solution is to change the cutting parameters. This is the main argument for using the application below.
Mill+ is an application developed by the University of the Basque Country [4,5] and the Tecnológico de Monterrey [6] thanks to a long collaboration of years, and is designed to prevent and control vibrations that occur in milling. MATLAB App Designer offers stability maps via an interface in the environment so that the operator can select the most appropriate cutting parameters, such as the head turn speed (
In order to achieve an effective and high quality milling process, it is necessary to select the appropriate cutting parameters. These parameters, such as turning speed, tooth advancement and cutting depth, directly affect the quality of the piece, the productivity and the durability of the tools. From these parameters new, more elaborate (and predictable) are created: some variables – cutting power, cutting forces, chip flow, surface roughness… – play a fundamental role.
The understanding and control of these variables, besides helping to increase productivity, ensures the stability and overall quality of the milling process.
Therefore, the developed tool offers the following simulation capabilities:
Mill+ aims to be useful for both industry professionals and students in the academic field. Professionals will be able to perform a rapid analysis before milling operations and optimize parameters and reduce the probability of errors; the application is easy to use and does not require much training to integrate into the workflow. In the academic field, it is already used at the Tecnológico de Monterrey and at the University of the Basque Country to teach the vibrations and stability of the milling process, so that they can see and analyze how cutting parameters affect the behavior of tools and work pieces and they can better understand the theory and apply it in practical situations.
[1] Tlusty, J. Polac, M. The stability of machine tools against self-excited vibrations in machining. International Research in Production Engineering Conference, 1963, pp. 465-474.
[2] Altintas, Y. Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and CNC Design, 2012, Cambridge University Press.
[3] Schmitz, T., As for Miguel Strogoff and Miguel Strogoff, the two gentlemen, one of them Smith and the other K. Machining dynamics: Response to Improved Productivity. Springer, 2009
[4] Urbikain, G. Artetxe, E. López de Lacalle, L.N., Numical simulation of milling forces with barber-shaped tools considering runout and tool inclination angles. Applied Mathematical Modelling, 2017, vol. 47, pp. 619–636.
[5] Urbikain G. Modelling of static and dynamic milling forces in inclined operations with circle segment end mills. Precision Engineering, 2019, vol. 56, pp. 123–35.
[6] Olvera D., Elias - Zuñiga A., D. Martínez Alfaro H., López de Lacalle L.N., Rodríguez C.A., Campa F.J. Determination of the stability lobes in milling operations based on homotopy and simulated annealing techniques. Mechatronics, 2014, vol. 24(3), pp. 177–85.