Morphing into Medical

About three years ago, Wawaka, IN-based B&J Specialty Inc., a tool and die shop serving the automotive industry, found itself in the doldrums. The company wanted to leverage its expertise in high precision 5-axis machining to expand into a new marketplace. Medical components were an attractive possibility.

Scott Sizemore, who is now plant manager for B&J Medical, had worked with the parent company for more than 13 years as a machinist, CNC programmer, and manufacturing engineer. He explains that the transition into a new marketplace was just a natural extension of the way the company had always done business. “One of our sales people made an effective presentation to a medical device manufacturer. [In addition,] we had a couple staffers in-house who had done medical work on Swiss machines. So, we started doing prototypes for bone screws and various broaches.

“Success with this work led to more customers asking us to do production work,” Sizemore states. “Once word got out about what we could do, along with our consistent quality, medical work began to ramp up. That was mid-2008.”

Transferable Skills
Tool and die seems like a long way from medical parts manufacturing. However, Sizemore enumerates a number of attributes that made B&J a good fit for its chosen new market.

“First, there is our persistence and dedication to what we do and our excellent service. Then, we have many years of programming off-line with Mastercam (from CNC Software Inc., Tolland, CT). We were already skilled in it 10 years ago when many others were still trying to punch numbers at a machine. We program everything off-line, post it down to the machine over our network, download it into the machine’s controller, and away we go.

“Then there is our high-speed surface machining capability and the fact that we have been cutting hardened steel for about a decade now,” Sizemore explains. “Of course, blemish-free surface finish is important for medical parts. We already knew how to achieve that from making multi-cavity production molds.”

It took B&J’s Mastercam reseller, CAD/CAM Technologies, less than a week to develop a post-processor that satisfied the staff at B&J Medical. Shown at the controller is B&J Medical’s Shane Hall.After working with medical product manufacturing customers for 18 months, the management of B&J Specialty felt that a company totally dedicated to the requirements of their industry would better serve this customer base. So, a special group with its own staff and equipment was established to work exclusively on medical part manufacturing.

Sizemore says that, “Medical parts manufacturing is an entirely different world, with new challenges everyday. Precision is everything. In the tool and die business, we had to make one or two perfect components. With medical parts, quantities can be enormous, and they all have to be perfect.”

At the same time that B&J segmented its medical part manufacturing operations internally, it also began planning for the launch of a separate company with its own facility located near Warsaw, IN. The new dedicated plant for B&J Medical, located in Albion, IN, is fully air conditioned and equipped with state-of-the-art computer systems and software, as well as a technologically advanced high-speed 5-axis CNC mill with multi-position tool changers, a 3-axis mill, and five Swiss machines, all of them new.

The new division has a staff of 15 people, all with medical manufacturing experience, and there are plans to add several more to the staff. In addition, the facility has already been awarded ISO 9001:2000 and ISO 13485 registration.

As soon as B&J Medical launched their new plant, customers began sending in more work, particularly for the 5-axis machine. Some typical examples of this atypical work B&J is doing with Mastercam follow.

Bone Funnel (Marrow)
One challenging project was a 10" long funnel machined from a single piece of 17-4 stainless steel in a single setup. Very long tools were used to machine the central tube. The part had to be rotated so that the machine could access this tube from both sides. Surface blending of the toolpaths was used so that there were no cosmetic blemishes in the transition areas between the funnel mouth and the tube. Programming and machining had to be ultra-efficient because these costs could only spread over two parts. Sizemore said that this part would be astronomically expensive and perhaps even impossible to produce without 5-axis capabilities.

Part Holding
One of the biggest challenges of efficient 5-axis machining is creating part-holding fixtures that anchor the part securely, while presenting all the critical features for cutting without having to refixture the part. These are easy to design in Mastercam, which is a CAD/CAM system in its own right. Sizemore selects a surface on the part model that he would like to use for securing the part. Next, he makes a mirror image that will then be cut into the holding fixture.

Bone Broaches
Among the most interesting parts Sizemore has programmed for 5-axis machining are broaches, which are used for shaping bones to prepare them for accepting an implant. This calls for machining multiple high-tolerance surfaces in tight places so the bone can be precisely prepared to mate with the corresponding surface on the implant. There are many different styles of bone broaches, and each style is made in multiple sizes depending on the age, sex, and size of the implant recipient. Mastercam makes it efficient to program these because toolpaths can be automatically transferred from broaches that have already been programmed.

5-Axis A Driver
The company is also doing prototyping on its new 5-axis CNC. New projects typically come into B&J Medical as a Parasolid file (usually a SolidWorks file). Mastercam can import these seamlessly, regardless of CAD brand. Once the toolpaths are created, they are posted to a Grob 5-axis mill with a Siemens controller. The company was very impressed with the features of the system, however, purchase was contingent on being able to acquire a post-processor for Mastercam that would provide high quality output to the machine’s Siemens-based controller. B&J’s Mastercam reseller, CAD/CAM Technologies, assured them that this would be accomplished.

Using a generic Siemens post for Mastercam as a starting point, it took less than a week to develop a satisfactory post-processor. The reseller worked by phone and over the Internet to expedite the development process. When an issue surfaced, B&J engineers would describe the problem over the phone and send a video showing what the machine was doing.

It was not long before Sizemore could dive into his backlog of prototyping work. In addition, he found that it was easy to repost files that had been previously written for the other 5-axis system back at B&J, even though the other machine was a vertical and the new one is a horizontal mill.

Sizemore says he used to spend all day writing programs. Today, with Mastercam X, he can get everything he needs to accomplish done in half the time, even with the heavy influx of work.

CNC Software Inc. (Mastercam)
Tolland, CT
mastercam.com

B&J Medical
Albion, IN
bjmedicalinc.com