Multi-tasking CNC

Stryker Corporation is known for its medical devices and equipment. Its products range from orthopedic implants to various surgical apparatus.

stryker cnc
The 3-axis crane simulator motion platform uses Baldor BSM servomotors.

The company’s production, experimental, and R&D groups work together at its Michigan facility. These entities exchange information, investigate technologies, and generate prototype products. The demands for parts from the various groups call for a robust machining capability. As a result, Stryker maintains a variety of machine tools and other metalworking equipment at this site including basic milling and drilling tools, 3- and 5-axis CNC machining centers, and electrical discharge machines (EDMs). Among the newest advanced CNC machines is a DMG DMC 635 Veco – a 3-axis vertical milling center with an 8,000 rpm spindle and a 20-position tool changer operated by a Siemens 810D CNC running ShopMill software.

According to Rich Mitchell, experimental group supervisor, “We typically store a few programs on the CNC and keep our backlog of programs on a network drive for easy recall. We use IGES or PRT 3D files and program directly from the digital content using MasterCAM and ShopMill. The Sinumerik 810D control receives good ratings from our operators.”

renshape-being-machined
RenShape being machined on the DMG milling center.

Said Randy Carpenter, a senior project engineer for Stryker’s instrument production group, “We run family of parts. We have one set of parts run in 416 and 17-4 grades of stainless steel with 38 Rockwell hardness. We typically run dimensional tolerances down to the ten-thousandths. Compared to older machines and controls, we have tracked our cycle times in relation to our target Cpks and are obtaining better than 20% reductions as a result of the DMG machines with Siemens CNC onboard. We have seen improvements in surface finish, owing to the smoother translations line-to-line in the milling and turning programs.” He also adds that the production department achieves higher change-over efficiencies that allow more jobs to run per shift.