002-cnc machine tools+programming

8/6/2019 002-CNC Machine Tools+Programming

1/136


2/136

20042004 22

AUTOMATION IN MANUFACTURING AUTOMATION IN MANUFACTURINGSYSTEMSSYSTEMS

TRENDS IN INDUSTRY TRENDS IN INDUSTRY THE OBJECTIVE:THE OBJECTIVE:

TO BE COMPETITIV TO BE COMPETITIV THROUGH THROUGH INCREASING PRODUCTIVITY AND TOTALINCREASING PRODUCTIVITY AND TOTAL

QUALITY ASSURANCE QUALITY ASSURANCE

JURUSAN TEKNIK MESIN dan INDUSTRIJURUSAN TEKNIK MESIN dan INDUSTRIFT FT -- UGMUGM


3/136

20042004 33

EFFICIENCY OF EFFICIENCY OF MANUFACTURING MANUFACTURING

COST = COST OF MANUFACTURING ANDCOST OF MATERIAL

HANDLING

PROFIT = INCOME - COST

PRODUCTIVITY = AVERAGE OUTPUT PER MAN-HOUR



4/136

20042004 44

PROFITPROFIT increases as increases as COSTCOST decreases decreases

an d as an d as PRODU CTIVITYPRODU CTIVITY increases.increases.

PRODUCTIVITY throug hPRODUCTIVITY throug h AU AUTOMATIONTOMATION



5/136

20042004 55

AUTOMATION AUTOMATION

any means of helping theworkers to perform their

tasks more efficiently

transfer of the skill ofthe operator to themachine



6/136

20042004 66

Transferred skill Results

muscle power engine driven machinetools First industrial

revolution

manipulating skill mechanization hard automation

vision skill use of positiontransducers,

cameras

increase of accuracy, part

recognition

brain power cnc machines, industrial robots, soft automation,

computer control of manufacturing systems

second industrial revolution



7/136


8/136

20042004 88

The me t al cu tt ing opera t ions The me t al cu tt ing opera t ions ( also ( also

called mac hining) called mac hining) is one of the mos t is one of the mos t impor t an t manufac t uring processes in impor t an t manufac t uring processes in indus t ry t oda yindus t ry t oda y ( as it w as yes t erda y ) ( as it w as yes t erda y ). .



9/136

20042004 99

MACHINING MACHINING Is The Removal Of Is The Removal Of

Materials In Forms Of Chips From TheMaterials In Forms Of Chips From TheWorkpiece By Shearing With A SharpWorkpiece By Shearing With A Sharp

Tool.Tool.



10/136

20042004 1010

The main func t ion of a mac hine t ool is The main func t ion of a mac hine t ool is t o con t rol the w orkpiecet o con t rol the w orkpiece--cu tt ing t ool cu tt ing t ool

posi t ional rela t ions hip in suc h a w ay as posi t ional rela t ions hip in suc h a w ay as t o achieve a desire d geome t ric shape t o achieve a desire d geome t ric shape

of the w orkpiece w ith sufficien t of the w orkpiece w ith sufficien t dimensional accurac y.dimensional accurac y.



11/136

20042004 1111

Machine tool provides :

work holding

tool holdingrelative motion between tooland workpiece

primary motionsecondary motion



12/136

20042004 1212

Primary motion

Relative motion

between tool and workpiece Secon dary mo t ion

Cutting motion

Cutting speed

Feed motion

Feed rate



13/136

20042004 1313

machine control unitposition transducers

work holding device

tool holding device



14/136

20042004 1414

CLASSIFICATION OF THECLASSIFICATION OF THECHIP REMOVINGCHIP REMOVING

METHODS ACCORDING TOMETHODS ACCORDING TOTHE RELATIVE MOTIONTHE RELATIVE MOTION



15/136

20042004 1515

CLASSIFICATION OF MACHINE TOOLSCLASSIFICATION OF MACHINE TOOLS

THOSE USING

SINGLE POINTTOOLS

THOSE USING

MULTIPOINTTOOLS

THOSE USING

ABRASIVETOOLS

lathesshapers

planersboring m/cs

etc.

drilling m/csmilling m/cs

broaching m/cshobbing m/cs

etc.

grinding m/cshoning m/cs

etc.



16/136

20042004 1616

ISO MACHINEISO MACHINETOOL AXISTOOL AXIS

DEFINITIONDEFINITION



17/136

20042004 1717

ISO MACH INE T OOL AX ES

D EFINI T IONS

AXIS MACHINE TOOL WITH SPINDLE MACHINE TOOL WITH NO SPINDLE

Z

axis of spindle,(+Z) as tool goes away from the work piece

perpendicular to workholding surface, (+Z) astool goes away from theworkpiece

MACHINE

TOOL WITH ROTATING WORKPIECE

MACHINE TOOL WITH ROTATING TOOL

HORIZONTAL AXIS

VERTICAL AXIS

X

radial andparallel tocross slide,(+X) when toolgoes awayfrom the axisof spindle

horizontal andparallel to workholdingsurface, (+X)to the rightwhen viewedfrom spindletowards workpiece

horizontal andparallel to thework holdingsurface, (+X)to the rightwhen viewedfrom spindletowardscolumn

parallel to and positivein the principal directionof cutting (primarymotion)

Y apply right hand rules



18/136

20042004 1818

RIGHT HAND RULERIGHT HAND RULE Ver t ical Machine Horizon t al Ver t ical Machine Horizon t al MachineMachine



19/136

20042004 1919

STANDARD LATHE COORDINATE STANDARD LATHE COORDINATE SYSTEMSYSTEM



20/136

20042004 2020

STANDARD MILLING MACHINESTANDARD MILLING MACHINECOORDINATE SYSTEMCOORDINATE SYSTEM



21/136

20042004 2121

N UMERI CALL Y CON TRO LLED M ACH I N E N UMERI CALL Y CON TRO LLED M ACH I N E TOO LS :TOO LS :

An NC mac hine t ool is func t ionally th e same as An NC mac hine t ool is func t ionally th e same as a conven t ional mac hine t ool. The t echnological a conven t ional mac hine t ool. The t echnological

capa bilit ies NC mac hine t ools in t erms of capa bilit ies NC mac hine t ools in t erms of mac hining are no differen t from those of mac hining are no differen t from those of

conven t ional ones. The difference is in the w ayconven t ional ones. The difference is in the w ayin which th e various mac hine func t ions an din which th e various mac hine func t ions an dslide movemen t s are con t rolled.slide movemen t s are con t rolled.



22/136

20042004 2222

The func t ions an d mo t ions suc h as ;The func t ions an d mo t ions suc h as ;

t urning the spin dl e on an d off t urning the spin dl e on an d off se tt ing cu tt ing spee dsse tt ing cu tt ing spee dsse tt ing fee d r a t ese tt ing fee d r a t et ur ning coo l an t on an d off t ur ning coo l an t on an d off

moving t oo l w ith r espec t t o w orkp iecemoving t oo l w ith r es p ec t t o w orkp iecear e p er for me d by Machine Con tr ol Unit (MCU)ar e p er for me d by Machine Con tr ol Unit (MCU)in NC mac hine t oo l s.in NC mac hine t oo l s.



23/136

20042004 2323

INTRODUCTION TO CNCINTRODUCTION TO CNC


24/136

20042004 2424

HISTORYHISTORYUS Air Force commissioned MIT to develop the firstUS Air Force commissioned MIT to develop the first

"numerically controlled" machine in 1949. It was"numerically controlled" machine in 1949. It wasdemonstrated in 1952.demonstrated in 1952.

At 1970 At 1970- -1972 first Computer Numeric Control machines1972 first Computer Numeric Control machineswere developed.were developed.

Today, computer numerical control (CNC) machines areToday, computer numerical control (CNC) machines arefound almost everywhere, from small job shops in ruralfound almost everywhere, from small job shops in ruralcommunities to companies in large urban areas.communities to companies in large urban areas.



25/136

20042004 2525

D EFINITIOND EFINITION

InIn CNCCNC ((Computer Numerical ControlComputer Numerical Control), ), thetheinstructions are stored as a program in a microinstructions are stored as a program in a micro- -computer attached to the machine. The computer computer attached to the machine. The computer will also handle much of the control logic of thewill also handle much of the control logic of themachine, making it more adaptable than earlier machine, making it more adaptable than earlier hardhard--wired controllers.wired controllers.



26/136

20042004 2626

CNC APPLICATIONSCNC APPLICATIONSMachiningMachining

-- 2.5D / 3D2.5D / 3D

-- Turning ~ Lathes, Turning CentreTurning ~ Lathes, Turning Centre-- Milling ~ Machining CentresMilling ~ Machining Centres

FormingForming

-- 2D2D-- Plasma and Laser CuttingPlasma and Laser Cutting-- Blanking, nibbling and punchingBlanking, nibbling and punching-- 3D3D-- Rapid PrototypingRapid Prototyping



27/136

20042004 2727

SAMPLESAMPLECNC MACHINESCNC MACHINES


28/136

CNC TURNINGCNC TURNING



29/136

CNC MILLINGCNC MILLING



30/136


31/136

20042004 3131

CNCPLASMA CUTTINGCNCPLASMA CUTTING



32/136

20042004 3232

CNCPRESSCNCPRESS



33/136

20042004 3333

CNC RAPID PROTOTY PINGCNC RAPID PROTOTY PING



34/136

20042004 3434

INDUSTRIES MOST AFFECTED byINDUSTRIES MOST AFFECTED byCNCCNC

Aerospace Aerospace Machiner yMachiner yElect rical Elect rical Fabrica t ion Fabrica t ion

Aut omo t ive Aut omo t ive Ins t rumen t a t ion Ins t rumen t a t ion Mold making Mold making



35/136

20042004 3535

SAMPLEPRODUCTSSAMPLEPRODUCTS

OFOFCNC MANUFACTURINGCNC MANUFACTURING


36/136

20042004 3636

AUTOMOTIVE INDUSTRY AUTOMOTIVE INDUSTRY Engine BlockEngine Block



37/136


38/136

20042004 3838

AEROSP ACE INDUSTRY AEROSP ACE INDUSTRY Aircraf t Turbine Machined by Aircraf t Turbine Machined by

55-- Axis CNC Milling Machine Axis CNC Milling Machine



39/136

20042004 3939

CNC MOLD MAKINGCNC MOLD MAKING



40/136

20042004 4040

ELECTRONIC INDUSTRY ELECTRONIC INDUSTRY



41/136

20042004 4141

RAPID PROTOTY PINGRAPID PROTOTY PINGPRODUCTSPRODUCTS



42/136

20042004 4242

ADVANTAGES of CNC ADVANTAGES of CNC

ProductivityProductivityMachine ut ilisat ion is increase d because more Machine ut ilisat ion is increase d because more t ime is spen t cu tt ing an d less t ime is t aken byt ime is spen t cu tt ing an d less t ime is t aken byposi t ioning. posi t ioning. Reduce d se t up t ime increases ut ilisat ion t oo. Reduce d se t up t ime increases ut ilisat ion t oo.



43/136

20042004 4343


Q ualityQ ualityPar t s are more accura t e. Par t s are more accura t e. Par t s are more repea t able. Par t s are more repea t able. Less w as t e due t o scrap.Less w as t e due t o scrap.



44/136

20042004 4444


Re duc e d inv e ntoryRe duc e d inv e ntoryReduce d se t up t ime permi t s smaller economic Reduce d se t up t ime permi t s smaller economic ba t ch quan t it ies. ba t ch quan t it ies. Lower lea d t ime allows lower st ock levels. Lower lea d t ime allows lower st ock levels. Lower st ock levels reduce int eres t charges an dLower st ock levels reduce int eres t charges an dworking capi t al requiremen t s. working capi t al requiremen t s.



45/136

20042004 4545


Machining Compl ex s hap es Machining Compl ex s hap es Slide movemen t s un der compu t er con t rol. Slide movemen t s un der compu t er con t rol. Compu t er con t roller can calcula t e st eps. Compu t er con t roller can calcula t e st eps. First NC mac hine built 1951 a t MIT for aircraf t First NC mac hine built 1951 a t MIT for aircraf t

skin milling.skin milling.



46/136

20042004 4646


Manag e m e nt ControlManag e m e nt ControlCNClea ds t o CADCNClea ds t o CADProcess planning Process planning Produc t ion planning Produc t ion planning



47/136

20042004 4747

D RAWBACKS of CNCD RAWBACKS of CNCHigh capi t al cos t, Machine t ools cos t High capi t al cos t, Machine t ools cos t $30,000 $30,000 - - $1,500,000 $1,500,000

Re t raining an d recrui t men t of st aff Re t raining an d recrui t men t of st aff

New suppor t facilit ies New suppor t facilit ies

High main t enance requiremen t sHigh main t enance requiremen t s

Not cos t Not cos t- - effec t ive for loweffec t ive for low- - level pro duc t ion on simple par t slevel pro duc t ion on simple par t s

As geome t ric comple xity or volume increases CNC becomes As geome t ric comple xity or volume increases CNC becomes more economicalmore economical

Main t enance personnel mus t h ave both mec hanical an dMain t enance personnel mus t h ave both mec hanical an delec t ronics exper t ise elec t ronics exper t ise



48/136

20042004 4848

CNC SYSTEM ELEMENTSCNC SYSTEM ELEMENTS


49/136

20042004 4949

CNC SYSTEM ELEMENTSCNC SYSTEM ELEMENTS A typical CNCsyst em consis t s of th A typical CNCsyst em consis t s of the e

following six elemen t s following six elemen t s Par t program Par t program Program inpu t d evice Program inpu t d evice Machine con t rol uni t Machine con t rol uni t

Drive syst em Drive syst em Machine t ool Machine t ool Fee dback syst em Fee dback syst em



50/136

20042004 5050

NC SYSTEM ELEMENTSNC SYSTEM ELEMENTS



51/136


52/136

20042004 5252

P ART PROGRAMP ART PROGRAM A par t program is a series of coded inst ruc t ions require d t o pro duce A par t program is a series of coded inst ruc t ions require d t o pro duce a par t . It con t rols the movemen t of the mac hine t ool an d th e on/off a par t . It con t rols the movemen t of the mac hine t ool an d th e on/off con t rol of au xiliary func t ions suc h as spin dle ro t a t ion an d coolan t . con t rol of au xiliary func t ions suc h as spin dle ro t a t ion an d coolan t .

The coded inst ruc t ions are compose d of lett ers , num bers an dThe coded inst ruc t ions are compose d of lett ers , num bers an dsymbols an d are arrange d in a forma t of func t ional blocks as in the symbols an d are arrange d in a forma t of func t ional blocks as in the following example following example

N10 G 01 X5. 0 Y2.5 F1 5. 0N10 G 01 X5. 0 Y2.5 F1 5. 0|| || || || | |

|| || || || Fee d ra t e (15 in/min )Fee d ra t e (15 in/min )|| || || Y Y --coor dina t e (2 .5")coor dina t e (2 .5")|| || X X --coor dina t e (5 .0")coor dina t e (5 .0")|| Linear int erpola t ion mo de Linear int erpola t ion mo de

Sequence num ber Sequence num ber



53/136

20042004 5353

PROGRAM INPUT DEVICEPROGRAM INPUT DEVICEThe program inpu t d evice is the mec hanism for The program inpu t d evice is the mec hanism for

par t programs t o be en t ere d int o the CNCpar t programs t o be en t ere d int o the CNCcon t rol. Thcon t rol. The mos t e mos t commonl y use d program commonl y use d program inpu t devices are inpu t devices are keyboar dskeyboar ds,, punc hed t ape punc hed t ape rea der , d iske tt e drivers , th rog h RS 232 serial rea der , d iske tt e drivers , th rog h RS 232 serial por t s an d ne t workspor t s an d ne t works. .



54/136

20042004 5454

MACHINE CONTROL UNITMACHINE CONTROL UNITThe mac hine con t rol unit (MCU) is the hear t of a CNCsyst em. It is The mac hine con t rol uni t (MCU) is the hear t of a CNCsyst em. It is use d t o perform the following func t ions :use d t o perform the following func t ions :

Rea d coded inst ruc t ionsRea d coded inst ruc t ionsDeco de coded inst ruc t ions Deco de coded inst ruc t ions Implemen t int erpola t ions ( linear , circular , an d helical) t o genera t e Implemen t int erpola t ions ( linear , circular , an d helical) t o genera t e axis mo t ion comman ds axis mo t ion comman ds Fee d axis mo t ion comman ds t o the amplifier circuit s for driving the Fee d axis mo t ion comman ds t o the amplifier circuit s for driving the

axis mec hanisms axis mec hanisms Receive the fee dback signals of posi t ion an d spee d for eac h d rive Receive the fee dback signals of posi t ion an d spee d for eac h d rive axis axis Implemen t au xiliary con t rol func t ions suc h as coolan t or spin dle Implemen t au xiliary con t rol func t ions suc h as coolan t or spin dle on/off , an d t ool changeon/off , an d t ool change



55/136

20042004 5555

TYPES of CNC CONTROLTYPES of CNC CONTROLSYSTEMSSYSTEMS

OpenOpen--loop con t rolloop con t rolClose dClose d--loop con t rolloop con t rol



56/136

20042004 5656

OPE NOPE N--L OOP CON TRO L SYSTEMLOOP CON TRO L SYSTEMIn openIn open--loop con t rol syst em st ep mo t ors are use dloop con t rol syst em st ep mo t ors are use d

St ep mo t ors are driven by elec t ric pulsesSt ep mo t ors are driven by elec t ric pulsesEvery pulse ro t a t es the mo t or spin dle throug h a cer t ain Every pulse ro t a t es the mo t or spin dle throug h a cer t ain amoun t amoun t

By coun t ing the pulses , th e amoun t of mo t ion can be By coun t ing the pulses , th e amoun t of mo t ion can be con t rolledcon t rolled

No fee dback signal for error correc t ionNo fee dback signal for error correc t ion

Lower posi t ioning accurac yLower posi t ioning accurac y



57/136

20042004 5757

CLOSEDCLOSED--LOOP CONTROL SYSTEMSLOOP CONTROL SYSTEMS

In close dIn close d--loop con t rol syst ems DC or ACmo t ors loop con t rol syst ems DC or ACmo t ors

are use dare use dPosit ion t rans ducers are use d t o genera t e Posit ion t rans ducers are use d t o genera t e posi t ion fee dback signals for error correc t ionposi t ion fee dback signals for error correc t ion

Be tt er accurac y can be achieve dBe tt er accurac y can be achieve dMore expensiveMore expensive

Suit able for large size mac hine t oolsSuit able for large size mac hine t ools



58/136

20042004 5858

DRIVE SYSTEMDRIVE SYSTEM A drive syst em consis t s of amplifier circuit s, A drive syst em consis t s of amplifier circuit s,

st eppingst epping mo t orsmo t ors or servomo t orsor servomo t ors an d ball lea dan d ball lea d--screws. The MCUfee ds con t rol signals ( posi t ion screws. The MCUfee ds con t rol signals ( posi t ion an d spee d) of eac h axis t o the amplifier circuit s. an d spee d) of eac h axis t o the amplifier circuit s. The con t rol signals are augmen t ed t o ac t ua t e The con t rol signals are augmen t ed t o ac t ua t e st eppingst epping mo t ors which in t urn ro t a t e the ball mo t ors which in t urn ro t a t e the ball lea dlea d--screws t o posi t ion the mac hine t able. screws t o posi t ion the mac hine t able.


dd


59/136

20042004 5959

STEPPI NG MOTORSSTEPPI NG MOTORS A st epping mo t or provides open-loop , d igit al con t rol of

the posi t ion of a workpiece in a numerical con t rol mac hine. The drive uni t receives a direc t ion inpu t ( cw or ccw) an d pulse inpu t s. For eac h pulse it receives , th e drive uni t manipula t es the mo t or volt age an d curren t,

causing the mo t or shaf t t o ro t a t e bya fixed angle ( one st ep ). The lea d screw conver t s the ro t ary mo t ion of themo t or shaf t int o linear mo t ion of the workpiece .



60/136

JURUSAN TEKNIK MESIN d INDUSTRIJURUSAN TEKNIK MESIN d INDUSTRI


61/136

20042004 6161

RECIRCULATING BALL SCREWSRECIRCULATING BALL SCREWSTransform ro t at ional mo t ion of the mo t or int oTransform ro t at ional mo t ion of the mo t or int o t ransla t ionalt ransla t ionalmo t ion of the nu t att ached t o the mac hine t able.mo t ion of the nu t att ached t o the mac hine t able.



62/136


63/136

20042004 6363



64/136

20042004 6464

POSITIONINGPOSITIONINGThe posi t ioning resolu t ion of a ball screw drive

mec hanism is direc t ly propor t ional t o the smalles t angle tha t th e mo t or can t urn.

The smalles t angle is con t rolled by th e mo t or s t ep size.

Micros t eps can be use d t o decrease the mo t or s t ep size.

CNCmac hines typically have resolu t ions of 0.00 25 mmor be tt er.




65/136

20042004 6565

MACHINE TOOLMACHINE TOOLCNCcon t rols are use d t o con t rol various types CNCcon t rols are use d t o con t rol various types of mac hine t ools. Regar dless of which type of of mac hine t ools. Regar dless of which type of mac hine t ool is con t rolled, it alwa ys has a slide mac hine t ool is con t rolled, it alwa ys has a slide t able an d a spin dle t o con t rol of posi t ion an dt able an d a spin dle t o con t rol of posi t ion an dspee d. The mac hine t able is con t rolled in the X spee d. The mac hine t able is con t rolled in the X

an d Y axes , while the spin dle runs along the Zan d Y axes , while the spin dle runs along the Zaxis. axis.



66/136

JURUSAN TEKNIK MESIN dan INDUSTRIJURUSAN TEKNIK MESIN dan INDUSTRI


67/136

20042004 6767

CNC MACHINES FEEDBACK CNC MACHINES FEEDBACK DEVICESDEVICES




68/136

20042004 6868

POTENTIOMETERSPOTENTIOMETERS




69/136

20042004 6969

POTENTIOMETERSPOTENTIOMETERS



70/136



71/136

20042004 7171

ENCODERSENCODERS




72/136

20042004 7272

INDUSTRIAL APPLICATIONS of ENCODERSINDUSTRIAL APPLICATIONS of ENCODERS




73/136

20042004 7373

RESOLVERSRESOLVERS

A resolver is a ro t aryt ransformer tha t pro duces an ou t pu t signal tha t is a func t ion of the rot or posi t ion.




74/136

20042004 7474

SERVOMOTORwith RESOLVERSERVOMOTORwith RESOLVER




75/136

20042004 7575

VELOCITY FEEDBACK VELOCITY FEEDBACK Tachom e t e rs :

Elect rical ou t pu t is propor t ional t o ra t e of angular ro t a t ion.

Encod e rs, R e solv e rs, Pot e ntiom e t e rs :

Num ber of pulses per t ime is propor t ional t ora t e change of posi t ion.




76/136

20042004 7676

CNC CUTTERSCNC CUTTERS

Turning cen t er cu tt ers Turning cen t er cu tt ers Machining cen t er cu tt ersMachining cen t er cu tt ers




77/136

20042004 7777

TURNING CENTER CUTTERSTURNING CENTER CUTTERSTypes of cu tt ers use d on CNC t urning cen t ers

Carbides (an d other hard ma t erials ) inser t t urning an d boring t ools

Ceramics

High Spee d St eel (HSS) drills an d t aps




78/136

20042004 7878

STANDART INSERT SHAPESSTANDART INSERT SHAPES V use d for profiling , w e ak e st ins e rt , 2 edges per side.D somew ha t st ronger , use d for profiling w hen the angle allows it, 2

edges per side.T commonl y use d for t urning because it has 3 edges per side.C popular inser t b ecause the same holder can be use d for t urning an dfacing. 2 edges per side.

W newes

t sh

ape.C

ant urn

an

dface

like the C, but 3 edges per side.S Ve ry strong , b ut mos t ly use d forchamfering because it won t cut a square s houlder. 4 edges per side.R st ronges t inser t b ut leas t commonl y use d.




79/136

20042004 7979

TY PICAL TURNING,THREADINGan d P ARTING TOOLS



80/136



81/136

20042004 8181

M ACH I N I NG CEN TER CUTTI NG M ACH I N I NG CEN TER CUTTI NG TOO LS TOO LS (con t (con t ss))

Facemills flatt en largesurfaces quickly an d withan excellen t finish. Not icethe engine block being

finished in one pass witha large cu tt er.




82/136

20042004 8282

M ACH I N I NG CEN TER CUTTI NG TOO LS M ACH I N I NG CEN TER CUTTI NG TOO LS (con t (con t ss))

Ball en dmills (both HSS an dinser t) are use d for a varie ty of profiling opera t ions suc h as the mold shown in the pict ure.

Slitt ing an d side cu tt ers are use d when deep , narrow slot s

mus t be cu t .




83/136

20042004 8383

M ACH I N I NG CEN TER CUTTI NG TOO LS M ACH I N I NG CEN TER CUTTI NG TOO LS (con t (con t ss))D rills, Taps, and Reamers

Common HSS tools such as

drills, taps, and reamers arecommonly used on CNCmachining centers.

Note that a spot drill is usedinstead of a centerdrill. Also,spiral point or gun taps are usedfor through holes and spiral flutefor blind holes. Rarely are handtaps used on a machining center.

FT FT -- UGMUGM



84/136

20042004 8484

TOO L HOLDERSTOO L HOLDERS All cutting tools must be held in a holder that fitsin the spindle. These include end mill holders(shown), collet holders, face mill adapters, etc.

Most machines in the USA use a CAT taper whichis a modified NST 30, 40, or 50 taper that uses apull stud and a groove in the flange. The machinepulls on the pull stud to hold the holder in thespindle, and the groove in the flange gives the

automatic tool changer something to hold onto.

HSK tool holders were designed a number of years ago as an improvement to CAT tapers, butthey are gaining acceptance slowly.

FT FT -- UGMUGM



85/136

20042004 8585

CNC PROGRAMMINGCNC PROGRAMMING

FT FT -- UGMUGM



86/136

20042004 8686

CNC PROGRAMMINGCNC PROGRAMMINGOfflin e programmingOfflin e programming linked t o CADprograms. linked t o CADprograms.

Conv e rsational programmingConv e rsational programming by th e opera t or. by th e opera t or. MDIMDI ~ Manual Da t a Inpu t . ~ Manual Da t a Inpu t .

Manual ControlManual Control using jog butt ons or ` elec t ronic using jog butt ons or ` elec t ronic

han dwheel'. han dwheel'. W ordW ord --A ddr e ss Coding Addr e ss Coding using st an dard Gusing st an dard G--codes an d Mcodes an d M--codes. codes.

FT FT -- UGMUGM



87/136

20042004 8787

Basics of NC Part Programming :Basics of NC Part Programming :

FT FT -- UGMUGM

During secondary motion, either the tool movesDuring secondary motion, either the tool movesrelative to the workpiece or the workpiece movesrelative to the workpiece or the workpiece movesrelative to the toolrelative to the tool

In NC programming, it is always assumed thatIn NC programming, it is always assumed thatthe tool moves relative to the workpiece nothe tool moves relative to the workpiece nomatter what the real situation is.matter what the real situation is.



88/136

20042004 8888

FT FT -- UGMUGM

The position of the tool is described by usingThe position of the tool is described by usinga Cartesian coordinate system.a Cartesian coordinate system.

If (0,0,0) position can be described by theIf (0,0,0) position can be described by theoperator, then it is calledoperator, then it is called fl oating z erofl oating z ero ..

In defining the motion of the tool from oneIn defining the motion of the tool from one

point to another, either point to another, either absolu

teabsolu

te positioning positioning mode or mode or incrementa l incrementa l positioning positioning modemode cancanbe used.be used.



89/136

20042004 8989

FT FT -- UGMUGM

1.1. A bso lu te positioning A bso lu te positioning . In this mode, the desired. In this mode, the desiredtarget position of the tool for a particular movetarget position of the tool for a particular move

is given relative to the origin point of theis given relative to the origin point of theprogram.program.

2 .2 . I ncrementa l positioning I ncrementa l positioning . In this mode, the next. In this mode, the next

target position for the tool is given relative totarget position for the tool is given relative tothe current toolthe current tool position.position.



90/136

20042004 9090

Structure of an NC Part Program :Structure of an NC Part Program :Commands are input into the controller inunits called b l ocks or statements .

Block Format :

1. Fixed sequential format

2. Tab sequential format3. Word address format

FT FT -- UGMUGM


91/136



92/136

20042004 9292

1 . Fixe d s eq u e ntial format1 . Fixe d s eq u e ntial format0050 00 + 0025400 + 0012500 + 0000000 0000 000050 00 + 0025400 + 0012500 + 0000000 0000 000060 01 + 0025400 + 0012500 0060 01 + 0025400 + 0012500 --00 10000 0500 080010000 0500 080070 00 + 0025400 + 0012500 + 0000000 0000 090070 00 + 0025400 + 0012500 + 0000000 0000 09

2.Tab sequential format

2.Tab sequential format0050 TAB 00 TAB +0025400 TAB +0012500 TAB +0000000 TAB TAB

0060 TAB 01 TAB TAB TAB -0010000 TAB 0500 TAB 080070 TAB 00 TAB TAB TAB -0000000 TAB 0000 TAB 09

3 . Word address format3 . Word address formatN50 G00 X25400 Y125 Z0 F0N60 G01 Z-10000 F500 M08N70 G00 Z0 M09

FT FT -- UGMUGM



93/136

20042004 9393

M oda l commands M oda l commands :: Commands issued in theCommands issued in theNC program that will stay in effect until it isNC program that will stay in effect until it ischanged by some other command, like, feedchanged by some other command, like, feed

rate selection, coolant selection, etcrate selection, coolant selection, etcN onmoda l commands N onmoda l commands :: Commands that areCommands that areeffective only when issued and whose effectseffective only when issued and whose effects

are lost for subsequent commands, like, a dwellare lost for subsequent commands, like, a dwellcommand which instructs the tool to remain in acommand which instructs the tool to remain in agiven configuration for a given amount of time.given configuration for a given amount of time.

FT FT -- UGMUGM



94/136

20042004 9494

CNC PROGRAMMINGCNC PROGRAMMING

FT FT -- UGMUGM



95/136

20042004 9595

INFORMATION NEEDED by a CNCINFORMATION NEEDED by a CNC1. Preparatory Information : units, incremental or absolute positioning

2. Coordinates: X,Y,Z, RX,RY,RZ

3. Machining Parameters: Feed rate and spindle speed4. Coolant Control: On/Off, Flood, Mist

5. Tool Control: Tool and tool parameters

6. Cycle Functions: Type of action required

7. Miscellaneous Control: Spindle on/off, direction of rotation, stops for partmovement

This information is conveyed to the machine through a set of instructionsarranged in a desired sequence sequence ProgramProgram .

FT FT -- UGMUGM



96/136

20042004 9696

BLOCK FORM ATBLOCK FORM ATSampl e B lockSampl e B lock

N135 G01 X1.0 Y1.0 Z0.125 F5N135 G01 X1.0 Y1.0 Z0.125 F5Restrictions on CNC blocks

Each may contain only one tool move

Each may contain any number of non-tool move G-codes

Each may contain only one feed-rate

Each may contain only one specified tool or spindle speed

The block numbers should be sequentialBoth the program start flag and the program number must beindependent of all other commands (on separate lines)

The data within a block should follow the sequence shown in theabove sample block

FT FT -- UGMUGM



97/136

20042004 9797

W ORDW ORD --A DDRESS CODI NG ADDRESS CODI NG

N5 G90 G20N5 G90 G20N10 M06 T3N10 M06 T3N15 M03 S1250N15 M03 S1250N20 G00 X1 Y1N20 G00 X1 Y1N25 Z0.1N25 Z0.1N30 G01 ZN30 G01 Z- -0.125 F50.125 F5N35 X3 Y2 F10N35 X3 Y2 F10

N40 G00 Z1N40 G00 Z1N45 X0 Y0N45 X0 Y0N50 M05N50 M05N55 M30N55 M30

Exampl e CNC ProgramExampl e CNC Program

Each instruction to the machine consistsof a letter followed by a number.

Each letter is associated with a specifictype of action or piece of informationneeded by the machine.

Letters used in Codes

N,G,X,Y,Z,A,B,C,I,J,K,F,S,T,R,M

FT FT -- UGMUGM



98/136

20042004 9898

G & M Cod e sG & M Cod e s

N5 G90 G20N5 G90 G20N10 M06 T3 N10 M06 T3 N15 M03 S1250N15 M03 S1250N20 G00 X1 Y1N20 G00 X1 Y1N25 Z0.1N25 Z0.1N30 G01 ZN30 G01 Z--0. 125 F50.125 F5N35 X 3 Y2 F10N35 X 3 Y2 F10

N40 G00 Z1N40 G00 Z1N45 X 0 Y 0N45 X 0 Y 0N50 M05N50 M05N55 M30N55 M30

Exampl e CNC ProgramExampl e CNC ProgramG-codes : Preparatory Functions

involve actual tool moves.

M-codes : MiscellaneousFunctions involve actionsnecessary for machining (i.e.spindle on/off, coolant on/off).

FT FT -- UGMUGM

JURUSAN TEKNIK MESIN dan INDUSTRIJURUSAN TEKNIK MESIN dan INDUSTRIFTFT UGMUGM


99/136

20042004 9999

G Cod e sG Cod e sG00G00 Rapid traverseRapid traverseG01 Linear interpolationG01 Linear interpolationG02G02 Circular interpolation,Circular interpolation,

CWCW

G03 Circular interpolation,G03 Circular interpolation,CCWCCWG04 DwellG04 DwellG08 AccelerationG08 AccelerationG09 DecelerationG09 DecelerationG17 XG17 X--Y PlaneY PlaneG18 ZG18 Z--X PlaneX PlaneG19 YG19 Y--Z PlaneZ PlaneG20 Inch Units (G70)G20 Inch Units (G70)G21 Metric Units (G71)G21 Metric Units (G71)

G40 Cutter compensationG40 Cutter compensation - - cancelcancelG41 Cutter compensationG41 Cutter compensation - - leftleftG42 Cutter compensationG42 Cutter compensation - - rightright

G70 Inch formatG70 Inch formatG71 Metric formatG71 Metric formatG74 FullG74 Full- -circlecircle programmingprogramming off off G75 FullG75 Full- -circle programmingcircle programming on onG80 FixedG80 Fixed- -cycle cancelcycle cancel

G81G81--G89 Fixed cyclesG89 Fixed cyclesG90 Absolute dimensionsG90 Absolute dimensionsG91 Incremental dimensionsG91 Incremental dimensions

FT FT -- UGMUGM



100/136

20042004 100100

Modal GModal G--C od e sCod e s

Mos t GMos t G--codes se t th ecodes se t th e mac hine in a mo demac hine in a mo de

which st ays in effec t which st ays in effec t un t il it is change d orun t il it is change d orcancelle d by ano ther Gcancelle d by ano ther G--co de.code. These comman dsThese comman dsare called mo dal .are called mo dal .

FT FT -- UGMUGM



101/136

20042004 101101

Modal GModal G--C od e ListCod e ListG00G00 Rapid TransverseRapid TransverseG01G01 Linear InterpolationLinear InterpolationG0 2G0 2 Circular Interpolation, CWCircular Interpolation, CWG0 3G0 3 Circular Interpolation,Circular Interpolation,

CCWCCWG17G17 XY PlaneXY PlaneG18G18 XZ PlaneXZ PlaneG19G19 YZ Plane YZ PlaneG2 0/G70G2 0/G70 Inch unitsInch unitsG2 1/G71G2 1/G71 Metric UnitsMetric Units

G40G40 Cutter compensationCutter compensationcancelcancelG41G41 Cutter compensation leftCutter compensation leftG4 2 G4 2 Cutter compensation rightCutter compensation rightG4 3 G4 3 Tool length compensationTool length compensation

(plus)(plus)

G4 3G4 3 Tool length compensationTool length compensation(plus)(plus)

G44G44 Tool length compensationTool length compensation

(minus)(minus)G49G49 Tool length compensationTool length compensationcancelcancel

G80G80 Cancel canned cyclesCancel canned cyclesG81G81 D rilling cycleD rilling cycleG8 2G8 2 Counter boring cycleCounter boring cycleG8 3G8 3 D eep hole drilling cycleD eep hole drilling cycleG90G90 Absolute positioningAbsolute positioningG91G91 Incremental positioningIncremental positioning

FT FT -- UGMUGM



102/136

20042004 102102

M Cod e sM Cod e sM00M00 Program stopProgram stop

M01M01 Optional program stopOptional program stop

M02M02 Program endProgram end

M03M03 Spindle on clockwiseSpindle on clockwise

M04M04 Spindle on counterclockwiseSpindle on counterclockwise

M05M05 Spindle stopSpindle stop

M06M06 Tool changeTool change

M08M08 Coolant onCoolant on

M09M09 Coolant off Coolant off M10M10 Clamps onClamps on

M11M11 Clamps off Clamps off

M30M30 Program stop, reset to startProgram stop, reset to start

FT FT -- UGMUGM



103/136

20042004 103103

N Cod e sN Cod e sGives anGives an iden t if ying num ber for eac hiden t if ying num ber for eac h block block of informa t ion.of informa t ion.

It is generall y goo d prac t ice t oIt is generall y goo d prac t ice t o incremen t incremen t eac h b lock num ber byeac h b lock num ber by 5 or 10 t o allow 5 or 10 t o allow addit ionaladdit ional blocks t o be inser t ed if fut ureblocks t o be inser t ed if fut urechanges are require d.changes are require d.

FT FT -- UGMUGM



104/136

20042004 104104

X,Y, and Z Cod e sX,Y, and Z Cod e s

X, Y, and ZX, Y, and Z codes are use d t ocodes are use d t o specif y the specif y the

coor dina t e axis.coor dina t e axis.Num ber following the codeNum ber following the code defines the defines the coor dina t e a t th e en dcoor dina t e a t th e en d of the move rela t ive t o of the move rela t ive t o

anan incremen t al or absolu t eincremen t al or absolu t e reference poin t .reference poin t .

FT FT -- UGMUGM



105/136

20042004 105105

I,J, and K Cod e sI,J, and K Cod e s

I, J, and KI, J, and K codes are used tocodes are used to specify thespecify the

coordinate axiscoordinate axis when defining the center of awhen defining the center of acircle.circle.

Number following the codeNumber following the code defines thedefines therespective coordinaterespective coordinate for the center of thefor the center of thecircle.circle.

FT FT -- UGMUGM


106/136



107/136

20042004 107107

Application of Som e Cod e s Application of Som e Cod e sG01 Lin e ar Int e rpolationG01 Lin e ar Int e rpolation

Format : N_ G01 X _ Y _ Z _ F _Format : N_ G01 X _ Y _ Z _ F _

Linear Int erpola t ion resul t s in a st raig ht line fee dLinear Int erpola t ion resul t s in a st raig ht line fee dmove.move.

Unless t ool compensa t ion is use d, th eUnless t ool compensa t ion is use d, th ecoor dina t es arecoor dina t es are associa t ed with th e cen t erline of associa t ed with th e cen t erline of the t ool.the t ool.

FT FT -- UGMUGM



108/136

20042004 108108

Application of Som e Cod e s Application of Som e Cod e sG01 Lin e ar Int e rpolationG01 Lin e ar Int e rpolation

As an example As an example , for the mo t ion tha t occurs in , for the mo t ion tha t occurs in xx--yy

plane with th e same ma ximum spee d for the xplane with th e same ma ximum spee d for the x--an d yan d y--axis, init ial mo t ion is a t an angle of 45o t o axis, init ial mo t ion is a t an angle of 45o t o the axes un t il mo t ion in one of the axes is the axes un t il mo t ion in one of the axes is comple t ed an d th en the balance of the mo t ion comple t ed an d th en the balance of the mo t ion

occurs in the other axis. This is calledoccurs in the other axis. This is called poin t poin t --t ot o--poin t mo t ionpoin t mo t ion..

FT FT -- UGMUGM



109/136

20042004 109109

Applica t ion of Some Codes Applica t ion of Some CodesG01 Linear Int erpola t ionG01 Linear Int erpola t ion

55

1010

1515

2020

2525

55 1010 1515 2020 2525 3030

AA

BB CC

P ositioning motion from A to CP ositioning motion from A to CN10 G00 X30000 Y20000 F 0N10 G00 X30000 Y20000 F 0

FT FT -- UGMUGM



110/136

20042004 110110


G01 is another preparatory function to specify thatthe tool should be moved to a specified locationalong a straight line path. It is referred to as l inear interpo l ation .

This function is typically used to specify machiningof straight features such as turning a cylindricalsurface in turning, cutting a slot in milling, etc.

FT FT -- UGMUGM



111/136

20042004 111111


5

10

15

20

25

5 10 15 20 25 30

A

C

L inear interpolation from A to CN10 G01 X30000 Y20000 F 2500

FT FT -- UGMUGM



112/136

20042004 112112

N10 N10 G00 X1G00 X1 ZZ11NN115 Z0.15 Z0.1NN 2 02 0 G01 ZG01 Z--0 .1 2 5 F50 .1 2 5 F5NN 22 55 X 2 Z2 X2 Z2 F10F10

G01 Linear Int erpola t ionG01 Linear Int erpola t ion

X

Z

FT FT -- UGMUGM

JURUSAN TEKNIK MESIN dan INDUSTRIJURUSAN TEKNIK MESIN dan INDUSTRIFTFT -- UGMUGM


113/136

20042004 113113

G02 Circular Int erpola t ionG02 Circular Int erpola t ionG02 is also a prepara t ory func t ion t o specif y th a t th e G02 is also a prepara t ory func t ion t o specif y th a t th e t ool should be move d t o a specifie d loca t ion along a t ool should be move d t o a specifie d loca t ion along a

circular pa th in a clockwise direc t ion. circular pa th in a clockwise direc t ion. In order t o specif y th e pa th t o the MCU, the en d poin t In order t o specif y th e pa th t o the MCU, the en d poin t of the arc an d th e loca t ion of the cen t er of the arc of the arc an d th e loca t ion of the cen t er of the arc should be specifie d. should be specifie d.

With in the block in which th e G02 code is programme d,With in the block in which th e G02 code is programme d,the cen t er of the arc is given by specif ying it s loca t ion the cen t er of the arc is given by specif ying it s loca t ion rela t ive t o the st ar t of the arc. rela t ive t o the st ar t of the arc.

FT FT -- UGMUGM



114/136

20042004 114114

G02 Circular Int erpola t ion (CW)G02 Circular Int erpola t ion (CW)

The G02 comman dThe G02 comman d re quiresre quires an an en dpoin t an d a ra diusen dpoin t an d a ra dius inin order order t o cu t th e arc.t o cu t th e arc.I,J, an d K are rela t iveI,J, an d K are rela t ive t o the t o the st ar t poin t .st ar t poin t .

N_ G0 2 X2 Y1 I 0 JN_ G0 2 X2 Y1 I 0 J --1 F101 F10oror

N_ G0 2 X2 Y1 R1N_ G0 2 X2 Y1 R1

FT FT -- UGMUGM



115/136

20042004 115115

G02 Circular Int erpola t ion (CW)G02 Circular Int erpola t ion (CW)

5

10

15

20

25

5 10 15 20 25 30

C

C

C ircular interpolation from A to Babout a circle centered at C N10 G02 X20000 Y10000 I 5000 J 15000 F 2500

A

B

I= 5

J= 15

FT FT UGMUGM



116/136

20042004 116116

The sequence of some machining operations is maybe the same for any part and for any machine. For example, drilling a hole involves the following steps :

Position the tool above the point where the hole willbe drilled

Set the correct spindle speed

Feed the tool into the workpiece at a controlled feedrate to a predetermined depthRetract the tool at a rapid rate to just above the pointwhere the hole started

Canned CyclesCanned Cycles

FT FT UGMUGM


117/136


118/136



119/136

20042004 119119

Three Main par t s of a CNCprogramThree Main par t s of a CNCprogram

N5 G90 G2N5 G90 G211 ( Absolu t e uni t s,( Absolu t e uni t s, me t ricme t ric))

N10 M06 T2N10 M06 T2 (St op for t ool change , use (St op for t ool change , use t ool # 2)t ool # 2)

N15 M03 S1200 N15 M03 S1200 (Turn the spin dle on CW t o (Turn the spin dle on CW t o 1200 rpm )1200 rpm )

Par t 1Par t 1 -- Program Pe t upProgram Pe t up

FT FT UGMUGM



120/136

20042004 120120

Three Main par t s of a CNCprogramThree Main par t s of a CNCprogram

N20 G00 X1 Y1N20 G00 X1 Y1 (Rapid t o X1,Y1from origin poin t)(Rapid t o X1,Y1from origin poin t)

N25 Z0.125N25 Z0.125 (Rapid down t o Z0.125)(Rapid down t o Z0.125)

N30 G01 ZN30 G01 Z--0. 125 F0.125 F1 00100 ( Fee d down t o Z(Fee d down t o Z--0. 125 a t 0.125 a t 100 mm/100 mm/mminin))

N35 G01 X2 Y2N35 G01 X2 Y2 (Fee d d iagonall y t o X2,Y2)(Fee d d iagonall y t o X2,Y2)

N40 G00 Z1N40 G00 Z1 (Rapid up t o Z1)(Rapid up t o Z1)

N45 X 0 Y 0 N45 X 0 Y 0 (Rapid t o X 0,Y 0)(Rapid t o X 0,Y 0)

Par t 2Par t 2 -- Chip RemovalChip Removal

FT FT UGMUGM



121/136

20042004 121121

Three Main parts of a CNC programThree Main parts of a CNC program

N50 M05N50 M05 ( Turn the spin dle off )( Turn the spin dle off )

N55 MN55 M000 0 ( ( PProgramrogram s t opst op ))

Par t 3Par t 3-- Syst em ShutdownSyst em Shutdown

FT FT UGMUGM



122/136

20042004 122122

EXAMPLE OPERATION on CNC MILLING MACHINEEXAMPLE OPERATION on CNC MILLING MACHINE



123/136

20042004 123123

GG--C ODE PRO GR AMCODE PRO GR AMFirst pass : conventional mill to adepth of 0.125 around edge profile.Tool 1 is a inch dia. end mill.

%:1002N5 G90 G20N10 M06 T1N15 M03 S1200N20 G00 X 0.125 Y 0.125N30 Z0.125N35 G01 Z-0. 125 F5N40 X 3.87 5N45 Y4.125N50 X 0.125N55 Y 0.125



124/136

20042004 124124

Se cond pass : conven t ional millt o a dep th of 0.25 aroun d edgeprofile.

N35 Z-0. 250

N40 X 3.87 5

N45 Y4.125

N50 X 0.125

N55 Y 0.125

N60 Z0.125



125/136

20042004 125125

Third pass : conven t ional millt o a dep th of 0.125 aroun dpocke t profile.

N65 G00 X1.25 Y1.0

N70 G01 Z-0. 125 F5

N75 X1.75

N80 Y2.5N85 X1.25

N90 Y1.0

N95 Z0.125



126/136

20042004 126126

Four th pass : climb mill t o adep th of 0.125 acrossremaining ma t erial.

N100 Y2.125N105 X2.625N110 Z0.125N115 G00 X -5 Y -5 Z5

N120 M05N125 M30



127/136

20042004 127127

Advanc e d fe atur e s Advanc e d fe atur e s ::

Execu t ion of the par t of the program in a ro t a t edExecu t ion of the par t of the program in a ro t a t ed

or mirrore d posi t ion.or mirrore d posi t ion. Ability t o scale the program an d pro duce larger or Ability t o scale the program an d pro duce larger or smaller programs.smaller programs.

Three dimensional circular int erpola t ion whichThree dimensional circular int erpola t ion whichpro duces a helical shape.pro duces a helical shape.Para bolic an d cubic int erpola t ion.Para bolic an d cubic int erpola t ion.



128/136

20042004 128128

Program Loa ding :Program Loa ding :Throug h keyboar d

Throug h punc hed t ape rea derThroug h d iske tt e drive

Throug h RS 232 serial por t

Throug h ne t work int erface car d



129/136

20042004 129129

A syst em in which a cen t ral compu t er downloa ds

the NC programs block by b lock t o man y NCmac hine t ools simul t aneousl y is called Direc t Numerical Con t rol (D NC) syst em.

D irect Numerical Control ( D NC) :D irect Numerical Control ( D NC) :



130/136

20042004 130130

This syst em use d t o work with th e earl y NC mac hine t ools which can no t rea d more than a block of informa t ion a t a t ime.

The cen t ral compu t er fee d th e program informa t ion one block a t a t ime. When the mac hine execu t e the

informa t ion , th e ne xt b lock of informa t ion would be fed.

D irect Numerical Control ( D NC)D irect Numerical Control ( D NC) :: ( conts )



131/136

20042004 131131

Dist ribut ed NC is known by th e same acron ym as Direc t Dist ribut ed NC is known by th e same acron ym as Direc t Numerical Con t rol (DNC). Af t er the int roduc t ion of CNC,Numerical Con t rol (DNC). Af t er the int roduc t ion of CNC,the mac hine t ools have had th e capa bility of st oring the mac hine t ools have had th e capa bility of st oring

large amoun t of informa t ion. large amoun t of informa t ion. Therefore , th ere have been no nee d t o have drip fee dTherefore , th ere have been no nee d t o have drip fee dinforma t ion syst em , like, Direc t Numerical Con t rol. informa t ion syst em , like, Direc t Numerical Con t rol.

Ins t ea d, Dist ribut ed Numerical Con t rol is int roduce d. In Ins t ea d, Dist ribut ed Numerical Con t rol is int roduce d. In suc h a syst em , a hos t compu t er communica t e with man ysuc h a syst em , a hos t compu t er communica t e with man yCNCmac hine t ools via ne t works an d d ownloa d or uploa dCNCmac hine t ools via ne t works an d d ownloa d or uploa dprograms.programs.

D istributed Numerical Control ( D NC)D istributed Numerical Control ( D NC) ::



132/136

20042004 132132

With Dist ribut ed Numerical Con t rol syst ems , it is With Dist ribut ed Numerical Con t rol syst ems , it is

possi ble t o moni t or the ac t ivit ies in individual CNCpossi ble t o moni t or the ac t ivit ies in individual CNCmac hine t ools on hos t compu t er. mac hine t ools on hos t compu t er.

Therefore , b e tt er shop floor con t rol can be achieve d.Therefore , b e tt er shop floor con t rol can be achieve d.

D istributed Numerical Control ( D NC)D istributed Numerical Control ( D NC) :: ( conts )



133/136

20042004 133133

NC program prepara t ion ma y be t edious an d d ifficult NC program prepara t ion ma y be t edious an d d ifficult if the par t t o be mac hined h as a comple x geome t ry. if the par t t o be mac hined h as a comple x geome t ry. The main difficulty is t o find ou t th e cu tt er loca t ions The main difficulty is t o find ou t th e cu tt er loca t ions during the mac hining. during the mac hining.

Compu

t ers

ma

y be

use

d t o

assis

t the

programmers

in

Compu

t ers

ma

y be

use

d t o

assis

t the

programmers

in

preparing the NC codes.preparing the NC codes.

Computer Aided Part Programming :Computer Aided Part Programming :



134/136

20042004 134134

Advantag e s of applying comput e r Advantag e s of applying comput e r -- aid e d aid e d part programming includ e th e follo w ingpart programming includ e th e follo w ing :

It re duces the manual calcula t ions involves in It re duces the manual calcula t ions involves in

de t ermining the geome t ric charac t eris t ics of the par t .de t ermining the geome t ric charac t eris t ics of the par t .It provides the cu tt er pa th simula t ion.It provides the cu tt er pa th simula t ion.

It provides t ool collision checking.It provides t ool collision checking.

It short ens the program prepara t ion t ime.It short ens the program prepara t ion t ime.

It makes the program prepara t ion easier.It makes the program prepara t ion easier.


135/136


136/136

002-cnc machine tools+programming

Documents