Chip Rejection in Internal

Key way

“Milling Process”GUIDED BY :

1. Mr. Nishit Dalal

N T E R N S H I PI P R O J E C T

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N T E R N S H I PI P R O J E C T

Rejection Rate for Key way Process _ Data range From January-2013 to March-2014

Month No. of Rejection % Rejection by Month

Jan-13 1 3.03030303

Feb-13 2 6.060606061

Mar-13 3 9.090909091

Apr-13 4 12.12121212

May-13 2 6.060606061

Jun-13 1 3.03030303

Jul-13 2 6.060606061

Aug-13 5 15.15151515

Sep-13 0 0

Oct-13 0 0

Nov-13 2 6.060606061

Dec-13 1 3.03030303

Jan-14 1 3.03030303

Feb-14 6 18.18181818

Mar-14 3 9.090909091

33

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N T E R N S H I PI P R O J E C T

Average Rejection Per Month

2.20

Current Performances

Target Rejection/Month

2.00

By March 20151

2

3

4

2

1

2

5

0 0

2

1 1

6

3

0

1

2

3

4

5

6

7

Reje

cti

on

Month

Month wise Rejection Data

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N T E R N S H I PI P R O J E C T

Machine wise key way Rejection

Machine Number of RejectionCumulative % Rejection

Key Seating 32 96.96969697

Broaching KS 100 1 100

32

10

5

10

15

20

25

30

35

Key Seating Broaching KS 100

Machine wise key way RejectionNeglect the Broaching KS

100 for analysis , Since it

has only one case of

Rejection

B Y : S U N A R A M T U D U

N T E R N S H I PI P R O J E C T

Reason for Rejection Frequency % of Rejection

Wrong Dimension 22 68.75

Damage 5 15.625

Surface Roughness 3 9.375

Wrong Milling slot 1 3.125

Heat Treatment 1 3.125

Rejection Data Table for Key Seating

22

5 3 1 1

68.75 %

15.625 %9.375 %

3.125% 3.125 %0

10

20

30

40

50

60

70

80

Wrong Dimension Damage Surface Roughness Wrong Milling slot Heat TreatmentReje

cti

on F

requency/%

Rejection Type

Rejection Chart

Frequency % of Rejection

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N T E R N S H I PI P R O J E C T

Rejection Type- Cause Frequency % Rejection

Wrong Dimension 22 68.75

Width + 15 46.875

Depth + 5 15.625

Taper Depth 1 3.125

Wrong axis inclination 1 3.125

Damage 5 15.625

Internal Key way wall Damage 5 15.625

Surface Roughness 3 9.375

Ra > 3.2 ,Not OK 2 6.25Key-way width measured : 0.20/0.24mm from

USL, Demand: 32 JS9(±0.031) 1 3.125

Wrong milling slot 1 3.125

Heat Treatment 1 3.125

Pivot Analysis

84.375%

Neglect These

for Analysis

Purpose

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N T E R N S H I PI P R O J E C T

S.No. Rejection Comment/s Reason

1Key way width plus

Dimension

Parallel key will be fitted on shaft and will create internal

backlash. Theoretically, it should not have any effect after that.

As bore dimension is with in designed tolerance data, this

deviation will not effect any functional activities.

2

Key-way width

Dimension

Reason for Non-Conformity

Keyway width found plus by 0.05mm from upper limit.(36JS9)

Recommended action

Already the necessary action(CAPA) has been taken by the

shift officer and operator.

Cutter with adjusted by tool room as per requirement.

3 Key-way width

Dimension

The deviation was generated due to machine vibration. The

same was already rectified with the help of maintenance.

4 Key way width

DimensionTo be used in GB KZA 225.

5 Key way width found

plus by 7mm,Key way

width required 18 JS9

,Measured 25 JS9

Job-card & drawing was not supplied/available to machine/operator along with the job during operation.8D

MD SL-KGP_8d 2014-04-03

6Key way width plus.

Used by increasing the matting pinion key-way width & key width.Re-GEN done as GR No. 5010521003 dt 20.08.13Rejection Memo cancelledRefer mail dated 21.08.13 by Mr. N. Dalal & Re mail dated 23.08.13

Width + (15)

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Width +(15)

S.No. Rejection Comment/s Reason

7 Key-way width plus by 10mm.,Specification:

22 JS9,Measured: 32 JS9

[Normal key-way made as per DIN 6885-1,

JS9]

Job-card & drawing was not supplied/available to machine/operator along with the job during operation.8D,MD SL-KGP_8d 2014-04-03

8 Key-way width plus by 10mm.Specification:

22 JS9,Measured: 32 JS9

[Normal key-way made as per DIN 6885-1,

JS9]

Job-card & drawing was not supplied/available to machine/operator along with the job during operation.8D,MD SL-KGP_8d 2014-04-03

9 Key way width plus by 0.2mm

Operator mistake

8D

IFAWS-13-07-003

10 REJECTED DUE TO KEYWAY WIDTH(+)

BY 0.08MM DURING KEYWAY ENDING

11 REJECTED DUE TO KEY WAY WIDTH (+)

BY 0.04 mm

12 Rejected due to Key Way width (+) by

0.03mm.

13 Rejected due to Key Way width (+) by

0.03mm.

14 Rejected due to internal keyway width (+) by

0.05mm.

15WRONG KEYWAY WIDTH DONE DURING

INTERNAL KEYWAY OPERATION; OBSERVED -

28, REQUIRED - 25

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Depth + ( 05 )

S.No Rejection Reason CommentsReason

1

Key-way depth

Dimension

Operator (Mr. Amal Koley was being informed

to be very much cautious while doing the

keyway operation specially for big gears.

Though the limit failed after two jobs.

2

Key-way depth

Dimension

Due to mal-functioning of limit switch key-way

depth got increased.

Limit switch has been repaired and

successive jobs are accepted without any

deviation.

3

1Pc Rejection due to keyway

depth (+) by 3.5mm.

Required : 311.9+0.3

Observed: 317.70.

8D

IFAWS-13-08-001

4

KEY WAY DEPTH + BY 1.3MM

FROM USL. SPECIFICATION

FOR KEY WAY DEPTH IS -

3.8+0.2mm, MEASURED VALUE

5.3mm

5

Dimension

Reason for Non-Conformity:

In key way milling m/c there is no scope for

adjusting the proper depth. Depth is being

purely set by the operators on the basis of

experience. - By Parts Mfg.

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Wrong Axis’s Inclination ( 01 )

S.No Rejection Reason Comments Reason

1Key-way depth taper

Dimension

Comments by Parts Mfg.

Being the old machine (Key-way setting m/c) there is

always some taper but being the higher length this taper

is more.

The machine will be replaced within 2 months.

Taper Depth ( 01 )

S.No Rejection Reason Comments Reason

1Dimension

Recommended action by Parts Mfg.:

During setting os this type so big gears at key-way seating machine

operators must be very much cautious, so that probability so axis out

does not occur.

Clamping wasn’t done

properly.

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H

Damage ( 05 )

S.No Rejection Comments Reason

1

Key way damaged during key-

way cutting.

Chilled material, some machinability related issue as reported by Parts Mfg.Hardness verified and found within the acceptable limit.Hardness verified on Other parts (finished parts) manufactured with same bar/heat batch, hardness results found almost same (acceptable). There is no issue of machinability of those parts.

2 Keyway wall damage during

keyway cutting.

3 Internal Keyway Damaged

during keyway cutting operation

4Internal Key way wall damaged.

Surface very rough & uneven,

step present on key-way wall.

5 Both side key-way wall damaged

during key-way cutting.

Key-way wall surface roughness

not acceptable.

(TR 14-01-114-3)

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Surface Roughness ( 03 )

S.No Rejection Comments Reason

1 Deviation 1:

Key-way surface roughness / surface quality

non-conforming.

Deviation 2:

Key-way width measured over size by

0.20/0.24mm from USL.

Demand: 32 JS9 (±0.031)

Measured value: 32.23/32.27mm

Note: The same was offered at 18.02.14 finished part. Defect detected at finish part inspection, rectification done but not satisfactory.Hence rejected (withdrawn the QM lot & re GRN done at location 16, scrap yard) -> Rejected

2 Key way surface roughness NOT OK.

Very rough.

Ra > 3.2 NOT OK

3 Key way surface roughness NOT OK.

Very rough.

Ra > 3.2 NOT OK

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