TURN-MILL PROCESS OPTIMIZATION OF A … PROCESS OPTIMIZATION OF A COMPLEX ELECTRONIC ... to be able to significantly reduce the total setup time and manufacturing cost by ... NX-7.5

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Int. J. Mech. Eng. & Rob. Res. 2014 P Anjaneya Reddy and B Subbaratnam, 2014

TURN-MILL PROCESS OPTIMIZATION OF ACOMPLEX ELECTRONIC COMPONENT

P Anjaneya Reddy1* and B Subbaratnam2

*Corresponding Author: P Anjaneya Reddy,[email protected]

Mill turning is a process applied in the milling of a curved surface while the work piece rotatesaround its center. Depending on the eccentricity of the tool, when a flat-end mill tool performs acurved trajectory perpendicular to the rotation axis of the tool, its bottom part is engaged inremoving material. This paper presents the techniques of tool path planning for the simultaneousturn-mill machining. The new turn-mill machine tools allow the parallel processing of both multi-axis milling and turning operations simultaneously. Turn-mill machine tools have been identifiedto be able to significantly reduce the total setup time and manufacturing cost by milling andturning the complex parts with a single setup. In this paper, computational geometric analysis ofa complex electronic component has been presented for turn-mill machine tool operations. Theelectronic component presented in this paper is a type of low resistance resistor that acts as asacrificial device to provide over current protection, of either the load or source circuit. Its essentialcomponent is a metal wire or strip that melts when too much current flows, which interrupts thecircuit in which it is connected. This component is complex because it has huge number ofoperations and is very difficult to manufacture in 3 and 4 axis milling machines because it requires46 tools to load at a time for manufacturing. Dimensions are also highly critical and complex. Inthis paper optimized process plan has been developed for the turn mill process of the electroniccomponent which gives high surface finish and less machining time. CAD/CAM systems havebeen implemented to develop the optimum turn mill process plan.

Keywords: Manufacturing process plan, Tool design, NX-CAD, NX-CAM, DMG 5-axis millingmachine

INTRODUCTIONThe presence of multiple spindles and livetools on a turn-mill machine allows complexparts to be machined within single setupwithout the time-consuming multiple set-ups

ISSN 2278 – 0149 www.ijmerr.comVol. 3, No. 4, October 2014

© 2014 IJMERR. All Rights Reserved

Int. J. Mech. Eng. & Rob. Res. 2014

1 M.Tech Student, Department of Mechanical Engineering, Krishna Chaitanya Institute of Technology and Sciences, Markapur, AP,India.

2 Professor, Deprtment of Mechanical Engineering, Krishna Chaitanya Institute of Technology and Sciences, Markapur, AP, India.

and transferring among different machinetools.

It is preferred to reduce the number ofsetups since setup operations are costly andaffect part precision. Turn-mill machine tools

Research Paper

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are opening new ranges of applications inmanufacturing due to their capability ofperforming milling, turning, drilling, and boringoperations within the same machine. Using theturn-mill machine tools can significantly reducethe total machining lead-time and eliminate thenon-value added multiple set-ups in machiningof complex parts.

Due to the lack of CAD/CAM support forturn-mill machine tools, there are stillshortcomings in using the turn-mill machinesin manufacturing industry. Some of theseshortcomings include:

• Few CAD/CAM systems supportingsimultaneous turn-mill machiningprocesses.

• Few tool path generation methods for thespecial turn mill machining.

• Lack of manufacturing cost analysis for turn-mill machining.

It is very difficult to manufacture a complexelectronic component in 3 and 4 axis millingmachines because it requires 46 tools to loadat a time for manufacturing. Special tools mustbe designed to manufacture such a complexpart.To achieve a high surface finish, propertool path, tooling and Fixturing has to bedefined. Dimensions are highly critical andcomplex. Iterations/experiments cannot bedone on a CNC machine, because of its highoperating cost. Developing the optimummachining process plan, this gives highsurface finish and less machining time.

COMPUTER AIDED DESIGNFinal 3D model of electronic component usingUnigraphics NX-7.5

Manufacturing process plan

• Identify suitable machine.

• Selecting suitable tools for manufacturingelectronic component component.

Figure 1: Final 3D Model

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• Selection of fixture.

• Listing down the Sequence of operationperformed on electronic componentcomponent.

• Generating tool path using NX-CAMsoftware.

• Designing tools for reducing machiningtime.

Identify Suitable MachineDMG 5-axis milling machine is used formanufacturing electronic componentcomponent. In DMG 5-axis milling machine X,Y, Z, B, C are 5 vectors, X and Y are toolmovement and Z is for table upwardsmovement, B for spindle movement, C for tablerotation.

Facing in the context of turning work involvesmoving the cutting tool at right angles to theaxis of rotation of the rotating work piece.

SPOT_DRILLING

This operation subtype allows the tool to pauseat the tool tip or shoulder depth of the tool by aspecified number of seconds or revolutions.

DRILLING

This operation subtype allows you to do basicpoint-to-point drilling.

END MILL

A milling cutter that performs a mix ofperipheral and face milling.

Figure 2: DMG 5-Axis Machine

MORI SEIKI 4-AXIS CNC turning machineis used for machining electronic component.DMG MORI SEIKI offers the industry’s bestlineup of high-performance lathes with betterprecision and rigidity, greater multi-axiscompatibility and smaller footprints.

Selecting Suitable Tools

OD_80_L facing, roughing

Figure 3: MORI SEIKI 4-Axis Machine

Figure 4: 3-Jaw Chuck

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Selection of Fixture3-jaw chucks provide the quickest and easiestway of holding work in the milling and lathemachines.

Sequence of operation

• OD_Facing operation

• OD_Rough operation

• GROOVE _OD operation

• ROUGH BORE_ID

• Planar mill operation

• Spot drilling operation

• Drilling operation

• Reamer operation

Generating Tool PathTurning Operations on ElectronicComponentMaterial of electronic component is aluminumalloys. Aluminium alloys are light weight andhigh strength material.

Below image shows ROUGH TURN_ODoperation of electronic component with 1300rpm speed and 0.24 mmpr feed

Below image shows verification of ROUGHTURN_OD operation

Milling Operations on ElectronicComponentBelow image shows planar mill operation ofelectronic component with 1400 rpm speedand 230 mmpm feed.

The Manufacturing Process ofElectronic Component on CNCMachineRaw material is placed on the machine, anddegree of freedom is arrested using fixtures.3-jaw chuck is used for arresting degree offreedom of the electronic component.

First step: Facing operation is done on theraw material.

Second step: Planar mill operation will bedone on sides of the electronic component.

Figure 5: ROUGH TURN_OD Operation

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Third step: Angular planar mill operation willbe done on electronic component.

Fourth step: Drilling operation will be doneto create holes.

Fifth step: After completing setup_1operation component is removed from fixtureand it is reversely placed in fixture for setup_2operations.

Figure 6: Verification of ROUGH TURN_OD Operation

Figure 7: Planar Mill Operation

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Sixth step: Again facing, planar milling anddrilling operations will be done on thecomponent. Finally finish operation will bedone.

Below image shows time taken formanufacturing electronic component.

DESIGN OF TOOLSTools are designed for typical operations toreduce manufacturing time and cost and to gethigh surface finish. These tools reduce numberof operations. Each designed tool can donearly four operations at a time and reducemachining time, tool change and tool setuptime as well as part cost. Tools are designedas per the dimensions required for machiningsuch operations.

Using designed tools we can go for highcutting speed and feeds. The machining timewill be reduced at high speed cutting as wellas component cost is reduced.

Tool 1Below image shows 2D input of designedtool-1

Figure 8: Time Taken for Manufacturing Electronic Component

Figure 9: 2D Input of Designed Tool-1

Below image shows final part of designedtool

Figure 10: Final Part of Designed Tool-1

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Tool 2Below image shows 2D input of designedtool-2

Below image shows final part of designedtool

Figure 11: 2D Input of Designed Tool-2Figure 12: Final Part of Designed Tool-2

Figure 13: Time Taken for Manufacturing Electronic Component Using Designed Tools

The Manufacturing Process ofElectronic Component on CNCMachine with Designed ToolsManufacturing process will be same for

machining electronic component but designedtools were used to reduce machining time andcost of the part. The time taken for manufacturingelectronic component is shown below

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RESULTS AND DISCUSSIONProduct Cost Reduction, ReductionMachining Time

Manufacturing Component on CNCMachine Using Default ToolsManufacturing component with regular toolsconsumes more time and increasesmanufacturing cost.

Time and cost calculation for manufacturingelectronic component as shown below

Manufacturing time taken by singlecomponent = 6 hrs 24 mins

Machining cost per hour for millingoperations = 1200 rs

Machining cost per hour for drillingoperations = 800 rs

Machining cost per piece for turn-milloperations (machining cost per min xmachining time in min) = 1200/60*198 min =3960 rs

Machining cost per piece for drillingoperations (machining cost per min xmachining time in min) = 800/60*186 min =2480 rs

Total machining cost per piece = turn-mill +drilling = 3960 + 2480 = 6440 rs

can be reduced and manufacturing time willbe reduced as well as part cost is reduced

Manufacturing time taken by singlecomponent= 5 hrs 6 min

Machining cost per hour for turn-milloperations = 1200 rs

Machining cost per hour for drillingoperations = 800 rs

Machining cost per piece for turn-milloperations (machining cost per min xmachining time in min) = 1200/60*198 min =3960 rs

Machining cost per piece for drillingoperations (machining cost per min xmachining time in min) = 800/60*108 min =1440 rs

Total machining cost per piece = turn-mill +drilling = 3960 + 1440 = 5400 rs

Turn-Mill 198 RS. 1200/HR RS. 3960

Drilling 186 RS. 800/HR RS. 2480

Total 384 RS. 6440

Table 1: Table of Machining Time and CostUsing Default Tools for Manufacturing

SET UPOperations

TimeRequiredin Mins.

MachiningCost per

HourMachiningCost/Piece

Manufacturing Component on CNCMachine Using Designed ToolsUsing designed tools number of operations

Turn-Mill 198 RS. 1200/HR RS. 3960

Drilling 108 RS. 800/HR RS. 1440

Total 306 RS. 5400

Table 2: Table of Machining Time and CostUsing Designed Tools for Manufacturing

SET UPOperations

TimeRequiredin Mins.

MachiningCost

MachiningCost/Piece

Figure 14: Graph of Machining Time andCost

0

10 00

20 00

30 00

40 00

50 00

60 00

70 00

manufacturingwith re gular

tools

manufacturingwith desi gned

tools

timeimmins,costinrs

TIME

COST

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Graphical representation of manufacturingtime and cost of the component.

CONCLUSIONModeling of electronic component is doneusing unigraphics software. Proper tools arespecified which will support for machiningtypical components like electroniccomponent. Manufacturing processsequence of electronic component is shownin the document. Manufacturing time is notedwhen part is manufactured with regular tools,to reduce time and cost tools are designedas per the operations. New tools aredesigned to do 4 operations at a time andreduce manufacturing cost and time.Graphical representation of Product costreduction, Reduction of manufacturing timesis shown in results. Graphical representationof Product cost reduction rate of electroniccomponent shows reduction of time as wellas cost of component when manufactured byusing designed tools which will reducemanufacturing time and cost of thecomponent. Optimization of manufacturingprocess by using designed tools to reducemanufacturing cost and time.

REFERENCES1. Degarmo, Black and Kohser (2003),

Materials and Processes inManufacturing, 9th Edition, p. 223, Wiley.

2. Mechanical Finish Designations ,Retrieved 2009-01-04.

3. Michael Mattson (2010), CNCProgramming , Delmar CengageLearning.

4. Mike Lynch (1995), Managing ComputerNumerical Control Operations, Societyof Manufacturing Engineers.

5. Peter Smid (2003), CNC ProgrammingHandbook, Industrial Press Inc.

6. Thyer G E (1988), Computer NumericalControl of Machine Tools, ProfessionalPublishing, Heinemann.

7. Tony Uccello, Derek Murphy and FrankNanfara (2002), The CNC Workshop,Prentice Hall.

8. Whitehouse D J (1994), Handbook ofSurface Metrology, Institute of PhysicsPublishing Bristol.

9. www.agapea.com/Jig-tool-Fixture-Design-n1244984i.htm

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TURN-MILL PROCESS OPTIMIZATION OF A … PROCESS OPTIMIZATION OF A COMPLEX ELECTRONIC ... to be able to significantly reduce the total setup time and manufacturing cost by ... NX-7.5