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
The HAAS VF-10 CNC milling machine is a machining centre by numerically controlled machine tool designed to shape cold metal by the application of rotating
cutting tools capable of performing two or more machining processes, example boring, drilling, milling, thread tapping. The table 3.4 is showing the machine specifications.
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Table 3.4: Machine specifications
SPECIFICATIONS DETAIL
Travels
x = 610mm y = 500mm z = 610mm
Rapid traverse
43mmin in x and y 1690in.min 36mmin in z 1410in.min
45mm diameter ballscrew 1.8in.
Maximum speed
7,500 rpm
Feed rate
12700 mmmin
Acceleration ms2
GE Fanuc: x = 6.0 y = 5.0 z = 4.0
tool changer
24 position
3.6 DESIGN CNC PROGRAM
This experiment is conducted with using CNC milling machine and the programming should be creating directly on the CNC machine which called Manual Data Input
MDI. In CNC program, there is programming language that called G and M codes. CNC program need to be setup and programmed in order to evaluate the desired cutting
direction. The operation of CNC machine tool is controlled by program design which called NC part program. The CNC program involves a sequences of block, being
originally commands indicates the direction to be execute and the auxiliary operations for example spindle onoff, spindle speed, feed rate to be finished by the CNC
machine. The NC program is executed sequentially at a time. Once program is executed, the
movements are generated then go on to second command. The programming language is made up of words. Apart from that there are numerical digits in the element of
program constitute a word. Each of the codes has a various function, it depending on the following two digit number. Generally G-codes can be defined as a preparatory
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function code while M-codes is namely miscellaneous function code basically used in operation onoff. Table 3.5 show the basic programming codes include G and M code.
Table 3.5: Programming codes
CODE MEANING
N Block number
G Preparatory function
M Miscellaneous function
X,Y,Z Coordinates direction
R radius of arc or circle
I,J,K Coordinates values of arc centre
P or Q Parameter in machining cycle block
F Feed rate
3.7 DESIGN OF EXPERIMENT DOE
