The energy consumption was measured using a power meter
(SK-PM200, Seon Kwang System, Korea). This device was installed
in the main power line to the stage and spindle controller. The
overall electricity usage varied with the machining state. The
amount of electricity required for independent driving was
measured individually for each preparation step to obtain the power
consumption of each component. During machining, the
overall energy consumption was measured and averaged while
drilling 500 holes, with three repetitions.