Compact air bearing spindle for manufacturing and application of micro end mills
Final Report Abstract
The aim of the project was the manufacture of micro structures with constant feed per tooth and the development of an air-bearing tool spindle for micro milling tools. The micro milling tools had to be operated at very high speeds with low run-out error to achieve high accuracy and surface quality during milling. The project consisted of the design of the pneumatic drive in the form of a turbine, the design of the speed control, the characterization of the air bearing spindle, the manufacture of the milling tools, and the machining tests. During the design of the turbine and the development of the speed control, new insights were gained into the performance and dynamics of various parameters of turbine-driven spindles. The control system developed was suitable, but the turbine was unsuitable for speed control with constant feed per tooth, as the low torque did not provide sufficient dynamics. As a result, an alternative spindle was used in which the speed adjustment was integrated directly into the machine control system based on the previous controller development. The run-out measurements showed that the polygonal chuck had better run-out properties than the shrink fit chuck and that the run-out of the milling tools was more dependent on the speed than that of the blanks. The machining tests showed that micro milling with a constant feed per tooth did not lead to any improvement in the surface quality of the grooves. Furthermore, micro milling with constant speed and alternating tooth feed was better suited to achieving the set groove depth and groove width than micro milling with constant feed per tooth and alternating speed.
Publications
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Numerical analysis of different turbine designs for high-frequency spindles. Proceedings of the 23nd euspen International Conference (2023): S. 211-214. ICE23105.pdf (euspen.eu)
A. Lange, N. Altherr, B. Kirsch & J.C. Aurich
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Influence of constant feed per tooth via spindle speed adaption on groove quality in micro milling. Procedia CIRP, 123, 458-463.
Kirsch, Benjamin; Lange, Andreas; Altherr, Nicolas & Mayer, Tobias
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Modelling and control of turbine-driven spindles for micro machining with constant feed per tooth. Proceedings of the 24th international conference of the euspen (2024): S. 463-466. ISBN: 978-1-9989991-5-6
A. Lange, N. Altherr, F. Zell, B. Kirsch & J.C. Aurich
