3.4 CUTTING PARAMETER SETUP
3.4.1 Parameter Setting
The objective of this research is to identify the surface roughness using end mill in order to test several type of parameter that will be used in this experiment. The
parameter of CNC milling machine consists of cutting speed, feed rate, depth of cut, and width of cut. The parameters are set up according to the range of the CNC milling
machine. The depth of cut, ap 0.2 mm is set to constant for this experiment. The experimental condition and the parameter set are shown in table below. The table 3.3
is show the variable input consists of cutting speed, feed rate, axial depth of cut, and radial depth of cut. The selection of cutting parameters is taken after considering from
the previous study that had been measure in chapter 2 of literature reviews. The work piece material used for this experiment is AISI D2 tool steel with hardness 63 HRC.
A 200 mm x 210 mm x 100 mm block was smoothen at a maximum of 0.5 mm on the surface to remove any defects or irregularities from previous process. The cutting tools
were made of tungsten carbide coated with PVD titanium aluminium nitride TiAlN. An insert was attached to the tool holder with a 20 mm diameter.
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Table 3.3: experimental conditions
3.4.2 Factors Selection of Parameter Range
1. The range of cutting speed,Vc for high speed machining on tool steel material is between 100-300 mmin based on coated carbides cutting tools
Luis N.Lopez et al.,2002. The selection of cutting speed also based on the previous research. With reference from the tool manufacture PALBIT
cutting tool, it is recommended to used the value of cutting speed between 140 mmin minimum and 210 mmin maximum
2. Basically, Feed rate fz, are affecting the surface finish in machining process. The ranges are 0.1-0.3mmtooth is the same from manufacturer
recommendation PALBIT cutting tool. Where 0.1 mm tooth are a minimum value and 0.2 mmtooth maximum.
3. Axial depth of cut ap is used for finishing process as a cutting range, where the value is 0.2 mm and it is constant. According a Luis Lopez et al.,
CONDITIONS DESCRIPTION
Cutting speed, Vc mmin 100-150
Feed rate, fz mmtooth 0.1-0.2
Width of cut,ae mm 2.0-8.0
Coolant type Flooded coolant system
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2002 axial depth of cut is 0.2 mm for semi finishing operation in order to avoid crossing of semi-finishing on the previous machining which would
produce important change of the cutting forces.
4. Based on Buj-Corral et al. 2012 at low radial depth of cut ae=0.05 mm, experimental roughness values obtained are quite similar, regardless of
feed Fz employed and at higher ae values, feed Fz has a great influence on surface roughness obtained. In the experiment the range of ae is 2.0-8.0
mm, the high value of width of cut, ae is choose because it can more clearly to see the marks generated on a flat surface during milling process.
3.5 MACHINE SPECIFICATIONS
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