Centerless Grinder Delivers Precise Arthroscopic Shaver Application

Arthroscopic shavers allow surgeons to insert a small and hollow cylindrical metal tube into a small incision in a patient. They allow surgeons to remove bone and tissue while at the same time flushing fluids and debris through the tube and out of the patient. A new arthroscopic shaver application, developed by Glebar Company (Franklin Lakes, NJ)) for its advanced GT-610 CNC centerless grinder, is now delivering the most precise inner and outer tubes for use by orthopedic surgeons.

The first two systems equipped with the innovative application have been sold to a major manufacturer of arthroscopic shavers. The system was on display for the first time at the 11th Annual Orthopaedic Manufacturing and Technology Expo and Conference (OMTEC 2015) that was held at the Donald E. Stephens Convention Center in Chicago on June 17-18.

“Part size and tolerance is critically important, especially on the tip of these devices, and have been difficult to manufacture in volume since their design requires as minimal a gap as possible – as small as 0.0005 inches between parts so that the inner sleeve moves freely inside the outer tube without the risk of binding due to debris caught between the surfaces,” said John Bannayan, the president of Glebar.

Using the GT-610 CNC to infeed grind the shape of the inner tube, Glebar is able to maintain a ± 0.0002 in tolerance on the elliptical tip dimensions. The team developing the application also ground three diameter features to within .0002 in, maintaining a TIR of 0.0001 in and producing a smooth 9 Ra surface finish on 304V stainless steel with a ± 0.001 in wall thickness. They removed 0.012 in of stock for the majority of the part and 0.004 in off the tip geometry.

“The entire automated process was complete in under 20 seconds adjusting for part length variation, heat expansion and a near zero tip geometry requirement,” noted Bannayan. “Our process eliminates an extra step in previous manufacturing methodologies which also left unacceptable tool marks on the surface and vastly reduced the scrap rate due to geometry imperfections.”

Outer sleeve manufacturing occurs on a GT-610 thrufeed grinder, which grinds the OD of the blank tubes maintaining a surface finish between 3-6 RMS and maintains a comfortable 2-3 Cpk on the outside diameter of the part. Material removal of 0.005 in, with a tolerance requirement of ± 0.0005 in, is met easily in a turnkey, fully automated process.

Glebar is already active in serving the needs of the medical marketplace with guidewire grinding machines that are considered the industry standard and used by several leading manufacturers. The company is ISO 9001 certified and manufactures all of its machines in the United States to the highest quality standards and delivers them to clients around the world. They support clients with a 24/7 customer service team consisting of technicians, design engineers and customer service reps and maintains a standby inventory of critical parts available for next-day delivery.

Glebar is an innovative engineering and manufacturing firm that designs and configures its standard platform of machine systems – from an affordable job shop machine to fully automated, lights-out grinding packages – to provide custom solutions focused on maximizing a customer’s return on investment. The company serves shops in many market segments, including medical, automotive, aerospace, consumer goods, metals and mining. Its machines are known for their precision, longevity, flexibility and efficiency.

Founded in 1952, the privately owned company is headquartered in Franklin Lakes and will be moving to a new state-of-the-art facility in Ramsey in July 2015.