In order to machine this part, we use cylindrical bar steel 37 Cr 4 with diameter 12 f6 mm. The cylindrical bar steel diameter 12 f6 mm is existed in the market, so we don’t need to use cylindrical bar steel diameter 15 mm. and do finishing operation.
7.2. Phase 10:
The cylindrical bars usually come with the long length shape. To be suitable for the Lathe Machine, the bars have to be cut by Manual Disc Saw Machine. The total distance of the final shape is 85 mm., we have to add 1.5 mm. for the both end of bar to be machine in Finishing Operation. So we have to cut the bar to have the length 88 mm. with the tolerance +1, -0 mm.
The calculation of this phase can be done in the same way as Shaft1 ( by using the method of milling machine ) and the results are shown in table7.1.
Figure7.1: Operation of Phase10
Tool Data
Step d(mm) az(mm.) Zt(teeth) n(rpm) av(mm/turn) Vam(mm/min) 1 210 0.015 60 60.63 0.9 54.567
p(mm) b(mm) Fc(N) Pc(kW) Pm(kW) L(mm) tc(min) 12 2 43200 0.039 0.052 12 0.22
Table7.1: Calculation data of Phase10
7.3. Phase20:
We employ CNC Lathe Machine in this phase. We fix the raw part at one end by fixing plate with hard jaws of CNC Lathe Machine.
Step1:
We start machining the part by taking out front surface. In this operation, we employ Stellram cutting tool SNMG120408E-3G with the holder MSKNR/L-124B [2]. The tool insert SNMG120408E-3G is square shape which is suitable for
machining front surface and rough machining. The tool is Right hand tool because we fix the part with Lathe Machine on the left.
Figure7.2: Operation of Phase20 Step1
Calculation of Step1:
The calculation in this step is similar to the one of Shaft1 Phase20 Step1. The only difference is the average diameter of the shaft, in this shaft d = (12+0)/2 = 6 mm.
We can calculate by utilizing the equations 1,2,3,4,5,6 and 7 of Shaft1.
Step2:
This step is to machine finishing surface to have diameter 8 h7 mm. length 7.5 mm. at the end of part. We use Stellram tool insert DNMG150408E-3G and tool holder MDJNR/L-124B, right hand.
Figure7.3: Operation of Phase20 Step2
Calculation of Step2:
In order to calculate rotation speed (n), advance speed (a), cutting force (Fc), cutting power (Pc), machine power (Pm), cutting time (tc) and advance velocity (Va), all can be calculate by the equations 1,2,3,4,5,6 and 7. In this step, we use the average diameter to calculate the rotation speed as we have said in the calculation of phase20 step1 and we use Vc for finishing surface with carbide tool (see table1.2).
The rotation speed we obtain from calculation will be very high because of the diameter of bar is very small. We should limit the maximum rotation speed in order to protect machine from damage. In this process, we limit at 3000 rpm.
The cutting length (L) in this step is the summation of the movement of part, we find L = 7.5 mm.
Step rp(mm) d(mm) n (rpm) p(mm) Ra(mm) a(mm/turn) S(mm2) Fc(N) 1 0.031 6 3000 1.5 1.6 0.045 0.067 120
2 0.031 10 3000 2 1.6 0.045 0.089 160
Step Pc(kW) Pm (kW) L (mm) Va(mm/min) tc(min) 1 0.301 0.401 6 133.626 0.045 2 0.401 0.535 7.5 133.626 0.056
Table7.2: Calculation data of Phase20
7.4. Phase30:
We are still at CNC Lathe Machine. We fix the raw part at another end by fixing plate with soft jaws of CNC Lathe Machine.
Step1:
We take out front surface. In this operation, we employ Stellram cutting tool SNMG120408E-3G with the holder MSKNR/L-124B [2]. The tool insert SNMG120408E-3G is square shape which is suitable for machining front surface and rough machining. The tool is Right hand tool because we fix the part with Lathe Machine on the left.
Figure7.4: Operation of Phase30 Step1
Calculation of Step1:
It’s exactly the same as Phase20 step1 of this part.
Step2:
This step is to machine finishing surface to have diameter 10 h7 mm. length 20.5 mm. at the end of part. We use Stellram tool insert DNMG150408E-3G and tool holder MDJNR/L-124B, right hand.
Figure7.5: Operation of Phase30 Step2
Calculation of Step2:
In order to calculate rotation speed (n), advance speed (a), cutting force (Fc), cutting power (Pc), machine power (Pm), cutting time (tc) and advance velocity (Va), all can be calculate by the equations 1,2,3,4,5,6 and 7. In this step, we use the average diameter to calculate the rotation speed as we have said in the calculation of phase20 step1 and we use Vc for finishing surface with carbide tool (see table1.2).
The rotation speed we obtain from calculation will be very high because of the diameter of bar is very small. We should limit the maximum rotation speed in order to protect machine from damage. In this process, we limit at 3000 rpm.
The cutting length (L) in this step is the summation of the movement of part, we find L = 20.5 mm.
Step rp(mm) d(mm) n (rpm) p(mm) Ra(mm) a(mm/turn) S(mm2) Fc(N) 1 0.031 6 3000 1.5 1.6 0.045 0.067 120 2 0.031 11 3000 1 1.6 0.045 0.045 80.2
Step Pc(kW) Pm (kW) L (mm) Va(mm/min) tc(min) 1 0.301 0.401 6 133.626 0.045 2 0.2 0.267 20.5 133.626 0.153
Table7.3: Calculation data of Phase30
7.5. Phase40:
In this phase, we move to CNC Milling Machine. We fix the part by Index plate with soft jaws.
Step1:
In this step, we will drill a 120 degree hole at diameter 10 h7 mm. end. We use drill Garant 112110 , 120 degree , diameter 5 mm.
Figure7.6: Operation of Phase40 Step1
Calculation of Step1:
The calculation of this step can be done by follow the method and formula in Phase20 Step2 of Shaft1. We use the diameter 5 mm. and the depth 1 mm. The total cutting length equal to the depth.
Step2:
In this step, we will drill a 120 degree hole at diameter 8 h7 mm. end. We use drill Garant 112110 , 120 degree , diameter 5 mm.
Figure7.7: Operation of Phase40 Step2
Calculation of Step2:
The calculation of this step can be done by follow the method and formula in Phase20 Step2 of Shaft1. We use the diameter 5 mm. and the depth 1 mm. The total cutting length is equal to the depth.
Tool Data
Step d(mm) az(mm.) Zt(teeth) n(rpm) av(mm/turn) Vam(mm/min) p(mm) b(mm)
1 5 1273 0.05 63.662
2 5 1273 0.05 63.662
Step Fc(N) Pc(kW) Pm(kW) V(mm3/min) L(mm) tc(min)
1 225 0.038 0.054 1 0.016
2 225 0.038 0.054 1 0.016
Table7.4: Calculation data of Phase40
7.6. Phase50:
This phase is the heat treatment process. We will do heat treatment at the external dia 50 mm. to have the hardness 46-48 HRC ( 1mm. depth). The part will be heated by Induction heating and the time required for the process is 30 min/lot ( 1 lot contains 20 parts) or 1.5 min/part ( This operation will be done by the external company).
.