In 2006, Otto Bock HealthCare GmbH in Duderstadt, Germany, a wellestablished prosthetics manufacturer, invested approximately $8 million in the spatial, organizational and technical infrastructure of its development and production processes. As part of this investment strategy, the company purchased two high-speed fiveaxis milling centers.
The two new machines, both Chiron FZ 15K S models, reduced the amount of production time lost to multi-stage part processing. With batch sizes of 100 to 250, the company had to frequently re-clamp parts when processing 10 different knee joint parts in six versions using five machines. Frequent reclamping also made it difficult to meet required tolerances.
Besides providing fiveaxis milling, the Chiron (www.chironamerica.com) machines do drilling, threading and turning, which reduces machining time by 50 percent and order runthrough by 40 percent for Otto Bock. Plus the machines easily meet the company’s geometrical tolerances of 0.02 mm. Thanks to complete machining in one setup.
To fulfill Otto Bock’s machining requirements, Chiron engineers integrated torque motors into the machines’ 2-axis swivel rotary tables. Doing so accelerates the machines’ 450-mm faceplates to 1,000 rpm and lets Otto Bock do turn machining with 80 Nm of torque.
For Otto Bock’s investment to work long-term, high machine reliability is a must.
To ensure this, the two new milling/ turning centers and the company’s other eight Chiron machines use Siemens 840D controls and sport a “direct line” to Chiron’s Service Center via a tele-diagnosis system called ePS. The system automatically signals Chiron of any malfunctions, and the company then contacts Otto Bock immediately.
Most problems are remedied by means of tele-diagnosis, but if a technician is required, the cause of the error is narrowed down to the degree that the repair is quickly completed. The feature saves Otto Bock time and noticeably minimizes its service costs.
