Chips are often jammed in the interface between the spindle and the tool holder in ATC with taper and face fitting system such as HSK. Run-out of the tool is measured in every tool changing to reduce the machining error caused by the chips jammed. In general, the displacement sensor is placed on the table, because tools of different dimensions are used in the process on a machining center. The setup wastes time to move spindle to the place for run-out measurement, and it incurs the increase in cycle time. Objective of this study is to develop the short-time detection method for the chip jamming happened in ATC. Mounting displacement sensor on the spindle housing, reciprocal displacement of the flange of the tool holder is monitored without moving the spindle to the place for run-out measurement. Then, both radial and axial displacement is measured for improving sensitivity of the eddy current sensor. In addition, the signal processing method is considered for automatic detection. It is confirmed that measuring sensitivity is improved and that the signal can be processed in wide range of spindle speed. By this method, it is possible to detect chip jamming during the spindle moves to machining position after ATC, and the cycle time is not increased.
