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2 Experiment
In this section are presented setups of the conducted experiments. The equipment
consists of: (1) the machine CHARNOA CNC SYSTEMS (vertical milling machine),
(2) the milling cutter with proper diameter and APKT inserts and 3) tool holder
SANDVIK (Fig. 1). A microphone Bruel & Kjaer 2270 was used for measurements
of the sound pressure level (SPL). The distance between the centre of the cutter and
the microphone was 200 mm for the first set of experiments, 100 mm for the second
set of experiments and 100 mm for the third set of experiments [5].
The samples—workpieces had pre-defined shapes and dimensions, shown in
Fig. 2.
For the first and the third set of experiments, the material of the workpieces was
carbon steel S355, and the diameter of the cutter was 40 mm with four inserts. For
the second set of the experiments material of the workpiece was carbon steel 1C45,
while the diameter of the cutter was 20 mm.
2.1 The First Set of Experiments
The first set of experiments comprises measurements dependence of maximum sound
pressure level L Fmax [dBA] and the equivalent sound pressure level L eq [dBA] on
cutting parameters (axial depth of cut, feed rate, spindle speed and radial depth of
cut).
Table 1 presents the values of cutting parameters for each of the experiments of
the first set. The shaded table fields indicate the cutting parameter that was varied
during an experiment, while the three remaining parameters were kept constant.
Figure 3 shows individual cuts that arise due to passes of the cutter during each
of the experiments of the first set of experiments.
Fig. 1 The machine, tool
and the microphone used for
the experiments