No 36 - March 2002

T H E C N C A N D S E R V O M O T O R S + D R I V E S M A G A Z I N E

informationnum

Num,CNC Complete SolutionsNum,CNC Complete Solutions

CORPORATE NEWSA pro-active Strategy toanticipate Market Needs

SOLUTIONSTurning, Polishing,Grinding, Milling…

Num: CNC Complete Solutions

num information n° 362

rements, aims and pro-blems. This was exactlywhat Num decided toachieve: to be the CNCspecialist capable ofproviding complete sys-tems totally tailored toeach customer's needs.“Isn't the best way ofsatisfying customers tobe a significant factor intheir success?” queriesAlain Digeon, Num'sGeneral Director.

Multi-disciplinaryKnow-HowWith the CNC/Drivepackages they have beenrecommending for several

A Pro-active Strategyto Anticipate Market Needs

years, Num was alreadycatering to the OEM'sneed to find systemsrather than just products.The packages were ahomogeneous assemblyof units optimized to worktogether. Today Numdoes far more than justsupply equipment. “Weprovide our customerswith wide-ranging know-how,” states Alain Digeon.“We give them the benefitof our three areas ofexpertise: hardware, soft-ware and brainware. Thatis to say, technical exper-tise with not only hardwareand software, but alsoskills in production tech-niques and leading edgeapplications as well.”“It is essential to be fami-liar with the languageused by customers intheir area of activity,”continues Alain Digeon.“This makes it easier toanalyze their require-ments and specificfeatures so as to have abetter understanding ofwhat they want and tocomply with their needs.This approach must notbe restricted by salesarea,” he adds, “which iswhy we are organizedby markets. Segmentingour customers accordingto their main activity,s i m p l e o r c o m p l e xmetalworking machines,special machines, theautomotive industry orwoodworking machinesputs us in a better posi-tion to understand thechanges taking place ineach area on an interna-tional scale. In this, we

are completely in phasewith our parent company,Schneider Electric.”

A SystemsApproach for EndUsers As Well“Our familiarity with theapplications,” adds HansBachmann, Vice Presi-dent of Num, “allows usto approach problemsfrom different angles tofind global solutions. Thisis moreover one of thereasons why we propose,in some cases, to takecomplete or partial res-ponsibility for a project.In the same philosophy,we develop applicationsdedicated to certain nichemarkets that we conti-nually improve and reno-vate. NUMROTOplus®,our tool machining andsharpening software, is aperfect example of this.”It is interesting to pointout that this customer-oriented strategy is notlimited to new equipmentand OEMs. Quite thecontrary. Num providessupport throughout thelife cycle of a machine,from inception throughinstallation, commissio-ning and operation toeventual re-engineering.Demonstrating the impor-tance of end users, HansBachmann confides, “Weconsider that our custo-mer's customers are ourcustomers, which is whywe propose a range ofservices (see opposite)and retrofit equipment(see p. 4). This can be thebest way for a user to keepa machine in production

CORPORATE NEWS

I n the current worldeconomic climate,the future successof a company hinges

on being able to satisfytwo contradictory needs:the need to be profitable,in the light of increasingpressure on prices, makinginvestment conditionsmore and more severe,and at the same time,the need to innovateand enhance in order todevelop, driven on bytechnological changes.Under these conditions,success may mean findingthe right partner, attentiveto the customers' requi-

Come andsee us atour stand:

C89,Hall 5.

With the rising pressure to be more competitive, more productive and keep ahead technologically,the relationship between customer and supplier is radically changing. Anticipating this, Num hasalready adopted a strongly customer-oriented strategy.

More Hardware, More Software, More Brainware

Alain DigeonNum’s General Director

(left)and Hans Bachmann

Vice-President of Num(right)

3num information n° 36

Num : Winning Services!

T oday, produc-tion units needto respond fast,establish and

meet a delivery schedule,be able to switch frommanufacture of one itemto another, manage just-in-time procurements andensure a consistently highlevel of quality.“In addition, it is becomingincreasingly difficult tohave a high level of exper-tise in all the new tech-nologies. That is why manycompanies are refocusingon their core businessand outsourcing periphe-ral jobs to specialists,”explains Jean Caubit,Manager of Num's Custo-mer Service Department.“Our expertise in machineautomation is widelyrecognized. So it waslogical for Num to allowits customers to benefitfrom its know-how.”

A StructuredRange ofServicesProviding service is nothingnew for Num. What hasdefinitely changed is thatNum now markets astructured range ofservices built around

identified needs. Forinstance, for spare parts,there are several typesof subscriptions andcontracts. Similarly, thehot line has now beenorganized as a call centerproviding different levelsof service, aimed atanswering customersmore rapidly. There havealso been changes intraining. A complete CNCtraining cycle is nowavai lable under theauspices of the SchneiderTraining Institute, withdifferent approachesdepending on the trai-nees' background: frominitiation, they progressto operation and fromthere to maintenanceand evendesign. Thet r a i n i n gm a i n l yconsists ofhands-onexercises,allowing thetrainees toi m p r o v etheir know-ledge andobtain a realoperationalbenefit. Inparallel, as

and get optimal returnson his investment,” headds.

The Powerof a Major GroupNum's strategic role in theSchneider Electric Groupshould also be noted. Forinstance, the purchase ofthe manufacturer BergerLahr definitely confirmedSchneider Electr ic 'sambitions in the area ofmachine automation. Thecreation of the MotionControl strategic activity,including Num for pathcontrol, Berger Lahr for

position control, Schnei-der's Lexium activity, etc.will allow the creation ofsynergies in order to bein an even better positionto meet OEM needs (seeNum Info No 35). But thatis not the only reason.“We feel it is essentialto integrate our systemsin Schneider Electric'sglobal automation archi-tectures, “concludes AlainDigeon.“It is now becoming neces-sary to take into accountthe New Information andCommunication Tech-niques (NICT).” It is true

an approved trainingcenter, Num also providesspecial training coursestailored to customerneeds.

EquipmentAudit forFuture-ProofingT h e a u d i t , a b a s i ccomponent of Num'sservices, has severalpurposes: to extend thelife of machines in thefield, plan investments,optimize spare partsmanagement, assesstraining needs, preventobsolescence, etc. “Thebyword is anticipation,”explains Eric Le Joliff,Services DevelopmentManager. “To be more

Jean Caubit,Manager of Num’sCustomer Service

Department:“Our expertise in

machine automationis widely recognized,

so it was logical forNum to allow its

customers to benefitfrom its know-how.”

For Alain Digeon, thebest way to satisfycustomers is to be asignificant factor intheir success. That'swhy Num developsand continuouslyupgrades integrationand operating toolsas well as completeapplications, asdemonstrated by themost recent versionof NUMROTOpluswith 3D simulation.

responsive, we have toavoid surprises by aserious, rigorous audit ofthe customer's equip-ment. That is the startingpoint for drawing up a listof preventive actionswhich will decrease therisks of failures and helpmake the right decisionsshould replacement provenecessary. This avoidspanic and disruption,because a problem thathas been planned for ismuch less traumatizingwhen it occurs. People aremore efficient becausethey know what to do!”These services were firsttested in France and willbe gradually extended toother countries.

Eric Le Joliff,ServicesDevelopmentManager: “Foraudits, thebyword isanticipation.”

that by the nature of itsproducts, Num is a keyelement between theworld of machines andinstallations.

num information n° 364

PRODUCTS

Num Power: Compact,Flexible and Highly Efficient

Get a New 10-Year Lease on Life with theNum Power 1760!

W h a t i sw o r s ethan tol o s e

confidence in a productiontool? That's what happenswhen you notice certainmachines are getting old.They may not seem to bewearing out and mayhave been kept in shiningcondition, but the risks ofdowntime jeopardizingproduction lead-times area real sword of Damocles.In such a situation, aretrofit is the solution thatcomes naturally to mind.But it isn't always easy,often requiring re-wiring,mechanical adjustmentsand at times even some

re-writing of part programs.That's why Num havedeveloped the NumPower 1760 CNC, in bothlathe and milling machineversions.Designed to upgrademachines equipped withNum 760 and 750 CNCs,this new CNC replacesthe old one without anychanges in wiring orinstallation. Moreover, itis fully compatible asregards part programsand axis connections,so that no changes arerequired in the drives. Asfor getting used to it, thatis no trouble because thekey arrangement is thesame as on the Num 760

and 750 keyboards.Even better, the mono-chrome screen is replacedby a 10.4 inch colour LCD

giving a much betterpicture. The Num Power1760 also has a highercalculation speed, which

D esigned toreplace theexisting 1000family, Num

Power CNCs benefit froma new platform providingdecisive extra power. Theperformance is 30 percent,

(in some cases 40 percent,)better than the currentplatforms!With their new generationprocessors, Num PowerCNCs have much shorterPLC program executionand block preparationtimes than their prede-cessors. In addition, thelook-ahead function alsoimproves the systemresponse and the availabilityof a co-processor optimizesfloating point calculationtimes for dynamic opera-tors in C.

More memory space isavailable for the CNC, PLCand HMI programs and asthe operating system is inFlash memory, it is veryquick to upgrade. NumPower CNCs also comewith a multi-standardserial line and an additionalinterrupt input.

From 2 to 32axesAll the connections aremade on the front tofacilitate wiring. The sys-tem is very compact,

saving considerable space,especially in high-endconfigurations. The NumPower 1000 line hasadded two additionalmodel to the Num’s rangeof analog CNC’s. Thenew series now covers fivereferences, Num Power1020, 1040, 1050, 1060and 1080 CNCs. Theyoffer highly efficient solu-tions for the automationof all types of machinesfrom 2 to 32 axes and upto 1024 PLC inputs/outputs.

Last, but by no meansleast, Num Power 1000CNCs are downwardlycompatible with theexisting 1000 family.Considering the numberof Num 1000 CNCsinstalled and their success,the Num Power 1000CNCs offer an excellentupgrade path which fullyprotects those invest-ments already made inpart programs and APIs.

The Num Power 1000 line includes five models:Num Power 1020, 1040, 1050, 1060 and 1080CNCs. They offer highly efficient solutions forautomation of all types of machines from2 to 32 axes and up to 1024 PLC inputs/outputs.

can mean gains inproductivity.The Num Power 1760CNC doesn't just have

functional advan-tages, it alsobrings security,allowing the useof the productiontool for at least 10more years.Don't hesitate tocontact us...

The Num Power1760 CNCis an attractiveway of solvingretrofitproblems.

5num information n° 36

O ne area where key knowledge is acquiredis in the field of application support.Experience gained on a wide varietyof cases can enhance efficiency and

responsiveness. Fully aware of this, Num hasgrouped all its applications support services intoa single department to create a genuinely inter-national centre of expertise. By building on its vastexperience, Num improves the quality of itssupport (consulting and technical assistance) andservices (analysis, creation of special programsfor customers, commissioning, etc.).

Strengthening the SubsidiaryInterchangesThis new department, called Application/Tech-nique, groups all the support services presentin each subsidiary. “Our aim is to establish realpartnerships with our customers,” explainsPeter Hutter, in charge of the activity, “because

Peter Hutter:“Our aim is toestablish realpartnershipswith our customers.”

Genuine International Support

the success of a personalizedsolution always has an impacton Num's reputation.We defi-nitely need to adopt a globalapproach without borders.Thiscan only be done by creatingconditions which encourageinformation exchange between us and ourcustomers and also among our subsidiaries.”With this new organization, Num demonstratesits determination to keep developing its appli-cations services as regards the implementationof technical solutions (see p.7 and 8), dedicatedHuman/Machine Interfaces (see below and p.6),and more generally, all possible collaborationsthat can contribute to customer satisfaction.

SOLUTIONS

T his manufacturer belongs to the leadingFrench machine tool group and has spe-cialized in turning for nearly a century.Today, it has one of the widest product

lines on the market, ranging from conventionallathes to the most sophisticated machines.The Optica machines are based on a conventionallathe structure and benefit from a CNC-assistedcontrol designed around a Num 1040 CNC witha dedicated Human/Machine Interface.This CNCwas chosen for its enormous possibilities forcustomization. In addition, both manufacturerswere keenly aware of training issues.

Complex Shapes and Roughingand finishing Cycles Initial functions implemented: display of certainmachine data on an LCD and replacement ofmechanical limit switches by software ones.Thisprocess led to a major decrease in setting times.For ease of setup, the thread re-workingfunction (metric, Whitworth, taper, etc.) wasobviously the center of attention. In conjunctionwith a special key, this function directly positionsthe tool in the thread to facilitate re-machining.

Similarly, automatictool offsets greatlysimplify the operator'sjob, and sequencingof radii and slopesallows the machiningof complex shapes,doing away with theneed for copyingmachines.This functionhas been recentlyenhanced.Even more recently,the possibi l i ty of machining very complexparts, both roughing and finishing, now allowsthe operator to save a great deal of time.With their new equipment, the Optica lathes canreadily produce single parts, prototypes and smallruns and are very easy to learn to use, becausethey were developed BY lathe operators FOR latheoperators.

When the Conventional BecomesCutting Edge!

With its new line ofOptica lathes,Cazeneuve hasachieved asuccessful blendbetween the user-friendliness ofconventional lathesand the power ofCNC lathes.

Turning

Num has globalised its applications support networkto keep in closer touch with the needs of its customers.

num information n° 366

“The best way of being universal is to usethe language of the trade”

C ertain industrial processes are a realart. That is the case with polishing.Several of the polisher's senses arecalled into service to make a part: vision,

to see the effect produced; touch, to perform theaction, and hearing, to judge whether moreabrasive paste is required and listen for brushwear. Although automation is necessary to meetindustrial requirements, the operator musthave some leeway for self-expression. “For severaldecades,” states Bernard Bula, President of Bula,“I have been convinced that the experience andknow-how of the operators are a crucial factor.The machine is a marvelous tool, but it mustbe there to serve the operator, not the contrary.This being our philosophy, it was natural forus to attach special importance to the point ofcommunication between operator and machine,i.e. the Human/Machine Interface.”

Using the Language of the Trade,Not That of the Automatic ControlSpecialistPolishing generates highly complex paths that requirecontrolling from 5 to more than 30 axes to repro-duce the complex motions of the human hand.Polishing machines therefore generally userobots.“We began to think about the ergonomics of ourmachines back in 1988, when we filed our firstpatent applications,” continues Bernard Bula.“Then, little by little, the search for gains in

The use of a portableoperator panel allowsthe operator to movearound the machine.Moreover the Bulainterface ismultilingual

Bula is a Swissfamily-ownedcompany that

exports 95% ofits production andcovers the needs

of various markets,each with stringent

requirements:jewellery,

clockmaking,surgery, and theautomotive and

aviation industries.Bula machinesare practically

mass-produced.

Surface Treatment

That is the conviction of the president of Bula, a company specializing in surfacetreatment, polishing, deburring, grinding, etc.

performance orientedus to a CNC-basedsolution. Polishingoperations requireincreasing rigidityand there was norobot on the mar-ket that met ourrequirements foruser-friendliness.In addition, theCNC allows us touse the same HMIfor all our machines,which is a definiteadvan tage fo r

customers who use several of them.That is whenand why we chose Num.”This was the start of a real team effort.The majordifficulty was to translate the CNC operating modesinto the language of the trade and vice versa. Forseven months, the shop operators explained howthey worked to information systems and electronicengineers. “We are especially proud of makinga real contribution to the polishing trade,” explainsBernard Bula. Our teach-in function allows thepolisher to work on the machine without havingto program a single line of code.The Num CNCis so user-friendly that only a few hours arenecessary to assimilate the basic operatingprinciples. It would have been much easier to trainthe operators of our Chinese customers a few yearsago if I had had a function like that. Thelanguage barrier is much less of an obstacle whenspeaking the language of the trade!”

Increasingly Independent OperationWith its integrated PLC, the CNC is also moreflexible.The same system controls brush speedand polishing paste distribution, and monitorsbrush wear. “With an ongoing concern foruser-friendliness, we are continuing to upgradeour machines, to make them increasinglyautomatic and independent,” continues BernardBula. “The newest generation includes accuratebrush wear monitoring, guaranteeing a constantquality of machining during the entire productionrun.”

SOLUTIONS

7num information n° 36

“Imitation Gets You Nowhere.You must innovate!”

Z aro was created in Italy in the 1960s andtoday is a recognized player in the toolsharpening and grinding market.The company is very successful and is

growing both in Italy and abroad (Germany, France,Switzerland, etc.). It's true that Zaro's success owesa lot to the personality of its president,TarcisioZaro, who based his entire strategy on beingattentive to market needs and to innovation. “Toget where we are today, we often needed toinnovate,” he explains. “We were the first onesin Italy in our sector to use horizontal axis CNCdividers. Also, to keep ahead of our largestcompetitors, we didn't hesitate to make thetransition from stepper motors to DC motors withencoders back in 1985. Already at that time, ourfirst 5-axis machine with gauging and dedicatedsoftware was machining tools using circular andhelical interpolation, not just linear.We developedthe system ourselves.Today, one of the keys to success is to get acomplete system to market rapidly. And in-housedevelopment can be a time-consuming process,which is why we chose NUMROTOplus® for our

most recent machine.”

Most recentZaro machine:Sharp Complet

Zaro, a tool sharpening and grinding machine manufacturer, has based its strategyon technologies and techniques for offering optimized solutions. Now Zaro haschosen NUMROTOplus®.

Tool Sharpening and Grinding

The Importance of a Global ApproachTool gashing and edge sharpening are complexoperations for which the quality of the algorithms,the sampling time and precision of execution areessential. Because of the special nature of thesemachining operations, the synergy or harmonybetween the mechanics, the software and the drivesystem must be perfect.The choice of an externalsolution must in no way detract from the conceptof the machine. “In addition to innovations suchas electric spindle with dual outlet or automaticcontrol of coolant, it was with this overall conceptin mind that we designed our most recent SharpComplet machine,” continues Tarcisio Zaro. “Wewere supported in this by the strong commitmentof the Num team, who not only adapted theNUMROTOplus® software to the mechanicalsystem of our machine,but also helped us optimizethe servo drives. This collaboration moreovercontinued during design of the PLC program andsetting of the system parameters. Tests rapidlydemonstrated the efficiency of our mechanicalsystems as well as the flexibility of the Num Power1050 CNC and drives.”“A performance analysis based on criteria suchas contour precision, surface finish, motionreversal speeds, programmed path look-ahead andthe speed of response of the Num MDLU andMBLD drives has demonstrated the structuralstability of our Sharp Complet machine,” he added.

Fast and Successful Implementation!All these features allow the users to create andsharpen their tools accurately while preservingthe symmetry and geometry of the cutting edges.Operations such as gashing and grinding thecutting and clearance angles are made easy byNUMROTOplus®'s user-friendly interface.Introduced at the recent Hanover EMO, theimplementation of NUMROTOplus® and the newdrive system only took a few months. Four monthslater, another a new machine was shipped toGermany. That made it the16th...Finally, innovating is not only finding a technicalsolution to satisfy market needs, but also inadapting it for the best possible implementation.

num information n° 368

SOLUTIONS

W e i n g ä r t n e rMaschinenbauis located inthe small Aus-

trian city of Kirchham, butits special milling machinesand thread cutting machinesare known all over theworld.They are the bench-mark for the manufacture ofeccentric gears, rotors/stators,injection molding and extru-sion screws and precisionthreaded spindles. Most oil

field equipment suppliers use Weingärtnermachines, because the milling of drive rotorsfor oil drilling (mud motors) is a specialty of theAustrian firm. It also has many enthusiasticcustomers among plastic processing machine manu-facturers.These activities require reduced machiningtimes and a high level of quality. A high-speedversion of the Vario machine was therefore deve-loped, partly at the instigation of the customers,even though the previous model had been intro-duced only 18 months earlier. Stated aim: reducethe milling speed to nine seconds per revolution,down from 12, on a reference part, i.e. a six startsthreaded drive rotor with a diameter of 60 mmfor drilling equipment, under actual productionconditions.

Two of Num's Strong Points:Competence and Co-operationIt was not enough to make a few minor changes.The entire mechanical system of the Vario 700had to be re-engineered and decisive factors suchas the X, C and A axes had to be re-designed.They needed to be made lighter and more dyna-mic. The CNC had an essential role to play inthis respect.The management of Weingärtner lostno time in choosing a supplier.They had alreadybeen using Num CNCs for many years on theirmachines, to their complete satisfaction. JosefGrimm, Manager of the Special MachineProduction Unit, clearly states why NumCNCs were chosen over and over: “Num hasdecisive advantages over its competitorsespecially in the field of special machines, in termsof CNC openness, speed, precision and surfacequality.” He adds: “I don't know any other

Control is by a NumPower 1050 CNC withan optical link for theI/O and digital bus for

the axes.

A Completely Digital SystemFor Faster WorkingWeingärtner's Vario HS 700 high-speed cutting machine is a special thread cutting machine which mainly machines rotors and wormscrews. Compared with the previous model, the machining time was cut in half by the new mechanical system, the Num Power 1050CNC and its digital drives.

manufacturer as competent as Num and asco-operative for developing new projects and newmachines.This saves us time and gives us confi-dence.”Since Num has vast experience in the area ofhigh-speed cutting, it was closely involved fromthe outset in the development of the high-speedmachine.The developers relied on the Num Power1050 together with its digital drives: “The onlyway of achieving the required speed andprecision was by complete digital coupling of thedrives and CNC, provided, of course, that themechanical system was up to par.”

Six SecondsInstead of Nine!This was recently demonstrated when thecustomer took delivery of the first Vario HS 700high-speed machine. It did much better than therequired nine seconds per revolution. Thecustomer is currently achieving a speed of sixseconds per revolution on this machine.The CNCand drives would be capable of doing evenbetter, down to just over four seconds, but thatwould cause excessive wear and therefore a lossof yield. Josef Grimm is rightly proud of thesuccess of his machine and appreciates Num'scollaboration on the project: “Num is ourpartner in the area of high-speed machining. Noother manufacturer can provide assistance likeNum's.”

The Vario HS 700 isabout twice as fast

as the earlier versionintroduced just 18

months before.

Milling and High-Speed Cutting (HSC)

The reference part, asix-start screw with adiameter of 60 mm, isnow machined at aspeed of six secondsper revolution.

9num information n° 36

M eccanica Ponte Chiese is an Italianfamily-operated company locatedin the province of Brescia. It hasspecialized in mechanical subcon-

tracting since 1973. In 1988, the companypurchased its first CNC machine: an MCMmachining center equipped with a Num 760 anda palletizing system controlled by a Robonum800.“With the arrival of this machine,” explainsGiovanni Ferraboli, company owner, “wesignificantly improved our performance, especiallyin terms of precision.We make medium and largeparts for construction machinery, the automotiveand textile industries and ships.”Because of the success of this first purchase,Meccanica Ponte Chiese initiated a majorflexible machine shop project.This project, veryexpensive but with huge potential, led to thesuccessive purchase of three new MCM Actionsystems, each with a 400-tool carousel andcontrolled by a Num CNC (two by Num 1060sand the last by a 12-axis Num Power 1050 CNCwith Num Drive digital axes and spindledrives). “We were attracted by the uniform lookand feel, the user-friendliness and the performanceof the Num products,” states Giovanni Ferraboli.At the same time, a multiplexed network was setup to monitor several machining stations fromthe same terminal and control them from thatsame panel. Finally, MCM software handledsupervision and communication between all unitsand with the production management system.“Not only did this new shop increase ourproductivity and profitability,” explains GiovanniFerraboli, “it also improved our workingconditions. The platform conveyor system is a

good example: robot-controlled and battery-operated, it has indisputable advantages ofconvenience and silence, considering thenumber and size of our parts.”

Simultaneous Machining of DifferentParts!Since the operation is continuous, loading andunloading take place in masked time. But the mostremarkable feature is the capability of mixingdifferent parts on the line. “Assubcontractors, we have toproduce batches of differenttypes and quantities,” saysGiovanni Ferraboli. “It wastherefore very important formachine operation and loadingto be very flexible, which is whywe designed a highly versatilesystem platform.”The speed at which the employeeswere operational, the generalview of the work area, the speedof movement and the level ofprecision achieved, as well as lasercontrol of the tools all convinceGiovanni Ferraboli that he made the right choice.“We have an undeniable edge over the compe-tition as regards production capacity and leadtimes, flexibility and cost price,” he asserts.“Todaymore than ever, we need to reduce our productioncosts and make our investments pay back. Fora subcontractor, definition of the production toolis a very sensitive issue, because it is thedominant factor for keeping our customersand winning new ones. That is why it is soimportant to have a flexible tool.”In addition, Meccanica Ponte Chiese is able toprovide additional services such as a dimensionalcheck of parts in the measurement room orqualification of materials.“The best way to remain competitive,” concludesGiovanni Ferraboli, “is through experience.Thatis why I chose Num.”

Automatic platformrouting phase

APPLICATIONS

Flexible Shop

Loadingof a blank

With its fully automatic shop including several MCM machining centers,all controlled by Num CNCs, Meccanica Ponte Chiese undeniablyhas a competitive edge.

Num Contributes to Meccanica Ponte Chiese's Productivity

Schematic diagram ofthe systems of PonteChiese Shop - Theparts are conveyedfrom one machine toanother by anautomatic shuttle.

num information n° 3610

Often misunderstood, the RTCP function has considerableadvantages for 5-axis machining.

PRATICAL INFORMATION

RTCP Function: Never Lose Contact

F or shaping jobsin the molding,bodywork andwoodworking

industries, it is oftennecessary to accuratelykeep a constant anglebetween the tool and thesurface to be machined.This is what we naturallydo with our wrist when wepaint: to draw a thin line,we hold the tip of the brushperpendicular to thecanvas, whereas to drawa thicker line, we naturallyhold the brush at anangle and pull it in thedirection of the bristles. Weinstinctively keep thebrush in contact with thecanvas and at the desiredangle to the surface to bepainted.For machining, it is therotary axes of the machinethat play the part of thewrist (e.g. a dual rotarytool-head, or a table andcradle holding the part).These axes allow the toolor part to rotate aroundaxes exactly like a wrist.This type of setup isfound on 4- and 5-axismilling machines.Things are much morecomplicated when thesurface to be followed isn'tflat like a canvas but hasan irregular shape. Keeping the tool in contactwith the part then requirestaking into account all theoffsets due to the tool-head mechanics, toollength, etc. (see sketchopposite). The enormousadvantage of the RTCPfunction is that it notonly manages all theseoffsets automatically butin addition guaranteesthat the tool is effectively

X

Y

Z

B

45

C

B

C

L

Y1

Z1

Yc

XcZc

Zb

Xb

Yb

45

Milling, Molding, Shaping, etc.

The RTCP function (Rotation around Tool Center Point) determinesthe tool position with respect to the part using the tool center asreference.

Pict

ure:

For

est-

Liné

- Ae

rost

ar 5

axe

s M

achi

ne

i n contac t w i th theprogrammed point.

A Guaranteeof EnhancedPrecisionOne of the advantages ofthe RTCP function is thatit uses the contact pointas the reference point inall the calculations. Theuser therefore directlyprograms the machineusing the part contour andindicating the desiredtool angle. The CNC thendetermines the position ofthe tool-head and all theaxes so as to reach thispoint. In addition to asignificant saving of timeand simplification of theCAD/CAM system, theuser is also certain ofcorrectly remaining incontact with the surfaceto be machined. Conver-sely, without the RTCPfunction, the referencepoint is the tool-headposition and the contactpoint is determinedmechanically from thisreference point byapplication of all themechanical shifts.This difference between“contact point used asreference point” and“contact point obtained

RTCP at Num

As a pioneer of the RTCP function, Num hasa definite advantage in this area. As is its

habit, Num has also developed a particularlyuser-friendly application, designed to allowOEMs to set up the function rapidly and easilybased on the mechanical properties of hismachine.To do so, the OEM defines the tool-headgeometry on graphic views and entersthe dimensions of his specific mechanicalsystem (see screen below).

the tools used, since theprogrammed coordinatesare those of the contour,not the machine. Similarly,it is possible to apply a tooloffset without changing thepart program. In addition,RTCP is part of the CNCpost-processor, whichmakes part programsmore portable.The quality of surfacecondition is controlledmuch better, since, hereagain, the programmedspeed is applied to thecontact point, not to therotary tool-head, whichpreserves optimal surfaceconditions.Last but not least, withRTCP, the part programis smaller and takes upmuch less memory space.Still not convinced?

11num information n° 36

HIGHLIGHTmechanically” is key. Forinstance, with a pivotlength of 600 mm (thelength between the tool tipand the center of the rotaryhead), a positioning errorof only one-hundredthof a degree (1/36,000revolution!) causes anerror of 0.1 mm.With the RTCP function,this error exists on thetool-head, but the contactpoint remains correct.Without the RTCP function,this error exists on the tooltip with the result that thepart may be either dama-ged or the tool doesn'ttouch!

ProgrammingIndependentof the Machineand Tool!This RTCP function alsohas many other importantadvantages! The programis independent of themachine and especially of

RTCP parametersetting screen.In addition to the fourkinematic variables(angle 1, U1, V1, W1),24 different geometriesare proposed (dualrotary tool-headsand tables).

Throughout this year,right across Europe,we will be pleased towelcome you at variousexhibitions.

You can discuss yourprojects with us andtogether we will deter-mine the best solutionfor your requirements.

During the first halfof 2002 you can findus at :

BIEHM11th - 16th March

Bilbao, Spain

Machine-Outil19th - 23th March

Villepinte, France

GrindTec20th - 23th March

Augsburg, Germany

Num’s ExhibitionsHannover Fair15th - 20th April

Hannover, Germany

MayPiedra8th - 11th May

Madrid, Spain

Xylexpo 21th - 25th May

Milano, Italy

SIAMS23th - 27th May

Moutier, Switzerland

Drives and Control28th - 30th May

Birmingham, GB

JuneMETAV4th - 8th June

Düsseldorf, Germany

Published by Num SA21, avenue du Maréchal-Foch - BP 68F-95101 Argenteuil CedexTel.: +33 (0)1 34 23 66 66Fax: +33 (0)1 34 23 65 49www.schneider-num.comUnited StatesNum Corporation (USA)603 East Diehl Road,Suite 115,Naperville, IL 60563Tel.: +1 630/505-7722Fax: +1 630/505-7754E-mail: sales@num-usa.comwww.num-usa.comUnited KingdomNum (UK) LtdUnit C, Brandon Court,Leofric Business ParkCoventry CV3 2TETel.: +44 24 7644 4233Fax: +44 24 7644 4117E-mail: sales@num-uk.comwww.num-uk.comEditor: Laurence PetitguyotRealized by: AVANAOrléans (France)33 2 38 77 88 88ISSN 0248-73061st quarter 2002

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Computer Numerical ControlsMore Hardware, more Software,more Brainware. More Num.

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