Carl Zeiss Prismo VAST CMM Benefits Automatically scans profiles Provides inspection reports on multiple parts Accommodates automatic probe changer www.zeiss.com

Investment in Scanning CMM Generates Business Rewards

Superior Tool LLC, a small contract manufacturer located in Maple Grove, Minnesota, provides high-precision gaging and tooling to computer hardware and medical device leaders such as IBM, Hewlett-Packard and Medtronic.

To meet the increasingly demanding specifications of its high-precision customers, Superior Tool purchased a Carl Zeiss Prismo VAST (Variable Accuracy and Speed Probing Technology) coordinate measuring machine. The Prismo's combination of high data density and high-speed scanning was just the answer the high- precision tooling manufacturer needed to satisfy customers whose product designs reflect what can be done on today's machine tools.

"We were confident that certain products we manufactured every day would benefit from upgrading our measurement abilities to more closely match our continuously improving process capabilities," says Mark Davis, a Superior Tool engineer. "But we don't typically look at a CMM as a direct source of revenue. So we had to build an aggressive case to support making the investment required to purchase a scanning CMM."

To make a measuring system recommendation, Davis and his team thoroughly researched and evaluated current CMM capabilities against three key requirements: a healthy and measurable investment return, high accuracy and user friendliness. "The number one issue clearly is return on investment," notes Davis.

In the end, the Superior team recommended the Prismo to conduct first-article, in-process and final inspections for a variety of high-precision prototype and small-run parts. Adjacent to the general manufacturing area in an inspection room, the scanning CMM measures part accuracy in the sub-tenths range and produces documentation that verifies precise machining.

Today, the company regularly manufactures to 0.0002", and it's seeing demand to move down to 0.0001". Davis says Superior has even had occasion to prove 40 millionths of an inch.

"For a smaller company, particularly a job shop, it's very challenging to justify a significant piece of equipment that doesn't directly produce income-generating parts," acknowledges Davis. "We approached it by educating ourselves about the long-term role that quality assurance capabilities can play in the future of the business. We concentrated on CMM-related indicators that translate into fortifying our shop and breaking new ground in the type of work we're able to attract."

During the evaluation stage, Superior evaluated investment return, ease-of-use and operator productivity. As a result, Zeiss' UMESS-UX operating system and KUM profiling software received close attention. "We looked at other CMM software, watched operators in action and talked to them about the amount of training involved," recalls Davis. "We determined that Zeiss programs are straightforward and user-friendly, work efficiently, and involve a short cycle from the training phase to running actual parts."

The graphically cued software makes Prismo operation very intuitive, even for the type of complexity that Superior deals with every day. "As a result, our operators were up and running on the CMM within a week," says Davis.

The new CMM technology has also paid its way by enhancing Superior's view backward into the production process. Jig grinding systems at Superior traditionally have been used for benchmarking center accuracy. "They're capable machines that can be positioned exactly where you indicate," explains Davis. "Even so, you might not get the machine to function the way you anticipate because of vibration, tool wear, chatter and other issues."

With the Prismo handling inspection, Superior can leverage high data density to consistently repeat inspection results. Sampling several hundred points significantly improves repeatability and reproducibility by eliminating dependency on where the data is taken from one trial to the next.

The investment in enhanced inspection competency also makes Superior feel more confident about the future and more prepared to compete for new business. "As we investigated CMMs, we looked at where we needed to be in the next five years," recalls Davis. "It's difficult to project much further out than that because the technology change in this business is so dynamic. But we decided if we're going to be in the high-precision tooling business, this is where we need to be five years from now with machine tool tolerance bands continuously decreasing."

Davis estimates that 90 percent of the hundreds of inspections Superior conducts daily using the new CMM previously could not have been completed in-house.

"Adding the scanning capability has elevated our inspection processes to match the machine tool capacity that customers require," says Davis. A significant amount of new business has come through the door since we upgraded our measurement capability. And the majority of those contracts are CMM-qualified prior to winning the business."

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