Precision work:
The six-axis Kuka KR 30 HA in action.
Aesculap has sent the staff members concerned to special grinding and polishing courses at the Kuka
College at SHL in Böttingen to ensure flawless operation. "We do not discriminate between programmer and operator. The person at the machine has full responsibility," explains Robert Braun.
"The familiar Windows interface of the Kuka control panel facilitates handling of the robots.”
The complete grinding and polishing system was designed and delivered by SHL
Automatisierungstechnik AG. The Kuka system partner provided a turnkey-system and accepted responsibility for the whole process, including project planning. The know-how of Aesculap was integrated into the planning. The scope of the order included the two Kuka robots KR 30 HA including their PC-based controls, the gripper and gripper change system, the grinding and polishing stations, the measuring devices, the washing and cleaning components with the respective pastes, the palletting system and the safety devices. "The greatest challenge for SHL was handling the complexity of the process," emphasized Bern Schöndienst. "In this respect, the interface between robot and grinding system is particularly important."
The pneumatic grippers, which were developed by SHL for this application, were an essential requirement for the success of the project. The actuators have to maintain a firm grip on the hip prosthesis shafts, but may never damage them. The grippers were shaped to fit the parts, taking into account that the shafts are hot-pressed parts and therefore have certain tolerances. SHL validated the process during pre-tests at its own site.
"SHL received the order, because it has competence in robotics as well as in grinding processes," explained Norbert Braun. "This know-how was optimally combined for our purposes. A further advantage is the geographical proximity. As soon as the test system was in operation, we could discuss important points on site and at short notice. It was therefore possible to clarify basic issues before initial operation and to commission the system from the manufacturer. SHL is furthermore a system partner of Kuka and as we have had good experience with several Kuka robots, we intend to focus on this supplier in future."
Increased productivity as well as reproducible and continuously high quality during grinding and polishing prove that Aesculap has chosen the right solution. The low space requirements of the robots are an additional benefit. Furthermore, the favourable price/performance ratio of the KR 30 HA made it possible to reduce the total investment required for the restructuring process.
SHL Automatisierungstechnik AG
Spaichinger Weg 14
D- 78583 Böttingen
SHL Automation Inc.
5126 South Royal Atlanta Drive
Tucker, Georgia 30084, USA i www.kuka.com
www.aesculap.de
www.shl-automatisierung.de
The Kuka robots have proven their value in polishing and grinding hip prosthesis shafts.
Reprint from Automation & Qualität 3/2005, Schlütersche Verlagsgesellschaft, Publishing Office Coburg

A esculap is a globally leading brand in medical technology that has been in existence for 134 years. The modern
Aesculap AG & Co KG is a branch of the B Braun Group, which develops and supplies implants, stitching material and surgical instruments and devices. These products are complemented by a wide range of services. The company produces approximately 25 000 different items in Tuttlingen and other production sites and the factory in Tuttlingen alone employs approximately 2400 staff members. The company generates 800 to 1000 new products every year and 25 percent of the turnover is therefore generated by products that are at most 36 months old.
The benchmark factory in Tuttlingen, which was opened in 2001, is a milestone in the history of Aesculap. In this flexible factory with an area of 11 000 square meters, approximately 250 staff members produce high-value implants that help many people regain their mobility and therefore their quality of life.
The productivity of the benchmark factory is supported by a future-oriented building technology that was planned with environmental protection and comfortable and safe workstations in mind.
Each robot performs several work steps without putting down the implant between steps.
Full automation provides significantly higher performance than manual handling.
By the middle of August 2004, two six-axis, articulated robots KR 30
HA of the Kuka Roboter GmbH in Augsburg started operation in the benchmark factory in Augsburg. They took over the handling of the hip prosthesis shafts during grinding and polishing, a highly specialised t a s k . T h e r o b o t s , w h i c h w e r e i n s t a l l e d b y S H L
Automatisierungstechnik AG, Böttingen, were provided with an absolute system of measurements to ensure that they could handle their tasks with the highest precision.
SHL Automatisierungstechnik was founded in 1989 by the owners Seelmann, Häring and
Lehr. It provides automation solutions for grinding, brushing, polishing, deburring, palletting, feeding and handling. The company currently employs a p p r o x i m a t e l y 5 0 s t a f f members at the site in Böttingen and has supplied approximately
400 SHL grinding and polishing robots as well as numerous specialised machines to major companies in the country and abroad. SHL offers a complete s e r v i c e r a n g e f o r t h e automation of production as well as the integration of the entire production process. The basis for reliable production solutions is the latest robotics technology and extensive k n o w - h o w r e g a r d i n g t h e machining of metals and many other materials.
"We have already used some automation in this area in the past, but most of the work was still manual," explained Norbert Braun, manager of the implants factory at Aesculap. "During recent restructuring we went beyond grinding and polishing and optimised the whole process, from forging to packaging of the implants. This was triggered by a high cost pressure and the resulting need for higher economic efficiency. It was therefore important to reduce the throughput times and the expenses.”
Based on these needs, Aesculap specified the requirements for the robots that each have a carrying capacity of 30 kg and a maximum reach of over two metres. "Apart from unattended processing, we first of all required high repeat accuracy to ensure a reproducible process that guarantees constant quality," said Bernd Schöndienst, departmental manager for production technology in the factory for implants. "Thereafter, flexibility was most in demand. The robots must be capable of handling diverse product families with six to eight different hip prosthesis shafts each, without putting down the shaft during the work process. If we would use another technology, we would be forced to remove the shafts and transport them to the next system on a continuous basis. Fast processing is essential as well. We achieve the required, short cycle times by using two robots."
After machining, the unfinished parts of the hip prosthesis shafts are forwarded to the robot cell, where grinding and polishing stations with integrated measuring devices are installed, on which the two six-axis robots process specific areas of the implants in a step-by-step manner. The KR 30 HA robots hold a specific shaft permanently in a specified position. To ensure that the second robot retains this position when the work piece is transferred, it takes each shaft together with the respective gripper. The Kuka robots grind and polish the implants in batch sizes of up to 200 pieces. Currently, shortly after the initial operation, the KR 30 HA robots are still being used in two-shift mode. However, Aesculap is planning a change to three shifts. The grinding and polishing process is followed by an additional surface treatment outside the robot cell.