The document discusses using Taguchi methods and design of experiments to optimize CNC EDM and WEDM process parameters. It describes selecting input factors like voltage, current, pulse on time and responses like material removal rate and machining time. Orthogonal arrays are used to design the experiments. Signal to noise ratios are calculated to analyze the experimental results and determine the most influential factors for both processes. The analysis found that voltage has the largest effect on material removal rate for EDM and voltage and current most affect machining time for EDM and WEDM respectively.

1. By,
KIRAN H G
RAGHUNANDAN H S
RAJESH S
VINITESH K V

3. A
B
S KEYWORDS: CNC EDM, CNC
WEDM, Taguchi method, DOE,
T Orthogonal array
R
A
C
T

4. INTRODUCTION
C DESIGN OF EXPERIMENT
O
TAGUCHI METHOD
N
EXPERIMENTRAL AND SLECTION
T OF PROCESS PARAMETERS
E EXPERIMENTRAL OBSERAVATION
N EXPERIMENTRAL RESULTS AND
ANALYSIS TAGUCHI METHOD
T
CONCLSIONS
REFERENCES

5. INTRODUCTION
EDM is an electro-thermal non-
traditional machining
process, where electrical energy
is used to generate electrical
spark and material removal
mainly occurs due to thermal
energy of the spark
The work material is
removed by a series of sparks
that cause localized melting
and evaporation of the
material
EDNC 32H MAKINO high precision CNC
EDM

6. EDM is mainly used to machine difficult-to-
machine materials.
The electrode is made from electrically conductive
material.
EDNC 32H MAKINO high precision CNC EDM
Dielectric fluid should be nonconductor of electricity

7. WIRE CUT ELECTRO
DISCHARGE MACHINING
(WEDM),
WEDM is electro-thermal
mechanisms to cut electrically
conductive material.
WEDM has become the
essential part of many
manufacturing process
industries, which need variety,
precision and accuracy
FA10S MITSUBISHI high precision CNC
WEDM

8. DESIGN OF EXPERIMENT
 Design of Experiments (DOE) refers to planning, designing
and analyzing an experiment so that valid and objective
conclusions can be drawn effectively and efficiently.
 The input variables are called Factors and the output
variables are called Response.

9. THE ADVANTAGES OF DESIGN OF
EXPERIMENTS ARE
 Numbers of trials is significantly reduced.
 Optimal setting of the parameters can be found
out.
 Qualitative estimation of parameters can be made.
 Experimental error can be estimated.
 Inference regarding the effect of parameters on
the characteristics of the process

10.  Dr. Genichi
Taguchi was
DR. GENICHI TAGUCHI Born in Japan,
1924. He is an
Electrical
Engineer and
Worked during
1950’s to
improve Japan’s
post-WWII
telephone
communication
system And also
called Father of
the
“Taguchi
Method” and
“Robust
Engineering

11. HE SUGGESTED THAT
THE DESIGN PROCESS
SHOULD BE SEEN AS
THREE STAGES
• SYSTEM DESIGN
1
• PARAMETER
2 DESIGN
• TOLERANCE
3 DESIGN
In this present work, the Taguchi method has been used to
plan the experiments for parameter design and subsequent
analysis of the data collected

12. PARAMETER DESIGN
 Parameter design determines the most appropriate,
optimizing set of parameters identifying the settings of
each parameter which will minimize variation from the
target performance
 The selection of control factors (parameters) and their
“OPTIMAL” levels
 The objective is to make the
“IMPROVEMENT OF QUALITY”
 The “ OPTIMAL ” parameter levels can be determined
through experimentation

13. INITIATING STEPS
2. BRAIN 3.
STORMING EXPERIMENTAL
SESSION DESIGN
1. PROBLEM
(Identify:- Factors
IDENTIFICATION
,Factors settings , (Choose orthogonal
Possible Interaction arrays, Design
, Objectives) Experiment )

14. 4. RUN EXPERIMENT
5. ANALYZE RESULTS
6.CONFIRMATION RUNS

15. EXPERIMENTRAL AND SLECTION OF PROCESS
PARAMETERS FOR CNC EDM
INPUT FACTORS FOR CNC EDM
1) VOLTAGE (V)
2) CURRENT (I)
3) PULSE ON TIME (TON)
RESPONSES MEASURED FOR EDM
1) MATERIAL REMOVAL RATE (MRR),
2) MACHINING TIME

16. TABLE 1:- LEVEL VALUES OF INPUT FACTOR
Symbols Testing parameters Level1 Level2 Level3
A Voltage (V) 6 7 5
B Current(I) 2 3 4
C Pulse ON time(Ton) 35 40 45
Array Selector

17. ORTHOGONAL ARRAYS
Orthogonal Arrays represent a versatile class of
combinational arrangements useful for conducting
experiments.
The standard two level and three level arrays are:
•Two level arrays: L4, L8, L12, L16, L32
•Three level arrays: L9, L18, L27

18. TAGUCHI L9 ORTHOGONAL ARRAY DESIGN MATRIX IS
SELECTED FROM ARRAY TABLE
Exp. Factor Factor Factor EXP PARAMETERS LEVEL
No. 1 2 3 NO
VOLT CUR PULSE
01 1 1 1 AGE RENT ON
02 1 2 2 TIME
03 1 3 3
1 6 2 35
04 2 1 2 2 6 3 40
05 2 2 3 3 6 4 45
4 7 2 40
06 2 3 1
5 7 3 45
07 3 1 3 6 7 4 35
08 3 2 1
7 5 2 45
8 5 3 35
09 3 3 2 9 5 4 40

19. SLECTION OF MATERIAL FOR EDM OF ALLOY
STEEL(SK-5) MATERIAL HAS BEEN CONSIDER USING
COPPER ELECTRODE
Dia Of Electrode :
9.4mm

22. EXPERIMENTRAL OBSERAVATION & CALCULATION
OF VARIOUS RESPONSE FACTORS BASED ON
TAGUCHI L9 ORTHOGONAL ARRAY
PARAMETER LEVELS MACHI MACHI MRR 1 MRR2
EXP VOLTA CURRE PULSE NING NIG In In
NO GE NT ON TIME 1 TIME 2 mm3/sec mm3/sec
TIME In secs In secs
1 6 2 35 92 94 0.2008 0.1511
2 6 3 40 79 83 0.2426 0.1994
3 6 4 45 45 43 0.3281 0.3097
4 7 2 40 38 34 0.2962 0.3036
5 7 3 45 49 46 0.3321 0.3416
6 7 4 35 69 70 0.2097 0.1987
7 5 2 45 68 67 0.2434 0.2247
8 5 3 35 96 97 0.1352 0.1359
9 5 4 40 73 70 0.1864 0.1805

23. SIGNAL TO NOISE RATIO
 Taguchi's emphasis on minimizing deviation from target
led him to develop measures of the process output that
incorporate both the location of the output as well as the
variation. These measures are called signal to noise ratios.
 The signal to noise ratio provides a measure of the impact
of noise factors on performance.

24.  There are 3 Signal-to-Noise ratios of common
interest for optimization of Static Problems
SMALLER- NOMINAL- LARGER-
THE-BETTER THE-BEST THE-BETTER
NOMINAL-THE-BEST
n = 10 Log10 [ square of mean/ variance ]
This case arises when a specified value is MOST desired,
meaning that neither a smaller nor a larger value is desirable

25. CALCULATION OF SIGNAL TO NOISE RATIO FOR
MRR AND MT
PARAMETER LEVELS SN SN
EXP NO VOLTAGE CURRENT PULSE ON RATIO for RATIO for
TIME MT MRR
1 6 2 35 36.3594 13.8276
2 6 3 40 29.1388 18.0704
3 6 4 45 29.8588 28.4448
4 7 2 40 22.0952 36.8242
5 7 3 45 27.0017 45.1361
6 7 4 35 39.8500 29.1000
7 5 2 45 39.5964 24.8895
8 5 3 35 42.7008 26.5849
9 5 4 40 30.5540 53.5758

26. Response Table for Signal to Noise Ratios for MT
LEVEL VOLTAGE IN V CURRENT IN PULSE ON
AMP TIME
1 37.6162 32.6788 39.6364
2 31.7912 32.9521 27.2640
3 29.6429 33.4194 32.1499
Δ 7.9733 0.7406 12.3724
RANK 2 3 1
Therefore, PULSE ON TIME has the maximum effect on MACHINING
TIME

27. Response Table for Signal to Noise Ratios for MRR
LEVEL VOLTAGE IN CURRENT IN PULSE ON
V AMP TIME
1 35.02 25.18 23.17
2 20.11 29.93 36.16
3 37.02 37.04 32.82
Δ 16.91 11.86 12.99
RANK 1 3 2
Therefore VOLTAGE has the largest effect on MATERIAL
REMOVAL RATE.

28. SIMILARLY (WEDM) OF AL-6061 MATERIAL HAS
BEEN CONSIDER USING WEDM WITH A BRASS WIRE
ELECTRODE

30. EXPERIMENTRAL AND SLECTION OF PROCESS
PARAMETERS FOR CNC EDM
Input Factors:- Responses measured:-
Voltage (v)  Machining time (MT),
Cutting speed (CS)
Current (Ip)
Voltage gap (Vg)
Wire tension (WT)
LEVEL VALUES OF INPUT FACTORS
Symbols Testing parameters Level1 Level2 Level3
A Voltage (V) 6 8 10
B Current(I) 4 7 9
C Voltage gap (Vg) 55 58 60
D Wire tension (WT) 8 9 10

31. EXPERIMENTAL RESULTS AND CALCULATIONS OF VARIOUS
RESPONSE FACTORS BASED ON TAGUCHI L9 ORTHOGONAL
ARRAY
Calculation of Signal to Noise ratio for MT
EXP PARAMETER LEVELS MT1 MT2 SN
NO In sec In sec RATIO
VOLTAGE CURRENT VOLTAGE WIRE
(V) (I) GAP (VG) TENSION
(WT)
1 6 4 55 8 12.54 12.07 31.3683
2 6 7 58 9 8.02 7.58 27.9796
3 6 9 60 10 15.20 14.54 30.0635
4 8 4 58 10 12.36 12.10 36.4588
5 8 7 60 8 6.57 6.54 49.7993
6 8 9 55 9 2.52 2.40 29.2427
7 10 4 60 9 12.46 12.01 31.6966
8 10 7 55 10 3.31 3.17 30.2966
9 10 9 58 8 3.02 2.50 17.4697

32. CALCULATION OF SIGNAL TO NOISE RATIO FOR CS
EXP PARAMETER LEVELS CS1 CS2 SN RATIO
NO VOLTAGE CURRENT VOLTAGE GAP WIRE TENSION In mm/sec In
(V) (I) (VG) (WT) Mm/sec
1 6 4 55 8 1.3 1.32 39.3348
2 6 7 58 9 1.7 1.89 22.5043
3 6 9 60 10 0.5 1.27 3.3082
4 8 4 58 10 1.1 1.40 15.3430
5 8 7 60 8 2.9 2.46 18.6745
6 8 9 55 9 5.6 6.18 23.1335
7 10 4 60 9 1.3 1.34 33.3795
8 10 7 55 10 4.6 4.89 27.2830
9 10 9 58 8 5.4 6.10 21.2855

33. RESPONSE TABLE FOR SIGNAL TO NOISE RATIOS FOR MT
LEVEL VOLTAGE IN CURRENT IN VOLTAGE WIRE
V AMP GAP TENSION
1 29.8038 33.1745 30.3025 32.8791
2 38.5002 36.0251 27.3027 29.6396
3 26.4876 25.5919 37.1864 32.2729
Δ 12.0126 10.4332 9.8837 3.2395
RANK 1 2 3 4
RESPONSE TABLE FOR SIGNAL TO NOISE RATIOS FOR CS
LEVEL VOLTAGE IN CURRENT VOLTAGE WIRE
V IN AMP GAP TENSION
1 21.7157 29.3524 29.9171 26.4316
2 19.0503 22.8206 19.7109 26.3391
3 27.316 15.9090 18.4540 15.3114
Δ 8.2657 13.4434 11.4631 11.1202
RANK 4 1 2 3

34. CONCLUSION FOR CNC EDM
 The MACHINING TIME (MT) mainly affected by
PULSE ON TIME, VOLTAGE has less effect on it.
Current (I) has a least effect on MT.
 The MATERIAL REMOVAL RATE (MRR) is mainly
influenced by VOLTAGE, The effect of PULSE ON TIME
is less and Current has least effect on it.
Exp no. 4 is the OPTIMIZED PARAMETER for MT
Exp no. 1 is the OPTIMIZED PARAMETER for MRR

35. CONCLUSION FOR CNC WEDM
The MACHINING TIME (MT) mainly affected by
VOLTAGE , CURRENT &VOLTAGE GAP has less
effect on it. WIRE TENSION has a least effect on MT
The CUTTING SPEED (CS) is mainly influenced by
CURRENT, The effect of VOLTAGE GAP ,WIRE
TENSION is less and VOLTAGE has least effect on it.
Exp no. 9 is the OPTIMIZED PARAMETER for MT
Exp no. 3 is the OPTIMIZED PARAMETER for CS

36. REFERENCES
 Abbas, N.M., Solomon, D.G., Bahari, M. F. (2007), “A
review on current research trends in electrical discharge
machining (EDM)”, International Journal of Machine Tools
& Manufacture, 47, 1214–1228.
 Adler, Yu. P., Markova, E.V., Granovsky, Yu.V. (1975),“The
design of experiments to find optimal conditions”, Mir
Publishers, Moscow.
 Pandey P C , Shan H S, Modern Machining Processes, Tata
McGraw-Hill publishing Company Limited, New Delhi,
(1999).
 Phadke M.S, Quality Engineering Using Robust Design,
Prentice- Hall, Englewood Cliffs,NJ, (1989).

38. QUERIES