Motion The customer magazine of - GRINDING · PDF fileMotion The customer magazine of ... Rulebreaker® – How to overtake your competitors by ... PRODEX.CH GRINDING SYMPOSIUM SYMPOSIUM

Motion01.2014

The customer magazine of the UNITED GRINDING Group

INTERVIEW Stephan Nell on the future of grinding

STATION TO STATION The technology presentations at a glance

TALKING HEADS The Symposium lectures

GRINDING SYMPOSIUM21 – 23 May 2014

Guide to all stations

All lectures available to read

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IN THIS MOTION EDITION YOU WILL FIND:

3 WELCOME

Stephan Nell, CEO of the UNITED GRINDING Group, on the Grinding Symposium

4 NEWS

“Added value”: The new machine design in the press; Symposium in numbers; Shower of accolades for Motion; Motion calendar

6 THE FUTURE OF GRINDING

The third Grinding Symposium of the UNITED GRINDING Group highlights the trends of tomorrow and beyond

8 “REDUCING AUXILIARY TIMES”

CEO Stephan Nell in interview, discussing new technolo-gies, innovative production systems and where the most signifi cant effi ciency gains can currently be achieved

11 STATIONS

Visitors to the Grinding Symposium can experience technologies in action at 14 stations

01_More effi cient production with the PROKOS XT 02_Tool and die making technologies03_Grinding of crankshaft bearings04_Internal grinding expertise 05_Software for effi ciency and precision06_Centerless grinding using angular plunge07_Customer Care 08_For high productivity 09_Quick and fl exible10_Productivity and complete machining11_Superproductive grinding of indexable inserts12_Laser or grinding technology? 13_Tool control with Tool Measure Interface14_Effi ciency using the latest software solutions

27 PRESENTATIONS

Developments in the grinding machine industry and in industrial production will be outlined in 20 presentations grouped into fi ve technical conferences

TECHNICAL CONFERENCES

I_INTELLIGENT PRODUCTION

Rulebreaker® – How to overtake your competitors by breaking rulesProfessional intelligenceTrends in grinding technologyManufacturing expertise as the basis for innovations

II_ SURFACE AND PROFILE GRINDING

Speed stroke grinding of high-performance ceramicsRazorTec® – Effective grinding wheel cleaningTrends in grinding tool developmentGrinding tool design

III_ PRODUCTION CYLINDRICAL GRINDING

Increasing performance in external cylindrical grindingVibrations during centerless grindingEffi cient use of cooling lubricantsCBN grinding in mass production

IV_TOOL GRINDING

Tool grinding with the highest precision3D laser material machiningUse of cutting-edge measuring technologySolid metal high-performance tools

V_UNIVERSAL CYLINDRICAL GRINDING

Thermal behavior of machine toolsLatest grinding and dressing technologiesDynamic stability of grinding machines Computer-aided cylindrical grinding processes

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EDITORIAL DETAILSPUBLISHER United Grinding Group AG, Jubiläumsstraße 95, 3005 Bern RESPONSIBLE Sandro Bottazzo PUBLICA-TION MANAGER Philippe Selot CHIEF EDITOR Michael Hopp (responsible for the purposes of press law) ART DIRECTION Jessica Winter OPERATION MANAGER Niels Baumgarten PICTURE EDITING Julia Peukert AUTHORS Klaus Jopp, Heinz-Jürgen Köhler (copy edi-tor), Merle-Sophie Röhl, Ira Schoers LAYOUT Tobias Heidmeier, Sandra Rudl PRODUCTION Claude Hellweg (Mgr.), Stefanie Albrecht PUBLISHING HOUSE AND ADDRESS OF EDITORIAL OFFICE HOFFMANN UND CAMPE VERLAG GmbH, Harvestehuder Weg 42, 20149 Hamburg, Tel. +49.40.44 188-457, Fax +49.40.44 188-236 MANAGEMENT Chris-tian Breid, Dr. Kai Laakmann, Christian Schlottau ACCOUNT MANAGER Niels Baumgarten LITHO PX2, Hamburg PRINT-ING Neef-Stumme premium printing, Wittingen. Printed on FSC®-certifi ed paper (FSC® - C 1857)

All brands denoted with ® are registered as a basic trademark at least in Switzerland or Germany, and are therefore entitled to use the mark.

“YOUR SUCCESS IS OUR SUCCESS – IN THIS SPIRIT, WELCOME TO THE GRINDING SYMPOSIUM.”

Stephan Nell,CEO, United Grinding Group AG

“Anyone who waxes lyrical about the future is all the more credible, if he takes account of reality.“

DEAR READERS,

Buzzwords that crop up immediately with reference to industrial production are Industry 4.0 and 3D printers, or additive, multidimensional manufacturing processes. Production machines communicate with each other, and the 3D printer produces complex parts. The engineers and software developers at UNITED GRINDING have for a long time been working on many developments aimed at networked production.

But anyone who talks about Industry 4.0 and 3D printers is all the more credible, if he also takes account of reality. And a number of questions then arise: What is the signifi cance of the still far from assured intelligence of the workpiece? What is the situation with the energy consumption of individual processes? And which surface quality can actually be achieved?

The UNITED GRINDING Group does not make its work subject to trends and buzzwords, but to one key objective. Our primary task is TO MAKE YOU, OUR CUSTOMERS, EVEN MORE SUCCESSFUL. Let’s be honest: It is always crucial to manufacture the required products in the highest quality, in the shortest time and with the lowest consumption of resources. This applies yesterday, today and tomorrow.

We can support you in this task. With machines of the best quality, with our extensive range of services, with our know-how – and now, this spring, with hours of inspiration at the Grinding Symposium. In this spirit I am delighted to welcome you to Thun, and LOOK FORWARD TO ENGAGING IN DIALOG WITH YOU AND TO HEARING YOUR SUGGESTIONS.

I wish you an enjoyable time at the GRINDING SYMPOSIUM 2014 and hope you enjoy reading this special edition of our Motion customer magazine!

WELCOME

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UNITED GRINDING GROUP NEWSUNITED GRINDINUNITED GRINDING GROUP NEWS

UNITED GRINDING GROUP

AT THE PULSE OF INNOVATION AT THE EMO METALWORKING TRADE SHOW in September 2013 the UNITED GRINDING Group presented its new machine design and its new group brand. “The Rhythm of Innovation” was the motto of the event, where rhythm and power were provided by a fi lm clip of employees from eleven countries together with percussionists and dancers live on the stand.

Much recognition was received in the international trade press. The added value of the new design for custom-ers was emphasized by the Canadian “ Metalworking”. In addition to the modern look there are “a number of additional ergonomic advantages”, pointed out the “maschine + werkzeug” trade paper from Germany. “New image, new highlight”, enthused “Machine Market” from China.

The STUDER S11, presented at the trade fair for the fi rst time, was met with great in-terest. Its compactness is astonishing, wrote the German “MM MaschinenMarkt”. The icing on the cake, according to “Schweizer Maschinenmarkt”, “is its modern look, which will make suppliers’ production build-ings more visually appealing”. The S11 is not just the answer to users’ requirements, wrote the Thai information portal “Thai PR”, “but also sets new industrial standards with its compactness.”

“BUT THAT’S NOT THE ONLY REASON FOR THE MODERN LOOK OF THE NEW MACHINE DESIGN. IT OFFERS A NUMBER OF ERGONOMIC ADVANTAGES.” maschine + werkzeug, Germany

The new machine design guarantees excellent ergonomics and operability

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MÄGERLE BLOHM JUNG STUDER SCHAUDT MIKROSA WALTER EWAG

Motion 01.2014 5


SHOWER OF ACCO-LADES FOR “MOTION”

“OUTSTANDING” was the jury’s verdict on the UNITED GRINDING Group’s customer magazine at the US Spotlight Awards, where the magazine won the silver award. “Motion” impressed the jury with its clear structure, relevant contents and creative layout. The magazine held its ground against international competition of over 1500 corporate media.

The magazine won two further awards in competitions for corporate communi-cation in 2013. “Motion” won a special mention at the Galaxy Awards and received the GOOD DESIGN Award in the design competition with the same name.


MOTION CALENDAR

JULY 2014

14.– 17.7.2014 EASTPO, SHANGHAI, CHINAWWW.EMTE-EASTPO.COM

SEPTEMBER 20141.– 5.9.2014 CIEME, SHENYANG, CHINAWWW.CIEME.ORG.CN 8.– 13.9.2014 IMTS, CHICAGO, USAWWW.IMTS.COM

16.– 20.9.2014 AMB, STUTTGART, GERMANYWWW.MESSE-STUTTGART.DE/AMB

OCTOBER 201430.9.– 4.10.2014 Bi-MU, MILAN, ITALYWWW.BIMU.IT7.– 12.10.2014 TATEF, ISTANBUL, TURKEYWWW.TATEF.COM

NOVEMBER 201430.10.– 4.11.2014 JIMTOF, TOKIO, JAPANWWW.JIMTOF.ORG 18.– 21.11.2014 PRODEX, BASEL, SWITZERLANDWWW.PRODEX.CH

GRINDING SYMPOSIUM

SYMPOSIUM IN NUMBERS

16 294 m²

4 LANGUAGES

900min

174.9 t

is the area covered by Thun-Expo Exhibition Center, where the Symposium will take place. Seven percent of the area will be taken up by the stations, twelve percent by the catering tent.

of trends and innovations in the grinding machine sector and the manufacturing industry – presented by 20 renowned experts from all over the world.

will be spoken at the Grinding Sym-posium. Presentations and technology presentations will be held in German, Eng-lish, French or Italian and simultaneously translated into the other languages.

is the total weight of all machines that will be presented at the Symposium. These include several world innovations.

technology presentations at the 14 stations of the Grinding Sympo-sium will demonstrate application solutions to visitors – live on the spot.

3 days during which everything will revolve around hard fi ne machining in Thun.

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UNITED GRINDING GROUP RUBRIK

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THE FUTURE OF GRINDING At the Grinding Symposium from 21 – 23 May 2014 in Thun in Switzerland the UNITED GRINDING Group will discuss the grinding machine industry of tomorrow with its customers and external experts. The main focus will be on innovative production methods such as laser technologies and fully networked production concepts

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For the third time the UNITED GRINDING Group is inviting its cus-tomers to the Grinding Symposium.

Talks will be given by 20 prominent grind-ing and manufacturing experts from both the UNITED GRINDING Group and from research and industry during the three day event. These will encompass scenarios on the future of grinding, as well as outlin-ing the possibilities of innovative indus-trial production beyond the actual grinding process.

This theoretical approach to topics about the future will be complemented by practical demonstrations. Different innovations of the UNITED GRINDING Group can be experienced in action at 14 stations. During these technology pre-sentations new machines will be presen-ted, such as the JUNG JE600 for highest surface quality in die and tool making, or the SCHAUDT CrankGrind for high speed grinding of crankshafts. Customers can

THUN EXPO: BETWEEN LAKE AND MOUNTAINSThe Thun Expo Exhibition Center is located in the west of the city, between the castle and Lake Thun. The Grinding Symposium will occupy three auditori-ums, one for the technical colloquium and its talks, one for the technology presentations and one where visitors can meet and exchange information (photo, right).

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UNITED GRINDING GROUP INTERVIEW

IN CONVERSATION

STEPHAN NELLStephan Nell (46) joined STUDER in 2003 as Head of Sales. In 2005 he moved up to the Management. Since 2012 he has been CEO of the United Grinding Group AG.

“OUR CUSTOMERS’ SUCCESS IS THE KEY FACTOR”From laser to 3D printing: In this interview Stephan Nell, CEO of the UNITED GRINDING Group, talks about the relevance of new technologies for grinding machine manufacture and the true renewal and savings potential in the industry

“We look forward to discussing the

future of the industry with you in Thun”,

you write on the Grinding Symposium

website. What does the future hold for

the industry? How is it evolving?

Stephan Nell: If we already knew that, we wouldn’t need to discuss it. There are many trends, but no clear direction can be identifi ed at present. Buzzwords are defi nitely Industry 4.0 and 3D print-ers. We also pick up on topics beyond actual hard fi ne machining at the Grind-ing Symposium: How do I approach topics, how do I generate ideas, how do I deal with innovations?

It’s never quite clear what is meant by

the buzzword Industry 4.0. How can

it be defi ned for the grinding machine

industry?

Stephan Nell: One of the major themes is the networking of produc-tion. The main challenge in my view is that the workpiece in transit in production must have information. It must know in which processing state it is currently, and which processing step comes next. Today’s machines, their control and software, can process information, that’s not the problem.

also experience software demonstrations in Thun. These will include 13 innovative features from STUDER and the tool mea-sure interface, which connects grinding and measuring software on the WALTER HELITRONIC.

The combination of hardware and soft-ware, service topics and questions from the periphery of grinding illustrates the integ-rated approach of the UNITED GRINDING Group. CEO Stephan Nell cites making cus-tomers successful as the primary objective of his business activities. “The aim is to pro-duce the customer’s part in the highest qua-lity, in the shortest possible time, with the smallest possible use of resources.” High tech solutions are not always required here; sometimes it’s a matter of improved acces-sibility of the machine, as with the STUDER S11. “Often it’s the simple things that show potential for optimization”, says Nell.

The Symposium’s location on Lake Thun is also the headquarters of Fritz Studer AG. The UNITED GRINDING Group’s philosophy is also refl ected in the choice of location. We also want to fulfi ll the European quality pro-mise in international markets. “If you can ad-vertise Swiss or German quality”, says Ste-phan Nell, “that’s certainly no disadvantage in the global marketplace.” The customers of the UNITED GRINDING Group come from all markets in the world. “It is important to us”, emphasizes Stephan Nell, “to build a lo-cal, customer-oriented organization, which understands the customer’s language and culture. We want to offer our service and support for the customer’s production pro-cess locally.”

The question is, how do I provide the work-piece with this information?

Is the success of 3D printers continuing

in the industry? Will printing become the

new grinding? Stephan Nell: No, it won’t. Generically produced parts never have the surface quality of ground parts. In this respect the process is limited by the grain sizes, by the diameter of the laser beam – they cannot produce such fi ne surfaces. That’s why it won’t replace grinding. It will have an impact, as 3D printing infl uences global tool consumption – and tools are ground, after all. Also, the energy consumption of 3D printers is still far too high at present. In my opinion the process will therefore only become established to a limited extent in the near future.

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MÄGERLE BLOHM JUNG STUDER SCHAUDT MIKROSA WALTER EWAGP

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Futuristic maintenance tools are now

available, buzzword: Augmented Reality,

virtual space. Which role do such tech-

nologies play at UNITED GRINDING? Stephan Nell: We have been develop-ing the virtual machine for some years at STUDER. This represents a huge expendi-ture, and the advantages which it brings in comparison to the present simulation are negligible. We can simulate any machine room and mount any part, or conduct crash tests. The advantage of the virtual machine is so small that the costs are not feasible. We are developing in this direction for training purposes, but not for production at present.

How are innovation processes organized

within the group at UNITED GRINDING?

Stephan Nell: Each of our company brands has an innovation department, whose employees are solely concerned with the question of what the produc-tion process of tomorrow will be like. We control the amount that is used exclusively for innovations through the development budget. We thus avoid the danger of having no time for innovation in good times and no money for it in bad times. Then there are projects like the laser development at EWAG, which by no means concerns only EWAG. Such projects are often conducted in cooperation between the groups. One company is in the lead in development, but behind this an exchange always takes place between the technologies, and the knowledge gained naturally benefi ts each technology. This is one of the advan-tages that we have and utilize as UNITED GRINDING.

Where do you see the essential innova-

tion potential for grinding?

Stephan Nell: In the past, the main priority was optimal design of the grinding process. Today, the processes are already exhausted to some extent. There are constant in-novations on the machine side, or from wheel manufacturers or cooling lubricant suppliers. Higher removal rates are also made possible by higher machine rigidities. But I believe that the essential steps to be taken now are in reducing auxiliary times. Not just through the possibility of adapt-ing machines more easily and quickly. It is also possible to eliminate entire logistics chains through combination machining on one machine, for instance. A present-day MÄGERLE machine, for example, is in principle no longer a grinding machine, but a grinding-machining center, which

“WE TRY TO PROVIDE OUR CUSTOMERS WITH THE BEST POSSIBLE SUPPORT THROUGHOUT THE ENTIRE PRODUCT LIFE CYCLE, SO THAT THEIR PRODUCTION IS AS EFFICIENT AS POSSIBLE.”

Stephan Nell

can also mill, turn and drill. There are projects in which the number of machine tools involved in the production process can be substantially reduced – through the combination of machining technologies on our machines. This means advantages in investment, space requirement and in logistics: You don’t have to operate and fi t a large number of machines. These are all areas in which time can be hugely reduced.

This results in real leaps in productivity. One of UNITED GRINDING’s promises is

to increase its customers’ competitive-

ness. How do you plan to achieve this

today and in the future? Stephan Nell: We don’t just sell the customer a machine, but know-how. This starts with the initial consultation: What are the process steps like, how is the value creation chain structured and what is the

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UNITED GRINDING GROUP INTERVIEW

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sequence of the grinding process? We also offer support or training for employees. We have set up academies, in which we train customer employees and enable them to utilize the technology to its full potential and fi nd out where the limits are. Through preventive maintenance we endeavor to support the customer in optimizing the overall equipment effectiveness and to pre-vent unplanned machine downtimes. We record a large amount of data from the ma-chines, so that we can predict what must be replaced when and carry out scheduled maintenance. If the customer wishes to machine another part, we offer retooling support. We try to provide our customers with the best possible support throughout the machine’s entire life cycle, so that pro-duction is as effi cient as possible.

How do you handle data-based

customer care?

Stephan Nell: This involves a huge amount of effort. You have to collect and analyze a lot of data. Of course this also has a data protection aspect: The more data you have, the closer you may come to the customer’s production secrets. This is naturally a diffi cult boundary, and the whole process requires the customer’s input and agreement.

How does the group ensure its manufac-

turing expertise? Stephan Nell: Manufacturing expertise – this is an important aspect of our PuLs®

program. PuLs® stands for precision and passion, and this is our corporate philoso-phy. The emphasis is on avoiding waste, optimized processes and training our employees. For our production processes this means setting the benchmark in our industry worldwide. And if you consistently pursue this strategy, this means you must constantly improve.

“Close to the customer”, “zero distance”

– these are buzzwords that describe a

new customer proximity. What does

customer proximity mean for you? How

do you achieve it? Can digital technolo-

gies help?

Stephan Nell: Digital technologies certain-ly enable us to connect to a machine online. This certainly helps, but is not enough on its own. Proximity also has to do with the fact that we are present locally in the markets in which our customers operate. Proximity is geographical proximity on the one hand and cultural proximity on the other, which means understanding: What does my customer want? How does he live? What are his production processes? What is right for him? More than 450 employees in our after-sales division around the world apply themselves to such issues in the UNITED GRINDING Group.

To what extent does this customer prox-

imity inversely affect innovative power?

Stephan Nell: The closer you are to the customer, the better you understand your

customers, and an exchange takes place regarding their requirements. This helps to create innovations for other cultures, which we perhaps would not see of our own accord. This is how the S11 came about.

Another topic, which is connected with

innovation and leads us directly to the

Symposium: One of the speakers has

coined the term ‘Rulebreaker’. Where

has the UNITED GRINDING Group been

a rulebreaker?

Stephan Nell: In the past there have been developments, which were trend-setting innovations. The entire industry was infl u-enced by the grinding head with several wheels and the fi rst CNC-based machine, for instance. This really changed something, there were major upheavals. At the moment I can imagine that laser will be like this, but the potential of this technology is still at a very early stage. Finally: What are your expectations of

the Symposium, and what is your own

personal plan?

Stephan Nell: I will be there – but for the customers more than for the Symposium. I want to spend as much time as possible with customers, talk to them and hear what they want from us. This is an opportunity to see customers from all over the world. It would be fantastic if the customers go home and say, that was really worthwhile. What is also important to me: It’s not just about grinding. We also offer topics that have nothing to do with grinding – but with optimization, with improving in a wide range of different areas. And that is what we have established as our motto: We want to make our customers successful. And so we hope that we can add value for our customers.

Interview: Michael Hopp

“THE FOCUS IS ON AVOIDING WASTE THROUGHOUT THE ENTIRE PROCESS CHAIN – PuLs® IS OUR ANSWER TO THIS.”Stephan Nell

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SCHLEIFRING GRUPPE RUBRIK

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01 MORE EFFICIENT PRODUCTION WITH THE PROKOS XT

02 TECHNOLOGY FOR TOOL AND DIE MAKING

03 GRINDING OF CRANKSHAFT BEARINGS

04 INTERNAL GRINDING EXPERTISE

05 SOFTWARE FOR EFFICIENCY AND PRECISION

06 CENTERLESS GRINDING USING ANGULAR PLUNGING

07 CUSTOMER CARE

08 FOR HIGH PRODUCTIVITY

09 QUICK AND FLEXIBLE

10 PRODUCTIVITY AND COMPLETE MACHINING

11 SUPERPRODUCTIVE GRINDING OF INDEXABLE INSERTS

12 LASER OR GRINDING TECHNOLOGY?

13 TOOL CONTROL WITH TOOL MEASURE INTERFACE

14 EFFICIENCY USING THE LATEST SOFTWARE SOLUTIONS

Technologies can be experienced in action at 14 stations – from hardware and software through to a comprehensive service concept

STATION

STATION TO

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MORE EFFICIENT PRODUCTION WITH THE PROKOS XTSHORTER PROCESSING TIMES, reduced set-up effort and automated work processes ensure greater effi ciency in the production process. These production parameters can be positively infl uenced with the PROKOS XT complete machining center. It combines technologies such as speed stroke grinding, creep feed grinding as well as drilling and milling with a new, trend-setting software package for CAD/CAM connection. The result: an effi cient production solution, not just for machining turbine blades.

With the new software solution grind-ing, drilling and milling operations can be developed, simulated and subjected to a collision test on the PC, before the program is transferred to the machine. The software also supports BLOHM’s proven cycle pro-gramming. This range of functions is as yet unrivalled. The software allows the operator to change technological parameters such as number of cutting passes or dressing time directly on the machine as usual. If re-quired, these changes can be reintegrated

Simulation of the program in the design phase enables realistic information about the expected process times at an early stage

THE ADVANTAGES AT A GLANCE

Combination machining: grinding, drilling and milling in a single clamping

Reduction of set-up and auxiliary times thanks to CAD/CAM connection

Quick tool changer with 24 stations

Automation possible thanks to robot connection

Highest availability and reliability thanks to Siemens control system

“THE CAD/CAM CONNECTION M AKES A SIGNIFICANT CONTRIBUTION T O REDUCING SET-UP AND AUXILIARY TIMES.”Arne Hoffmann, Blohm Jung GmbH

into the program and all technological data can be stored in the CAM tool database.

The new software solution prevents errors during program creation, which can cause damage to the machine. Set-up of the machine is accelerated.

In combination with the trend-setting GreenCap® clamping concept and an ad-ditional rotational axis the PROKOS can be expanded into a six-axis machine, which is ideally suited for machining turbine blades in a single clamping.

Also demonstrated at Station 1 of the Grinding Symposium is RazorTech® – the new method for dressing and cleaning grinding wheels at process-dependent intervals, which reduces grinding wheel wear by up to 30 percent.

CONTACT [email protected]

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Motion 01.2014 13

02MÄGERLE BLOHM JUNG STUDER SCHAUDT MIKROSA WALTER EWAG

WITH TWO NEW SERIES, JUNG seamlessly continues the successes of the past: The J series, a CNC machine based on the familiar JUNG interface, currently com-prises two sizes: the J600 with a work area of 600 x 300 millimeters and the J800 (800 x 400). The new JE600 will be pre-sented at the Grinding Symposium for the fi rst time. It is the fi rst machine in the new JE series with EasyProfi le control system. Both machine variants can be individually supplemented with dressing systems from the BLOHM and JUNG range of accessories.

Regardless of which combination the user chooses: highest precision and best surface quality paired with a user-friendly operating concept guarantee a successful result.

A vital prerequisite for excellent surface quality are the extremely low-friction EasySlide hydrodynamic guideways, with which the machine is equipped. They guar-antee outstanding damping characteristics and very smooth running. High-precision recirculating ball screw linear drives

TECHNOLOGY FOR TOOL AND DIE MAKING

enable high accelerations of 300 strokes per minute and infeed speeds of up to 50 meters per minute, creating the conditions needed for cost-effective operation. The precise mechanical design of the machines guarantees consistently fi rst-class grinding results. “The user can be confi dent that the workpieces, which he machines on the new JUNG machines, will exactly meet his expectations – even without constant intermediate inspections”, explains Thomas Mank, Area Sales Manager at JUNG. The machines offer superior ergonomics particularly during set-up. Two electronic handwheels, which can be operated in-dependently of each other, facilitate the process. The PA-K37 profi le dressing device optionally available for the J series guaran-tees an unlimitedly usable grinding range, thanks to its automatic tool adjustment.



Highest precision and surface quality

Maximum fl exibility

Wide variety of workpieces

Handwheels for manual infeed of axe

Short-stroke function with 330 strokes over a length of 25 millimeter

“THE NEW MACHINES FROM THE JUNG BRAND

OFFER MAXIMUM FLEXIBILITY A ND

PRECISION FOR TOOL AND DIE MAKING.”

Thomas Mank, Blohm Jung GmbH

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14 Motion 01.2014

03

World fi rst: The new CrankGrind grinds main and pin bearings with the highest precision and shortest machining times

WITH THE CRANKGRIND SCHAUDT for the fi rst time presents a machine for high speed grinding of crankshafts for the fi rst time, which is considered the elite class of precision grinding. Decades of experi-ence in non-cylindrical grinding have been incorporated into the new machine type, which is now making its world debut at the Grinding Symposium.

The machine is equipped with twin cross slides, where by each of the slides can be moved independently from one an-other. Each slide has a Z-axis and a highly dynamic X-axis, which are optimized for plunge and traverse grinding of crankshaft main and pin bearings. In addition they are each equipped with a large grinding wheel 600 millimeters in diameter, which has a high- performance direct drive. Simultane-ous machining of adjacent main and pin bearings is thus possible, considerably reducing machining time.

The CrankGrind is built on the proven Granitan® machine bed and offers a high level of thermal stability as well as excellent dynamic damping.

The basis for high-precision and stable grinding processes is provided by the optimized machine base and the proven StuderGuide® on the Z-axis, a combination of a hydrodynamic guideway and a hydro-static guideway. The X-axes are equipped with linear motors and wear-free hydro-static guideways, which enable a very fl at highly dynamic guideway.


GRINDING OF CRANKSHAFT BEARINGS


Dual cross slide for highest productivity

Grinding speeds up to 200 m/s

Granitan® machine bed for high thermal stability and dynamic damping

Proven StuderGuide® guideway on the Z-axis

Non-wearing, vibration-damping, hydrostatic guideways on the X-axes

Optimal machine ergonomics

“WHEN DEVELOPING THE CRANKGRIND WE FOCUSED PRIMARILY ON THE BEST POSSIBLE ERGONOMICS, IN ADDITION TO A HIGH LEVEL OF FUNCTIONALITY AND PRODUCTIVITY.”Daniel Mavro, Schaudt Mikrosa GmbH

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STUDER’S COMPREHENSIVE EXPERTISE in internal grinding is demonstrated at Station 4 of the Grinding Symposium. The S110, a compact, fl exible entry-level machine and the CT960, an all-round machine with four-spindle turret and measuring probe, have already been successfully introduced.

The special feature of the S110 is its technical concept, in which the workpiece is moved on the cross slide. The grinding spindles permanently mounted on the machine base remain stationary, however. This variant enables exceptional ease of use. The spindle set-up can be adapted to customer requirements, with up to three grinding spindles in a linear arrangement.

The much larger CT960 has a B-axis with direct drive, which swivels from plus 61 degrees to minus 91 degrees, enabling

use in different working ranges. The machine grinds very hard materials such as tungsten carbide and ceramic very successfully.

STUDER will present the new S141 at the symposium for the fi rst time, complet-ing its extensive portfolio in the direction of larger workpieces. The swivelling table of the S141 can accommodate parts up to 1300 mm in length and 400 mm in diameter and with a maximum weight of 250 kilograms.

The positionable swivelling table oper-ates between minus 10 degrees and plus 15 degrees. The machine can optionally be equipped with up to four internal spindles (diameter up to 140 millimeters) on a tur-ret with direct drive. Up to two external spindles with wheels up to 300 millimeters can be used.

The machine also has one or two swivel-ling dressers. These are equipped with diamonds or dressing turbines (dressing spindles) if required. New steady rests have been developed for precise setting and clamping of long parts. The new machine design is ergonomically optimized and ena-bles extremely good access for easy set-up.


INTERNAL GRINDING EXPERTISE

Combined internal grinding expertise: STUDER presents

three machines, which cover the complete spectrum up to

large workpieces

THE ADVANTAGES OF THE S141 AT A GLANCE

Workpiece length up to 1300 millimeters

Workpiece weight up to 250 kilograms

Large selection of grinding spindles and dressing units

Optimized ergonomics

EN_15_Motion_01_2014 15 29.04.14 13:54


16 Motion 01.2014

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A TOTAL OF 13 SOFTWARE FEATURES for increasing effi ciency and precision will be presented by STUDER on Station 5 at the Grinding Symposium. With the “wheel imprint” function (StuderDress) a copy of the grinding wheel profi le can be generated directly from the workpiece drawing – saving a lot of time. The “A-axis thread grinding” function enables threads to be ground with much larger pitch angles than in the past. Ball screws, multiple-start threads and worms can also be machined. “StuderWINtraining” enables training to be carried out on the user’s own PC.

The “StuderTechnology” feature for designing grinding process parameters allows the user to measure himself against the best grinders – irrespective of his experience. This feature is available as standard on all machines with StuderWIN.

The simplifi ed StuderWINfocus operating software, which focuses on large scale production, is being launched on the market together with the new S11. It contributes to reliable programming and effi cient use of the machine and enables

SOFTWARE FOR EFFICIENCY AND PRECISION

standardized programming of different systems. With the “Measuring tools” module, active measuring probes can be redefi ned as measuring tools and freely programmed for different purposes.

The StuderGRIND offl ine program-ming system allows programs for STUDER grinding machines to be conveniently cre-ated from the offi ce, without the machine being stationary during this period. The tool also provides support for the creation of workpiece drawings, for time and cost calculation and order processing, and thus promises effi ciency increases of up to 50 percent.

A simulation software program has been developed under the name of StuderSIM which enables the creation of high-precision internal contours and radii during the manufacture of die plates.


A host of new features:STUDER has improved and expanded its software in many areas


StuderWINtraining – Training for STUDER machines on the user’s own PC

StuderTechnology – Support for designing grinding process parameters

StuderGRIND – Offl ine creation of programs for grinding machines, while the machines continue production

StuderSIM – Simulation software, for detailed adjustment of the grinding process

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Motion 01.2014 17


THE KRONOS S 250 from MIKROSA, the newest generation of which will be presented at the Grinding Symposium, features a unique machine concept with dual cross-slide systems on the grinding and regulating wheel side. In addition to through and plunge grinding, the machine also enables the combination of several grinding operations in one machine. The spindle unit can be angled by six degrees. This enables targeted precision grinding of diameter and faces in one operation. Regardless of which grinding process is used, the cross slides with digital drives guarantee high precision and high dynamics. The number of axes required is reduced from six to four, while machining fl exibility is increased. The proven Granitan® machine bed ensures a high thermal stability and optimal vibration damping.

A further highlight of the machine is the dressing of grinding and regulating wheels via four CNC axes on the height of the

CENTERLESS GRINDING USING ANGULAR PLUNGING

With dual cross-slide systems on the grinding and regulating wheel side: the KRONOS S 250


Highest precision

Productivity advantage thanks to multiple production

Flexible technological application possibilities

Standardized automation solutions

Simple programming thanks to optimized operator interface

“THE KRONOS S 250 ACHIEVES OPTIMUM VALUES IN CYCLE TIME AND COST EFFECTIVENESS.”Karsten Otto, Schaudt Mikrosa GmbH

workpiece plane. This results in a higher profi le accuracy as well as compensation of the temperature-related displacement of the slide systems and relevant spindles.

MIKROSA will demonstrate the special capabilities of the KRONOS S 250 when grinding symmetrical barrel rollers with a spherical end face in double production using angular plunge grinding. Even with crowned forms, which are considered the most challenging to grind, the ma-chine demonstrates the highest precision combined with high productivity. The KRONOS S 250 is thus ideally suited for small and medium series for the diameter range up to 40 millimeters.


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18 Motion 01.2014

07THE ADVANTAGES AT A GLANCE

More than 50 HelpLines worldwide

More than 250 service technicians close to the customer

More than 450 Customer Care employees in the UNITED GRINDING Group

Better contact with customers thanks to technicians from their local environment

Better knowledge of customers’ language, mentality and customs

“WE WILL NO LONGER SEND SERVICE TECHNICIANS OUT ACROSS THE WORLD. WE WANT TO INVITE THE WORLD TO COME TO US.” Marco Vallesi, Customer Care, Fritz Studer AG

CUSTOMER CARE

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Motion 01.2014 19

MÄGERLE BLOHM JUNG STUDER SCHAUDT MIKROSA WALTER EWAGP

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A COMPREHENSIVE VISION of Customer Care has been developed by the UNITED GRINDING Group. As solutions are becom-ing increasingly complex and the compa-nies in the group are increasingly operating on a global level, direct local service for customers is particularly important. The Grinding Symposium is therefore dedicat-ing a special station to this fi eld.

When it comes to fulfi lling market and customer requirements, it will no longer be necessary to send technicians from Germany or Switzerland all over the world to carry out maintenance, service, repairs or software updates in future. “Our idea is to turn this obsolete principle on its head. We want to invite the world to come to us”, explains Marco Vallesi, Customer Care, Fritz Studer AG. The prerequisite for this is the establishment of academies in the companies of the UNITED GRINDING Group, which will undertake the training of service technicians in-situ according to requirements. At this special school – Station 7 of the Grinding Symposium has been partially modeled as a classroom for good reason – not only the group’s own

service technicians, but also technicians from sales agencies and directly from large customers will be trained.

STATE-OF-THE-ART MACHINE DEVELOPMENT“If the local service technicians from Singapore, for example, come to us, this has many advantages, as they know their customers’ wishes and demands far bet-ter”, says Vallesi. A course system will be developed for the academies, which will be based on existing capabilities, whilst also imparting knowledge in state-of-the-art machine development.

This will result in the development of an annual training plan, which covers all re-quirements. As Henry Ford said: “ Success consists in having precisely those capabili-ties, which are in demand at a given time.” This naturally applies for training capabili-ties too.

To enable comprehensive training the academies will provide the infrastructure and above all the training personnel, the group’s own machines and additional exhibits. The training courses should be considered as part of an ongoing process, with elements that build on each other and cover the entire range – divided into three different levels – from basic knowledge through to expert knowledge. The topics are primarily technically based, and there-fore deal with core competencies in service know-how, such as troubleshooting and fault analysis. These are supplemented by

general contents such as safety, organi-zation or customer care. In this way the UNITED GRINDING Group wants to create a new type of customer proximity, as well as confronting three trends: the increasing complexity of machines, the progressive shortage of technicians and higher turn-over of personnel.

FOCAL POINTS OF THE ACADEMIESThe work at the academies from the viewpoint of Customer Care will focus on the main topics of skills management and knowledge management. With skills management the level of training and knowledge of each individual employee, as well as that of external staff will be ascer-tained, in order to derive the training strat-egy and further improve each individual’s capabilities.

Knowledge management focuses on easy access to know-how and its protec-tion, which is threatened by the retirement and turnover of employees. Further tasks include the diffusion of knowledge, which is required by new systems and technology, as well as knowledge transfer, in order to widen knowledge and disseminate expert knowledge to more people.


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20 Motion 01.2014

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FOR LARGE-SCALE PRODUCTION as well as machining small batches with high fl ex-ibility, STUDER time and again offers machine with exceptional performance. At the Grinding Symposium the manufac-turer will demonstrate the effi ciency of its machines with the new S11, which was presented at EMO for the fi rst time, and with the proven S22, which now features the revolutionary dressing technology for CBN/diamond grinding wheels, WireDress®.

Thanks to its compact design, the S11 is superproductive for small workpieces in particular. It operates effi ciently and reliably on a mounting area of less than 1.8 square meters. However, optimum accessibility is also guaranteed. A grinding wheel with a diameter of 500 millimeters enables exceptional power density. STUDER will present the S11 in the HSG version for high-speed grinding (HSG) for the fi rst time at the Grinding Symposium. A second S11 is equipped with an arbor grinding fi xture for the high-volume production of nozzle bodies.

The focus of the S22 is on the mass produc-tion of medium-sized customer workpieces. The machine already offered a wide range of machining options such as cylindrical grinding, form and thread grinding, high speed grinding or heavy-duty applications with grinding wheels 160 millimeters in width. WireDress®, the new technology for dressing metal-bonded diamond grinding wheels, is unique throughout the world and patented. This technology enables profi ling of the wheels for the fi rst time; previously, only conditioning of the wheel could be per-formed in the best case. The new dressing technology was initiated by STUDER as part of a Switzerland-wide research project.

With these highlights both machines have upped their performance yet again.


FOR HIGH PRODUCTIVITY

At the Grinding Symposium STUDER will present two S11s for the automotive industry; one for machining the contour of turboshafts with HSG and one for effi cient machining of nozzle bodies


S11 – extremely compact design, high productivity, superior ergonomics, simple automation

S22 – diverse grinding options

STUDER-WireDress® – revolutionary dressing technology for CBN/diamond grinding wheel

EN_20_Motion_01_2014 20 29.04.14 15:39

Motion 01.2014 21


THE S41, the new universal cylindrical grind-ing machine from STUDER, has power in a number of respects. With the revolutionary StuderGuide® guideway system, high-precision axis drives with linear motors and the extremely fast direct drive of the B-axis, its machining speed is comparable “to the speed of a dragster”, explains STUDER expert John Richard.

In contrast to the “rockets on wheels”, however, the S41 can also stop within the range of a tenth of a micrometer. It will “bear” large workpieces up to a maximum weight of 250 kilograms and is designed for distances between centers of 1000 or

1600 millimeters and center heights of 225 or 275 millimeters.

The most important component for machining is the wheelhead with integrated B-axis. This swivels automatically and en-ables the use of up to four grinding wheels. Workpieces can therefore be completely machined in just a single clamping. The S41 demonstrates particular strength in its ver-satility: Combinations of up to four external or internal grinding spindles give more than 30 basic variants, which fulfi ll all customer requirements.

For effi cient and high-precision thread grinding STUDER offers an automatically

swivelling A-axis on the S41, with a swivel angle of plus/minus 15 degrees. Depending on the model there are variants for internal grinding as well as for standard grinding wheel peripheral speed and high speed for external grinding. If required by the customer, the S41 can even be equipped with two A-axes.

The position and speed controlled C-axis also enables form and thread grinding.


QUICK AND FLEXIBLE


StuderGuide® guideway system

High-precision axis drives with linear motors

Extremely fast direct drive for the B-axis

Over 30 basic variants enabled by up to four external and internal grinding spindles

Automatically swivelling A-axis

“THE S41 CAN DO ALMOST ANYTHING – FROM SIMPLE UNIVERSAL TASKS THROUGH TO COMPLEX TAILORMADE SOLUTIONS.”John Richard, Fritz Studer AG

Suitable for large workpieces: Workpieces with a weight of up to 250 kilograms can be machined on the new STUDER S41

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10

22 Motion 01.2014

Strongly positioned in the turbine industry: the MFP 50

PRODUCTIVITY AND COMPLETE MACHINING

THE MÄGERLE MFP 50 combines compact design, fl exibility and performance. The fi ve-axis precision grinding and machin-ing center has been specially developed for multiple-side and complete machining of complex workpieces such as turbine stator vanes for aircraft engines in a single clamping. High axis speeds and quick tool change guarantee minimal auxiliary times and high productivity.

The integrated tool changer of the MFP 50 equips the high-performance spin-dle with the necessary tool for the respec-tive machining task. In addition to grinding wheels, drilling and milling tools, there is also a measuring probe for automatic quality control.

The high-precision two-axis NC com-bination of a swivel axis and an integrated rotational axis fulfi lls high requirements on production tolerances. The clamping fi xture for the guide vanes is mounted on a zero point clamping system and is thus prepared for automated operation.


Customized adaptations thanks to modular system

High precision thanks to pre-stressed hydrostatic guideway systems

Cost effectiveness, reliability and long working life

RELIABLE AND EFFICIENT

An overhead dressing system controlled by two axes continuously dresses the grinding wheels. This guarantees optimum metal removal rates and profi le accuracy even with hard-to-machine materials. In addition, the intelligent design principle ensures maximum utilization of the grinding wheel diameter, resulting in signifi cant cost savings. The MFP 50 thus combines high manufacturing quality and reliability with high cost effi ciency.

The optimized cooling lubricant supply also contributes to the high productivity of the MFP 50. A dynamic balancing system for grinding wheels and a tool monitoring system with a comprehensive software package are also optionally available.

MÄGERLE will present the MFP 50 at Station 10 of the Grinding Symposium: The team will demonstrate different fi ve-axis simultaneous grinding, drilling and milling operations on the guide vane of an aircraft engine.


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Motion 01.2014 23


IN ORDER TO MEET HIGH REQUIREMENTS on fl ex-ibility and speed when machining indexable inserts, EWAG offers ideal solutions with the COMPACT LINE and INSERT LINE tool grinding machines.

The versatile and cost-effective COMPACT LINE has been specially devel-oped for fl exible grinding of indexable inserts made from different materials. The torque and linear drives of the machine guarantee a dynamic fi ve-axis kinematics and precise grinding results. Even complex tool geom-etries can be created thanks to 3D simula-tion with the innovative ProGrind software. Optimized clamping systems with a plug-and-play interface ensure short set-up times and precise grinding results. The machine’s compact dimensions and ergonomic design ensure a high degree of user friendliness.

SUPERPRODUCTIVE GRINDING OF INDEXABLE INSERTS

High speed peripheral grinding of indexable inserts – up to 70 percent faster on the INSERT LINE

The versatile COMPACT LINE with fi ve-axis kinematics and ProGrind software – ideal for grinding indexable inserts

INSERT LINE AT A GLANCE

High productivity with HSM peripheral grinding technology

Linear drives & hydrostatic guide systems guarantee highest precision

Integrated 3D simulation

COMPACT LINE AT A GLANCE

New, user-friendly, ergonomic design

Clamping system with plug-and-play interface

Flexible six-axis automation solution

wheel loading and increased productivity by the reduction of the grinding time by up to 50 percent – that’s the result of this innovative HSM technology (High Speed Machining).

The integration of a six-axis robot supports the high productivity of both machines. This is optimally supported with options such as pallet changer, cleaning station and “Vision System”. A newly developed measuring system (IP-M) is also available, which enables fl exible measure-ment and orientation of indexable inserts directly in the C-axis in even shorter cycle times.

CONTACT thomas.fi [email protected]

PRODUCTIVITY REDEFINED

Speed is the characteristic of the INSERT LINE. It enables fl exible high-speed periph-eral grinding of indexable inserts in very short production times, while delivering ex-cellent surface quality and precision. Linear drives paired with hydrostatic guideways guarantee the highest dynamics and raise the unique productivity of the INSERT LINE to a new level.

The drive and control technology (based on STUDER noncircular grinding) combines indexable insert grinding with peripheral grinding. The resulting linear contact between the grinding wheel and the workpiece reduces the contact zone and enables an improved cooling lubricant supply, thus reducing heat input. Signifi -cantly higher feed values with constant

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24 Motion 01.2014

12EWAMATIC LINEAR AT A GLANCE

Six-axis kinematics equipped with new NUM Flexium control system

Now with low-maintenance, dynamic linear motor drives in X, Y, Z-axis

Software ProGrind and NUMROTOplus

LASER LINE ULTRA AT A GLANCE

Five-axis kinematics with Fanuc control system

High-power picosecond laser for machining all established cutting materials

Intuitive LaserPro3D software

“OUR MACHINES GUARANTEE INCREASED

PRODUCTIVITY.”Thomas Fischer, Ewag AG

Ideal for machining super-hard materials: the EWAMATIC LINEAR

TWO NEW MACHINE CONCEPTS for machining indexable inserts and rotational tools from modern, super-hard materials are present-ed by EWAG with the EWAMATIC LINEAR and the LASER LINE ULTRA.

The new, superproductive EWAMATIC LINEAR comes with six-axis kinematics as well as low-maintenance, wear-resis-tant direct drives. This makes it ideal for high -precision machining of super-hard materials such as HM, PCB and PCD. In addition to force-controlled grinding, an extremely fast, star-shaped six-position wheel changer and customer-optimized clamping stations ensure the highest productivity. Specifi cally for the manu-facture and resharpening of rotationally-symmetrical tools, the user can optionally connect the EWAG ProGrind grinding software to the established software solu-tion NUMROTOplus.

No geometry is too complex and no material too hard for the new LASER LINE ULTRA with its unique fi ve-axis kinematics, three superposed optical axes and ultra-short pulse laser. It shapes even diamond

materials such as MCD, CVD-D or PCD as desired in a single clamping. The chip-free cutting edge surfaces achieved are less than three micrometers. The LASER LINE ULTRA thus opens up new applications for modern cutting materials, which previously could not or could only be machined to a limited extent using conventional methods. The machine is programmed using the LaserPro3D software with CAD/CAM plug-in. For machining complex 3D structures, the tool geometries are imported in an established 3D data format and decon-structed into individual stock removal layers. Machining strategy and scanner parameters for the stock removal can be defi ned and stored in a processing fi le. The integration of a six-axis robot ensures high productivity of both machines.

CONTACT thomas.fi [email protected]

LASER OR GRINDING TECHNOLOGY?

The LASER LINE ULTRA is equipped with fi ve-axis

kinematics and three superposed optical axes

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TOOL CONTROL WITH TOOL MEASURE INTERFACE

The new Tool Measure Interface ensures traceable measuring results and consistently high part quality

THE NEW INTERFACE Tool Measure Inter-face (TMI) from WALTER connects the HELITRONIC TOOL STUDIO grinding software to the QCM measuring software. Files written in HELITRONIC TOOL STUDIO can be read into QCM. TMI thus enables the complete integration of grinding and measuring machine – irrespective of the machine types used.

The user generates the measuring program when the tool ID number is cre-ated in the grinding software. He does this using the measuring point assistant in HELITRONIC TOOL STUDIO. The param-eters to be measured are clicked on in this plug-in. The result is a 3D image of the tool, on which all measuring points are visualized. The program saves this data as an XML fi le and imports it into the measuring software. The new measuring program is generated automatically and can be used immediately. A simple press of a button is all that is needed to start the automatic measurement of all parameters. The result of the measurement can then be used to correct the grinding program. The generation of the measuring program does not require any programming knowledge.

The fully automatic measurement is operator-independent.

ELIMINATION OF MANUAL INFLUENCES

“TMI eliminates manual infl uence during the creation of measuring programs and saves both time and human resources”, explains Ulrich Brändle, the responsible product manager at WALTER. “The pur-chase costs pay for themselves after just a few measuring cycles, even with simple tool geometries.”

WALTER will demonstrate the opera-tion of the new interface at Station 13 of the Grinding Symposium. A tool will be ground on the HELITRONIC VISION 400 and measured on the HELICHECK PLUS. The connection between both machines can be established in practice by means of cable, WLAN or USB stick.



Three simple process steps

No programming knowledge of QCM measuring software required

Full integration of grinding and measuring machine

Reduction of auxiliary times

Traceable measuring results

Consistent quality and fewer rejects

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26 Motion 01.2014

14

“OUR SOFTWARE OPTIONS OPTIMIZE GRINDING TIME AND TOOL QUALITY.”Torsten Wörner, Walter Maschinenbau GmbH

EFFICIENCY USING THE LATEST SOFTWARE SOLUTIONS


Feedrate Optimizer: save up to 40 percent of grinding time by optimizing the infeed speed

Quality Assurance: consistent tool quality irrespective of location

Sketcher: create CAD drawings, design tools, program tool ID numbers and grind tools with a single software program

MANY DIFFERENT FACTORS infl uence the du-ration of the grinding process and product quality. With the innovative extensions to the HELITRONIC TOOL STUDIO grinding software, WALTER now offers its custom-ers three options for optimizing these factors in terms of cost effectiveness.

The Feedrate Optimizer enables signifi -cant time savings through automatic opti-mization of the infeed and cutting speed. For example the grinding time for a three-edged standard cutter twelve millimeters in diameter and 40 millimeters long can be reduced by 26 percent with just a few mouse clicks. The calculation of the infeed speed is based on the fundamental process data such as feed, cutting speed and wheel characteristics. Wheel breakage or increased wear of the wheel are excluded thanks to constant wheel loading.

CONSISTENT QUALITY

For companies with global operation and production, it is crucial that their products reliably present consistently high quality – irrespective of where they are manufac-tured. With Quality Assurance WALTER now offers a software extension that

guarantees this. It eliminates the infl uence of operator and machine, by visualizing the deviations of an actual 3D tool model from the reference 3D model applicable at all company locations. The parameters are then adapted manually on the actual model.

With the Sketcher central software ex-tension, users can create CAD drawings in HELITRONIC TOOL STUDIO, design tools, program tool ID numbers and grind tools – and save time in the process. Tool simula-tion and CAD data are linked. Changes to individual parameters in the grinding program become visible in the simulation and are transferred to the CAD drawing immediately – double entries are no longer required. Operation is intuitive, via icons.


The Quality Assurance software extension guarantees product quality through comparison and visualization

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TALKING HEADS

28_ SVEN GÁBOR JÁNSZKYRulebreaker®: How to overtake competitors by breaking rules

30_ PROF. DR. GUNTER DUECKProfessional intelligence

32_ PROF. DR. BEREND DENKENATrends in grinding technology

34_ PROF. DR. JOSEF REISSNERManufacturing competence as the basis for product and process innovations

36_ FLORIAN HEITMÜLLERPotential applications in speed stroke grinding of high-performance ceramics

38_ PETER OPPELTRazorTec® – Cost-effi cient grinding technology with effective grinding wheel cleaning

40_ UDO MERTENSTrends in grinding tool development

42_ DR. HOLGER PÄTZOLD, DR. ERDMANN KNÖSELExploitation of productivity reserves through scientifi cally based design of grinding tools and process parameters

44_ PROF. DR. EKKARD BRINKSMEIERTechnologies for increasing performance in external cylindrical grinding

46_ KARSTEN OTTOVibrations during centerless grinding

48_ DR. DIRK FRIEDRICH“Only as much cooling lubricant as necessary!” – Effi cient use of cooling lubricants in grinding machines!

50_ DR. THOMAS MAGGNew concepts for minimal grinding forces during CBN grinding in mass production

52_ PROF. DR. WILFRIED SAXLERTool grinding – a process with the highest precision

54_ PROF. DR. CLAUS EMMELMANN3D laser material machining – opportunities and challenges for grinding technology

56_ OLIVER WENKETechnological leadership through the use of cutting-edge measuring technology

58_ PROF. DR. DIRK BIERMANNDevelopments towards the effi cient manufacture of solid carbide high-performance tools

60_ PROF. DR. KONRAD WEGENEREnergy effi ciency and thermal behavior of machine tools

62_ DR. FRANK FIEBELKORNThe latest grinding and dressing technologies for the use of very hard abrasives

64_ DR. SEVERIN HANNIGDynamic stability of grinding machines – potential and risks

66_ ERHARD KÄMPFComputer-supported, practice-oriented design of cylindrical grinding processes

Innovative developments in the grinding machine industry and industrial production will be presented in 20 lectures

EN_27_Motion_01_2014 27 29.04.14 15:58

GRINDING SYMPOSIUM

28 Motion 01.2014

SVEN GÁBOR JÁNSZKY

RULEBREAKER®: HOW TO OVERTAKE COMPETITORS BY BREAKING RULES

WHAT DO PEOPLE DO DIFFERENTLY, who change our world? They think differently! They fi nd rules, which they break consciously or unconsciously, but always with passion.

Rulebreakers® are especially important for our economy: they bring new technologies and prod-ucts, new partners and networks. They cross over boundaries, disrupt conventional models, break established rules and create new markets. And they don’t just bring new ideas – they also destroy old ones. Real innovation means the disruption of functioning business models, distributed markets, traditional industries and established networks!

HOW COMPANIES BECOME RULEBREAKERSIt’s a popular image, which is used time and again in management literature: the company as a big ship. Corporate groups und multinational com-panies often even see themselves as supertank-ers. These are large, cumbersome and have many capable experts on board, who work in a strict hierarchy. Their captains are carefully chosen and trained, are well advised and make wise decisions.

If you as the manager of a company believe that you are steering a big ship, then I can un-derstand that the idea of having a Rulebreaker® on board makes you uneasy. But who actually told you that you are the captain of the tanker? Don’t you have several vessels fl ying your fl ag, and aren’t you really the fl eet admiral? Then you have the optimum basis for emulating successful Rulebreakers®.

YOU HAVE TO CANNIBALIZE YOURSELF!The truth of all market conquests by big compa-nies is: they have to attack their own business model! But this never works in your own com-pany. Why wasn’t aircraft jet propulsion discov-ered by propeller drive manufacturers? Why didn’t fountain pen manufacturers develop the ballpoint pen? Why isn’t the music industry revo-lutionized by music labels and the book industry by publishers? It is in the nature of things that big, established companies do not strive to at-tack themselves. This is done by small compa-

Rulebreakers® destroy existing systems and create innovation and new markets.

To protect your company, you must critically question your business model and expertise on a regular basis.

Industries that have not changed for a long time and in which there are monopolies are particularly vulnerable to rule-breaking.

If you identify an oppor-tunity for rule-breaking, seize it and become a Rulebreaker® yourself.

SHORT SUMMARY nies, often from neighboring sectors. But why do these attackers have any chance at all of winning against the establishment?

The answer is: Because established compa-nies know their markets too well. They prevent innovation through their expertise. This relates particularly to those sectors, whose general con-ditions change quickly. These generally uninten-tional changes mean that the customers have new requirements, or that old requirements can be served differently. New technologies and business models are needed to do this.

EXPERTISE AS AN IMPEDIMENTIt is precisely at this point that the expertise of es-tablished companies becomes an impediment: They have invested too much time and money in their development and prevent innovation through their expertise in old technologies and business models. They fail to recognize that their value is not measured according to the investment put in, but by the quality of current solutions in the mar-ket. Accordingly they persist with their increas-ingly useless expertise and thus delay or prevent new business models.

For the attacking Rulebreakers® on the other hand, their largely naive, but intelligent approach becomes an advantage against the establishment. Their mental advantage: As they have not spent half of their working lives acquiring this expertise, they don’t attach any value to the old business models and their now obsolete expertise profi les. On the contrary: Rulebreakers® love and drive radi-cal innovations.

For established companies, it is important to identify rule-breaking threats in their sector and unconquered markets at an early stage. Naturally there is no silver bullet for this. But it is possible to identify patterns of industry confi gurations, which positively demand rule-breaking. Industries in which no changes have occurred for a long time and where monopoly-type structures dominate are particularly vulnerable. Particularly promising are disruptive innovations in sectors, which cur-rently still function according to old guild or pro-

21 MAY, 2014 – 14:00

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Motion 01.2014 29

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“THERE ARE MARKETS I N

WHICH IT IS BAD TO HAVE TOO

MUCH EXPERTISE. THIS ESPECIALLY

APPLIES TO INDUSTRIES

THAT CHANGE QUICKLY.”

Sven Gábor Jánszky

SVEN GÁBOR JÁNSZKY is a German trend researcher

and strategy coach. The 41-year old is Chairman of

the Board of Directors of 2b AHEAD ThinkTank AG in

St. Gallen

fessional rules. But irrespective of the sector in which you operate, there are ten signals that you must pay attention to:

1st signal: High margins and “layers of fat” among service providers

2nd signal: Predominantly rational argu-mentation of benefi ts

3rd signal: Non-emotive supplier-purchaser relationships in commodity markets

4th signal: Mass products for subjective expectations

5th signal: Largely individualized markets6th signal: Pension-related markets7th signal: Markets that are based on infor-

mation control8th signal: Commission-based markets

versus fee-based markets9th signal: Diverging trends in neighboring

sectors10th signal: Triangular relationship be-

tween seller, user and funder

RULES OF RULEBREAKERS®What happens, when you identify a rule-breaking threat? Then you have the rare opportunity to press ahead with it yourself, to conquer a new market and defi ne the rules in this market. You have the opportunity to do something similar to the fascinating people who I came across during may research: A fi nance manager, who discov-ers the bank of the future! A shipowner, who re-invents the cruise ship market! An estate agent, who stands up against the entire industry, and many more. They have discovered new markets, brought entire industries to the edge of the abyss, made millions and changed our world with their own hands. The price they have paid: A life lived as a balancing act, setbacks, impending bankruptcy, death threats and a life-long restless feeling of not yet having reached their goal.

SIMILARITIES IN THINKINGOf course, Rulebreaker® strategies cannot be cop-ied entirely. They are unique, because the indus-

tries in which they work are very different, because technology plays a large role here, a small role there, because competition is monolithic here, dispersed there. And yet there are similarities be-tween all rulebreakers. These are to be found in the thinking of the key players.

As a futurologist and innovation consultant I wanted to know, whether we “normal folk” could learn something from the best innovators? Wheth-er each of us can become a Rulebreaker®? The answer is: Yes! Rule-breaking is a guide to doing better, to crossing limits and changing the world! Start today! I wish you much success!

INTELLIGENT PRODUCTION

EN_29_Motion_01_2014 29 29.04.14 16:01

GRINDING SYMPOSIUM

30 Motion 01.2014

PROF. DR. GUNTER DUECK

PROFESSIONAL INTELLIGENCE

WHAT IS INTELLIGENCE? Professor William Stern de-fi ned it in 1911 as the “Ability to adapt to new con-ditions and to solve new problems”. The psycholo-gist developed the fi rst intelligence tests and also invented the concept of the intelligence quotient, IQ for short. We still use this 100-year old concept today. And we measure intelligence in IQ tests, which test abilities such as linguistic competence, retentive power and logical thinking. However, this intelligence concept can no longer satisfy the requirements of a modern economy.

FAR REMOVED FROM THE PROFESSIONAL WORLDIntelligence, as we commonly regard it today, is valuable, no question – but far from being ev-erything. Simply being clever is not enough. Intelligence is often criticized as being hard, un-emotional, impersonal, abstract and soulless – because there is a great deal missing from pure intelligence! We only use intelligence in relation to mathematics, logic and language. Everything that an intelligence test wants from us is disconcert-ingly far away from what is increasingly crucial in today’s professional world.

If I want to know about the pricing structure of an insurance policy or how an Indian technology share has developed to date, I look on the Inter-net. Quick, easy, free and without the need for any form of advice.

EXPERTS ARE LOSING THEIR POWER ADVANTAGEStandardized services are ceasing to exist in the Internet community or are delegated to other levels. Instead of being performed by the doctor, vaccinations are now performed by the vaccina-tion specialist – he is cheaper, has shorter waiting times and and has all vaccines in stock. Classic lecture-style teaching on basic topics? Lectures are recorded on video by a rhetorically trained pro-fessor – then each students can watch them online when, where and as many times as they wish, and the professor has more time for valuable research work. So-called experts such as doctors, fi nancial

advisers and professors are losing their power advantage. Knowledge is power? That was then. There is no longer any knowledge dominance. A deep division is developing between premium and commodity in the economy and in society. The commodity sector is covered by technologi-cal solutions or special service providers. What is required in the premium sector is professionals, who work independently in large networks. The competence profi le of these professionals con-stitutes a completely different professionalism to that required ten years ago.

We no longer have to work things out, we have to control constantly changing processes and solve complex problems. Professionalism in the era of knowledge requires a different kind of intelligence. We need an intelligence of success, an intelligence that ensures that everything works. Regardless of on which hierarchical level of a com-pany we work, our entrepreneurial personality is becoming increasingly important.

SUM OF PARTIAL INTELLIGENCESIn order to actively shape this development, we need many different kinds of intelligence, which together make up our professional intelligence:

IQ – the normal intelligence of the intellect: planning, ordering, formulatingEQ – the emotional intelligence of the heart and of cooperation, understanding others, team spirit VQ – the vital intelligence of the instinct and of action: assertiveness, gut feeling, willing-ness, taking risksAQ – the intelligence of attraction and instinctive joy and pleasure: sense of beauty, aesthetics, enchantment, the ability to bring something to the man/womanCQ – the intelligence of creation or intui-tive curiosity: love of innovation, unfettered thinkingMQ – the intelligence of meaningfulness and intuition: sense of ethically valuable, world-saving concepts, volunteerism

Intelligence in the sense of linguistic competence, retentive power and logi-cal thinking is no longer enough in a modern economy.

A holistic intelligence of success is needed, an intelligence that ensures that everything works.

A deep division is devel-oping between premium and commodity in the economy and in society.

What is required in the premium sector is professionals, who work independently in large networks.

SHORT SUMMARY

21 MAY, 2014 – 14:45

EN_30_Motion_01_2014 30 29.04.14 16:02

Motion 01.2014 31

“KNOWLEDGE IS POWER?

THAT WAS THEN.THERE IS NO LONGER ANY KNOWLEDGE

DOMINANCE.”Gunter Dueck

PROF. DR. GUNTER DUECK The Professor of Mathematics and former Chief Technology

Offi cer at IBM is one of the leading experts in Germany on questions relating to the

knowledge society

Professional intelligence is a different harmonic composition of these individual intelligences, de-pending on the profession. While the composi-tion may vary between sectors and professions – in order to be truly professional as a manager or employee and to be able to achieve a high level of knowledge and ability, the development of all partial intelligences is essential.

COMPANIES ARE SEEKING PROFESSIONALSModerate development of the various factors is equally important, because if the expression of in-dividual intelligences is too strong, this can have undesirable, disruptive consequences: Too high an IQ (intelligence of the intellect) may lead to a know-it-all attitude; too high an EQ (emotional intelligence) can lead to vulnerability to exploita-tion; too high a VQ (vital intelligence) can cause ruthlessness or lust for power. Only the balanced interaction of intelligences ensures that profes-sional work can succeed.

Only a few people have this overarching pro-fessional intelligence. This is why, amid a sea of desperate job seekers, employers complain that there are no longer any suitable professionals and the labor market has dried up. Companies are desperately seeking people who can think outside the box, who are capable of different perspec-tives, and who still have the resources to work a bit of magic.

EDUCATION AND TRAINING SYSTEMSThe working world still puts up considerable re-sistance to the upheaval which the Internet brings with it, and to the ideas of the digital natives, who are characterized by openness to new technolo-gies and the desire for committed, fulfi lling par-ticipation.

Digital natives are characterized by the fact that they simply try things out, make decisions quickly and, if they fail, simply start again. Failure is nothing to be ashamed of, but a learning experi-ence. This is also something that many still have to discover for themselves.

Our education, training and management systems are lagging behind this development. People often complain – but do nothing to remedy the situati-on – that children are not motivated, that pupils do not appear willing to learn in school and that employees are not professional enough. Only education based on the classic IQ is assiduous-ly instilled. The focus is solely on expertise, with the addition of a vast number of behavioral rules. Creativity, will, customer friendliness, innovativen-ess, enthusiasm, management skills or team spirit are required, but are not promoted or developed.

CHANGE IN HUMAN HISTORYNone of us yet understand that the present Inter-net revolution marks a change in human history, which is as huge as Gutenberg’s book printing. The availability of knowledge in books has con-tributed to the enlightenment of humans over the centuries. We experienced the Age of Enlighten-ment, in which our present-day educational con-cepts were decisively shaped.

Thanks to the Internet, knowledge is no longer just there in principle, but it is easily accessible at all times for everyone everywhere. We carry virtu-ally the whole world around with us digitally on our Smartphones in our trouser pockets or handbags. The Internet doesn’t just enlighten us, it empow-ers us! The former Enlightenment is now being expanded into Empowerment.


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GRINDING SYMPOSIUM

32 Motion 01.2014

PROF. DR. BEREND DENKENA

TRENDS IN GRINDING TECHNOLOGY

CURRENT DEBATES focus on the topics of an aging society, ecology, mobility, individualization and ur-banization. The discussed topics have far-reaching consequences for production technology, as they will result in the development of new markets and the disappearance of old ones, and they will shift the emphasis to other priorities.

Particularly important factors for production technology are the increasing average age of the population and the increasing awareness of eco-logical aspects. The consequence of the aging society is that the demand for medical products is increasing, and therefore the proportion of ma-terials that are diffi cult to machine is increasing. In order to be able to satisfy the high demand, exist-ing manufacturing processes must be further de-veloped in respect of productivity and automation.

ENERGY EFFICIENCY OF PRODUCTIONThe increasing awareness of the ecological as-pects of human activities affects production tech-nology both directly and indirectly. A direct conse-quence is that the energy effi ciency of production is now also considered, in addition to cost effec-tiveness. In order to make production more energy effi cient numerous approaches are pursued, such as optimization of the cooling lubricant supply and the use of new drive concepts or new tools.

In addition to these direct consequences there are a host of indirect consequences, as the market requires energy-effi cient products. This can be seen, for example, in fl ow machines such as pumps or turbines, as well as in vehicles. In the area of pump and engine manufacture a lot of effort is spent enabling effi ciency to be further increased. As a result the complexity of the sur-faces to be produced is increasing. Vehicle man-ufacturers use highly developed engine technol-ogy to reduce fuel consumption. At the same time demands on comfort and engine output are increasing.

Surface design is the key technology for dealing with these increasing requirements on products and components. Friction losses are reduced by increasing the surface quality, ad-

ditional functions are implemented by introduc-ing microstructures, and increased lifetimes are achieved thanks to modifi cation of the peripheral zone.

In the light of the frequent use of ultra-hard materials that are diffi cult to machine, grinding technology is of particular importance. “Made to measure surfaces” can only be produced if the necessary process understanding is present, so that the right tools are used in combination with the right process strategy, depending on the ma-terial to be machined and the target geometry of the surface. This presentation highlights chal-lenges and discusses approaches for selecting the right tool and the ideal process strategies. We shall also look at how innovative solutions for increasing product effi ciency can be achieved through the clever combination of tool and strat-egy design.

GRINDING TOOL CHARACTERISTICSThe characteristics of the grinding tool decisively infl uence the operational behavior, the surface quality, the component peripheral zone and pro-ductivity. The grinding wheel characteristics are defi ned by the type of cutting material, grain size, grain concentration and bond characteristics. Dia-mond is predominantly used as the cutting mate-rial for machining brittle materials. The bond must be selected so that the full potential of the grain is used. Metallic bond material has the greatest potential for further increasing the effi ciency of diamond grinding wheels.

Metallic bonds are wear-resistant, temper-ature-resistant and have a high thermal conduc-tivity. In combination with a porous structure, a “cool” grind can be achieved. This enables a considerable reduction in internal compressive stresses. In order to be able to produce a high sur-face quality with an Ra in the area of 0.1 μm dur-ing grinding, a small grain size must be used. By reducing the grain size, however, the grain surface and therefore the grain retention decrease. How-ever, this effect can be countered with specifi cally adapted sinter parameters.

For pumps, turbines and in vehicle manu-facture surface design is becoming a key technology from the viewpoint of energy effi ciency.

The use of innovative approaches such as bionic microstructures is possible for surface design.

In order to make produc-tion itself more energy effi cient numerous approaches are pursued, such as optimization of the cooling lubricant supply and the use of new drive concepts or new tools.

SHORT SUMMARY

21 MAY, 2014 – 15:30

EN_32_Motion_01_2014 32 29.04.14 16:07

Motion 01.2014 33

0

“DEMOGRAPHIC CHANGE AND

THE INCREASING AWARENESS OF ECOLOGI-

CAL ASPECTS ARE IMPORTANT

FACTORS FOR PRODUCTION

TECHNOLOGY.”Berend Denkena

PROF. DR. BEREND DENKENA directs the Institute of

Production Technology and Machine Tools (IFW) at the Production Technology Center of Leibniz University

Hannover

PROCESS STRATEGIESAfter selecting the right grinding wheel character-istics, the design of the right grinding strategy is crucial for a specifi c surface design. For aesthetic reasons, to optimize fl ow surfaces or due to new applications such as ceramic knee implants, the proportion of free form surfaces for machining is increasing. Suitable grinding strategies are re-quired for the cost effective production of high surface qualities in conjunction with a small form tolerance on free form surfaces. By placing the grinding wheel in or orthogonally to the infeed movement and the surface normal machining it is possible to achieve constant contact conditions, resulting in a higher shape accuracy and a higher metal removal rate in comparison with three-axis machining.

By placing the grinding tools in the infeed direction, the component roughness is also sub-stantially reduced, as cutting and infeed speed are not oriented in the same direction and the infl u-ence of the grinding wheel topology decreases. In the fi eld of machining with a geometrically defi ned cutting edge, fi ve-axis machining has long been the state of the art and widespread in the indus-try. Five-axis grinding is currently only present as a niche solution, which is designed explicitly for the specifi c application. The CAD/CAM programs used have previously been designed for geometri-cally defi ned machining. The use of this software for fi ve-axis grinding operations brings a number of problems with it. The resolution of the programs is inadequate for grinding operations. As a result,

the tool paths can contain unintentional infl ection points or undefi ned points, resulting in contour errors during grinding. In addition the CAD/CAM programs ignore the tool wear and are based on ideal tool geometries, rather than the tool geom-etries present after dressing. Consideration of the wear or the actual tool shape would enable an in-crease in the contour accuracy.

With an ideal combination of adapted grinding wheel characteristics and grinding strategy, the use of innovative approaches such as bionic mi-crostructures is also possible for surface design. Bionic structures such as riblets, which are de-rived from the structure of shark’s skin, reduce friction in proximity to walls by up to ten percent. When used in fl ow machines such as pumps, gas turbines or engines, effi ciency can thus be sig-nifi cantly increased. The microstructures have a width of up to 20 μm and a height of 10 μm and must be arranged in the fl ow direction.

EFFICIENCY THROUGH FREE-FORMED SURFACESFlow-relevant surfaces are free-formed to further increase effi ciency, and the fl ow is curved via a free form surface. The required structure dimensions can be produced by grinding, using micrograins in a metal bond and adapted sinter parameters. Tool paths which enable grinding of curved micro-structures on free form surfaces can be created using fi ve-axis grinding strategies. To this end the grinding wheel geometry must be adapted to the tool path radius and workpiece curvature.

Tool paths which enable grinding of curved microstructures on free form surfaces can be created using fi ve-axis grinding strategies


Nature

Ideal riblets Ground riblets

Compressor blade

s = 120 μm

s = 60 μm

s = 20 μm s = 21 μm

h = 60 μm h =

70 μm

s = 120 μm

Cutting

Grinding

5-a

xis

gri

nd

ing

[University of Florida]

Microstruc-turing

0.6mm

Krw/73601© IFW

-0.3-0.6

s = 55 μm

h = 23 μmh = 30 μm

h = 10 μm h = 9 μm 30 μm

30 μm

30 μm

EN_33_Motion_01_2014 33 29.04.14 16:07

GRINDING SYMPOSIUM

34 Motion 01.2014

PROF. DR. JOSEF REISSNER

MANUFACTURING COMPETENCE AS THE BASIS FOR PRODUCT AND PROCESS INNOVATIONS

NOT ONLY THE LONG-TERM SUCCESS of a company, but also its short-time survival is decided by the abil-ity to develop and implement innovations quickly. Innovation through fl ashes of inspiration gives the idea that a “big bang” of the imagination is re-quired. In reality, however, one has to sift through a structured area of knowledge with the help of four cognitive operations:

Wandering means, extensively exploring the possibilities.

Seeking out means, that you search for clues that lead in a specifi c direction.

Rethinking means, considering a problem from another perspective.

Departure means, discontinuing approaches that do not lead anywhere.

EXPANDING THE AREA OF KNOWLEDGEEnriching one’s own area of knowledge with the customer’s knowledge is certainly sensible, but unfortunately is often impeded by a number of psychological and structural barriers. Therefore only information about the customer’s specifi c needs is usually transferred via Marketing to the machine manufacturer’s Research and Develop-ment Department. However, the key to radical im-provement is the transfer of customer knowledge. The most effective route is therefore via After Sales Service.

An innovative company makes knowledge available via the cloud-based After Sales Service in the form of manuals, operating instructions, e-books and technology computers. Grinding sim-ulators will also be available in the not too distant future. The customer provides knowledge, by de-fi ning a problem with unique actual/target criteria and discussing it in forums on the end user portal. Only the correct application of knowledge leads to competence. If correct application is continually refl ected, expertise develops over time. But how do we achieve the required high level of manufac-turing competence?

We use a three-stage, prescriptive learning model: the well-known learning cycle.

Stage 1: Acquisition of knowledgeStage 2: The application of knowledge in the virtual factory leads to capability.Stage 3: Successful physical grinding in the industrial environment leads to competence.

Grinding knowledge is central to the UNITED GRINDING Group. We want to represent it as a brain-friendly semantic network (a model from cognition psychology for the representation of knowledge); the storage of knowledge in the long-term memory occurs in the form of nodes (processes and characteristics) and (associatively linking) edges. Rough part geometry, tool geom-etry, infeed, tool speed and cutting speed produce grinding stresses. They are infl uenced by plastifi -cation, solidifi cation and friction. Grinding stress-es cause a material fl ow, which is responsible for dimensional and form errors as well as roughness. This also includes changes in the surface zone through internal stresses, burn marks, grinding cracks and chatter marks. The material fl ow is also responsible for chip formation as well as grain and binder wear.

DIFFERENT KINDS OF KNOWLEDGEAs the application of knowledge is of central impor-tance for us, the division of grinding knowledge in-to workpiece, tool and machine knowledge makes sense. Workpiece knowledge encompasses chip formation, damage of the surface-near zone, grinding tribology, process simulation and moni-toring and grindability. Tool knowledge includes grinding wheels, conditioning, grain and binder wear; Maintenance is part of machine knowledge.

When cutting with geometrically undefi ned cutting edges the latter are formed with hard ma-terial grains, which are irregularly designed and fi xed in a bond. The execution of a machining simulation requires material data for deformation rates of more than 105 s-1, a thermal-mechanical

A company must have a strong area of knowledge in order to develop and implement innovations.

The company’s knowledge should be enriched with customer knowledge, which can ideally be obtained in After Sales Service.

The division of knowledge into work-piece, tool and machine knowledge is sensible.

Automated process monitoring delivers crucial knowledge.

SHORT SUMMARY

21 MAY, 2014 – 16:15

EN_34_Motion_01_2014 34 29.04.14 16:08

Motion 01.2014 35

PROF. DR. JOSEF REISSNERwas Director of the Institute

of Virtual Manufacturing and Forming Technology at ETH

Zurich from 1976 to 2004

coupling, a robust network regeneration as well as the possibility of an increased network density directly in the important area in front of the cutting edge. The determination of contact data is an al-most impossible task. With the contact of an indi-vidual grain the stock removal mechanisms of mi-crocutting-peel cutting, microcutting-continuous cutting, microploughing and microgrooving can be simulated, depending on the working depth, cutting speed and the position of the grain cutting face in relation to the grinding direction. Rough-ness, grinding cracks and burn marks can only be simulated if a large number of grains are in contact simultaneously. The big breakthrough with the Fi-nite Element Method in grinding is still to come.

PREVENTIVE QUALITY ASSURANCEPreventive quality assurance ranks as one of the most ambitious breakthrough strategies in mod-ern production technology. At the end of the sev-enties quality guru Joseph M. Juran (1904 – 2008) was already demanding “Quality from the outset”. Improved quality at all process stages enabled shorter processing times and reduced costs. The last correction in relation to zero errors must there-fore always take place during real-time grinding.

Workpiece-side measuring systems, which acquire static measured variables, are used in grinding technology. In order to replace the direct measurement of process variables, measuring methods are used to detect indirect process char-acteristics.

Piezoelectric dynamometers, which are arranged in the direct force fl ow between work-piece and clamping table, are used in various ap-plications. The less sensitive DMS are widely used for force measurement. Contact analysis provides a measured variable which, although it does not directly record the grinding forces, represents the grinding process well. The prerequisite is arrange-ment of the sensor close by.

The industry predominantly uses AE signals for fi rst cut detection, to reduce idle periods and for visual dressing and grinding process monitor-ing by the machine operator. First cut detection and visual process monitoring are sometimes also undertaken by determination of the electrical energy consumed on the grinding or workhead spindle and as on the infeed axis. Force sensors can also be used for this purpose. An in-process

control loop is not possible here in most cases. Good balancing systems can automatically re-duce the residual imbalance of the grinding wheel to a minimum. Narrow diameter and length toler-ances are adhered to in series production with in-process gauging.

Attempts are also made to obtain informa-tion on the tool side from rotating (grinding) tools. This measured variable acquisition is particularly challenging, as the process measured variables must be determined in the immediate vicinity of the contact zone between tool and workpiece. The sensor technology thus becomes part of the wear-ing tool. With the sensors integrated into the “sen-sitive grinding wheel”, central parameters such as force and temperature distribution on the grinding wheel can be acquired directly in the process. By combining the locally measured force and temper-ature values, conclusions can be drawn about the condition of the grinding wheel (current geometry, for instance).

THE ZERO ERROR GRINDING MACHINEDowntimes must also be minimal, however. This is only possible with condition-based tool and machine maintenance. Potential error sources must be identifi ed at an early stage and upcom-ing maintenance tasks integrated into the produc-tion cycle. Vibration monitoring is the most reli-able method for the early detection of mechanical damage to the machine. Self-learning algorithms can be used.

For the zero error grinding machine, the ge-ometry and material parameters measurable in the machine for the blanks are required for the pro-cess simulation fi rst of all. In the second stage, the zero error quality is obtained through an adaptive process control. This is achieved via in-process gauging of externally and self excited vibrations, of geometrical form errors such as roundness on the rotating workpiece and of the grinding wheel condition, based on process temperature mea-surement and/or process force measurement.

“INNOVATIONS ARE THE RESULT

OF FLASHES OF INSPIRA-TION WHEN SEARCHING THROUGH A

STRUCTURED AREA OF

KNOWLEDGE.”Josef Reissner


EN_35_Motion_01_2014 35 29.04.14 16:08

GRINDING SYMPOSIUM

36 Motion 01.2014

FLORIAN HEITMÜLLER

SPEED STROKE GRINDING OF HIGH-PERFORMANCE CERAMICS

FOR THE COST-EFFECTIVE MANUFACTURE OF CERAMIC

FUNCTIONAL AND PRECISION COMPONENTS, the use of high-performance, but cost-intensive diamond grinding wheels is essential. When selecting pro-cess control variables such as infeed, feed and grinding wheel peripheral speed, users generally choose rather conservative values, which subse-quently result in low material removal rates and low productivity. The reasons for this are the ma-terial characteristics of the ceramic, which tend towards brittle fracture under excessive stress, and the time-intensive – in comparison to con-ventional or CBN grinding wheels – conditioning processes for the diamond grinding wheels used. This also means that many grinding technolo-gies are unsuitable, and increased metal removal rates go hand in hand with increased tool wear, as downstream dressing processes often over-compensate for primary processing time-related increases in productivity. Grinding processes with diamond grinding wheels also pose an in-creased risk of unstable process behavior due to the wearing mechanisms that occur. This means that metal or resin bonded tools must generally be sharpened at fi xed intervals, in order to achieve an adequate grain protrusion, which in turn costs time and money.

EXAMPLE: SPEED STROKE GRINDINGAs an alternative ceramic bonds can be used, which are easier to dress, but wear much more quickly due to the smaller grain retention forces and brittle fracture properties. Despite continu-ous advancements in grinding tools, grinding methods and conditioning processes, the grind-ing process strongly contributes to the price formation in the value creation chain for the manufacture of ceramic functional and precision components, so that potential fi elds of applica-tion often cannot be developed for large quanti-ties for economic reasons. The example of speed stroke grinding can be used to demonstrate the possibilities for machining ceramic components superproductively and reliably, using suitable process control variables.

DEMONSTRATOR COMPONENT MADE FROM SILICON NITRIDEIn order to demonstrate the potential of speed stroke profi le grinding, a demonstrator compo-nent made of silicon nitride was ground very quickly, without interruption or measurable wear in an absolutely constant process at the Institute of Machine Tools and Factory Management at the Technical University of Berlin (IWF). In the light of the adjustable separating conditions, questions arise with regard to:

the appropriate process control variables for reliable high-performance machining,

cost-effective conditioning, the possibility of using high-concentration grinding wheels,

the surface characteristics of the ground surface-near zones and potential resulting from increased cutting speeds and damped wheel bodies.

Technological tests carried out at IWF to determine the fundamental separating and wearing mecha-nisms found that, for cost-effective machining, a specifi c chip thickness limit must not be exceeded on the process side, as otherwise – similarly to conventional ceramic-bonded abrasives – dispro-portionate wear can occur due to cascading grain breakout. This wearing behavior was observed at maximum infeed speeds of vw = 180 m/min. For cost-effective machining, on the other hand, average infeed speeds of vw = 100 m/min with increased peripheral speeds of vs = 120 m/s are best. Within these ranges the positive infl uences of increased infeed speeds in the form of reduced machining forces, combined with subcritical wearing behavior, can be utilized. G-ratios of well over 1000 mm³/mm³ are possible. In addition, due to the higher number of kinematic cutting edges throughout the machining process, the increased grinding wheel peripheral speeds lead to much better surface qualities in the average infeed range vw = 105 m/min, combined with a higher metal removal rate. In the tests carried out the load limit

The effi ciency of the grinding process for ceramic components can be signifi cantly increased using the speed stroke process.

Thanks to increased infeed speeds, the machining forces can be signifi cantly reduced.

Increased grinding wheel peripheral speeds result in better surface qualities.

SHORT SUMMARY

22 MAY, 2014 – 09:30

EN_36_Motion_01_2014 36 29.04.14 16:34

Motion 01.2014 37

“SPEED STROKE GRINDING ENABLES

PRODUCTIVE AND RELIABLE

MACHINING OF CERAMIC

COMPONENTS.“Florian Heitmüller

FLORIAN HEITMÜLLER works as Senior Engineer at the

Institute of Machine Tools and Factory Management at the

Technical University of Berlin

of the grinding wheel used was determined at a concentration of C100 with a specifi c material re-moval rate Q’w = 90 mm³/mms from a workpiece speed vw = 138 m/min.

MODULATED INFEED SPEEDFrom an economic perspective it seems sensible not to necessarily utilize the maximum available infeed speeds on the machine tool. The calculated individual stroke duration ts, composed of table acceleration, constant infeed speed during over-grinding and deceleration, initially decreases as the infeed speed increases, as the proportion of constant infeed speed is still high during grinding throughout the total stroke path. As the infeed speed increases, however, the required propor-tions of the acceleration phases increase consid-erably and outweigh the benefi t in the grinding range. The basis used here was the real accelera-tion of the machine system aw≈ 25 m/s² during the grinding tests.

If this time is taken into account in the cal-culation of the specifi c material removal rate, it becomes clear that the latter only increases on a diminishing scale as the infeed speed increases. If, in addition, we consider parameter combinations of infeed and workpiece speed with a constant specifi c metal removal rate, the increase in the infeed speed even leads to a noticeable decrease in the real material removal rate. It thus becomes clear that the economic benefi t is present partic-ularly with high material removal rates, and that speed stroke grinding is therefore more suitable for roughing. In the light of strategically altered separating mechanisms through signifi cantly increased infeed and grinding wheel peripheral speeds in comparison with the normal process pa-rameters often used for the production of ceramic

components, it is necessary to clarify to what ex-tent peripheral zone damage may be caused to the workpieces by the speed stroke process. To this end an analysis was carried out at IWF to evalu-ate whether the brittle chip formation, increasing as the infeed speed increases, can lead to more frequent crack formation and thus an increasing depth of damage on the workpiece.

A qualitative overview of damage was ob-tained using transverse sections. No trend could be established in relation to a dependency on the infeed speed or the material removal rate. The cracks found showed exclusively lateral forms run-ning parallel to the surface, which can be classifi ed as uncritical from a mechanical perspective. No critical transversally running cracks were found. Even with a maximum specifi c material removal rate of Q’w = 90 mm³/mms, no signifi cant dam-age to the peripheral zone could be demonstrated in comparison to surfaces that had been ground using the creep-feed or conventional oscillating process, or polished surfaces. One limitation that should be mentioned is that the analysis method described can only be applied locally and there-fore damage cracks cannot be generally excluded. Further metrological tests such as internal stress analyses are planned for the future.

COMPLEXITY CAN BE REDUCEDTaking account of the interactions between dress-ing process, dressing tool and process parame-ters, stationary processes with G ratios well above 1000 m³ / mm³ can be achieved. The development of bonds and dressing tools means that the high complexity of dressing with different strategies and tools can be reduced on available CNC pro-grams with a dressing tool.

A demonstrator component made from silicon nitride is ground at the In-stitute of Machine Tools and Factory Management at the Technical University of Berlin (IWF)

Grinding wheel:D46, C100, ceramic bondProcess parameters:ae = 10 μmvs = 120 m/svw = 105 m/minVw = 29 208 mm3

rp = 0,4 mm 4 mm

αy=45°

5 mm

Profi le grinding of GPSN without dressing interruptions (from solid material 100 x 100 x 6 mm3)

SURFACE AND PROFILE GRINDING

EN_37_Motion_01_2014 37 29.04.14 16:34

GRINDING SYMPOSIUM

38 Motion 01.2014

PETER OPPELT

RAZORTEC® – COST-EFFICIENT GRINDING TECHNOLOGY WITH EFFEC-TIVE GRINDING WHEEL CLEANING

GRINDING WHEEL CLEANING, also called fl ushing out or jet-cleaning, has already been established for around 40 years. It has been and still is helpful for process optimization, particularly with long- chipping and diffi cult-to-machine materials.

Due to the development of the CD process (CD: continuous dressing) grinding wheel clean-ing initially became superfl uous, as dressing is suffi ciently continuous. However, grinding wheel cleaning is once again becoming increasingly im-portant, in order to further increase removal rates in CD processes or in processes without continu-ous dressing. In surface and profi le grinding, such high-performance processes include creep feed grinding with interval or continuous dressing, and speed stroke oscillation grinding. In the case of nickel-based alloys, for example, specifi c removal rates up to 200 mm³/mm∙s can now be achieved thanks to effective wheel cleaning.

The parameters and settings used for the ap-plication of grinding wheel cleaning to fl ush out the grinding wheel pores with cooling lubricant have not been called into question for a very long time.

SCIENTIFIC RESEARCHIn recent years, extensive studies for the optimi-zation of processes with grinding wheel cleaning have been carried out at the Institute of Materi-als Science (IWT) in Bremen and at Blohm Jung GmbH in Hamburg. The infl uencing variables studied were:

Jet velocity Dynamic pressure/nozzle distance Impact pressure/nozzle distance Grinding forces with and without cleaning Deterioration of the wheels with and

without cleaning Nozzle angle Pressure on the nozzle

A further focal point of the studies was the com-parison of different nozzle types in terms of their cleaning effi ciency. Interestingly a rotor nozzle, which is also used in high-pressure cleaners as

a so-called “dirt blaster”, achieved considerably worse results than a fl at or fl at spray nozzle.

HIGH CLEANING EFFICIENCYThe impact pressure was studied with the aid of special pressure indicating fi lms, in which small colored spheres burst and cause coloration of the fi lm, depending on the impact pressure. The color intensity serves as a direct measurement for the level of the impact pressure. Grinding trials proved the high level of importance of this parameter: the higher the impact pressure, the better the clean-ing effect on the grinding wheel. The dynamic pressure on the other hand, which was highest directly in front of the nozzle, is less important for the cleaning effect.

In direct comparisons of grinding operations with and without wheel cleaning, the use of clean-ing nozzles results in signifi cantly smaller grinding forces, reduced grinding wheel wear and a higher workable specifi c removal rate without damage to the surface-near zone.

With regard to the evaluation of different cleaning nozzle types and cleaning pressures it is clear that the best results are delivered not by a large cooling lubricant quantity and high pres-sure, but by specifi cally metered feeding. The distance of the cleaning nozzle from the grind-ing wheel, which was previously kept as small as possible, is also an important parameter. The sensible distances in conjunction with an optimal nozzle are between 30 and 80 millimeters from the grinding wheel.

In order to make the technological benefi t available to the widest possible range of applica-tions, a new automatic coolant nozzle tracking system has been developed by Blohm Jung, which also enables the simple adaptation of an effective cleaning nozzle. The principle of a parallelogram linkage proven in the PROKOS has been further developed. Not only are the nozzles adapted to a smaller grinding wheel radius if required, but they are also guided more closely to the contact zone, which is important for the wandering contact point during down-grinding.

Effective grinding wheel dressing can optimize grinding performances to the highest level.

The RazorTec® process guarantees precise grinding without damage to the surface-near zone.

It reduces grinding wheel wear by up to 30 percent.

Continuous wheel clean-ing enables grinding wheel wear to be signifi cantly reduced.

SHORT SUMMARY

22 MAY, 2014 – 10:15

EN_38_Motion_01_2014 38 29.04.14 17:56

Motion 01.2014 39

“PARTICULAR IMPORTANCE IS

ATTACHED TO GRINDING WHEEL CLEANING IN CD

PROCESSES OR IN PROCESSES

WITHOUT CONTINUOUS

DRESSING.”Peter Oppelt

PETER OPPELTThe graduate machine tool

and production technician is Head of European Sales at

Blohm Jung GmbH.

TECHNOLOGICAL CONDITIONSThe nozzles can optionally be driven by a three-phase or servo motor. The servo motor also en-ables control of the nozzles in guideway grinding operation. There is also the option of moving the nozzles automatically in the Z-direction, i.e. in the direction of the grinding spindle axis. When using a set of wheels, which are used in succes-sion, this enables the nozzles to be positioned individually in relation to the respective grinding position, saving around 50 percent of coolant throughput. This nozzle tracking is now option-ally used on all PLANOMAT and PROFIMAT ma-chines with great success.

Without further optimization of the grinding wheel specifi cations, the potential increase in the removal rate would not be so high. The key to suc-cess lies in a very clean and very sharp grinding wheel for the roughing process. The grain must have a high grade of sharpness after dressing, which is retained for as long as possible in con-junction with wheel cleaning. This makes con-tinuous dressing superfl uous in many processes. The IPD process (Interval plunge dressing) is now available for process-parallel dressing.

Special emphasis should be given to speed stroke oscillation grinding for processes with separate dressing between the grinding cycles. The heat input into the workpiece is minimized by the high infeed speed of approx.120 m/min as part of the process. In conjunction with effective wheel cleaning the Q’w values of up to 200 mm³/mm∙s for nickel-based alloys indicated above have thus been achieved on real components and not just on test material blocks.

NO EFFECT ON THE SURFACE-NEAR ZONEIn conjunction with effective grinding wheel cleaning, grinding processes with conventional abrasives (corundum, silicon carbide) can be op-timized to give top performances, which were previously reserved exclusively for ultra-hard abrasives. RazorTec® combines a very sharply dressed grinding wheel, which remains clean during the process, with a cool grind without damage to the surface-near zone, and minimal grinding wheel wear.

Objective of the research project at IWT in Bremen: Reliable and

effi cient grinding processes thanks to effi cient grinding

wheel cleaning


EN_39_Motion_01_2014 39 29.04.14 17:56

GRINDING SYMPOSIUM

40 Motion 01.2014

UDO MERTENS

TRENDS IN GRINDING TOOL DEVELOPMENT

AS A FINISHING PROCESS, GRINDING HAS undergone a remarkable change in the last 25 to 30 years. In the eighties of the last millennium, grinding was still almost exclusively used in applications where the required work accuracies could no longer be achieved by other manufacturing processes in an economically feasible way. Permanently changing constellations in the context of a pro-gressive globalization, with aspects such as the increasing scarcity of raw materials and a shift in environmental awareness, almost inevitably re-sulted in changed market requirements. The pres-sure to produce increasingly effi ciently and cost effectively set a development in motion, which has led to improved machine concepts and quicker control and measuring systems.

TREND TOWARDS HIGH-PERFORMANCE ABRASIVESThe rapidly growing trend towards the use of high-performance CBN and diamond abrasives was particularly signifi cant for this development. As a consequence of this trend, technically adapted cooling systems and higher-performance cool-ing lubricants with substantially improved cooling and lubricating abilities had to be made available. Ultimately the hardness and machinability of the workpiece material had an ever decreasing infl u-ence on the limit of machinability.

This development was also accelerated by grinding with ever higher cutting speeds. It was fi nally possible to machine even hardened and diffi cult-to-machine materials with high removal rates through grinding. This stock removal was until recently carried out by machining with a geo-metrically defi ned cutting edge in a non-hardened, easily machinable state.

In the past, grinding tool requirements fo-cused on higher metal removal rates and com-ponent quality. These requirements have not been supplanted during the course of the last few years, but supplemented. Today, the focus is particularly on tools with higher tool life quanti-ties and shorter auxiliary times, whether during tool set-up or dressing. Such requirements can

only be fulfi lled if we consider the “grinding tool” system as a whole.

OPTIMAL GRINDING TOOLThe optimal grinding tool must be specifi ed de-pending on the grinding technology application. CBN and diamond tools comprise a relatively thin-walled abrasive coating, which is affi xed to a wheel body. During high-speed grinding with cutting speeds of currently up to 200 m/s, steel is still the standard material used for the wheel bod-ies. Particularly during crankshaft grinding with ever larger tool diameters of 1000 millimeters and more, the associated greater weight of the tools presents a disproportionately higher challenge for both the grinding spindle system and for handling.

An alternative material for wheel bodies is car-bon fi ber reinforced plastics (CFRP), which pos-sess a number of interesting characteristics.

HIGHLY POROUS METALLIC BONDOnly a few years ago it was still quite possible to machine a multitude of hard metals with a single grinding wheel specifi cation in the tool industry. This is no longer possible, due to the constant de-velopment of new qualities. Tools with an extreme specialization in respect of the workpiece material to be machined are standard today. There are also increasing requirements for grinding tools which, in addition to enabling smaller grinding forces, are also extremely easy to dress. Fulfi lling these requirements in combination with offering a high adjustable porosity – these are the demands on such a modern grinding tool.

CERAMIC HIGH-PERFORMANCE BOND Ceramic-bonded systems have enormous ad-vantages, particularly in terms of short auxiliary times. Tools with this bond system can be very easily dressed; a characteristic which makes them ideal for automated processes. Requirements for enhanced performance characteristics, such as a higher specifi c removal rate and also a much larger number of ground components per dress-ing cycle, are permanent market demands.

With porous metallic and ceramic high-per-formance bonds for dia-mond and CBN grinding tools, it is possible to respond individually to customer requirements.

Metallic bonds develop small grinding forces and are easy to dress.

Ceramic-bond systems offer enormous advan-tages with regard to short auxiliary times.

The use of a CFRP wheel body or a form roll with interrupted coating opens up further potential.

SHORT SUMMARY

22 MAY, 2014 – 11:00

EN_40_Motion_01_2014 40 29.04.14 17:58

Motion 01.2014 41

“IT IS NECESSARY TO CONSIDER

THE GRINDING TOOL SYSTEM AS A WHOLE.”

Udo Mertens

UDO MERTENShas worked for Saint-Gobain

Diamantwerkzeuge GmbH & Co. KG since 1989.

He is responsible for product management and product development of ceramic-

bonded CBN and diamond tools for Europe

CNC-CONTROLLED FORM ROLLSIn a fl exible production set-up one main rule ap-plies for modern dressing tools: They must be universally usable. CNC-controlled form rolls in particular are ideal for this. Modern versions have a closed coating arranged with multiple layers ver-tical to the rotation axis and a single layer in the direction of the rotating axis. An interesting variant is the form roll version with interrupted coating. With this version a higher actual surface rough-ness of the grinding wheel is achieved, with oth-erwise constant dressing parameters, resulting in reduced grinding forces. A side effect is that the profi le accuracy is also increased.

RESPONDING TO CUSTOMER REQUIREMENTS With the wide range of porous metallic and ce-ramic high-performance bonds now available for diamond and CBN grinding tools, it is often pos-sible to respond individually to customer require-ments. Whether small quantities or large volumes, the savings potential with these tools is enormous, and increases with increasing adaptation. The use of a CFRP wheel body or a form roll with interrupt-ed coating opens up further potential.

Grinding wheel made from carbon fi ber

reinforced plastic with CBN coating


EN_41_Motion_01_2014 41 29.04.14 17:58

GRINDING SYMPOSIUM

42 Motion 01.2014

DR. HOLGER PÄTZOLD, DR. ERDMANN KNÖSEL

INCREASED PRODUCTIVITY THROUGH GRINDING TOOL DESIGN

THERE IS A GENERAL EMPHASIS on signifi cantly in-creasing productivity whilst maintaining or even enhancing the workpiece quality criteria, through favorable design of grinding tools and the use of optimal cutting parameters in grinding processes. An example will be taken from industrial practice to show how the quality of grinding tools can be systematically increased by using a grinding wheel manufacturer’s wealth of experience.

PROBLEMThe task was to carry out simultaneous grinding of two rough-machined external surfaces in a single cycle. The process must be performed so that the previously produced central hole and the two ex-ternal surfaces do not suffer any thermal damage and no dimensional deviations occur. The goal was to more than double productivity.

In order to achieve the required machining of both external surfaces in a single cycle, two grind-ing wheels were arranged on an axis. Peripheral face grinding at synchronized speed is used. The infeed of the cutting depth ap occurs in the axial direction.

THEORETICAL PRINCIPLESIn the technological quality assessment of a grind-ing process for all peripheral grinding processes, the basic approach is assumed, in accordance with 1), 3) and 4), that a grinding process has a higher quality, the smaller the energy expenditure per ground workpiece volume. It is expected that if the energy expenditure is reduced, thermal sur-face damage will also be reduced. This approach requires the measurement of the performance-related cutting force.

By relating the expended energy to the ground workpiece volume, we obtain the average specifi c grinding energy per machined volume as a quality assessment parameter.

The test set-up comprises a 3D force measur-ing system on the workpiece with relevant evalu-ation electronics. The cross interferences on the forces due to the strong jet of cooling lubricant were eliminated by means of calculation after previous measurement.

SERIES GRINDING WHEEL AS REFERENCE TOOLAn attempt was made to increase productivity through technical changes, whilst observing the following restrictions:

Surface roughness Form tolerances Position tolerances No damage to the surface-near zone No error in circularity of the previously machined central hole

The following were unsuccessful:

Increasing the infeed speed for quicker movement of the heat source

An enlarged adjacent clearance angle from the previous 2 degrees to 5 degrees

Optimization of the conditioning achieved using a driven diamond roll through subsequent dressing

Improvement of the cooling lubrication conditions

The only way to achieve the goal of increasing productivity now remains redesign of the grind-ing wheel specifi cation. Using the series grinding wheel as reference tool, a specifi c limiting removal rate of 63.3 mm³/mms was established.

REDESIGN OF GRINDING WHEEL SPECIFICATIONSThe known ways of changing the grinding wheel specifi cation are variations in the grain, the bond and the structure. For both new grinding wheels that are considered as test wheels, a larger CBN grain was used, the pore space was increased by around 10 percent and the bond proportion was increased by around 5 percent. Both test wheels were designed with a ceramic bond. Test grind-ing wheel 1 was designed with a vitreous bond and test grinding wheel 2 was designed with an elastic bond.

Grinding tools with the smallest energy expenditure per ground workpiece volume have the highest technologi-cal performance.

There is a direct correlation between an optimally managed grinding process and its specifi c grinding energy minimum.

A redesign of the grind-ing wheel specifi cation can enable increases in productivity.

SHORT SUMMARY

22 MAY, 2014 – 11:45

EN_42_Motion_01_2014 42 05.05.14 11:48

Motion 01.2014 43

“IT IS IMPORTANT FOR THE USER

TO KNOW IN WHICH CUTTING

PARAMETER RANGE A GRIND-

ING WHEEL DEVELOPS ITS

OPTIMAL TECHNOLOGICAL PERFORMANCE.”

Holger Pätzold

DR. HOLGER PÄTZOLD is Technology Director of the

Motor Systems Division of Schaeffl er Technologies in

Herzogenaurach

SPECIFIC GRINDING ENERGYThe diagram shows clear differences in the spe-cifi c grinding energy expenditure. Each grinding wheel has – as can be expected according to 1), 3) and 4) – a different specifi c grinding energy minimum. This shows how important it is for the user to know in which cutting parameter range a grinding wheel develops its optimal technological performance.

The series grinding wheel has its specifi c grinding energy minimum of 11,000 Ws/cm³ at an infeed speed of 100 percent, and was therefore optimally used.

Different behavior is shown by test wheel 2, where the indicated specifi c grinding energy mini-mum of 10,000 Ws/cm³ is at an infeed speed of 250 percent, so that a material removal rate of 137 mm³/mms is achieved. It should also be noted, however, that test wheel 2 probably only reaches its actual specifi c grinding energy minimum after a further increase in the infeed speed, which is not shown. The Favorit is test wheel 1, with a specifi c grinding energy minimum of 8000 Ws/cm³ at an infeed speed of 250 % and a material removal rate of 157 mm³/mms. The productivity is thus in-creased 2.5-fold.

The fact that even with the remarkable increase in productivity the component quality is guaranteed, is of the utmost importance in these considera-tions. Or in other words, only a specifi c grinding energy of around 8000 Ws/cm³ delivers high-qua-lity components in this case.

SUMMARYA process developed at TU Dresden for deter-mining the technological performance of grind-ing tools for all peripheral grinding processes by means of the specifi c grinding energy was tested. The direct correlation between an opti-mally managed grinding process and its specifi c grinding energy minimum was demonstrated in an example.

The technological possibilities solely permit-ted redesign of the grinding wheels. With one of the tested grinding wheels the productivity could be increased 2.5-fold, which correlates specifi c grinding energy with the selected criterion. A grinding tool with the smallest energy expendi-ture per ground workpiece volume has the high-est technological performance.

Path of maximum specifi c grinding energy

References:

1) Künanz, K.; Knösel, E.; Franke, A.Diagnose zur Bewertung des Leistungsvermögens von Schleifwerkzeugen.Industrie Diamanten Rundschau 32, Nr. 3, 19982.) Werner, G.Schleifscheibenspezifi kation und Werkstückstoff als bestimmende Merkmale für anwendbare Schnittgeschwindigkeiten und Zeitspanvolumina.Jahrbuch „Schleifen, Honen, Läppen und Polieren“, Vulkan Verlag Essen, 19793) Knösel, E.Der Schleifdruck als bestimmende Größe für Oberfl ächendefekte an Hochleistungskeramik.Jahrbuch „Schleifen, Honen, Läppen und Polieren“, Vulkan Verlag Essen, 19934) Künanz, K.; Knösel, E.; Nikodemus, J.Gütebewertung der Schleifscheiben und des Schleifprozesses mittels der Konstanten einer modifi zierten Kraftgleichung.Jahrbuch „Schleifen, Honen, Läppen und Polieren“, Vulkan Verlag Essen, 19975) Knösel, E.Arbeitsbericht zum Projekt „Verfahrensgestaltung Flächenschleifen an der Innentasse F-346 101.32-0061“ für die Stufe I und II im Auftrag der INA SCHAEFFLER KG. TU Dresden 16.12.2005

Series grinding wheel

Test wheel 1

Test wheel 2

Ws / cm3

140 000

100 000

100 250%

80 000

60 000

40 000

20 000

Relative infeed speed vf

Max

imu

m s

pec

ifi c

gri

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en

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max

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EN_43_Motion_01_2014 43 05.05.14 11:49

GRINDING SYMPOSIUM

44 Motion 01.2014

PROF. DR. EKKARD BRINKSMEIER

INCREASING PERFORMANCE IN EXTERNAL CYLINDRICAL GRINDING

THE CURRENT DEVELOPMENT of grinding machines complies with the constantly increasing require-ments on macro and micro-geometry and edge zone characteristics of manufactured compo-nents. The goal is consistent work results and production times with decreasing production costs. We would like to present the following ap-proaches in this regard:

Prevention of thermal damage to the workpiece through new process control techniques,

Process-controlled and appropriate cooling lubricant supply and

Use of new tool concepts to achieve highest surface qualities.

Current research activities at the Institute of Ma-terials Science (IWT) in Bremen are focused on increasing the removal rate during grinding, but in most cases this is limited by undesirable thermal damage to the workpiece peripheral zone. In the past there have been numerous tests for identify-ing the so-called grinding burn limit with the aid of selected process variables. The crucial process variable is the contact zone temperature, which is technically diffi cult to determine due to the poor accessibility of the grinding slot and the high cut-tings speeds characteristic of grinding.

A tool-side temperature measuring system was developed for this purpose, with the integra-tion of infrared sensors for measuring the contact zone temperatures. The measured data is sent to the processing unit integrated into the grinding wheel, which guarantees processing of the data and its transmission to an external display unit via Bluetooth. The validity of the described tempera-ture measuring system has been verifi ed in exter-nal cylindrical grinding tests on selected model workpieces and in initial industrial trials. Further research is aimed at investigating the infl uence of the workpiece peripheral zone during the grind-ing process as a dependency between the con-tact zone temperature and the contact time. The process variables are heavily infl uenced by the set

control variables (infeed, workpiece infeed speed, cutting speed of the grinding wheel) and system variables (grinding wheel specifi cation, workpiece material). In future the results will be incorporated into so-called peripheral zone diagrams, which are based on the time-temperature diagrams from classic heat treatment. With the aid of these dia-grams the resulting edge zone characteristics will be evaluated as the result of the time-limited tem-perature loading of the material during the grind-ing operation.

SELF-OPTIMIZED COOLING LUBRICANT SUPPLYIn addition to the determination of peripheral zone diagrams, the described temperature measuring system will in future be used as a component of a self-optimizing cooling lubricant supply system, which varies the actual nozzle position as well as the volume fl ow and the delivery speed of the cooling lubricant according to the observed pro-cess variables. This system will enable the cooling lubricant supply conditions to be adapted prompt-ly and automatically, depending on the given com-bination of control variables and system variables. This can help to substantially reduce complex set-up work and ultimately to increase performance during the grinding process.

From an economic perspective, special em-phasis was given to the cleaning effect of the cool-ing lubricant in extensive tests; this has a substan-tial infl uence on the working life of the grinding tool, the associated tool costs and the frequency of the dressing process. During the tests it was found that an additional cleaning nozzle can help to signifi cantly decrease the degree of clogging and consequently to reduce the consumed grind-ing energy. The clogging behavior of the grind-ing wheel and the resulting cleaning effi ciency, depending on the process design, were quanti-fi ed with the aid of an optical measuring system, called “GrindingVision”. Use of a cleaning nozzle showed a signifi cant reduction in the specifi c grinding performance as well as in the resulting internal stresses introduced to the workpiece

Improved productivity can be achieved by reducing the grinding performance require-ment and improving the heat balance in the contact zone.

Further possibilities for increasing process performance are offered by the installation of a self-optimizing cooling lubricant supply system.

The use of elastic-bonded grinding tools improves the surface and edge zone characteristics of the component.

SHORT SUMMARY

22 MAY, 2014 – 14:00

EN_44_Motion_01_2014 44 29.04.14 18:07

Motion 01.2014 45

“AN ADDITIONAL CLEANING

NOZZLE HELPS TO

SIGNIFICANTLY DECREASE THE

DEGREE OF CLOGGING AND

THUS TO REDUCE THE GRINDING

ENERGY CONSUMED.”

Ekkard Brinksmeier

PROF. DR. EKKARD BRINKSMEIERis Director of the Main

Production Technology Department at the Institute of

Materials Science (IWT) in Bremen.

peripheral zone and the radial wheel wear under optimized cleaning conditions. With the aid of the set grinding tool cleaning, an increase in the pro-cess performance from Q’w = 30 mm³/(mm*s) to 50 mm3/(mm*s) was achieved, reliably and with-out thermal damage to the workpiece peripheral zone. As the concluded research work essentially concentrated on a surface grinding process, pres-ent studies are focused on the transfer and verifi -cation of these results for an external cylindrical grinding process.

ASPECTS OF COOLING LUBRICANT SELECTIONThe effectiveness of the cooling lubricant action during the grinding process can also be further increased through the selection of a suitable cool-ing lubricant. An important factor to be considered here is the tribological behavior of the grain dur-ing contact with the workpiece material, which is closely connected to the selection of a suitable cooling lubricant. Tests carried out for this purpose focused on the operational behavior of a CBN grain. The tests showed that the use of ester oils in comparison to emulsions is generally associated with lower frictional forces, which also results in lower workpiece material adhesion and conse-quently a lower grain wear.

Increased viscosity of the ester oil resulted in smaller grinding force ratios. In contrast to this, the grinding wheel-workpiece-cooling lubricant system shows increased normal forces and in-creased temperatures in the workpiece peripheral zone if ester oils with higher viscosity are used. In order to achieve an optimal work result cost ef-fectively, these two counteracting effects must be dealt with through optimal selection of the cool-ing lubricant characteristics.

COST-EFFECTIVE ACHIEVEMENT OF HIGHEST SURFACE QUALITIESHowever, increased performance of grinding pro-cesses should not only be considered in conjunc-tion with the reduction of primary process times, but can also mean increasing cost effectiveness whilst achieving high surface qualities through new process technologies and new tool concepts. Consequently current work is focused on the use of elastic-bonded tools during grinding, which in addition to achieving highest surface qualities (Rz < 1 μm) enable desirable internal compressive stresses (50 – 200 MPa) to be induced in the work-piece peripheral zone.

However, it has also been shown that the actual material removal during the grinding process is largely dependent on the radial pretensioning of the grinding wheel-workpiece system and on the deterioration of the grinding wheel. An important role is played by the elastic deformation of the grinding wheel structure, which can have much higher values in comparison to conventional ceramic- bonded grinding wheels. The required surface qualities have until now generally been produced using fi ne-grained ceramic-bonded grinding wheels, which means an increased risk of burning, among other things. This risk can be substantially reduced by using a porous ceramic-bonded grinding wheel in conjunction with an elas-tic-bonded grinding wheel. The porous structure of the ceramic- bonded grinding wheel also enables an increase in the metal removal rate during the grinding operation.

The abovementioned requirements on future machining processes can be fulfi lled by imple-menting these fi ndings in the form of process-supporting monitoring systems in the machine tool, or in the machine tool periphery. An improve-ment in the surface and edge zone characteristics of the component can be achieved by using elas-tic-bonded grinding tools in conjunction with ce-ramic-bonded grinding tools. The elastic- bonded grinding tool can be mounted on the same or a separate grinding spindle.

Further possibilities for increasing process performance during grinding are offered by instal-lation of the described self-optimizing cooling lu-bricant supply system and by the implementation of a tool cleaning system in the cooling lubricant supply system. As the research work described relates to current projects, further implementation possibilities can be expected in the future.

Position of the cleaning nozzle during the grinding process

PRODUCTION CYLINDRICAL GRINDING

EN_45_Motion_01_2014 45 29.04.14 18:07

GRINDING SYMPOSIUM

46 Motion 01.2014

KARSTEN OTTO

VIBRATIONS DURING CENTERLESS GRINDING

QUANTITY AND QUALITY – extreme demands clash in production. Often huge production volumes have to be handled, and at the same time pro-cess reliability and component quality must con-tinuously improve. Disruptions in highly sensi-tive and large scale production are expensive. Example of “undesirable vibrations in the grind-ing process”: They impair component quality, decrease output, reduce the service life of tools and shorten the machine’s life time – an incalcu-lable risk for any user. That this type of process disruption can be specifi cally avoided, is illus-trated by the grinding specialists from SCHAUDT and MIKROSA in Leipzig. Analysis of the cause of vibrations is the prerequisite for systematically eliminating them with intelligent solutions. The end result is centerless grinding processes with high-performance data.

TWO TYPES OF VIBRATIONSWith process vibrations, the programmed motion between grinding wheel and workpiece is super-imposed by a periodic disturbing motion. Under certain conditions this results in the formation of waviness on the workpiece surface. An oscillating machine structure and a time-dependent force or displacement excitation are responsible for this. A distinction is made between self-excited and externally- excited vibrations, depending on the type of excitation. Triggers for externally-excited vibrations are, for example, external disturbing forces such as shocks, which are introduced via the foundation. The machine oscillates at its char-acteristic frequency. Our machines have Granitan® machine beds, which ensure that vibrations die away quickly. However unbalanced masses, bear-ing failures, changing machining forces or inter-rupted cuts can also cause externally-excited vi-brations. The most frequent trigger for self-excited vibrations is the grinding process itself. The so-called regenerative effect is responsible for this. This is caused by the repeated occurrence of a waviness in the contact zone, generated during the grinding process. This leads to vibrations of the machine structure at its natural frequency. The

regenerative effect can occur on both the work-piece and on the tool.

COMPLEX CAUSE ANALYSISHow do you discover the cause of vibration? A systematic procedure is necessary. First of all, the machine is switched off. If it continues to vibrate, external disturbing forces are responsible. If vibra-tions occur during machine idle times, the cause may be machine elements such as bearings, belts or unbalanced masses.

If the machine only vibrates during the ma-chining process, the vibration frequency must be measured. The polygon shape occurring on the workpiece can be determined with the help of a harmonic analysis. The measurements must be repeated at a different workpiece speed. An iden-tical polygon and/or different vibration frequency indicate an externally-excited vibration, for exam-ple due to interrupted cuts. If, on the other hand, the vibration frequency remains the same and/or the shape changes, the vibration is self-excited.

TARGETED DAMPINGHow can vibrations be reduced, avoided or elimi-nated? The following measures reduce the chat-ter of the entire system:

Characteristic frequencies can be considerably reduced or even avoided by installing damping systems, such as auxiliary mass dampers.

“Soft” grinding and regulating wheels, with rubber bonding, for instance, utilize the so called “gooseneck” principle (damping element in the force fl ow of the machine). The compliant behavior of the entire system becomes much more balanced.

A reduction in the contact length of work-piece and regulating wheel reduces chatter ten-dency, particularly with very long workpieces. Resonance points are much more damped, due to the higher contact compliance.

Variation of the workpiece speed reduces or prevents the occurrence of regenerative effects.

Undesirable vibrations in the grinding process are an incalculable risk for the user.

An analysis of the cause of vibrations is the pre-requisite for systemati-cally eliminating them.

Reduction of chatter is achieved through balanced dynamic machine behavior.

Vibrations caused by interrupted cuts present a particular challenge in centerless grinding.

Software solutions for process simulation make a signifi cant contribu-tion to the avoidance of vibrations.

It is essential to examine the entire production sequence.

SHORT SUMMARY

22 MAY, 2014 – 14:45

EN_46_Motion_01_2014 46 29.04.14 18:09

Motion 01.2014 47

“OFTEN HUGE PRODUCTION

VOLUMES HAVE TO BE

HANDLED, AND AT THE SAME

TIME PROCESS RELIABILITY AND

COMPONENT QUALITY MUST CONTINUOUSLY

IMPROVE.”Karsten Otto

KARSTEN OTTO is the Head of Technology

at Schaudt Mikrosa GmbH

An easy-cutting grinding wheel reduces the forces in the grinding gap, so that no structural overloading occurs. This means, that grinding wheels must not be too fi nely dressed or even worn.

Non-wearing and backlash-free bearing positions guarantee vibration-free dressing with rotational dressing tools.

TASK FOR SPECIALISTSA major challenge in centerless grinding is deal-ing with vibrations caused by interrupted cuts. A typical example is workpieces with interruptions on the circumference such as bores, keyways or tooth couplings. In this case the workpiece itself becomes the “exciter”, as the “vibration pulses” that develop during rotation cannot be avoided. The focus is therefore on reducing the impacts. The fi rst measure is to eliminate the contact of the affected workpiece areas with the regulating wheel and work rest. As this does not usually suf-fi ce, the “Heureeka” software program is used at MIKROSA. This allows the geometric stability in-dex to be determined very easily for each polygon. The following rule applies here: The higher the value – the better the reduction of the shape. The aim is to obtain a geometrical grinding gap setting, in which the polygon shape (resulting from the in-terruptions) is reduced exceptionally well. Often changing the height of the workpiece is enough. Simple measure – big impact.

CALCULATING PERFORMANCE IN ADVANCEObviously the further development of simulation software opens up new possibilities in this area. A software program (prototype in testing) has there-fore been developed for process simulation – a calculation tool, which allows the process stability of the entire grinding process to be determined at a very early stage. Many factors are included in this calculation: Settings of the grinding geometry, technological process and dynamic settings (for instance, the compliance frequency response of the machine). The imbalance of the grinding wheel and the rough part quality are also included in the calculation.

This approach therefore goes far beyond the problem of vibrations. The parameters that guar-antee maximum process reliability in a centerless grinding process are systematically determined – long before the machine is in production with the customer. In other words: The existing machine

performance is optimally used. This is advanta-geous for the cost effectiveness of the entire pro-duction process.

THE ENTIRE PRODUCTION SEQUENCE AT A GLANCEAgainst this background, the tremendous impor-tance of the issue of process reliability becomes clear. At SCHAUDT and MIKROSA the entire pro-duction sequence for a customer’s workpiece is planned and created. This includes all processes, from loading and unloading of the workpieces, through their measurement, to the specifi c de-sign of the centerless grinding process. The end result is turnkey and highly effi cient production solutions – which are, of course, free from dis-turbing vibrations.

Regenerative chatter – formation of a polygon shape on the workpiece

Stable grinding process – no formation of a dominant polygon shape on the workpiece

1 000 μm

Gauss 50 %

90°

180°

270°

1

2

0°

0.500 μm

Gauss 50 %

90°

180°

270°

1

2

0°


EN_47_Motion_01_2014 47 05.05.14 11:44

GRINDING SYMPOSIUM

48 Motion 01.2014

DR. DIRK FRIEDRICH

EFFICIENT USE OF COOLING LUBRICANTS IN GRINDING MACHINES

IN EUROPE, COOLING LUBRICANT-RELATED COSTS ACCOUNT

FOR up to 16 percent of manufacturing costs. The now well-known savings potential was previously considered “irrelevant” as the cooling lubricant supply costs were included in the general manu-facturing costs for the production facilities, and were therefore not allocated to a specifi c cost cen-ter (machine, manufacturing group). Moreover, no savings potential was seen in this area, due to lack of technical improvement possibilities and exper-tise. Machine tool manufacturers also concentrat-ed less intensively on the “low-tech” components of their machines, which were necessary for cool-ing lubricant supply. The general topic of cooling lubricant supply was not considered a unique sell-ing point in technical competition for many years, due to its “plumbing nature”.

PROPORTION OF ENERGY COSTSThe requirements of some national governments to reduce CO2 emissions by 30 percent by the year 2020 led to a certain awareness regarding the use of cooling lubricants. It was recognized that the entire cooling lubricant periphery made up a sub-stantial proportion of the energy costs of a metal-working company. The size and energy design of such a cooling lubricant system is directly related to the quantity of cooling lubricant that is required in machine tools. The question of how much cool-ing lubricant is required for which machine, which component and, above all, for which manufactur-ing process, was increasingly asked. The answers remained elusive.

Machine tools can consume up to 50 percent of unnecessary cooling lubricant quantities in bed fl ushing and component cleaning, while the pro-ductivity-relevant points (tool – component con-tact) in the machine are often under-supplied. The machine cannot work as hard. Maximum produc-tivities and minimum cycle times are not achieved, as adequate cooling is not guaranteed. This results in an urgent information requirement. How much cooling lubricant goes where, and how much is required at which point, at which time and for which reason? With the “Coolant Audit” method

described below, Grindaix GmbH from Germany is able to rapidly identify all cooling lubricant-related savings potential in a metalworking company, to directly link this to the increasingly important inter-dependence of the indicators CO2 / kWh and euros, and to recommend and implement specifi c modifi -cation measures for the customer’s machine.

USE OF COOLING LUBRICANT WITHOUT PRODUCTION BENEFITSPipes, valves and nozzles are often designed with-out appropriate knowledge and wastefully and have too many unnecessary resistances such as angles and chokes, insuffi cient diameters and nar-row proportions. This leads to unnecessary waste-fulness and productivity losses! The supplies to the individual consumption points in a production machine are often completely unknown. In most applications there are no requirement criteria on the pressure supply and fl ow rate of the nozzles for cooling the production process. This hugely limits the productivity of a machine. Following the motto “The more the better”, pipe diameters are doubled according to gut feel and pumps are incorrectly dimensioned.

The result: Productivity losses due to under-supply of the machining point, combined with enormous wastefulness at the secondary con-sumer loads. Overall an excessively high cost- related use of cooling lubricant without productiv-ity benefi ts.

WHAT EXACTLY HAPPENS DURING A COOLANT AUDIT?Not uncommon: Up to 20,000 euros of annual operating cost savings per machine, if for ex-ample a single liter of cooling lubricant volume generates annual operating costs of 200.00 euros and over 100 liters/minute of supply volume are saved in just one machine without high invest-ments (ROI < 12 months).

However, the robustness of the manufactur-ing process must not be reduced in any way! This is a very clear customer requirement. In most cases robustness is even increased, as the

The entire cooling lubri-cant periphery makes up a signifi cant proportion of a metalworking com-pany’s energy costs.

Machine tools can con-sume up to 50 percent of unnecessary cooling lubricant quantities, while the productivity-relevant points in the machine are often under-supplied.

During a coolant audit the actual consumption values of the machine are examined, and this inspection reveals how much is being wasted where, and whether the machining point is under-supplied.

This enables a consider-able reduction of the annual cooling lubricant-related costs.

SHORT SUMMARY

22 MAY, 2014 – 15:30

EN_48_Motion_01_2014 48 05.05.14 11:50

Motion 01.2014 49

“THE TOPIC OF COOLING LUBRICANT

SUPPLY WAS NOT CONSIDERED A

UNIQUE SELLING POINT IN

TECHNICAL COMPETITION

FOR MANY YEARS.”

Dirk Friedrich

DR. DIRK FRIEDRICHThe graduate production

technician is Managing Director of Grindaix GmbH, which he

established in Aachen in 2005.

machining point is better supplied and the sec-ondary consumer loads use cooling lubricant far more effi ciently.

During a coolant audit in metalworking pro-duction the actual consumption values of the machine are examined, and this inspection very quickly reveals exactly how much is being wasted where, and whether the machining point is under-supplied. The process takes a total of six hours per machine, but less than one hour in the machine itself, so that minimal production time is lost. The entire cooling lubricant periphery of machines is measured, documented and analyzed quickly and practically using cutting-edge technology. Detailed information can be provided about the degree of wastefulness and possible productivity losses of a machine after just fi ve days.

Innovative measuring methods in combination with a high-tech software solution developed in-house are used by the Grindaix auditiors in-situ dur-ing production. No damage is caused to mechani-cal systems such as lines or other components of your cooling lubricant system during this process.

MACHINE IS OPTIMIZED AND MODIFIEDWhen designing the coolant, an appropriate and effi cient cooling lubricant supply is completely designed for all production requirements. All units such as cooling lubricant fi ltration, pumps and pipework are assembled according to

requirements and cooling lubricant nozzle sys-tems are developed for the machine tool. Each nozzle system ideally includes a pressure sensor, which allows the output quantity and cooling lu-bricant delivery speed to be monitored. The basis for this is the characteristic curve individually gen-erated for each nozzle, which documents the re-lationship between cooling lubricant type/cooling lubricant pressure/cooling lubricant fl ow rate and cooling lubricant delivery speed.

This means that when using such systems one always knows how much cooling lubricant it is best to use, at which point, at which delivery speed and during which machining task. Audit re-sults can be directly transferred to identically con-structed machines without any additional costs. Coolant audits do not therefore have to be carried out for each machine.

CONSIDERABLE COST REDUCTIONThe total cooling lubricant savings on all machines considerably reduces the annual cooling lubri-cant-related costs. After using this service cooling lubricant fi ltration systems can be used for more machines than previously or, in the case of new in-vestments, can be more specifi cally adapted (size, type …), thus reducing investment costs.

Fig. 1: Pressure booster station for on-demand cooling lubricant supply

Fig. 2: Control box for cooling lubricant regulation


EN_49_Motion_01_2014 49 05.05.14 11:50

GRINDING SYMPOSIUM

50 Motion 01.2014

DR. THOMAS MAGG

NEW CONCEPTS FOR MINIMAL GRINDING FORCES DURING CBN GRINDING IN MASS PRODUCTION

STRUCTURED ABRASIVE COATING combine machining and hydrodynamic advantages, and in conjunc-tion with optimized grinding wheel bodies sig-nifi cant increases in cost effectiveness can be achieved.

CUTTING AND RUBBING ABRASIVE GRAINSGrinding is the separation of material with geo-metrically undefi ned cutting edges. The lack of defi nition means that in addition to the cutting edges that remove material, a grinding tool also has many cutting edges, which only rub across the workpiece surface and thus generate undesir-able forces and heat. As the removal of material only begins from a minimum penetration depth, there is a danger with dressable CBN abrasive coatings in particular that, depending on the dressing conditions, the proportion of rubbing grains will also be high, due to the many individ-ual cutting edges at a uniform height. As a result the distance between the cutting edges becomes a key parameter for infl uencing the penetration depth and consequently also the ratio of cutting to rubbing abrasive grains.

STRUCTURED GRINDING TOOLMacro-structure, micro-structure and porosity are structuring methods for infl uencing the distance between the cutting edges. Macro-structure here refers to fl at keyways with millimeter dimensions, micro-structure refers to laser drill holes with a di-ameter of 0.3 millimeters, and porosity means the natural porosity of a ceramic abrasive coating or the porosity generated by pore formers. In relation to increasing the porosity micro-structure has the advantage that the basic strength of the bond and the grain retention can be higher, and thus enable a longer service life.

As the grains after a gap always penetrate deeper into the material than the grains in an un-broken line, structuring methods are a suitable means of increasing the proportion of cutting to rubbing abrasive grains and achieving a conse-quent lowering of the temperature of the contact zone. When designing macro-structures, however,

it is necessary to ensure that the abrasive grains af-ter the gap are not overloaded, and that the bond strength or grain retention is not exceeded.

The recesses or structurings also cause a signifi cant improvement in the absorption or dis-placement capacity of the abrasive coating in rela-tion to the cooling lubricant. Laser structuring in particular, due to its deep linear drill holes, has the advantage in relation to the porosity that the fi nal dimension of fl exible workpieces can be reached more quickly, in order to reliably achieve closely toleranced fi nished dimensions. This type of struc-turing therefore represents an important step to-wards designing abrasive coatings not only on the basis of machining aspects, but also on the basis of hydrodynamic aspects.

This design of super-hard abrasive coatings enables reliable fulfi llment of the latest high-pre-cision requirements in mass production, such as:

Observance of geometrical tolerances into the sub-μm range,

Creation of surface roughnesses with very narrow tolerance bands,

Grinding of heat-sensitive components with minimal damage and

Reduction of surface waviness (in the sub-μm range according to FFT analysis).

In addition to the design of the abrasive coating and precise observance of the grinding parame-ters, the selection of the wheel body is of decisive importance, not only with regard to waviness. The current state of development, thanks to the use of fi ber-reinforced materials, enables the design of light, high-strength wheel bodies, which can also be optimized in the direction of high damping or high lateral rigidity. The full potential here can naturally only be tapped, if abrasive coating and wheel body are developed together and harmo-nized with one another.

IMPLEMENTED PROCESSThe capabilities of currently available CBN grinding wheels will be illustrated using the example of a

Structuring methods lead to a lowering of the contact zone temperature.

The interaction between abrasive coating and wheel body is of decisive importance.

Laser structuring of super-hard abrasive coatings enables reliable fulfi llment of high- precision requirements in mass production.

CBN grinding with structured abrasive coatings enables a time saving of up to 30 per-cent, even with fl exible workpieces.

SHORT SUMMARY

22 MAY, 2014 – 16:15

EN_50_Motion_01_2014 50 05.05.14 11:51

Motion 01.2014 51

“STRUCTURED ABRASIVE

COATINGS A ND OPTIMIZED

GRINDING W HEEL BODIES TOGETHER

GUARANTEE SIGNIFICANT

INCREASES IN COST

EFFECTIVENESS.”Thomas Magg

DR. THOMAS MAGG is Head of Development at the Tesch GmbH diamond company in Ludwigsburg.

high-performance grinding process for grinding camshaft bearings on a KRONOS dual grinding machine. The special feature of this process is that, despite the use of superproductive center-less grinding, the workpiece reference axis must be retained. This was achieved as follows: The shaft is ground between centers, until the runout of the bearings is created for this axis, followed by fi nish grinding of the bearings using centerless plunge grinding. TIME SAVING WITH CBN GRINDINGThe most sensitive process step in relation to grinding forces is the unsupported grinding be-tween centers with a total contact width of around 150 millimeters. The advantage of the CBN pro-cess in relation to the process with conventional grinding wheels is impressively demonstrated by the fact that the grinding time between centers

was reduced by around 20 percent, and the cen-terless time by 25 – 30 percent. A multi-wheel was used for machining the com-pletely assembled camshaft; the regulating wheel for the centerless process is designed in the same way. Assuming that the spindle bearing is suffi ci-ently rigid, optimized CBN grinding wheels of the latest generation do not therefore always need to have a carbon fi ber reinforced body.

CBN grinding wheel set for the KRONOS dual centerless grinding machine (top and right). Left: CBN multi wheel with carbon fi ber reinforced body


EN_51_Motion_01_2014 51 05.05.14 11:51

GRINDING SYMPOSIUM

52 Motion 01.2014

PROF. DR. WILFRIED SAXLER

TOOL GRINDING – A PROCESS WITH THE HIGHEST PRECISION

THE MAIN MARKETS for grinding companies in the FDPW – Trade Association of German Precision Tool Grinders – are industries that are involved with metal machining, woodworking, plastics processing and paper processing. The FDPW em-braces the trade of the cutting tool mechanic.

GROWING REQUIREMENTS The cutting tool mechanic must continuously deal with growing requirements. Why is this?

Cutting tools contain very complex geometry elements. The preparation of cutting edges with small radii, chamfers or droplet-shaped geome-tries are common requirements of tool users today. In addition, chip breakers must be incorporated in-to the cutting faces – even with super-hard cutting materials such as diamond. This is possible with special laser machining processes, for example.

Quality requirements are constantly increas-ing. This doesn’t just concern the dimensional tolerance. The focus is also fi rmly on the require-ments on position and form tolerances and par-ticularly surface qualities. The combination of different technologies, such as drilling, reaming, countersinking and deburring – in so-called multi-functional tools, poses real challenges for the cut-ting tool mechanic.

AUXILIARY TIMES The benefi t for the user is clear: The change times due to different tool types are eliminated. This al-lows auxiliary times to be reduced. The position tolerances are also unparalleled. As the creation of (stepped) bores, ream drilling and countersink-ing can be performed with one and the same tool in a single work step, the eccentricities relative to each other are zero. The design of the cutting edge geometries is particularly demanding. Because the tool can only operate at one speed, different cutting speeds are present at the various stepped bores. This generates different wear behavior, which can be compensated for slightly through individual selection of the cutting edge angle at the respective steps. A diffi cult endeavor, which requires a high level of process understanding.

PROFESSIONAL EXPERTISE AND PROCESS UNDERSTANDING For both the manufacture and reconditioning of tools, high quality knowledge is essential to ful-fi ll the requirements described. A typical process chain is designed as follows:

1. Tool cleaning2. Inspect shaft and shaft end, repair and

deburr if necessary3. Measure tool on tool measuring

device in order to record the necessary geometric data

4. Determine regrinding values / parameters5. Program CNC tool grinding machine6. Grinding operation7. Clean tool8. Recoat if necessary9. Create measuring record

In addition to this work sequence, the grinding ma-chine must naturally be equipped with appropriate clamping devices for different sizes. In addition, the machines are often equipped with magazines, so that a lot of tools can be sharpened without manual intervention. Many tool manufacturers are now trying to keep resharpening inhouse and are setting up their own resharpening centers. They sometimes advertise with a label or an “original grinding” quality seal.

MAIN AIM: CUSTOMER LOYALTY The main aim is naturally customer loyalty. The ob-jective is to maintain customer proximity after the purchase of a new tool. There are price models in which the tool is not paid for, but the end customer obtains a price per bore, for example. The aim is to further reinforce customer loyalty. The type of technical equipment is generally identical for tool manufacturers and tool grinding businesses. In order to assure quality in a demanding production process such as the manufacture and recondition-ing of cutting tools, well trained personnel are nat-urally required. What counts is the qualifi cation of the employees. The job profi le specially developed

The quality require-ments on cutting tool mechanics in respect of quality, dimensional tolerance, position and form tolerances as well as on surface qualities are constantly increasing.

The combination of different technologies, such as drilling, reaming, countersinking and deburring in multi-functional tools reduces auxiliary times.

Tool manufacturers and tool grinding companies can exchange data in a standardized format via a newly developed interface.

SHORT SUMMARY

23 MAY, 2014 – 09:30

EN_52_Motion_01_2014 52 30.04.14 10:51

Motion 01.2014 53

1

2 3

“THE COMBINATION OF DIFFERENT

TECHNOLOGIES IN MULTIFUNCTIONAL

TOOLS POSES REAL CHALLENGES

FOR THE CUTTING TOOL

MECHANIC.”Wilfried Saxler

PROF. DR. WILFRIED SAXLERis Professor for Machine

Tools and Manufacturing Processes at the University of Applied Sciences in Cologne

and Managing Director of the Trade Association of German

Precision Tool Grinders (FDPW).

for these activities is the cutting tool mechanic. Vocational training leads to master craftsman’s training.

COOPERATION BETWEEN MANUFACTURERS AND GRINDING COMPANIESThe tool manufacturers have adapted to this situa-tion. The tool grinding companies don’t know any different. The share of sales that is achieved with the manufacture of special tools has signifi cantly increased in the last few years. Tool grinding com-panies generally use the same CNC tool grinding machines as manufacturers. They don’t use them just for sharpening, but also for manufacturing a wide variety of tools. The tool manufacturers could work well together with the tool grinding companies in this regard. A newly developed data interface will create the possibility of transmitting data, which is required for the manufacture and reconditioning of tools, in a standardized format. The information paths are very diverse. The solu-tion is called GDX-Standard.

STANDARDIZED TRANSMISSION The VDI Technical Committee FA114 has been drafting and further developing VDI guideline 3232 for the past two years. This guideline will be converted into a standard. The data, which is

documented in Version GDX 2.0, comprises in-formation on the geometry of cutting tools and blanks, the geometry of grinding wheels and mea-suring instructions. Subsequent versions will be gradually supplemented with further tools. In ad-dition, from Version GDX 2.1 grinding paths can also be transferred in standardized format. The lat-ter opens up brand new perspectives for coopera-tion. It is therefore conceivable for a tool manufac-turer to transfer the grinding paths for special drill grinds under license to a tool grinding company, which can then apply the exact grind to the cutting edge, irrespective of which machine or control system is used. The manufacturer does not have to disclose his expertise during this process. This means that the manufacturer’s own experience can be “protected” in principle. There are many representatives of well-known grinding machine, measuring machine and software manufacturers who are involved in the development of GDX and are supporting this ambitious but realistic project in the long term.

During tool manufacture the necessary data pass through many

interfaces, which can be standardized with GDX.

TOOL GRINDING

Workstation (CAD/CAM system)

Tool measuringmachine

Tool grindingmachine

SCENARIOS:

1 Workstation Tool measuring machine

2 Tool grinding machine Tool measuring machine

3 Workstation Tool grinding machine

CAD/CAM

EN_53_Motion_01_2014 53 30.04.14 10:51

GRINDING SYMPOSIUM

54 Motion 01.2014

PROF. DR. CLAUS EMMELMANN

3D LASER MATERIAL MACHINING – OPPORTUNITIES AND CHALLENGES FOR GRINDING TECHNOLOGY

DURING THE LAST FEW YEARS market requirements have constantly increased, continuously pre-senting new challenges for manufacturing com-panies. This has resulted in the requirement to reduce development times, particularly due to constantly decreasing product life cycles. This is only possible with profound consequences for the companies. The increasing demand for more indi-vidual products inevitably results in an increase in the number of different variants and thus a reduc-tion in the batch size per component, while the number of customers remains the same. In con-junction with a constantly increasing component complexity, this leads to increasing component costs and requires the company to confront the imposed challenges quickly and fl exibly.

In this connection the laser has developed into one of the most reliable tools in the past two de-cades. And its potential is far from being exhaust-ed. And so the laser has also recently appeared in grinding technology, where laser ablation is used in the form of a volume ablation. It extends the limits of conventional production by new machin-ing options for ever harder materials, which previ-ously could not or could only be machined to a limited extent.

CUTTING AND MACHINING TOOLSFields of application include, for example, the machining of hard materials for the cutting and machining tool sector or the direct profi ling of grinding wheels, as well as the direct manufac-ture of components, on which extremely fi ligree machining tasks must be performed. Brand new advantages result, such as the creation of three-dimensional free-form contours which cannot be ground using conventional methods, as well as non-contact and consequently force-free ma-chining. In addition, no direct tool wear is caused by the contact with the laser machining tool, so that consistent machining results are guaranteed over long periods of time. Excellent quality can be achieved in the form of a small thermal infl u-ence combined with intercrystalline machining of multi-phase carbide-binder materials, which can

be machined with the aid of laser beam sources in the ultra-short pulsed time range of just a few picoseconds.

MANUFACTURE OF CUTTING INSERTSThe manufacture of cutting inserts is a complex task, due to the natural composition and engrained characteristics of the blanks to be machined. The example of PCD (polycrystalline diamond) cutting material demonstrates that, in order to process very hard material, tool materials that are at least as hard are required. In addition, very demand-ing development goals result from machining in the micro-scale range. Cutting areas must have very small edge radii of up to 1 – 2 μm to ensure good sharpness and performance in use. Geom-etry elements, such as precisely defi ned negative chamfers as well as precisely formed chip breaker or chip shape geometries and exact clearance angles, must also be created.

For these innovative fi elds of application the basic processes must be developed through to industrial production stage using integrated, me-thodical development principles. High standards must therefore be set in the context of process development, in order to achieve the desired tech-nological goals in tandem with increased quality and productivity.

The use of laser beam sources, which are pulsed in the picosecond range, enables these goals to be achieved with laser ablation. During irradiation with pulsed laser light absorption pro-cesses occur on the surface of the machined ma-terial. Photons from free electrons are absorbed in spatially limited proximity to the focus position. The absorbed energy is spatially absorbed in a depth direction to the extent of the optical pen-etration depth. Heat conduction effects also oc-cur, which can be described by the thermal dif-fusion depth depending on the thermal diffusion coeffi cient and the effective duration of a laser pulse. If the thermal diffusion depth falls below the optical penetration depth, the defi nition of ul-trashort pulse machining applies. It thus becomes apparent that the classifi cation of an ultrashort

Laser technology extends the limits of conventional produc-tion by new machining options for ever harder materials.

It enables the creation of three-dimensional free-form contours which cannot be ground using conven-tional methods, as well as non-contact and consequently force-free machining.

No direct tool wear, small thermal effect.

Reduction of processing times by up to 65 percent.

SHORT SUMMARY

23 MAY, 2014 – 10:15

EN_54_Motion_01_2014 54 30.04.14 10:57

Motion 01.2014 55

“LASER ABLATION

IS USED IN THE FORM OF

A VOLUME ABLATION I N

GRINDING TECHNOLOGY.”

Claus Emmelmann

PROF. DR. CLAUS EMMELMANN

is a lecturer at the Institute for Laser and Equipment

Systems Technology at the Hamburg University of Tech-nology and Managing Direc-

tor of Laser Zentrum Nord

interaction between laser beam and material de-pends on the pulse duration of the laser beam source on the one hand, and on the characteristics of the machined material on the other.

COLD MATERIAL REMOVALIn summary, machining with ultrashort laser pulses is characterized by the fact that the heat-affected zone is considerably reduced, due to the almost cold material removal. Also, when machining plas-tics with low thermal conductivity for example, even laser pulses in the nanosecond range can be categorized as ultrashort. In respect of machining materials, the machining of metal-based, synthetic and many super-hard materials with picosecond lasers produces a very small heat-affected zone in conjunction with good removal effi ciency, in com-parison with even shorter pulse systems.

In order to achieve an optimal machining re-sult in an industrially proven series process on the basis of fundamental knowledge, methodical approaches can be used to identify optimal laser parameters in relation to the machining task and the material in question. In this way, as application scenarios from industrial practice have shown, a signifi cant increase in productivity can be achieved in comparison with the conventional process chain for the manufacture of cutting inserts, by reduc-ing processing time by 65 percent. Laser material machining can also be cost-effectively applied as a supplementary process in hard metal machining. Although hard metal is generally easy to grind, laser material machining also opens up new possibilities

for this material. For example, laser fi nishing of chip breakers and extended options such as the introduction of micro and nano structures onto the machined surfaces can be performed in the same work step in 3D machining. Pulsed laser beam sources in the nanosecond range generate ther-mally induced, undesirable infl uences in the struc-ture of hard metal. In comparison, picosecond- pulsed laser radiation only slightly changes the composition of the hard material matrix structure consisting of carbides and binder phase.

Laser ablation can also be used in diverse fi elds of application beyond the manufacture of machin-ing tools, for example in medical technology or general machine construction. In future laser abla-tion systems will thus also be able to undertake further-reaching applications in the area of struc-turing tasks. In comparison to conventional struc-turing methods, the laser-based process offers the advantage of exceptional fl exibility in respect of machinable materials and design freedom, includ-ing individualization of surfaces. The process can also be used on complex free form surfaces.

ON THE THRESHOLD OF INDUSTRIAL MATURITYUsing laser ablation to produce components from diverse materials, a process with the potential to enable new approaches to production and design is on the threshold of industrial maturity. This will extend the previously limited range of design free-dom with new manufacturing possibilities in fu-ture, particularly for demanding materials.

Fig. 1: Laser ablation of surface structures

Fig. 2: Laser ablation of cutting edges

TOOL GRINDING

EN_55_Motion_01_2014 55 30.04.14 10:57

GRINDING SYMPOSIUM

56 Motion 01.2014

OLIVER WENKE

TECHNOLOGICAL LEADERSHIP THROUGH THE USE OF CUTTING-EDGE MEASURING TECHNOLOGY

THE MACHINING OF MODERN NEW MATERIALS requires innovative tools and signifi cantly determines the pace of tool development today. Cutting material, coating and often also process control must be in-dividually adapted.

The customer’s objective: To improve tool life, reduce tool costs and ensure tool availability in each phase of the production process. Customers no longer buy ‘off the shelf’, but expect a com-prehensive service offer in the form of complete solutions, engineering and fi gures / facts includ-ing measuring records for high quality tools. This offers great opportunities for tool manufacturers, but also presents risks due to substantial changes (smaller batches, fewer processing steps, shorter production time).

The intensive involvement of the machine supplier as a reliable and experienced cooperation partner is necessary here.

OPTIMIZATION OF PRODUCTIONToday many companies already use a multi- layered, complex production management system, which continuously monitors and visualizes the comple-te process. An important process-oriented level is the “Manufacturing Execution System” (MES). It provides the connection between company ma-nagement and production, and provides the right information at the right time. It shows the decision makers how the actual conditions in production can be optimized, in order to increase output.

An important component here is ODA/MDA data acquisition (operating data/machine data ac-quisition), which acquires data from the process in response to trigger events. Quality management is the basic principle for assuring product quality and process capability (process quality).

“Quality” must be a consistent corporate phi-losophy! it must be precisely defi ned and actively lived from a holistic business perspective, in other words from the Management down to each indi-vidual employee.

“Doesn’t measurement cost money?” No, because the effi cient use of measuring technology

is a vital component for high process quality and productivity. It directly saves costs and thus makes a signifi cant contribution to business success!

SELECTION OF SUITABLE MEASURING EQUIPMENTThe more complex modern production machines and measuring equipment for quality assurance become, the higher the costs for maintenance, inspection and calibration.

Larger corporations may have up to 50 mea-suring machines in the HELICHECK series, for example. The customer accepts HELICHECK measuring technology as the standard in tool measuring technology and often uses the same technology himself. The common defi nition and exchange of measuring programs are already mandatory here today.

This enables perfect and complete documen-tation via tool ID number including all relevant data according to the documentation requirement un-der the EN ISO 9000 ff series of standards.

INSPECTION EQUIPMENT CAPABILITY TESTINGBefore using an inspection device, it is necessary to ensure that it continuously fulfi lls the relevant requirements during daily use. Measurement Systems Analyses (MSA) have been defi ned for this purpose. The aim is to ensure that a mea-suring device, used under production conditions and depending on the type of use, can measure a quality characteristic with a suffi ciently small result dispersion. The analysis can be performed conventionally or using special PLC software so-lutions, which are subject to the requirements of standards DIN EN ISO 9001, DIN EN ISO 10012, QS 9000 and VDA 6.1. As one of the most wide-spread corporate policies, the development of these processes is often based on publication series 10 (Bosch company), which has been de-veloped and grouped into different processes since 1990.

The effi cient use of measuring technology is crucial for high process quality and productivity.

The consistency of measurements through-out the production pro-cess and correct timing are important factors.

Controlled processes ultimately help to deliver the required high qual-ity, reduce costs and ensure a lead over the competition.

SHORT SUMMARY

23 MAY, 2014 – 11:00

EN_56_Motion_01_2014 56 30.04.14 10:59

Motion 01.2014 57

OLIVER WENKEis Head of the Measuring

Technology Development Center at Walter Maschinenbau GmbH

in Garbsen near Hannover, Germany.

MEASUREMENT CONSISTENCY AND ELIMINATION OF ERRORSThe consistency of measurements throughout the production process and correct timing are important factors. The measurement can be car-ried out externally or directly in the machine. In all cases the external measuring machine is the “arbiter” and recognized certifi ed reference! Tar-geted feedback, for quick correction and stabiliza-tion of the process in the form of “Closed Loop” solutions, avoids rejects and guarantees minimal tool tolerances. WALTER provides a number of applications that have already been successfully used for many years, including IMS (Integrated Measuring System), OTC (Online Tool Compensa-tion), HCC (Heli Contour Check) and FTC (Form Tool Compensation).

Controlled processes ultimately help to de-liver the required high quality, reduce costs and ensure a lead over the competition. They guar-antee effi cient production of small batch sizes in particular, as well as the quickest reaction times to new customer requirements. Simple, error-free programming and operation are vital. The creation of measuring programs should ideally be possible directly from the grinding program with the aid of the actual tool geometry. The TMI interface has been developed for WALTER TOOL STUDIO grind-ing software program for this purpose. WALTER is also a member of the “GDX Standardization” Tech-nical Committee, whose objective is to preserve a uniform standard and formulate it in the form of a VDI guideline.

From the manufacturers’ perspective, how-ever, it is best to use their own database for pro-gramming. The individual provision of interfaces

has already been successfully implemented in many instances to date. The measuring programs are created completely offl ine and can gener-ally be used directly on the measuring machines. If necessary, however, a simulation of a virtual measuring cycle is also possible as a check in production planning without a measuring ma-chine. To increase safety, barcode readers or RFID write/read units can also be used to read the rel-evant additional data completely automatically and error-free. The fully parameterizable, universal measuring software WALTER QCM Quick Check Modular offers this option for all types of tools in the product portfolio.

The HELICHECK series can replace a multi-tude of classic measuring equipment and be used in the various production steps. If a 100-percent inspection is essential, unmanned fully automatic series measurement with the robot loader option is possible for a capacity of up to 2000 tools.

SAFEGUARDING INNOVATIONS THROUGH MEASURING TECHNOLOGYMeasuring technology helps in tool development/optimization as well as in the reverse engineering sector. Macro or micro geometry (cutting edge preparation, for example) and sometimes also the complete 3D model of the tool are required. The aim is to fi nd key nuances on the tool in order to improve it, and to stand out from the competition with constantly new innovations.

The effi cient use of measuring technology is thus a signifi cant and important element for achieving dominance and success as a tool man-ufacturer. Our expertise: “We help you to under-stand tools – Creating Tool Performance!”

“CUSTOMERS EXPECT A

COMPREHENSIVE SERVICE OFFER

IN THE FORM OF COMPLETE

SOLUTIONS, ENGINEERING

AND FIGURES /FACTS INCLUDING

MEASURING RECORDS FOR HIGH QUALITY

TOOLS.”Oliver Wenke

“Closed Loop” solutions with targeted feedback of the measuring result for quick correction and stabilization of the process avoid rejects and guarantee minimal tool tolerances.

TOOL GRINDING

Logging

Correction

Grinding

Transfer

Measurement

Target / actual comparison

EN_57_Motion_01_2014 57 30.04.14 10:59

GRINDING SYMPOSIUM

58 Motion 01.2014

PROF. DR. DIRK BIERMANN

DEVELOPMENTS FOR THE EFFICIENT MANUFACTURE OF SOLID CARBIDE HIGH-PERFORMANCE TOOLS

MACHINING with a geometrically defi ned cutting edge is often one of the last processes in the value creation chain for component manufacture. It is therefore particularly important that the tools used guarantee high quality, ensured through opti-mized grinding processes, and adequate process stability in use. The process chain for the manufac-ture of solid carbide machining tools, starting from the sintered carbide blank to grinding and edge preparation as well as coating and subsequent treatment, has been adapted to the performance requirements of modern machining tools. There are a multitude of interdependencies within this process chain. Optimization measures must there-fore always take account of the entire production sequence. Measures for optimizing the manufac-ture of carbide machining tools are described be-low, with the help of selected examples.

GRINDING OF CHIP FLUTESThis starts with grinding of the tools. The process steps of peripheral machining, fl ute grinding and creation of the tip shape are usually demarcated from each other. Flute grinding assumes particu-lar importance here. The traverse/peripheral sur-face grinding process, which is often executed as a creep feed grinding operation, is characterized by complex contact conditions between grinding wheel and workpiece. Flute grinding directly in-fl uences the tool cross-section and decisively de-fi nes the shape of the main cutting edge and the quality of the cutting faces and secondary cutting edges. The chip form resulting during tool use therefore depends largely on the design of the chip fl utes.

The process step of creep feed grinding the chip fl utes is characterized by superimposition of the rotation of the workpiece blank and the move-ment of the rotating grinding wheel traveling in the workpiece axis direction. The pitch angle of the chip fl utes (fl ute lead angle) is determined by the relationship between the previously described movements. The cross-section profi le of the ma-chining tool, on the other hand, is defi ned by the

profi le and position of the grinding wheel in rela-tion to the workpiece.

In addition to the selection of suitable process parameters and cooling lubricant conditions, new grinding wheel compositions play an important role for optimizations in terms of the effi ciency of the fl ute grinding process. The possibilities result-ing from the use of hybrid grinding wheel bond systems will be discussed in the following. With an appropriate process design vf, infeed speeds of up to vf = 200 millimeters/minute can be reliably achieved with hybrid-bonded grinding wheels.

SURFACE MACHINING BY MEANS OF MAGNETIC FINISHINGAfter grinding the chip fl utes, their surface quality and thus the quality of the cutting face can be con-siderably improved using appropriate processes. One possible manufacturing process is magnetic fi nishing. In this process unbonded ferromagne-tic abrasive grains, which are located within two rotating magnets, remove material from the work-piece parts located between the magnets. Due to the magnetic bond, the powdered abrasive medi-um dynamically adapts to the workpiece shape to be machined. A wide variety of workpiece shapes can thus be machined with this process in addition to machining tools.

In comparison to the ground surface on cut-ting face and cutting point, the surface quality of the cutting face and the quality along the cutting edge can be substantially improved with magnetic abrasive machining. As the work head speed in-creases rounding also increases, particularly in the area of the cutting point. Magnetic fi nishing en-ables machining tools to be adapted to the machin-ing task, through targeted adjustment of process parameters, thus further increasing effi ciency.

The composition of the cutting edge of solid carbide tools is primarily infl uenced by the design of the grinding process for generating the fi nal tool macro shape. The grinding process causes micro defects such as break-outs and fl aking along the cutting edge. The high degree of chipping that

Optimization measures for the manufacture of solid carbide machining tools must always take account of the entire production sequence.

The effi ciency of the fl ute grinding pro-cess can be increased through new grinding wheel compositions, the selection of suitable process parameters and cooling lubricant conditions.

Magnetic abrasive machining improves the surface quality of the machining surface and the quality along the cutting edge.

SHORT SUMMARY

23 MAY, 2014 – 11:45

EN_58_Motion_01_2014 58 30.04.14 11:02

Motion 01.2014 59

“ MACHINING WITH A

GEOMETRICALLY DEFINED CUTTING

EDGE IS OFTEN ONE OF THE LAST

PROCESSING STEPS IN COM-

PONENT MANU-FACTURE – AND

IS THEREFORE SUBJECT TO

SPECIAL QUALITY REQUIREMENTS.”

Dirk Biermann

PROF. DR. DIRK BIERMANNdirects the Institute of

Machining Technology (ISF) at Dortmund Technical University

results from this can have a disadvantageous ef-fect on operational behavior and cause increased tool wear. Tool preparation processes are usually used after the grinding process, in order to im-prove operational behavior. Common preparation processes are jet cutting, drag fi nishing, brushing and magnetic abrasive machining.

CUTTING EDGE PREPARATIONThe various preparation processes are currently used especially for substrate pretreatment before coating. The aim of the cutting edge preparation is to reduce chipping by smoothing the cutting edge. In addition, the generation of a defi ned rounding increases the cutting edge stability and consequently the tool life. The adherence of a sub-sequently applied wear protection coating can al-so be increased.

The jet cutting process is used for the prepara-tion of single-fl uted deep-hole drills. Through de-fi ned rounding of the cutting edge, the tool micro shape can thus be adapted to the requirements of the drilling process and wear resistance can be increased thanks to increased edge stability.

ADAPTATION TO MACHINING TASKSSelected examples have been used to demon-strate how complex production can be designed more effi ciently along the process chain for the manufacture of solid carbide high-performance tools. How modern high-performance tools can be specifi cally adapted to the respective machin-ing tasks by means of suitable manufacturing processes and their control has also been dem-onstrated. The result is increased process stability and the possibility of increasing productivity.

Contact ratios during fl ute grinding of twist drills

AwKg

Fn ns

nw

Vf

Drill

Grinding wheel

Ft

Faλ

ae

ap

TOOL GRINDING

ns: Grinding wheel speednw: Workpiece speedvf: Forward motion of the workpieceFt: Tangential grinding forceFn: Normal grinding forceFa: Axial grinding forceAwKg: Geometrically ideal contact area between grinding wheel and workpieceae: Working contactap: Lateral infeedλ Flute lead angle

EN_59_Motion_01_2014 59 30.04.14 11:02

60 Motion 01.2014

GRINDING SYMPOSIUM

PROF. DR. KONRAD WEGENER

ENERGY EFFICIENCY AND THERMAL BEHAVIOR OF MACHINE TOOLS

DRIVEN BY THE ERP DIRECTIVE by the EU, machine tools for all process technologies are currently being put to the test in respect of effi cient use of energy. The energy analysis of 25 machine tools with a wide variety of process control has shown that a stan-dard process to improve energy saving is incon-ceivable. However, it is apparent that power consumption of auxiliary units is not in accordance with the vari-ous process requirements and is sometimes heav-ily overdimensioned.

FOUR AREAS OF ACTIONIn general four areas of action for better use of energy can be identifi ed, which often do not re-ceive suffi cient attention in the conventional de-sign process:

Effi cient processes Avoidance of unnecessary operation Production hall integration Heat management

As practically all energy supplied to a machine tool is converted into heat and thus causes tem-perature changes, and this heat must then be dissipated again, which results in temperature gradients, economical use of energy is the best primary measure for curtailing temperature varia-tions. Energy saving measures also generate a signifi cant secondary benefi t for manufacturing quality. Temperature control measures drastically increase energy consumption, as production must be preceded by warm-up cycles of several hours, and since the machine’s thermal behav-ior when running is different to when it is idling, reject parts are unavoidable with high precision requirements.

Up until 15 years ago it was a hard and fast rule that air-conditioning must be provided for a machine with higher precision requirements. To-day, the temperature variation of a machine tool has changed from being a problem for the operat-ing company to one for the manufacturer, because

the thermal behavior of machine tools varies depending on design.

Understanding the thermal behavior of a ma-chine tool in the form of a model, which makes the temperature variation predictable from the perfor-mance data of the main energy consumers and the ambient conditions, is also the key to success in saving energy with not only identical, but even improved component quality. With the aid of the model it is possible to calculate compensation val-ues for the machine tool axes, which can be made available to the machine control via an appropriate interface, which then converts the compensation into temperature-compensated axis movements, with practically no additional energy consumption.

MODELING CHALLENGEAs power input is only converted into tempera-ture-related position changes of the TCP relative to the workpiece (WCP) with large delays due to the high thermal capacity of the machine, the complete history of the power fl ows must be taken into account when calculating the compensation values. This signifi cantly impedes modeling of the thermal behavior.

Different modeling methods are therefore available. In the physically “most correct” approach to calculating the temperature variation, the dissipation losses are obtained from a rigid body model, which for example gives the neces-sary forces on guides and bearings to determine the frictional energy.

Considering the ambient temperatures as boundary conditions, which must be set by means of temperature measurements as part of a compensation model, the heat transfer equation, which delivers the history-dependent temperature fi eld on the machine, can be solved. The next step is to determine the thermal displacement due to the temperature fi eld, where only the relative dis-placement between TCP and WCP is interesting, but depending on the position in which the ma-chine is located. The high level of associated com-putational effort is offset, as the thermal move-ments are slow and even for real-time simulation

Understanding the thermal behavior of a machine tool in the form of a model is the key to successful management of the temperature variation as well as for saving energy. Temperature compensa-tion should always be viewed as an additional measure to an engineer-ing design optimized in terms of thermal criteria.

SHORT SUMMARY

23 MAY, 2014 – 14:00

EN_60_Motion_01_2014 60 30.04.14 11:06

Motion 01.2014 61

“ENERGY SAVING MEASURES

GENERATE A SIGNIFICANT SECONDARY

BENEFIT F OR MANUFACTURING

QUALITY.”Konrad Wegener

PROF. DR. KONRAD WEGENERis Professor of Production

Technology and Machine Tools at ETH Zurich and Director of

IWF (Institute of Machine Tools and Manufacturing)

a new compensation value must only be available approximately every minute. In addition, the com-puting time can be considerably reduced through skilful organization of the calculation, dimension reduction processes, set-up of the system matri-ces for different poses beforehand and interpola-tions between the processes.

MODELING VARIANTSIt is nevertheless worth considering simplifi ca-tions of this complex modeling. In the so-called thermal balance model the individual bodies of a machine tool moving in relation to each other are modeled with homogeneous temperature. This dramatically reduces the number of degrees of freedom, however to improve the correspon-dence between model and reality a parameter identifi cation is necessary, i.e., the model cannot function without an implemented machine and the relevant measurements. But it provides new displacement and compensation values within fractions of a second.

Another modeling variant is phenomenological modeling, i.e., results-oriented modeling which pri-marily focuses on the results, or the displacements between TCP and WCP. The fundamental behavior of the machine is illustrated by PT1 links between each relative displacement of interest and each thermal load. Time constants and prefactors must also be experimentally determined. From the cal-culated relative displacements the axial compensa-tion value is calculated and communicated to the control system via an interface.

HIGH BENEFITNumerical and axial temperature compensation is the most effi cient measure against thermally-caused errors on the workpiece and is thus essen-tial in modern machine tool manufacture, particu-larly in respect of energy effi ciency. With all results that can be achieved today with model-based tem-perature compensation, it must not be forgotten that even greater efforts are required to achieve a high-precision compensation.

The precision with which the linear expan-sion coeffi cients of the materials used in machine tool manufacture can be set is only ±10 percent. Conditions of heat transfer to the environment and the entrainment of thermal energy by cooling lubricant are only inadequately modeled today. Temperature compensation should therefore al-ways be viewed as an additional measure to an engineering design, which takes account of ther-mal aspects. Effi cient use of energy, thermosym-metrical machine design, displacement of heat sources to the periphery and effi cient temperature compensation in relation to the environment are aspects that must be taken into account in the de-sign of a machine tool.

Compensation results achieved with the thermal balance model

UNIVERSAL CYLINDRICAL GRINDING

Y0

C [μ

m]

30

20

10

0

10

0 1 2 3 4 5 6 7

Time [h]

Not compensated

Compensated

EN_61_Motion_01_2014 61 30.04.14 11:06

62 Motion 01.2014

GRINDING SYMPOSIUM

DR. FRANK FIEBELKORN

THE LATEST GRINDING AND DRESSING TECHNOLOGIES FOR THE USE OF VERY HARD ABRASIVES

THE GRINDING MANUFACTURING PROCESS, as a fi nishing technology, has a wide variety of requirements made on it, depending on the specifi c sector in which it is used. During the last few years, for ex-ample, manufacturers of components made from brittle materials, such as hard metals or ceramics, have recorded constantly increasing demands on the quality characteristics of these components. Two research projects aimed at optimizing these production processes are discussed in this pre-sentation as an example – “Ultrasound-assisted grinding” and “Wire electrical discharge dress-ing” (STUDER-WireDress®), which have been initiated by Fritz Studer AG – as cooperative proj-ects (KTI projects) in the framework of Swiss re-search promotion.

ULTRASOUND-ASSISTED GRINDINGResearch into ultrasound-assisted grinding has fo-cused primarily on the internal cylindrical grinding process for machining ceramics (ZrO2, Al2O3, Si-3Ni4) with diamond grinding wheels. Components made from these materials can be subsequently used in medical technology or precision measuring technology (calibration balls) for example.

The method presented here assumes that an adaptation of the ultrasonic grinding spindle to to-day’s machine concepts or retrofi tting of existing machines is conceivable. This patented approach takes account of the possibility of integrating the actuators for ultrasound generation into estab-lished grinding spindle concepts for internal grind-ing. The sonotrodes are calculated in combination with the grinding tools and manufactured accord-ingly. Equally small grinding wheel diameters (< 3mm) are essential for the planned operational conditions.

The development of the ultrasonic spindle components was therefore fi xed at high spindle speeds of 60,000 – 100,000 rpm, so as to also uti-lize the advantage of higher cutting speeds on the grinding tool. These operational conditions result-ed in new requirements on the ultrasonic grind-ing spindles to be developed, in order to utilize the theoretical advantages of ultrasound-assisted

machining. In the example presented here, these advantages consist particularly in a reduction of the machining forces (around 30 – 50 percent in some cases) during internal cylindrical surface grinding into the solid ceramic material, enabling higher material removal rates or lower tool wear.

REDUCED SURFACE ROUGHNESSESThe axially superimposed ultrasonic movement, induced by the integrated piezo actuators, assists the chip formation process during the machining of brittle materials. In order to realize this poten-tial, a transmission of the ultrasonic movement of 70 kHz was implemented synchronously to the high spindle speed. This confi guration now repre-sents a new state of the art.

Further research with the same test set-up was also carried out in relation to internal cylindri-cal plunge grinding of ceramic components. The effect of the reduction of surface roughnesses was also observed, which opens up further eco-nomic potential for future users of this process.

WIRE ELECTRICAL DISCHARGE DRESSING TECHNOLOGYDiamond grinding wheels in a wide variety of bond systems are generally used for the abovemen-tioned brittle materials. These ultra-hard abrasives are necessary due to the material characteristics of hard metal and high-performance ceramics (including hardness, viscosity). However, these abrasives are also subject to physical wear, which puts the problem of the dressing process on the agenda. The established dressing technologies are often problematic and are not suffi ciently re-producible.

In the past STUDER has therefore concentrat-ed its basic research on the electro-erosive dress-ing of metal-bonded diamond grinding wheels, and transferred these basic principles together with the latest knowledge to the conditions of dressing grinding wheels for external grinding in practical operation. The research focused on the use of metal-bonded diamond grinding wheels and the use of oil as a cooling lubricant, which

The demanding machin-ing of brittle materials is assisted by newly developed processes, such as ultrasound-assisted grinding or the electro-erosive dressing process.

Ultrasound-assisted grinding can reduce the machining forces during internal cylindrical surface grinding by around 30 – 50 percent in some cases.

Wire electrical discharge dress-ing technology with STUDER-WireDress® results in a grinding time reduction of around 30 - 40 percent with metal-bonded grinding wheels.

SHORT SUMMARY

23 MAY, 2014 – 14:45

EN_62_Motion_01_2014 62 30.04.14 11:09

Motion 01.2014 63

DR. FRANK FIEBELKORNis Head of Production

Development, Research and Technology at Fritz Studer AG

“MANUFACTUR-ERS OF COMPO-

NENTS MADE FROM BRITTLE

MATERIALS FACE CONSTANTLY INCREASING

DEMANDS ON THE QUALITY CHARACTER-

ISTICS OF THE COMPONENTS.”

Frank Fiebelkorn

also acts as an insulating material, and the prin-ciple was also tested for applications with metal- bonded CBN grinding wheels.

The renaissance in the use of metal-bonded diamond grinding wheels, which are also used today for high-speed processes, can also lead to higher removal rates at lower cutting speeds, as excellent grain protrusions and consequently de-fi ned chip spaces for the material removal can be achieved with the eroding process, in addition to generation of the regular grinding wheel profi le. In combination with the high grain retention of the metal bond, these grain protrusions result in excel-lent removal rates.

SIGNIFICANT REDUCTION IN GRINDING TIMEA production-oriented series simulation incor-porating STUDER-WireDress® technology gave a signifi cant grinding time reduction of around 30 – 40 percent per workpiece in comparison with the present grinding process with metal-bonded grinding wheels.

The wire spark erosion process was chosen for the STUDER-WireDress® system, as in com-parison with the die-sinking erosion process a constant wire diameter is continuously used. Re-generation of a die-sinking erosion tool for a com-plete grinding wheel profi le is therefore not nec-essary. A specially developed wire guide system ensures a continuous wire feed for high-precision contours and guides the wire precisely and with minimal vibrations during the dressing process.

With the aid of a defi ned wire diameter, internal radii < 0.2 millimeters and external radii < 0.05 mil-limeters can be generated on the grinding wheel profi le. These parameters create brand new pos-sibilities for the use in his production philosophy.

PROFILE ACCURACY OF THE GRINDING WHEELThe overall profi le accuracy of the grinding wheel is also determined by the quality of the grinding machine axes, as these undertake tracing of the wheel contour. Precise grinding machines offer the optimum basis here, for technical reasons. The concept of STUDER-WireDress® is com-pletely tailored to the conditions of a machine integration, i.e. the grinding wheel is conditioned in the machine (without changing the wheel) and at operating speed if necessary. This mea-sure has a signifi cant infl uence on the quality of the grinding process. In comparison with the wheel topographies that were generated by the STUDER-WireDress® process instead of with SiC dressing tools, further additional positive ef-fects, such as reduced grinding forces and higher grinding ratios (G values), were recorded.

The optimum parameters for dressing grinding tools using the wire spark erosion process are preset for the machine operator via the control system. The technological integration of STUDER-WireDress® is thus controllable for the user and comparable with familiar methods for the operation and program-ming of a grinding machine.

STUDER-WireDress® – Wire erosion dressing technology


EN_63_Motion_01_2014 63 30.04.14 11:09

64 Motion 01.2014

GRINDING SYMPOSIUM

DR. SEVERIN HANNIG

DYNAMIC STABILITY OF GRINDING MACHINES – POTENTIAL AND RISKS

THE MACHINE’S DYNAMIC RIGIDITY determines the sta-bility of the grinding process and consequently the grinding quality. Due to its complexity, the ac-quisition and correct assessment of the dynamics has always been the king of inspection methods on production machines. Cutting-edge measuring and simulation technologies help with the analy-sis and prognosis of the complex interactions be-tween the dynamic characteristics of a machine and the effects on the grinding result.

DIFFERENT VIBRATION CAUSESChatter marks often appear during operation, when new machines are commissioned or the pro-cess has been changed in respect of parameters, abrasives and clamping devices or workpieces. The economic boundary conditions generally re-quire a process design at the limits of what is fea-sible and often at the machine’s performance limit.

The causes of chatter marks are diverse, as are the possibilities for the user to implement time and cost intensive improvement measures. Be-fore implementing appropriate measures, it must be possible to reliably isolate the causes. Wavi-ness components with proportionality to spindles, units, bearings or transmissions can easily be de-termined. Chatter marks that are associated with specifi c natural vibrations of the machine can also be assigned, if the dynamic system resilience is known. This equates to a “fi ngerprint” of the dy-namic machine quality.

More diffi cult is the assessment of cross- process error components, which for example oc-cur during dressing and are repeated as a pattern of the wheel during grinding. Vibration infl uences from external machines or units via the foundation constitute a special area.

The most diffi cult to identify are waviness com-ponents that result from beat vibrations of several adjacent characteristic frequencies, or between vibration and rotation frequencies. They can be recognized as sidebands or amplitude patterns in the FFT order analyses. As the described tolerance limits are reduced waviness problems, which are not caused by classic “chatter”, i.e. regenerative

upswing during a resonance, increase. In fact the rotation frequency of the wheel is only located in a frequency range in which the machine reacts with a slightly higher resilience. RISKS OF DYNAMIC CALCULATIONThe causes of natural vibrations of a grinding machine can in many cases be assigned to the workpiece, grinding, or dressing unit or the basic machine, according to the point of origin. But is a statistical classifi cation possible? How are vibra-tion problems distributed among different ma-chine types?

The chatter causes for 62 examined grinding machines were analyzed as an example. Percent-age distribution of chatter causes in this example:

45 %: Natural vibration of grinding unit 19 %: Imbalance/runout problems 17 %: Natural vibration of workpiece unit 8 %: Natural vibration of dressing unit 6 %: Installed vibration of basic machine

Without any claim to completeness, the selection fi rstly shows that problems can occur on all units of a machine, but the grinding unit is extremely important here.

The majority of the axes were on the grind-ing side on the problematic machines. To enable high machining fl exibility, the grinding units are equipped with slides and swivel devices arranged on top of each other; these have dynamic resil-iences that can accumulate unfavorably and lead to tilting or sliding vibrations. The second cause lies in combinations of large grinding wheels with often relatively heavy wheel fl anges. The systems have a large overhang and in conjunction with spindles, whose dimensions and bearing arrange-ment or spacing are limited by the installation space, pose a risk for the occurrence of natural spindle vibrations.

The workpiece, grinding or dressing unit can execute sliding or tilting movements of the slides. Spindle systems on the described units hold the risk of natural bending, axial or torsional

Vibrations endanger the stability of the grinding process and consequently the grinding quality.

Natural machine vibra-tions can occur on all components. The causes can be determined quickly and reliably using measurements.

An integrated machine simulation can address weak points at the machine planning stage.

SHORT SUMMARY

23 MAY, 2014 – 15:30

EN_64_Motion_01_2014 64 30.04.14 11:16

Motion 01.2014 65

DR. SEVERIN HANNIGis Managing Partner of planlauf GmbH. The company supports

manufacturers and users of production machines in fi nding

the causes of and eliminating dynamic vibration problems

“THE ACQUI-SITION AND

CORRECT ASSESSMENT OF

THE DYNAMIC MACHINE

RIGIDITY I S THE KING OF INSPECTION

METHODS ON PRODUCTION

MACHINES.”Severin Hannig

vibrations. The wheel can execute plate vibrations, which can present a problem for CBN wheels with poor cushioning behavior of the metallic body un-der spatially acting forces of the angular meshing.

Every machine concept has particular dy-namic risks, which can be taken into account in the concept phase. As an example the vibration causes were investigated for 40 large machine tools in portal, gantry or column design with a ver-tical slide. The chatter causes were distributed as follows in this example:

55 %: Pendulum vibration of the slide 22 %: Vibration of workpiece/table 9 %: Tilting vibration of column/portal

The high percentage for the pendulum vibration of the slider is often caused by the heavy spindle heads with a limited cross-section of the slide, which is used in the lowest position. The described dynamic fi ngerprint in this slide projection can say a great deal about the machine’s effi ciency and is particularly recommended during acceptance.

FLEXIBLE MULTIPLE-BODY SIMULATIONSIf the concept-related weak points are known, they can be addressed at the machine planning stage. planlauf GmbH supports machine manu-facturers and users in calculating the dynamic rigidity behavior. The current state of research constitutes integrated machine simulations using fl exible multiple-body simulation, which in addi-tion to the structural components take account of the installation, bearings, guides and drives. The control of the drive trains can also be integrated. A database comprising a large number of rigidity measurements on machines is the prerequisite for models that are as realistic as possible. The

potential for improvement of design variants and size scalings as well as new vibration risks can be calculated and compared with initial versions. Ma-ny years of experience show that only half of vibra-tion problems are so serious that immediate mea-sures must be taken. The second half have often already existed since installation of the machine. One tries to live with dynamic weak points or puts a strain on maintenance with the superfl uous re-placement of components. Unknown weak points limit the effi ciency of a machine over the years, which is disproportionate to the time spent on a detailed metrological cause analysis (2 to 3 days) or a computational investigation (1 to 2 weeks) of the dynamic behavior.

MEASURES FOR IMPROVEMENTOnce the cause has been found and the weak point located, the potential of improvement measures can be determined. While problems due to unfa-vorable rpm ratios and residual imbalances can still be reduced by changing process parameters, dynamic problems usually require structural inter-ventions, in order to increase either the dynamic ri-gidity of the machine or the damping of individual components. Structural simulations for the design of components, optimal clamping of workpieces or the design of auxiliary mass dampers offer sig-nifi cant time and cost advantages here in compari-son with the empirical approach.

The latest developments by planlauf GmbH already enable the simulation of process stability, taking account of the dynamic machine condition. In addition to standard processes with a defi ned cutting edge, complex grinding processes, such as centerless grinding, can be simulated in the time domain and stability diagrams can be calculated for optimum geometrical setting of the process.

Dynamic rigidity measurement on a cylindrical grinding machine


EN_65_Motion_01_2014 65 30.04.14 11:16

GRINDING SYMPOSIUM

66 Motion 01.2014

ERHARD KÄMPF

COMPUTER-SUPPORTED, PRACTICE-ORIENTED DESIGN OF CYLINDRICAL GRINDING PROCESSES

NOT TOO MANY YEARS AGO photographers had to select all of the settings on their cameras them-selves. This was very time-consuming and often a challenge for laypersons. Built-in programs now ensure that the camera automatically fi nds the right setting for practically every occasion.

The right settings are also crucial in the grind-ing process. To this end, STUDER has developed the StuderTechnology grinding technology com-puter, thus offering its customers a unique soft-ware solution.

Effi ciency, quality, time, performance, repro-ducibility, continuity, know-how and so on are the buzzwords, but this also means that the sequence from workpiece drawing via grinding process to a perfect, effi ciently manufactured workpiece must be as lean as possible.

But what are the constituents of the sequence from workpiece drawing to fi nished part, where are there recurring unnecessary losses?

RECURRING ACTIVITIESThe costs can essentially be split into the recur-ring activities of set-up, programming, profi ling of grinding wheels, optimization, production and documentation. The ratio of pure production costs to the remaining activities is heavily dependent on the batch size. The use of StuderTechnology is especially worthwhile for individual components, small and medium batch sizes.

The process always begins with the work-piece drawing or a work instruction. This shows the dimensions as well as the dimensional, form, position and surface tolerances. The user is always faced with the question of how he must set the machine, in order to fulfi ll the requirements. He must also take account of infl uencing variables such as material and hardness, as well as abrasive and cooling lubricant, clamping situation and so on when making a decision. From these variables he derives his setting values, which are shaped by personal experience.

For the automation of these tasks StuderTechnology provides production goals, similarly to a camera, on which exposure pro-

grams and auto controls for different exposures and subjects can be selected on the setting dial.

The “Normal grinding” production goal stands for applications in the tolerance range ~ H5/h5 and surface quality ~ Ra0.3. Accordingly, there is a pro-duction goal for increased removal capacity, which is used primarily for pregrinding operations. And there are two further production goals in the direc-tion of greater precision or higher surface quality.

SPECIFIC REMOVAL RATEWith all of these production goals everything re-volves around the material removal or the Q’w , the specifi c removal rate. Users must deal with a wide variety of materials on a daily basis. But which user knows which removal capacity, which Q‘w or which resulting infeeds are used for which material (hardening process) / abrasive combina-tion? It is very hard to achieve an optimum result without support.

But what goes into the model that is used to provide this support? It is a combination of formu-las from grinding technology, empirical data and many years of expertise from countless customer applications and basic experiments.

PROBLEMS IN USER BEHAVIORWith the help of the grinding task in our illustration we can see why there is a state of emergency as regards user behavior. The red curve shows the grinding times achieved. The fastest on the left, the slowest on the right. The number of partici-pants is shown at the bottom.

The lower green curve shows the degree of fulfi llment of the six assessment criteria (three roughnesses and three roundnesses). Only those for whom the green curve reaches the red one have fulfi lled all criteria. Failure to fulfi ll at least one or more criteria is indicated by a greater distance between the green curve and the red one. Only eleven percent of participants fulfi lled all six assessment criteria! Despite a longer machining time, the roughness and roundness tolerances are generally not achieved straight away, usually hours or days of further optimization are necessary.

StuderTechnology offers a unique software solution for effi ciency, quality, time, perfor-mance, reproducibility and continuity.

Existing programs can be analyzed and the optimization potential determined.

Set-up and operation plans can be generated.

Job order manufactur-ers can generate quota-tions for their customers directly from the data.

All inputs are checked with a validation process.

SHORT SUMMARY

23 MAY, 2014 – 16:15

EN_66_Motion_01_2014 66 30.04.14 11:22

Motion 01.2014 67

ERHARD KÄMPFis responsible for offl ine

programming of cylindrical grinding machine control

systems at Fritz Studer AG

“THE COSTS CAN ESSENTIALLY

BE SPLIT INTO RECURRING ACTIVITIES

SUCH AS SET-UP, PROGRAMMING,

PROFILING OF GRINDING WHEELS AND

PRODUCTION.”Erhard Kämpf

The reason for this is that most machine opera-tors err on the safe side with their empirical values when designing process parameters. The aim is to have a good part straight away. This means that the feeds are too slow and the spark-out times are too long. Despite this, the required tolerances are often not achieved. One of the biggest problems is the subsequent costly optimization phase, which must be minimized or eliminated.

INDISPENSABLE EXPERIENCEProcess parameters calculated by StuderTechnology, on the other hand, are already close to an opti-mized variant in respect of quality and cost effec-tiveness.

At this point it should be stressed that the op-erator’s experience is still indispensable for deter-mining the procedure or operation sequence, for set-up and resetting of the machine and much more, but process data automatically calculated by StuderTechnology enables a grinding process that is much more cost effective and of better quality.

TWO VARIANTS OF THE TECHNOLOGY COMPUTERThere are two variants of StuderTechnology. The StuderTechnology integrated variant runs on the control system under the StuderWIN operator in-terface and is standard on all machines.

The StuderTechnology variant for the StuderGRIND offl ine programming station of-fers additional functions such as time and cost calculation, as well as simulation of the created grinding programs. In addition, previously created programs can be analyzed and the optimization potential can be determined. Set-up and operation plans can also be generated. Job order manufac-turers can generate quotations for their customers directly from the data.

If the best abrasive is not available for a specifi c material, this is indicated to the user and the sug-gested process parameters are adapted automa-tically. The support must not fail at such times. The suggestions can be overridden at any time, or saved as in-house company know-how and repro-duced again and again independently of specifi c individuals.

All inputs are checked with a validation pro-cess. The user is notifi ed if the part or internal grinding arbor may be bent, or if there is a risk of burning, if unfavorable rpm ratios are present and much more. In addition, StuderGRIND is com-patible with machines up to ten years old (Fanuc Release B), so that this technology can also be retrofi tted on older machines to give a marked increase in effi ciency.

RETROFITTING OF MACHINESMany users are now using StuderTechnology. More and more customers are retrofi tting their existing machinery. Many production managers, techni-cians and grinders would not have expected that their parts could be produced even more quickly. They were all the more amazed when the improve-ment predicted by StuderTechnology was actually achieved. Once accustomed to using the software, users fi nd it easy and practical to operate.

Grinding times alone can generally be reduced by 25 – 50 percent. Set-up, programming and documentation times are also reduced by using the software. The optimization times, which gen-erally account for a signifi cant amount of effort, can even be completely avoided in most cases. The costs per part are thus substantially reduced.

Degree of fulfi llment of all tolerances f (machining time) (six assessment criteria)

Mac

hini

ng ti

me

[min

]

Participants

StuderTechnology:2min 30s: Degree of fulfi llment 100%

Machining time

Degree of fulfi llment

Surface roughness max. Ra 0.3 μmRoundness: max. 0.001 mmAllowance: 0.3 mm/ØDressing: 1x at the start (Fliese)

Ø 5

5 m

m

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73

1

0

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Ø 4

0 m

m

Ø 3

0 m

m

11 % to 89 %

Optimize!


EN_67_Motion_01_2014 67 30.04.14 11:22

United Grinding Group AG Jubiläumsstrasse 95

3005 Bern, Switzerland

Fon +41 31 356 01 11 Fax +41 31 356 01 12

[email protected]

Körber Schleifring Machinery(Shanghai) Co., Ltd.1128, Tai Shun RoadAnting TownJiading DistrictShanghai 201814, ChinaPhone +86 21 3958 7333Fax +86 21 3958 [email protected]

Körber Schleifring Machinery(Shanghai) Co., Ltd.Beijing Branch Of ceRoom 202, Building 18Tower B, Universal Business ParkNo.10 Jiuxianqiao RoadChaoyang DistrictBeijing 100015, ChinaPhone +86 10 8526 1040Fax +86 10 6500 [email protected]

Körber Schleifring Machinery (Shanghai) Co., Ltd.Chongqing Branch Of ce15-11 Building 4,No.18 Jinshan Road,Longxi Street, Yubei District, Chongqing 401147, ChinaPhone +86 23 6370 3600Fax +86 23 6374 [email protected]

Körber Schleifring Machinery(Shanghai) Co., Ltd.Guangzhou Branch Of ceRoom 2003, 20/FCenter Plaza Tower B161 Linhexi RoadTianhe DistrictGuangzhou 510620, ChinaPhone +86 20 3862 1241Fax +86 20 3862 [email protected]

United Grinding GmbHIndia Branch Of ceNo. 487 - D1 & D2A4th Phase, KIADB Main RoadPeenya Industrial AreaBangalore 560058, IndiaPhone +91 80 415 54 601Fax +91 80 415 54 [email protected]

United Grinding GmbHMoscow Of ce1-j Kasatschij Pereulok 5/2,Strojenije 1119017 Moskau, RussiaPhone +7 495 956 93 58Fax +7 495 956 93 [email protected]

United Grinding North America, Inc.510 Earl Blvd.Miamisburg, OH 45342, USAPhone +1 937 859 1975Fax +1 937 859 [email protected]

United Grinding North America, Inc.5160 Lad Land DriveFredericksburg, VA 22407, USAPhone +1 540 898 3700Fax +1 540 898 [email protected]

United Grinding Mexico S.A. de C.V.Blvd. Bernardo Quintana No. 7001Of. 1003Queretaro, Qro. 76079, MexicoPhone [email protected]

UNITED GRINDING Group International

SURFACE AND PROFILE

CYLINDRICAL TOOLS

Mägerle AG MaschinenfabrikAllmendstrasse 508320 Fehraltorf, SwitzerlandPhone +41 43 355 66 00Fax +41 43 355 65 [email protected]

Blohm Jung GmbHKurt-A.-Körber-Chaussee 63–71 21033 Hamburg, GermanyPhone +49 40 7250 02Fax +49 40 7250 [email protected]

Blohm Jung GmbHJahnstraße 80–8273037 Göppingen GermanyPhone +49 7161 612 0Fax +49 7161 612 [email protected]

Fritz Studer AG3602 ThunSwitzerlandPhone +41 33 439 11 11Fax +41 33 439 11 [email protected]

Fritz Studer AG Lengnaustrasse 122504 Biel, SwitzerlandPhone +41 32 344 04 50Fax +41 32 314 06 [email protected]

Schaudt Mikrosa GmbHSaarländer Straße 2504179 Leipzig, GermanyPhone +49 341 4971 0Fax +49 341 4971 [email protected]

StuderTEC K.K.Matsumoto Bldg. 2F4-10-8, Omorikita, Ota-kuTokyo 143-0016, JapanPhone +81 3 6801 6140Fax +81 3 6662 [email protected]

Walter Maschinenbau GmbHJopestraße 572072 Tübingen, GermanyPhone +49 7071 9393 0Fax +49 7071 9393 [email protected]

Ewag AGIndustriestrasse 44554 Etziken, SwitzerlandPhone +41 32 613 31 31Fax +41 32 613 31 [email protected]

Walter Kurim s.r.o.Blanenská 128966434 Kurim, CzechiaPhone +420 541 4266 11Fax +420 541 2319 [email protected]

Walter Ewag Japan K.K.1st oor MA Park BuildingMikawaanjo-cho 1-10-14Anjo City 446-0056, JapanPhone +81 556 71 1666Fax +81 566 71 [email protected]

Walter Ewag Asia Paci c Pte. Ltd.25 International Business Park#01-53/56 German Centre609916 SingaporePhone +65 6562 8101Fax +65 6562 [email protected]

Walter Ewag UK Ltd.B 13 Holly Farm Business ParkHoniley, CV8 1NP KenilworthGreat BritainPhone +44 1926 4850 47Fax +44 1926 4850 [email protected]

Walter Ewag Italia S.r.l.Via G. Garibaldi, 4222070 Bregnano (CO), ItalyPhone +39 31 7708 98Fax +39 31 7760 [email protected]

Walter Ewag do Brasil Ltda.Avenida XV de Agosto, 5-060 Jd. Leocádia18 085-290 Sorocaba, BrazilCEP: 18 085 290Phone +55 15 3228 6910Fax +55 15 3228 [email protected]

EN_68_01_Motion_01_2014 68-1 30.04.14 12:25

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