An Efficient CNC Programming Approach Based on Group Technology

TheThe common common solutionsolution forfor similarsimilar problemsproblems CSSPCSSP fea­ fea-ture ture ofof GTGT andand thethe parametricparametric programmingprogramming capabil­ capa

An Efficient Efficient CNC CNC Programming Programming Approach Approach

Based

Based on on Group Group Technology Technology

Manocher

Manocher Djassemi, Djassemi, Dept Dept of of Industrial Industrial and and Engineering Engineering Technology, Technology, Murray Murray State State University, University,

Murray,

Murray, Kentucky, Kentucky, USA USA

Abstract

Abstract

Many

Many studies studies and and reports reports support support the the significant significant impact impact of of

the

the application application of of group group technology technology on on various various aspects aspects of of

product

product design design and and manufacturing manufacturing The The fact fact that that group group tech­

tech-nology

nology is is the the common common solution solution to to similar similar problems problems is is the the main main

source

source of of such such impact impact In In this this paper, paper, one one of of the the less less frequent­

frequent-ly

ly utilized utilized features features of of GNG GNG technology technology known known as as parametric parametric

part

part programming programming is is used used to to implement implement the the common common solution solution

feature

feature of of group group technology technology in in processing processing a a set set of of similar similar

parts.

parts Using Using three three part part families, families, the the advantages advantages of of blending blending

the

the concept concept of of group group technology technology and and parametric parametric programming programming

for

for CNC CNC machining machining operations operations are are illustrated illustrated The The efficiency efficiency

improvement

improvement due due to to the the use use of of parametric parametric programming programming in in

terms

terms of of number number of of setups setups and and size size of of program program is is discussed discussed

Keywords:

Keywords: Group Group Technology, Technology, Computer Computer Numerical Numerical Control, Control,

Parametric

Parametric Part Part Programming Programming

Introduction

Introduction

Group

Group TechnologyTechnology (GT)(GT) isis aa broadbroad conceptconcept thatthat

uses

uses conunonconunon attributesattributes toto reducereduce redundantredundant workwork inin

design

design andand manufacturingmanufacturing andand resultsresults inin shortershorter

product

product developmentdevelopment andand productionproduction time.time ThisThis GTGT

feature-shorter

feature-shorter productproduct developmentdevelopment andand produc­

produc-tion

tion time-providestime-provides aa significantsignificant advantageadvantage forfor man­

man-ufacturers

ufacturers byby enablingenabling themthem toto respondrespond fasterfaster toto mar­

mar-ket

ket demand/changesdemand/changes andand runrun productionproduction moremore eco­

eco-nomically

nomically inin today'stoday's highlyhighly competitivecompetitive manufactur­

manufactur-ing

ing environment.environment

A

A significantsignificant amountamount ofof researchresearch andand casecase studiesstudies

in

in groupgroup technologytechnology showsshows thatthat GTGT improvesimproves produc­

produc-tivity

tivity inin oneone oror moremore aspects.aspects.II ,2,2 TheThe applicationapplication ofof GTGT

covers

covers areasareas asas diversediverse asas design,design, processprocess planning,planning,

tooling,

tooling, scheduling,scheduling, partpart programming,programming, andand materialmaterial

handling

handling InIn allall cases,cases, GTGT isis usedused toto findfind aa commoncommon

solution

solution toto aa setset ofof similarsimilar problems,problems, thatthat is,is, design­

design-ing

ing similarsimilar productsproducts oror processingprocessing similarsimilar parts.parts

Likewise,

Likewise, OTOT isis usedused toto classifyclassify partpart designs,designs, allow­

allow-ing

ing thethe efficientefficient groupinggrouping ofof similarsimilar designsdesigns thatthat cancan

be

be manufacturedmanufactured onon thethe samesame machinemachine oror machinemachine

cell

cell First,First, thethe approachapproach avoidsavoids duplicationduplication ofof datadata inin

reduc­

aa database;database; andand second,second, itit resultsresults inin significantsignificant

reduc-tion tion inin bothboth numbernumber andand varietyvariety ofof CADCAD files,files, processprocess plans,

plans, andand NCNC partpart programs.programs ManyMany companiescompanies inin thethe US

US andand EuropeEurope havehave adoptedadopted OTOT forfor standardizationstandardization of

of designdesign andand productionproduction techniques?techniques?

This This studystudy isis focusedfocused onon thethe implementationimplementation ofof thethe GT

GT conceptconcept toto aa specificspecific aspectaspect ofof computer-aidedcomputer-aided manufacturing,

manufacturing, thatthat is,is, numericalnumerical controlcontrol (NC)(NC) pro­ pro-gramming

gramming ofof machiningmachining andand turningturning centers.centers TheThe common

common solutionsolution forfor similarsimilar problemsproblems (CSSP)(CSSP) fea­ fea-ture

ture ofof GTGT andand thethe parametricparametric programmingprogramming capabil­ capabil-ity

ity ofof computercomputer numericalnumerical controlcontrol (CNC)(CNC) machinesmachines will

will bebe usedused toto developdevelop aa singlesingle NCNC programprogram forfor eacheach part

part family.family ForFor CNCCNC machinemachine users,users, thethe combina­ combina-tion

tion ofof CSSPCSSP andand parametricparametric programmingprogramming approaches

approaches isis expectedexpected toto createcreate thethe opportunityopportunity toto generate

generate NCNC codescodes andand operateoperate CNCCNC machinesmachines withwith greater

greater efficiency.efficiency CNCCNC machiningmachining oror turningturning centerscenters lend

lend themselvesthemselves toto thethe CSSPCSSP conceptconcept inin twotwo ways:ways: common

common toolingtooling andand commoncommon programmingprogramming forfor aa family

family ofof parts.parts WhenWhen aa familyfamily ofof partsparts isis processedprocessed on

on thesethese machines,machines, tooltool indexingindexing andand loading/unloading

loading/unloading areare performedperformed lessless frequentlyfrequently because

because mostmost partsparts cancan bebe machinedmachined byby aa setset ofof common

common tools.tools Similarly,Similarly, thethe parametricparametric program­ program-ming

ming featurefeature ofof modernmodern CNCCNC machinesmachines allowsallows aa common

common programprogram toto bebe usedused forfor machiningmachining aa numbernumber of

of similarsimilar parts.parts

Considering Considering thethe potentialpotential benefitsbenefits ofof suchsuch anan application

application forfor groupgroup technologytechnology andand CNCCNC machinemachine users,

users, aa studystudy toto link link thethe parametricparametric programmingprogramming technique

technique toto OTOT systemsystem isis appropriate.appropriate UsingUsing threethree examples,

examples, thethe efficiencyefficiency improvementimprovement duedue toto thethe joint

joint applicationapplication ofof thethe twotwo technologiestechnologies isis discusseddiscussed in

in thethe followingfollowing sections.sections

Parametric Parametric Part Part Programming Programming

Traditionally, Traditionally, separateseparate partpart programsprograms areare writtenwritten forfor individual

individual partsparts withinwithin aa partpart family;family; thenthen thethe pro­ pro-grams

grams areare loadedloaded toto thethe machinemachine controllercontroller oneone byby one.one

Most CNCCNC machinesmachines havehave aa specialspecial featurefeature knownknown

as

as parametricparametric programming,programming, alsoalso referredreferred toto asas

macro,4

macro,4 inin whichwhich aa partpart programprogram cancan bebe writtenwritten usingusing

variables

variables andand parametricparametric expressionsexpressions toto representrepresent thethe

machine

machine axisaxis positionposition (x, (x, y, y, z, z, a, a, etc.),etc.), feed,feed, andand speedspeed

functions

functions.ss SimilarSimilar toto computercomputer programmingprogramming lan­

lan-guages

guages suchsuch asas PascalPascal oror C,C, computer-relatedcomputer-related featuresfeatures

such

such asas variables,variables, arithmetic,arithmetic, logiclogic statements,statements, andand

looping

looping cancan bebe implementedimplemented inin aa parametricparametric program.program

This

This programmingprogramming featurefeature allowsallows thethe useruser toto loadload aa

single

single partpart programprogram forfor aa familyfamily ofof partsparts toto thethe CNCCNC

controller

controller TheThe partpart programprogram isis thenthen calledcalled upup forfor

machining

machining aa similarsimilar partpart oror similarsimilar featurefeature onon differ­

differ-ent

ent parts.parts TheThe processprocess involvesinvolves aa simplesimple entryentry ofof para­

para-meter

meter valuesvalues intointo thethe machinemachine controller.controller ForFor example,example,

several

several cylindricalcylindrical partsparts maymay havehave twotwo commoncommon para­

para-meters,

meters, suchsuch asas diameterdiameter andand overalloverall length.length AA singlesingle

parametric

parametric partpart programprogram cancan bebe calledcalled upup fi'omfi'om aa mainmain

program

program forfor machiningmachining suchsuch aa groupgroup ofof similarsimilar parts.parts

Upon

Upon loadingloading thethe mainmain program,program, thethe valuesvalues ofof thethe twotwo

parameters

parameters areare entered;entered; thenthen thesethese valuesvalues areare trans­

trans-ferred

ferred toto parametricparametric subprograms.subprograms ThisThis approachapproach

could

could minimizeminimize thethe numbernumber ofof programprogram changeovers,changeovers,

reduce

reduce thethe redundantredundant codescodes inin thethe partpart program,program, andand

shorten

shorten thethe lengthlength ofof thethe program.program

Methodology

Methodology

In

In thisthis study,study, threethree partpart familiesfamilies areare consideredconsidered toto

investigate

investigate thethe effectseffects ofof blendingblending CSSPCSSP andand para­

para-metric

metric programmingprogramming inin improvingimproving thethe efficiencyefficiency ofof

CNC

CNC operations.operations TheThe efficiencyefficiency improvementimprovement isis

determined

determined basedbased onon twotwo factors:factors: (a)(a) numbernumber ofof pro­

pro-gram

gram changeoverschangeovers andand (b)(b) numbernumber ofof NCNC filesfiles andand

size

size ofof partpart program.program AsAs thethe numbernumber ofof partpart typestypes

within

within aa partpart familyfamily increases,increases, thethe numbernumber ofof programprogram

changeovers

changeovers oror setupssetups isis expectedexpected toto increase.increase TheThe

number

number ofof NCNC filesfiles andand thethe sizesize ofof thethe partpart programprogram

can

can havehave aa significantsignificant effecteffect onon filefile managementmanagement andand

memory

memory spacespace whenwhen thethe numbernumber ofof partpart typestypes withinwithin

aa partpart familyfamily isis relativelyrelatively high.high BasedBased onon thethe afore­

afore-mentioned

mentioned factors,factors, anan efficiencyefficiency improvementimprovement (EI)(EI)

measure

measure isis defineddefined asas follows:follows:

n-l

n-l (I~INln)-P

n

n (1:,;' (1:,;' NJn) NJn)

where

where

n� isis thethe partpart familyfamily sizesize

n

N i�i isis thethe numbernumber ofof NCNC instructionsinstructions (lines)(lines) inin thethe conventional

conventional NCNC programprogram forfor aa partpart typetype ii inin thethe family

family

P

P isis thethe numbernumber ofof NCNC instructionsinstructions (lines)(lines) inin thethe parametric

parametric programprogram forfor thethe samesame partpart familyfamily

Wisis thethe weightweight factorfactor The

The methodologymethodology consistsconsists ofof thethe followingfollowing steps:steps:

Step Step 1.1 DevelopDevelop CADCAD filesfiles forfor thethe threethree partpart

families

families

Step Step 2.2 GenerateGenerate NCNC codescodes usingusing CAD/CAMCAD/CAM soft­

soft-ware6 6 forfor thethe parts'parts' CADCAD files.files

Step Step 3.3 WriteWrite aa singlesingle parametricparametric programprogram forfor eacheach

part part family.7family.7

Step Step 4.4 CompareCompare thethe twotwo typestypes ofof partpart programsprograms

developed developed inin stepssteps 22 andand 33 usingusing thethe EIEI measure

measure

The The weightweight factor,factor, W, W, isis empiricallyempirically determineddetermined using

using aa BridgeportBridgeport CNCCNC millmill andand aa PC.PC ItIt waswas observed

observed thatthat thethe ratioratio betweenbetween thethe timestimes toto changechange programs,

programs, includingincluding clearingclearing thethe controlcontrol memory,memory, and

and locatinglocating aa programprogram toto programprogram downloadingdownloading timetime from

from aa PCPC toto CNCCNC isis roughlyroughly 4:14:1 (W (W ==== 80%).80%) ThisThis indicates

indicates thatthat forfor thethe casescases studiedstudied here,here, thethe effecteffect ofof program

program lengthlength onon EIEI isis notnot asas significantsignificant asas thethe effect

effect ofof machinemachine stoppagestoppage forfor programprogram changingchanging (see

(see Table Table 1) 1)

Analysis Analysis of of Results Results

Part Part familyfamily II consistedconsisted ofof fivefive partsparts (n (n == == 5),5), asas illustrated

illustrated inin Figure Figure 1.1 AA singlesingle parametricparametric partpart pro­ pro-gram

gram forfor machiningmachining thisthis partpart familyfamily isis shownshown inin thethe Appendix

Appendix

The The numbersnumbers ofof instructionsinstructions inin conventionalconventional NCNC programs

programs forfor individualindividual partpart typestypes werewere 66,66, 37,37, 132,132,

104,

104, andand 132.132 TheThe numbernumber ofof executableexecutable NCNC instruc­ instruc-tions

tions inin thethe correspondingcorresponding parametricparametric programprogram waswas

45

45 lines.lines TheThe overalloverall EIEI duedue toto applicationapplication ofof para-

para-Table Table 1 1

Program Program Changeover Changeover and and Downloading Downloading Times Times (seconds) (seconds)

Part Part Family Family II

Changeover

Downloading

ParI ParI Family Family II Part Part Family Family III III

Part Part familyfamily IIII consistedconsisted ofof fourfour partsparts (Figure (Figure 2) 2)

The The numbernumber ofof NCNC instructionsinstructions forfor individualindividual partpart types

types werewere 27,27, 53,53, 8,8, andand 3434 lineslines forfor thisthis group.group TheThe number

number ofNCofNC instructionsinstructions inin thethe correspondingcorresponding para­ para-metric

metric programprogram waswas 2525 lineslines (see(see thethe Appendix).Appendix) TheThe use

use ofof parametricparametric programmingprogramming resultedresulted inin aa 64%64% improvement

improvement inin programmingprogramming efficiency.efficiency WhenWhen aa larger

larger numbernumber ofof similarsimilar partsparts (n (n = = 15)15) werewere includedincluded by

by changingchanging thethe valuevalue ofof thethe parameters,parameters, includingincluding external

external radius,radius, thickness,thickness, diameterdiameter ofof centercenter pocket,pocket, and

and numbernumber ofof holes,holes, thenthen thethe EIEI improvedimproved fromfrom 64%64% to

to 78%.78%

Figure Figure 2 2 PartPart familyfamily IIIIII consistedconsisted ofof fourfour partsparts (Figure (Figure 3) 3).

Part Part Family Family II II

The The numbernumber ofof NCNC instructionsinstructions inin thethe conventionalconventional part

part programprogram remainedremained atat 5353 forfor allall partpart types.types TheThe metric

metric programmingprogramming waswas 74%.74% However,However, ifif thethe num­num- numbernumber ofof NCNC instructionsinstructions inin thethe correspondingcorresponding para­ para-ber

ber ofofpartpart typestypes inin thethe partpart familyfamily growsgrows andand thethe newnew metricmetric programprogram waswas 2525 lines.lines TheThe useuse ofof parametricparametric part

part membersmembers areare differentdifferent fromfrom thethe oldold onesones onlyonly inin programmingprogramming resultedresulted inin aa 64%64% improvementimprovement inin pro­ pro-terms

terms ofof valuesvalues ofof specifiedspecified parametersparameters inin thethe pro­pro- gramminggramming efficiencyefficiency forfor thisthis partpart family.family ByBy changingchanging gram,

gram, suchsuch asas diameterdiameter andand overalloverall length,length, thenthen EIEI thethe valuevalue ofof fourfour parameters,parameters, includingincluding length,length, width,width, yields

yields greatergreater efficiencyefficiency inin programmingprogramming thethe CNCCNC thickness,thickness, andand numbernumber ofof slots,slots, additionaladditional partsparts maymay bebe machine

machine ForFor example,example, forfor 1515 partpart typestypes (n (n ;=: ;=: 15)15) thethe includedincluded inin thisthis group.group IncreasingIncreasing thethe numbernumber ofof partpart EI

EI increasesincreases fromfrom 75%75% toto 85%.85% typestypes toto 1515 improvedimproved thethe EIEI fi:omfi:om 64%64% toto 85%.85%

Table Table 2 2 Summary

Summary of of Numerical Numerical Results Results No.

No of of Avg Avg No No of of No No of of Efficiency Efficiency Efficiency Efficiency Part

Part Instruction Instruction Instruction Instruction in in Improvement Improvement Improvement Improvement No.

No of of Types Types No No of of Lines Lines per per Parametric Parametric (EI) (EI) (EI) (EI)

Part

Part Program Program (n) (n) Part Part Program Program Part Part Family Family Program Program n=5 n=5 n=15* n=15*

II

III

*The

*The number number of of part part types types in in each each family family increased increased by by 15 15 by by changing changing the the value value of of parameters parameters

Table 22 summarizessummarizes thethe comparisoncomparison resultsresults ofof thethe

two

two methodsmethods ofNCofNC programmingprogramming appliedapplied toto thethe threethree

part

part familiesfamilies underunder study.study

Conclusion

Conclusion

The

The resultsresults ofof thisthis studystudy supportsupport thethe findingsfindings ofof

many

many otherother reportsreports andand studiesstudies regardingregarding thethe effectseffects

of

of adoptingadopting groupgroup technologytechnology inin improvingimproving thethe effi­

effi-ciency

ciency ofof manufacturingmanufacturing operations.operations TheThe parametricparametric

programming

programming approachapproach waswas usedused asas aa meansmeans toto

implement

implement thethe commoncommon solutionsolution forfor similarsimilar problemsproblems

(CSSP)

(CSSP) featurefeature ofof groupgroup technologytechnology inin CNCCNC machin­

machin-ing

ing operationsoperations wherewhere therethere areare somesome similaritiessimilarities

among

among thethe parts.parts TheThe numericalnumerical resultsresults showedshowed anan

improvement

improvement inin efficiencyefficiency ofof NCNC programmingprogramming afterafter

applying

applying thethe parametricparametric programmingprogramming approachapproach toto

three

three partpart families.families SuchSuch improvementimprovement isis moremore signif­

signif-icant

icant whenwhen thethe numbernumber ofof partpart typestypes 'within'within aa partpart

family

family isis relativelyrelatively high.high ItIt isis recommendedrecommended thatthat GTGT

users

users adoptadopt parametricparametric programmingprogramming forfor largelarge partpart

families

families oror wheneverwhenever therethere isis aa growinggrowing trendtrend inin thethe

size

size ofof thethe partpart familyfamily toto minimizeminimize programprogram

changeovers

changeovers andand thethe numbernumber ofof similarsimilar NCNC files.files AA

threshold

threshold valuevalue forfor partpart familyfamily sizesize cancan bebe deter­

deter-mined

mined basedbased onon aa cost-benefitcost-benefit analysisanalysis consideringconsidering

the

the timetime forfor programprogram changeoverchangeover andand thethe timetime toto writewrite

the

the NCNC programprogram inin conventionalconventional andand parametricparametric fash­

fash-ions

ions

In

In today'stoday's competitivecompetitive economy,economy, manufacturingmanufacturing

companies

companies havehave nono alternativealternative otherother thanthan takingtaking

advantage

advantage ofof thethe newnew technologiestechnologies inin improvingimproving thethe

efficiency

efficiency ofof theirtheir operation.operation ParametricParametric program­

program-ming

ming asas thethe best-keptbest-kept secretsecret ofof modernmodern CNCCNC

machines5 5 isis alreadyalready atat thethe machinemachine tooltool users'users' dis­

dis-posal

posal SurveysSurveys onon successfulsuccessful applicationsapplications ofof paraparamet­

met-ric

ric partpart programmingprogramming inin groupgroup technologytechnology facilitiesfacilities

would

would bebe anan appropriateappropriate extensionextension toto thisthis study.study

AppendiX

AppendiX

Parametric

Parametric PartPart ProgramsPrograms

0001

G20

G20

GO

GO TOlOlT0101

G97

G97 SlS00SlS00 M3M3

G96

G96 S1200S1200

(CHECK

(CHECK RIGHTRIGHT SHOULDER)SHOULDER)

(PI0 (PI0 EXTERNALEXTERNAL DIAMETERDIAMETER OFOF BAR)BAR) (P11

(P11 LENGTHLENGTH OFOF RIGHTRIGHT SHOULDER)SHOULDER) (P13

(P13 SHOULDERSHOULDER DIAMETER)DIAMETER) IF

IF PP1111 =0=0 GOTOGOTO N3N3 GO

GO X[PI0]+.1X[PI0]+.1 Z.1Z.1 (MACHINING(MACHINING RIGHTRIGHT SHOULDER)

SHOULDER) G71

G71 PIPI Q2Q2 1010 KOKO RORO D.05D.OS

N1 N1 GO

GO XX [P13][P13]

G1 G1 ZOZO Z

Z [-Pll][-Pll]

X

X [P10][P10]

N2 N2

o

o

N3 N3 (CHECK(CHECK THETHE THREAD) THREAD)�

(P12 (P12 ## OFOF PASSES) PASSES)�

(P13 (P13 MAJORMAJOR DIAMETER) DIAMETER)�

(P14 (P14 ## OFOF THREADS/INCH) THREADS/INCH)�

(PIS (PIS LENGTHLENGTH OFOF THREAD)THREAD) IF

IF P12=0P12=0 GOTOGOTO N4N4 GO

GO T0202T0202 (MACHINING(MACHINING THETHE UNCUNC THREAD,THREAD, H=.6495P)

H=.6495P) GO

GO Z.5Z.S

P6=0 P6=0 WHILE WHILE P6P6 LTLT [P12][P12]

P6=P6+1 P6=P6+1 GO

GO X[P13-[P6*[[.6495/P14]/P12]]]X[P13-[P6*[[.6495/P14]/P12]]]

Z[-P15] EOOSEOOS G32

G32 Z[-P1S]

GO

GO X[P13]X[P13]

GO

GO Z.lZ.l WEND N4 N4 (CHECK(CHECK LEFTLEFT SHOULDER)SHOULDER) (P16

(P16 DISTANCEDISTANCE FROMFROM RIGHTRIGHT FACEFACE TO)TO) (SHOULDER)

(P17 (P17 OVERALLOVERALL LENGTHLENGTH OFOF PART)PART) (P18 DIAMETERDIAMETER OFOF LEFTLEFT SHOULDER)SHOULDER) (PIS

N3 N3 IFIF P16=P17P16=P17 GOTOGOTO N10N10 GO

GO T0303T0303 (MACHTI"fING(MACHTI"fING LEFTLEFT SHOULDER)SHOULDER) GO

GO X[PlO]X[PlO]

Z[-P16]

G71 G71 P5 Q6PS Q6 1010 KOKO RORO D.OS

N5 GO

GO X[P18]X[P18]

G1 G1 Z[-P16]Z[-P16]

Z[-P17]

X[P18]

N6 N10 GO

GO T0404T0404 (CUTOFF(CUTOFF THETHE PART)PART) GO

GO X[P10]+.1X[P10]+.1

Z[-PI7]

Gl

Gl XOXO

Gl

Gl X[PlO]+lX[PlO]+l

M5

M5

M30

M30

0002

0002 (PART (PART FAMILY FAMILY II) II)

HOLES)�

(PlO

(PlO ## OFOF HOLES)

CIRCLE)�

(Pll

(Pll RADIUSRADIUS OFOF HOLEHOLE CIRCLE)

DIAMETER)�

(P12

(P12 EXTERNALEXTERNAL DIAMETER)

PART)�

(P13

(P13 THICHNESSTHICHNESS OFOF PART)

INCREMENT)�

(PI4

(PI4 ZZ INCREMENT)

(PISO

(PISO CENTERCENTER POCKETPOCKET RADIUS) RADIUS)�

(P

(P 155155 CUTCUT WIDTH) WIDTH)�

YO�

G92

G92 X[PX[P 11]11] YO

S

S10001000 M03M03 DD 11 (EXTERNAL(EXTERNAL CONTOUR) CONTOUR)�

M06

M06 TOITOI G43G43 HI�HI

GO

GO 20�20

GO

GO X[-PI2]X[-PI2] YO�YO

FIS�

G

G11 2[2[-P13]-P13] FIS

G02

G02 X[P12]X[P12] YOYO R[PI2]R[PI2] F80�F80

X[-PI2]�

X[-PI2]

GO

GO 2.1�2.1

GO

GO XOXO YOYO (CENTER(CENTER POCKET) POCKET)�

F20�

F20

G24

G24 Z[-P13]Z[-P13] Q[PI4]Q[PI4] FlO�FlO

M06

M06 T02T02 (BOLT(BOLT HOLEHOLE PATTERN) PATTERN)�

GO

GO X[PIl]X[PIl] YO�YO

G8l

G8l Z[-P13]Z[-P13] R.lR.l F20�F20

GO

GO AAOAAO ABOABO R[Pll]�R[Pll]

AB[360/PlO]�

AAO

AAO AB[360/PlO]

P6=O�

P6=O

[[PIO]-I]�

WHILE

WHILE P6P6 LTLT [[PIO]-I]

P6=P6+1�

P6=P6+1

AA[[360/[PlO]]*P6]�

GO

GO AA[[360/[PlO]]*P6]

AB[[360/[PlO]]*[P6+1]]

AB[[360/[PlO]]*[P6+1]] R[Pll]R[Pll] F20F20

WEND

WEND

MOS

MOS

M30

M30

0003

0003 (PART (PART FAMILY FAMILY III) III)

(PlO

(PlO ## OFOF SLOTS)SLOTS)

(PU

(PU THICKNESSTHICKNESS OFOF PART)PART)

(P12

(P12 LENGTHLENGTH OFOF PART)PART)

(P13

(P13 WIDTHWIDTH OFOF PART)PART)

(P14

(P14 ## OFOF PASSESPASSES ININ Z)Z)

(PIS (PIS DEPTHDEPTH OFOF SLOTS) SLOTS)�

G54�

TOI TOI M6�M6 M3�

SlOOO SlOOO M3 GO

GO XOXO YOYO ZO�ZO P6==0�

P6==0 WHILE WHILE P6P6 LTLT [P14]�[P14]

P6==P6+1�

P6==P6+1 Gl

Gl Z[-[PlllP14]*P6]Z[-[PlllP14]*P6] F5�F5 Y[P13]

Y[P13] FSO� FSO

P7=0�

WHILE WHILE P7P7 LTLT [[PlO]]�[[PlO]]

P7==P7+1�

P7==P7+1

*P7]�

G

G 11 X[[PX[[P l2/[[Pl2/[[P 110]+0]+ 1]]1]] *P7]

091�

091 Y[-P15]�

Y[-P15]

Y[PlS]�

Y[PlS]

090�

090 WEND�

WEND X[P12]�

X[P12]

YO�

YO XO�

GO

GO Z.l�Z.l WEND�

WEND M30�

M30

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Author's Author's Biography Biography

Manochcr Manochcr Djassemi Djassemi received received aa BSlE BSlE from from the the University University of of Science Science and and Technology

Technology in in Tehran, Tehran, Iran, Iran, and and an an MS MS and and PhD PhD from from the the University University of of Wisconsin-Milwaukee.

Wisconsin-Milwaukee He He is is an an assistant assistant professor professor in in the the Dept Dept ofIndustrial ofIndustrial and

and Engineering Engineering Technology Technology at at Murray Murray State State University University He He has has also also taught taught in

in the the industrial industrial studies studies department department at at the the University University of of Wisconsin­ Wisconsin-Platteville.

Platteville Dr Dr Djassemi Djassemi has has five five years years of of industrial industrial experience experience and and is is aa cer­ cer-tified

tified manufacturing manufacturing engineer engineer His His primary primary areas areas of of teaching teaching and and research research are

are conventional conventional and and CNC CNC machine machine tools, tools, robotics, robotics, CAD/CAM, CAD/CAM, group group tech­ tech-nology,

nology, and and cellular cellular manufacturing manufacturing