C&A Tooling distributes QC labs equipped with CMMs and other quality equipment in each of its dedicated equipment pods as well as at a final inspection point.
tact sensing is in equipment such as Zygo Corporation (Middle- field, CT) surface profilers. Multiple quality labs scattered around the facility reduce the amount of time required to move pieces (and people) away from important machining operations to inspection. Cutting and grinding is still where the money is. In fact, metrology at the machine is the ideal. “Utopia is if our skilled associates do not have to walk away from the machine to measure a part,” Marr says.
One such system C&A uses for this is an OASIS optical pro- file inspection system supplied by George Products Company (Middletown, DE). They program this 2-D digital shadowgraph to measure critical features for a particular part, which is stored in a library. “During production, we simply place the part on the machine and it automatically identifies the part from its library and gives a go/no go on each critical dimension,” says Marr, requiring no fixturing for speedy, accurate measurements.
“Utopia is if our skilled associates do not have to walk away from the machine to measure a part”
“This machine is sometimes described as an optical com- parator on steroids,” says Jeff Palmer, a manager with George Products. The system is accurate to ±0.0001" (2.54 µm), according to the company. “When a part program is created, the OASIS looks at the edges of the part using what we call Tool Windows,” explains Palmer. “It searches through all the stored parts programs to see what lines up best with that part. If there
are similar parts, it may offer up to three different files of part programs that are close for the user to choose.” He reports the system as frequently used by medical device manufacturers, for parts with maximum dimensions of over 6" (152.4 mm) down to less than 0.5" (12.7 mm), such as dental implants. In some respects, the GD&T requirements for medical devices are not very different from other industries, such as aerospace, according to Gary Meyer, C&A’s go-to-guy for medical quality. While each part requires a thorough first- article inspection, like many other industries, the difference is the depth and breadth of documentation. They tend to rely on the expertise of their customers, the medical device OEMs, to know the details of meeting regulatory requirements. “I just had one assembly submitted for first-article approval with 250 pages of documentation—for that one assembly. It only had eight or nine component level parts,” he explains. Joe Huelsenback, the medical machining go-to-guy for the company notes that tolerances for spinal implants are typically 20 µm. A 10:1 gage R&R means they need inspection capa-