END USER: Hommer Tool and Manufacturing Inc., (847) 394-3355, www.hommer.com.
CHALLENGE: Increase complexity of ground parts while maintaining tight tolerances.
SOLUTION: CNC cylindrical grinding machines.
SOLUTION PROVIDER: United Grinding North America Inc., (937) 859-1975, www.grinding.com.

Hommer Tool and Manufacturing Inc. literally centers its operation on precision and quality. The company's 24,000-sq.-ft. Arlington Heights, Ill., facility is laid out in a hub-and-spoke arrangement that puts QC in the center of its 11 machining departments. This strategy, along with a transition from manual to automatic OD grinding, has helped the manufacturer of custom mold-ready components succeed.

When James "JR" Hommer Jr. assumed responsibility for the company 15 years ago, its business model was to manufacture simple, round components for the injection-molding market, but customers were beginning to ask for more complex parts. Because its CNC OD grinding was basic, the company could only make pieces up to 1 " (25.4mm) in diameter and 12 " (279.4mm) long.

"My first major move was to hire a marketing manager," Hommer said. "Then, out of the blue, I received a promotional mailer from a manufacturer of automated grinding machines, which put that kind of machine on my radar."

After researching the available options, Hommer opted for the Studer line of cylindrical grinders from United Grinding North America Inc., Miamisburg, Ohio. Today, Hommer's OD grinding department consists of five Studer machines: two S40s, an S31, a basic S33 and an S33 with B axis.

The S40 machine offers a grinding length up to 63 " (1,600mm) and a fast direct drive of the infinite B-axis, a functionality that has created new business opportunities for the shop.

James "JR" Hommer Jr. (left) and Operations Manager Rick Frankowitch with a Studer S33 grinding machine.

The Studer grinders enabled Hommer to change its focus from manufacturing commodity parts to larger, more complex parts, while commonly achieving tolerances as tight as 0.0002 "(5.1µm). Coupled with an increase in communications with customers, this capability helped Hommer triple its business, finding its niche as a provider of cavity components, custom cores, rotating cores, custom core pins, thin-wall ejector sleeves and stack-up tooling, according to the company.

The shop creates the components out of various materials, including tool steels, such as S-7, H-13, D-2, M-2 and 420, copper and beryllium copper. Most of its components range from 0.25 " (6.35mm) to 3 " (76.2mm) in diameter. The bulk of Hommer's pieces require an average of 15 operations, beginning with soft-state chipmaking operations, including cutting off, gundrilling, turning and milling. After heat treating, the parts can undergo centerless grinding, OD and ID grinding, form grinding, surface grinding, honing, hard turning, hard milling and wire and sinker EDMing.

As business grew, the company added a new Studer about every 2 years. "I initially selected Studer because the programming was the same across all machines," Hommer said. "That's a huge benefit to us because our lot sizes are small, averaging around 32 pieces, and our cycle times are around 3 to 5 minutes. We do about four changeovers per shift, and the simple setup and mechanical processes on the Studers allow us to set up in a half hour or less."

The department's capacity is about 350 hours per week and includes two shifts, which complete more than 2,000 unique details per year. According to the company, 93 percent of Hommer's jobs involve parts the company has never made before and most likely will never make again.

"One advantage we have over companies just now entering the market for complex, custom parts is that we have invested in these machines over time and have the skilled labor to operate them," Hommer said. "It would be very difficult for a shop to invest in all of this equipment at once."

Operations Manager Rick Frankowitch explained that customers hold Hommer to an extremely high standard and don't want any variability in the tool.

Because these customers need to guarantee that their molds can produce millions of parts, Hommer can't deviate when it comes to quality. Hommer is often more expensive than the competition, but customers are willing to pay the higher price because the company says it consistently produces parts that are true to the print specifications.

"I had a customer pay our company the ultimate compliment," Frankowitch said. "He said he wastes a lot of time checking perfect parts."