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11 8 4 HEIDENHAIN A Sense of Feeling for Accuracy and Efficiency KinematicsOpt: No Chance for Drift & Co. 5-Axis Machining: Getting a Grip on the Accuracy of Rotary Axes News from the World of HEIDENHAIN Controls Issue 49 + 9/2008 � Editorial Dear Klartext Reader, Encoders from HEIDENHAIN make machines more accurate – as lin- ear encoders and angle encoders directly on the machine, or in the form of touch probes for tools and workpieces. An even greater benefit can be gained with the TNC controls from HEIDENHAIN: “A Sense of Feel- ing for Accuracy and Efficiency” and “KinematicsOpt: No Chance for Drift & Co” will certainly convince you. A new section focuses on reality: With the title “Are you familiar with this function?” we outline practical TNC functions to simplify or signifi- cantly accelerate your tasks. The editorial staff of Klartext wishes you informative reading! Image Page 4: Stock.xchng.Kliverap Page 17: Synthes All other images © DR. JOHANNES HEIDENHAIN GmbH E d it o ri a l HEIDENHAIN show places machine tool accuracy on center stage The motto of the HEIDENHAIN exhibi- tion at this year’s AMB trade show is “HEIDENHAIN shows the way to precision.” Demo units and presenta- tions will help illustrate the differences between machining on machine tools equipped with linear encoders – bringing dramatically higher position- ing precision and higher production efficiency – and machines that operate without them. The accuracy of 5-axis machines with rotary and swivel axes is also a topic at the AMB. Here HEIDENHAIN shows the KinematicsOpt feature, which makes it possible to easily measure the tilting ac- curacy of rotary axes. In addition, at several iTNC programming stations our application experts will be available to demonstrate the newest fea- tures of the control. The new touch probes are also in focus. With its TS 740, HEIDENHAIN will present a high-accuracy infrared touch probe for very demanding 3-D measuring tasks on machine tools or measuring machines. The device operates with a piezo sensor and features a repeatability of better than 0.3 µm. The TS 444 is a version with small- er dimensions that, like its larger cousin, is also a 3-D touch probe with infrared transmission of the trigger signal. The TS 444 needs no batteries. The power supply consists of integrated capacitors charged from a small wind turbine driven by the compressed air of the machine. Visit us! Hall 4 Boot h 4.E12 AMB 2008 Sep. 9 - 13, 2008 Communications Linear and Angular Encoders Digital Readouts for Manually Operated Machine Tools Accuracy of Machine Tools DCM Dynamic Collision Monitoring/ KinematicsOpt Info Touch probes Controls Programming with smarT.NC A nw en d u n g en Klartext + Issue 49 + 09/2008 � Production Publisher DR. JOHANNES HEIDENHAIN GmbH Post box 1260 83292 Traunreut, Germany Tel: +49 8669 31-0 HEIDENHAIN on the Internet: www.heidenhain.de Editor Frank Muthmann Fax: +49 8669 31-1888 E-mail: info@heidenhain.de KLARTEXT on the Internet: www.heidenhain.de/klartext Layout and Typesetting Expert Communication GmbH Richard-Reitzner-Allee 1 85540 Haar, Germany Tel: +49 89 666375-0 E-mail: info@expert-communication.de www.expert-communication.de Touch Probes A Sense of Feeling for Accuracy and Efficiency 4 Applications 5-Axis Machining: Getting a Grip 8 on the Accuracy of Rotary Axes Software KinematicsOpt: 11 No Chance for Drift & Co. Controls Special Functions of the iTNC 530: 14 Tool-Oriented Machining (TOM) The Real World iTNC 530 – Application for Innovative 16 Medical Technology Training All-Round Support 18 for CNC Apprentice and Advanced Training Service HEIDENHAIN Service Product Information − 19 40 Years of Service Know-How Available Online! HEIDENHAIN controls used at SYNTHES in the medical technology sector. Page 16 C o n te n ts Check out our in teractive KLART EXT e-magazine as w ell, with even m ore background info rmation, animat ions, and expert know ledge. Take a loo k at www.heidenha in.de/klartext HEIDENHAIN controls together with HEIDENHAIN touch probes – an unbeatable combination. Page 4 � A Sense of Feeling for Accuracy and Efficiency Insects feel their way through life. Their antennae register the environment, assess hazards, search for and evaluate objects and thus secure survival. What has been hap- pening for thousands of years in Nature was only hesitantly learned by machine tools. Elementary. Save time, increase quality Machine tool experts have known it for a long time: both workpiece touch probes as well as tool touch probes help to reduce setup times, increase utilization times of machines and improve the dimensional accuracy of finished workpieces. Decisive for their success are the high accuracy levels of the touch probes and their effi- cient use, which must claim as little time as possible. Exact coordination between the touch probe and the control, includ- ing the whole range of components and functions, is therefore of particular signifi- cance. Only the combination of HEIDENHAIN touch probes with HEIDENHAIN controls guarantees particularly high accuracy. To u ch P ro b e s Decisive. Fine synchronization between control and touch probe Operators of HEIDENHAIN controls ap- preciate the combination of convenient operation, powerful functions and highly developed technology that together en- able a high level of contour fidelity and dimensional accuracy. Optimal results can be expected from machines whose entire control loops are implemented with coor- dinated components from HEIDENHAIN: This includes the control, a complete elec- tronics package, the drives and also the linear and angle encoders. For the sake of consistency, no compromises should be made in connection with the touch probes either! There are very good reasons for this: + HEIDENHAIN controls make available countless practical functions based on workshop reality and optimally coor- dinated to the various HEIDENHAIN touch probes. This is shown by the di- versity of cycles available on the con- trols, ranging from calibration of touch probes via simple cycles for setup and datum setting to programmed measu- ring and testing during machining. All of this is simply documented in the “Touch Probe Cycles” User's Manual within the TNCguide, for downloading from www.heidenhain.de  Services and Documentation  TNCguide. + Especially demanding measuring tasks can also be implemented: with the aid of additional software, free-form sur- faces can be measured directly on the machine. Machining errors are detected immediately and can still be corrected during setup. Even More Accuracy via Kinematics Optimization The KinematicsOpt TNC func- tion helps to further increase machining accuracy of 5-axis machines: In this case it concerns the perfect coordination of the control to the machine kinemat- ics. For more information about this topic, see the KLARTEXT article on page 11 Despite initial scepticism, many ma- chine tools cannot now be imagined without touch probes. The sensitive helpers create technological and eco- nomic advantages over the competition – provided that the symbiosis between control and touch probe functions. Optimal coordination between HEIDENHAIN touch probes... A nw en d u n g en Klartext + Issue 49 + 09/2008 � A Sense of Feeling for Accuracy and Efficiency To u ch P ro b e s ... and HEIDENHAIN controls. What is... ? Probe accuracy The probe accuracy specifies the error resulting from probing a test component from various directions at 20 °C ambient temperature. The probe accuracy also includes the effective ball radius. The ef- fective ball radius is calculated from the actual ball radius and the stylus deflection required to produce the trigger signal. This also includes stylus bending. Probe repeatability Probe repeatability is the dispersion of the results derived from repeated probing of a test component from the same direc- tion. Influence of the styli: Stylus length and stylus material significantly influence the trigger characteristics of a 3-D touch probe. Styli from HEIDENHAIN ensure a probing accuracy grade of better than ±5 µm. + HEIDENHAIN‘s tradition of providing highly accurate encoders for machine tools also applies to touch probes. The sensors function wearfree and gener- ate trigger signals of the highest qual- ity, which are optimally evaluated by HEIDENHAIN controls (signal propaga- tion times, for example, influence the probe repeatability of the 3-D touch probe). TNC cycle: Setting the datum for the aligned workpiece. TNC cycle: Workpiece measurement. + If especially tricky measuring and test- ing tasks have to be carried out in con- nection with a HEIDENHAIN control, the HEIDENHAIN hotline is there to help with its extensive wealth of knowl- edge. � To u ch P ro b e s Application oriented. Suitable technologies for varied demands As well as the ideal combination of a HEIDENHAIN control with HEIDENHAIN touch probes, selection of the right tech- nology is also the key to success. Fine matching is primarily possible when the optimal touch probe is available for spe- cific applications. Workpiece Touch Probes For series production, machines with au- tomatic tool changers are practically stan- dard. Time-consuming, manual fitting of the spindle or disruptions to machining are unthinkable. A workpiece touch probe must therefore be just as easily exchange- able from the magazine as a tool is. All requirements clearly defined: + Because touch probes must guaran- tee unobstructed workpiece machining for series production, their function- ality must be absolutely reliable. The TS 440, TS 444 and TS 640 touch probes are thus equipped with an op- tical sensor. The advantage: the sensor works without wear and therefore has long-term dependability. + When using a tool changer, connection via cable is of course not possible. The triggering signal is therefore transmitted via infrared to the NC. An interesting technology shows that the development of new touch probes is ori- ented to practical and economic criteria. The TS 444 is without batteries and kills two birds with one stone: an air turbine generator creates electrical energy that is stored in high performance capacitors. Compressed air that is supplied through the spindle drives the turbine. The com- pressed air can also be used for cleaning the workpiece. The capacitors are charged very quickly, and workpiece cleaning oc- curs with the same operation, so ancillary time is reduced even further! Some applications have demands in terms of accuracy that are even greater than usu- al. In this case, use of the TS 740 is rec- ommended. Instead of an optical sensor, a highly precise pressure sensor creates the triggering signal. Probing requires only low levels of force – an important prereq- uisite for particularly high probe accuracy and repeatability. Tool touch probes HEIDENHAIN also listened to the various demands made by operators, and offers two technologies regarding tool touch probes. When tools are particularly small or if ma- terials sensitive to breakage are used, the TL Laser System is especially suitable. The contact-free measuring method by la- ser beam enables you to check even the smallest tools rapidly, reliably and without collision. Because the tool is measured at rated speed, errors on the tool, spindle Control and measuring technology are best from a single supplier. That leads to optimal results. TS 444 workpiece touch probe Battery-free power supply with integrated air turbine generator via central compressed air supply TS 740 workpiece touch probe Highly precise pressure sensor and holder are detected and corrected directly. The measuring result is oriented to operating conditions and is therefore especially accurate. If normal or larger tools are used, the TT 140 – a 3-D touch trigger probe − is suitable. For specification of the exact tool dimensions, a disk-shaped probing element is deflected by probing. An opti- cal sensor then creates a triggering signal - reliably and without wear. Whichever tool touch probe is used: a measuring pro- cess normally consists of several steps. These of course do not need to be manu- ally performed or programmed. Instead, measuring cycles measure tool lengths and diameters, inspect the form of the in- dividual teeth and check for tool wear or breakage. The control automatically saves the results of measurement in the tool ta- ble. This is very fast and uncomplicated. Under program control, the NC control po- sitions the tool and starts the measuring cycle. In order to secure constant produc- tion quality, cyclical measurements are re- commended, either before machining or A nw en d u n g en Klartext + Issue 49 + 09/2008 � To u ch P ro b e s between machining steps. Uncritical. Rapid amortization with high levels of production quality. It sounds good: ancillary times down, ma- chine operation times up and at the same time, quality optimization. If this evalua- tion does not suffice, then facts are need- ed that withstand economic inspection. And that works best with an amortization calculation. An example − a task:  Align the workpiece blank parallel to the axes.  Set the reference point in the machining plane at a corner.  In the tool axis, set the reference point on the surface of the workpiece blank. The time saved: If this setup process is performed with a TS 3-D touch probe system from HEIDENHAIN, the time saved is approx. 4 minutes or approx. 72 %. Meaning that if this setup process is carried out once a day, you save over € 1,000 in one year with 220 workdays (at an hourly machine rate of € 70). Tip: Repeat the calculation with figures from your production experiences. If the advantages gained from accuracy and the reduction in rework and scrap are considered, then an investment in a HEIDENHAIN touch probe really proves its worth, especially for series production. Conclusion. Stretch out your antennae and make contact with us. With the combined use of HEIDENHAIN touch probes and HEIDENHAIN controls, best results can be expected from the symbiosis between accuracy and efficiency. For example: + In terms of functionality and technol- ogy, control and touch probes are per- fectly matched + The range of touch probes offered is oriented according to the typical de- mands of diverse applicationsTL tool touch probe Optical contact-free tool measurement + Reduction of ancillary times and in- creased production quality creates competitive advantages Ask for information directly from HEIDENHAIN. Contact: hd3@heidenhain.de Wear-free and dependable tool measurement via disk-shaped TT 140 probing element � A p p li c a ti o n In contrast to conventional 3-axis ma- chines, 5-axis machining has com- pletely new demands in terms of axis accuracy. It is not only a question of the precision of individual axes here, but of their accuracy in the working space. As a result, however, the number of error sources is significantly increased by the higher number of mechanical com- ponents in the machine design. Depen- ding on the specific machine design, angle measurement is of particular im- portance here. What sources of error exist? The many mechanical components of a machine are all possible sources of errors. These are all stressed by the enormous dynamics of the working processes. Typi- cal causes for inaccuracies are + Wear caused by high mechanical loads, for example, or collisions during machin- ing + Elasticities in transfer elements, e.g. the worm shaft, or instabilities of the bearings + Geometric errors e.g. radial eccentric- ity of mechanical transfer elements or incorrectly installed components How can sources of error be avoided or reduced? During the design of a machine, sources of error in connection with the rotary axes should be ruled out as far as possible. As a part of the kinematic influences, different mechanical and control-oriented designs of rotary axes should be compared. Rotary axes feature complex mechanics with various components subjected to possible sources of error. Optimal com- pensation would have as a prerequisite the recognition of all possible error sourc- es for every situation. And exactly that is not possible. A possibility for getting a grip on position deviations of rotary axes is the use of a suitable HEIDENHAIN angle encoder. For bet- ter understanding of the effect, here are two basic strategies for the design of ro- tary axes in control loops: + “Semi-Closed Loop” If the position of the rotary axis is meas- ured solely via the rotary encoder on the motor, then we refer to a “semi-closed loop”. Not only is the lack of accuracy of the motor encoder significant with this arrangement, but many other errors also play a part such as wear, elasticity devia- tions and geometric errors of the mechan- ical transfer elements. 5-Axis Machining: Getting a Grip on the Accuracy of Rotary Axes A nw en d u n g en Klartext + Issue 49 + 09/2008 � A p p li c a ti o n + “Closed Loop” If an angle encoder mounted direct- ly on the rotary axis is used for position measurement, most sources of error can be avoided. This method is known as the “closed loop” method. Use of an angle en- coder with integral bearing is recommen- ded in this respect so that the previously described elasticity deviations do not lead to additional angle deviation. When using an angle encoder with integral bearing it is presumed that the minimal angle error of an axis lies within the system accura- cy of the angle encoder (the accuracy of an angle encoder of ± 2’’ corresponds to a deviation of ± 5 µm for a table diameter of 1 m). Of course spatial deviations also accumulate due to elasticity of the axes. Angle encoders with integral bearing and a hollow shaft have an additional advantage: an integrated coup- ling that compensates for shifts of the axis midpoints without additional an- gle errors. On the other hand, an- gle encoders without integral bearing would lead to ec- centric deviations and would therefore provoke additi- onal angle errors. Understanding challenges to accu- racy and being able to judge meas- urement concepts help in gaining an insight into measuring technology and machine tools. That can be im- portant, for example, when selecting a suitable machine tool for your own applications. Especially if produc- tion quality has a high priority. After placing emphasis on the accuracy of linear axes in the last Klartext edition, this time we are concentrat- ing on rotary axes. The best solution is angle encoders with integral bearing, integrated coupling and absolute position measurement, directly mounted to the rotary axis. Angle encoders The term angle encoder is typically used to describe encoders that have an accuracy better than ± 5". In contrast, rotary encoders are encod- ers that typically have an accuracy worse than ± 12". Angle encoders are found in applications requiring precision angular measurement to accuracy within several arc seconds. These include rotary tables and swivel heads on machine tools, C axes of lathes, measuring ma- chines for gears, printing units of printing machines, spectrometers, telescopes, etc. The following mechanical design principles can be defined: + Angle encoders with integral bear- ing, hollow shaft and integrated stator coupling + Angle encoders with integral bear- ing for