Hastening measurement on the screws

The city of Sheffield is renowned worldwide for its expertise in the production of steel. To meet society's changing needs the city continues to reinvent itself and exploit its specialised metallurgical knowledge.

Illustrating its ongoing industrial evolution, Sheffield boasts a rapidly growing base of more than 100 healthcare technology companies. A leading member of this burgeoning sector is the Sheffield division of Tecomet OEM Solutions, formally Symmetry Medical Inc.

Tecomet OEM Solutions is a global leader in the design and manufacture of high quality healthcare products such as contract implants, instruments and cases. In addition the company's reputation for the quality of its products has allowed it to extend its reach beyond the healthcare market to other innovative areas such as the aerospace industry.

Tecomet's Sheffield division offers advanced forging and casting capabilities and a large machine shop equipped with a range of advanced CNC machine tools. The facility manufactures a wide range of products including orthopaedic trauma plates, hip implants, shoulder implants, orthopaedic screws, femoral and fixed knee systems. Although the company's range of orthopaedic screws may appear unremarkable to the untrained eye, the critical functions that these components perform means that they have multiple highly precise features.

Beating the bottlenecks

To keep pace with growing global demand for the company's orthopaedic screws and to help guarantee their continued quality, Tecomet Sheffield uses a range of highly precise barfeed lathes. Although the company's machine tools have the capacity to satisfy the ever increasing demand for orthopaedic screws, as the multiple features of each individual screw undergo meticulous quality control checks, bottlenecks recently began to occur at the final inspection stage. To rectify this situation, research was undertaken for a precise, rapid inspection technology system.

Mark Kirby, business improvement manager explains: “Tecomet Sheffield is internationally renowned for the quality of our products. Our customers can be confident that they are dealing with knowledgeable professionals who understand the importance of innovative design, manufacturing excellence and meticulous quality control. Each Tecomet manufacturing facility maintains a comprehensive quality assurance system, integrating the control, monitoring and management of quality at the production source.”

He continues: “As ever increasing orthopaedic screw production volumes were beginning to place a strain on our critical inspection resources, we recently investigated the available inspection aids that had the required levels of precision to ensure the dimensional accuracy of our orthopaedic screws. In addition, it was crucial that the chosen system had the speed to keep pace with both our current and anticipated output.

“In addition to observing practical demonstrations we compared the inspection cycle times of the measuring systems that we considered and also undertook in-depth gauge R&R (Repeatability and Reproducibility) studies to verify the performance of each device.

“Having completed our evaluations, it became clear that the OGP SmartScope Flash 200 outperformed each of the other systems when measured against each of our selected criteria. Not only did the OGP optical measuring device deliver the best accuracy figures; its impressive speed of operation was much quicker than the other considered measuring systems.

“Prior to the installation of the new SmartScope Flash CNC system, the comprehensive inspection routines that we make on 100% of our output took approximately 15 minutes for each orthopaedic screw. As some of our screws have more than 20 features, including threads that require very accurate measurement, we previously used a combination of micrometers with thread wires and a conventional optical projector. In addition to these methods being slow and labour intensive, as we were manually inputting each measurement into our system and to ensure no transcription errors occurred, we would double check each entry.

“Following the purchase and installation of the SmartScope, we are now able to load 20 orthopaedic screws into a specially designed fixture, load it onto the SmartScope, recall the relevant part program and press start. Each feature of all loaded screws is then accurately measured in a fully automatic CNC mode that takes less than 10 minutes. The system then generates a fully detailed statistical inspection report related to each screw.

“The use of the SmartScope has eliminated the potential for human error in our inspection routines, further improved our accuracy capability, enhanced our reporting function and removed the potential for hold-ups in our inspection department.”

In focus

SmartScope Flash CNC systems are ideal for the automatic dimensional measurement of critical parts. Solid-state illumination sources, a colour camera, Measure-X metrology software and a high quality, 12:1 zoom lens that calibrates itself at every magnification change, combine to create a powerful and accurate video measuring system.

To enable the delivery of a SmartScope Flash CNC system to match the specific needs of each customer, all models can be customised by the inclusion of a range of high quality options.

OGP UK managing director Andrew Fulton adds: “SmartScope Flash CNC systems are popular throughout the world in situations where there is a need for high levels of precision and an urgent requirement for speed of inspection to keep up with production volumes. “As gauge R&R studies are now regularly used by potential customers to compare the performance of gauging systems, the results that are consistently achieved by OGP systems give us a real advantage. Gauge R&R is effectively a statistical tool that measures the amount of variation in the measurement system owing to the measurement equipment being used and the people taking the measurement.

“The automated CNC nature of the SmartScope Flash systems, the inherent accuracy of OGP products and minimal operator input requirement, mean that whenever our systems are subjected to such studies, they are able to pass with flying colours.”

OGP
www.ogpuk.com