CAM accelerates orthopedic manufacturing

Islikon, Switzerland-based Jossi Orthopedics AG manufactures orthopedic implants and surgical instruments to strict customer specifications and continuously seeks to incorporate the latest manufacturing technologies and solutions by adhering to ISO 9001 and ISO 13485 standards and regular FDA inspections.

“We define ourselves as a pure supplier. The products always carry our customer’s name, and they are all well-known orthopedic companies,” says Dr. Martin Schmidt, business development at Jossi Orthopedics AG.

Orthopedic components have complex geometries and are manufactured with challenging materials such as titanium alloys, cobalt-chromium, and high-alloyed steels. Jossi has mastered the materials and the processes required to machine them. Founded in 1957 as Hans Jossi Präzisionsmechanik, the company has manufactured various parts and mechanisms, specializing in challenging geometries and materials. Among other things, Jossi built robust, durable presses and received a request in the 1970s on whether it would be possible to cold-form titanium.

“At that time, titanium was forged but not known to be suitable for deep-drawing. Nevertheless, Hans Jossi and his team managed to develop an appropriate process,” Schmidt says.

This process resulted in significant cost-savings compared to complete machining from solid stock. The Jossi process costs up to 70% less compared to pure machining (including material and processing costs), creating a competitive advantage that led Jossi to start manufacturing implants. Today, the Jossi Group employs approximately 150 people.

“Our comprehensive expertise, command of the processes and use of the latest tools allow us to produce parts 3x faster than our competitors,” Schmidt notes.

In the computer-aided manufacturing (CAM) area, Open Mind Technologies’ hyperMILL CAM software contributes to this competitive advantage. Open Mind Technologies AG is in Wessling in Upper Bavaria, Germany, with North American headquarters in Needham, Massachusetts.

Broad machining strategies

Jossi Orthopedics needed a CAM software solution that worked with a wide range of machining centers. Jossi uses turn-mill centers from Mori Seiki (now DMG MORI) and several machining centers from Hermle, and Hurco to machine implants and tools. Finding the best CAM system required reviewing two CAM systems.

“hyperMILL came out on top in the end, as it provides simple and efficient operation during 5-axis programming,” notes Midhat Dedovic, head of multi-axis manufacturing at Jossi Orthopedics.

Jossi engineers use two hyperMILL workstations for manufacturing and another to train apprentices.

“When it comes to the two production workstations, we use the complete set of general-based machining strategies in hyperMILL,” Dedovic explains.

Productivity advantages

Jossi uses the CAM software’s tool database as much as possible, enabling machinists to import tools, define individual tools and custom-assemble complete tools, including holders. In addition to the material-specific cutting data, users can create various profiles for each tool defined in the database. Therefore, different applications and processes can be predefined and then selected in the job steps, even for the same workpiece and cutting materials.

To simulate hyperMILL CAM programs, Dedovic and his team store machine models in the CAM system. This makes it possible to check programs, either by tool paths created or in terms of complete workspace and machine monitoring.

“We alternate in this respect,” Dedovic says. “For 5-axis programs, we perform collision checks directly during programming. For 2D paths, the check is performed at the end as part of the complete simulation.”

CAM experts use existing simplification and acceleration options by copying jobs or the entire job list. For example, if there are five sizes of components for a knee joint, and programming steps for Size 4 are identical to Size 5, copying the job list speeds programming.

“We also use automatic feature recognition (AFR) to speed things up,” Dedovic says.

AFR detects geometries from solids and surface models, such as holes, stepped holes with and without threads, and open and closed pockets. Parameters required for machining programming and tool selection are automatically generated. Jossi Orthopedics uses this for inserting holes on free-form surfaces that can be placed anywhere. The automatic feature recognition guides the user to the target much faster.

Ease-of-use

Within a standardized user interface, hyperMILL allows users to program any type of machining – 2.5D, 3D, HSC, and 5-axis milling, as well as mill-turning. Users are presented with options that are task-oriented, practical, and safe, instead of every imaginable configuration.

Another hyperMILL specialty is the ability to machine with indexed axes. Five-axis machining is not only about performing intricate movements, but milling efficiently and profitably. To create programs with as few movements as possible, hyperMILL automatically indexes axes that are not required. Machining continues simultaneously only on those axes where work is necessary, reducing wear on the machine. In addition, hyperMILL’s feature and macro technology enables users to standardize and automate geometric programming.

Dedovic notes Jossi Orthopedics’ positive experience with hyperMILL. “I’m fully satisfied with the product, so much so that I don’t want to use any other CAM system. We were also very pleased with Open Mind’s support.”

Jossi Orthopedics AG
www.jossi-orthopedics.ch/en

Open Mind Technologies USA Inc.
www.openmind-tech.com