April 2007 Edition

CNC

Modernization Cuts Cycle Time in Half

A machining company that pre-dates the Civil War found old machines cost it time, efficiency, and cash

Working with 14-year-old ma-chine centers wasn’t cutting it after Greg G. Wright & Sons, LLC, Cincinnati, received a large order for precision jet parts. It was time for the fi rm to modernize and cut production time. While a long company history was an asset, legacy machinery was a liability.

“When I stepped in, the company was near death,” Carl Fries, president and CEO, said. The company pioneered steel block engraving, custom tags, and plates, and metal stamping since its founding in 1860.

“I had to breathe new life into the company. I got rid of 25 to 35 manual machines and about 30,000 lb of scrap. There was a small CNC router to make patterns, but not a single computer-aided machine tool in the shop.”The company occupies 34,000 ft² and employs about 20 operators and tool and die craftsmen. Three have more than 40 years experience with the company and many others with more than 20 years.

Thoroughly Modern Manufacturing

“My first purchase was a CNC EDM sinker,” Fries said. “At the time engraving was our primary market. My background was CNC turning and milling, and I knew that I’d move the company in that direction ”Fries said originally there were two divisions of the company, and when he took over, he combined them. He sold the company’s manual machines and replaced them with CNC machines. Much of the equipment was used, but in good condition. Fries also moved away from Wright & Sons traditional engraving and metal stamping markets. He used two Internet matching services to raise the company’s profile and emphasize the new focus on CNC turning and milling.

Nothing Beats Face-time

The Internet experiment met with mixed success. Fries said it is hard to replace face-to-face, palm-to-palm relationships, especially when working on large dollar- and time-commitment jobs.

“For example, we’ve been working on a special project for lock manufacturer CompX Fort,” Fries said. “We turn a ring on a Hardinge Quest Super Precision, roll mark it, and then EDM a cut. The final EDM work is done by a third party.

“We visited CompX Fort to show them samples of the job. They were pleased. This is a $50,000 contract, and they don’t do business with a $2 million to $3 million company that often. If this relationship blossoms, there are quite a few other parts we could make for them. We’re working face-to-face with them. There’s a certain comfort in that, as un-founded as many may think that is today.”

Speeding CNC Usage

Now, Fries said, the focus is getting Wright & Sons up to speed on CNC: CNC turning, CNC milling and CNC Swiss turning. A new Bridgeport 760XP3 vertical machining center from Hardinge Inc., Elmira, NY, is part of the modernization.

“We bought the 760 when we started getting more and larger contracts for precision milling work,” Fries said. “Our existing VMC just couldn’t keep pace.

”Wright & Sons’ original VMC was 14-years-old and technology advanced since then. He was so pleased with the modernization that the firm bought another 760 before the setup of the first was completed. What drove the order for the first Bridgeport was a large order for precision gas flanges for commercial jet engines.

Gary Foster, tool room manager, often runs the 760. “We run these parts chucked face up in a vise four at a time,” he said. “Cycle time is roughly 28 minutes. The material is 410 stainless. The tolerance on the overall height is ±0.001" and ±0.005" or ±0.0010" on the shoulder. The Fanuc 18i MB handles all the interpolation of the holes: the large center hole, the perimeter holes, the face milling, and radii. When the top face is finished, the part is turned over and re-fixtured in an adjacent vise on the table where the bottom is fly cut to assure proper part thickness.”

After the parts are fly cut, 20 at a time are placed on a fixture for finish grinding of the backside, which brings the part into final finish dimension.

“That’s the only operation that isn’t done on the 760,” Foster said. “In the past there were a number of secondary operations to finish this part. Now, this is the only one, this light grinding to bring the thickness

Faster Cycle Time

Foster said all 11 tools he needs are in the 30-tool automatic tool-changer – ATC.

“Between the control and the ATC, we’ve got a cycle time of 28 minutes,” he said. “The previous method took twice that long. The 290-psi through-spindle coolant feature makes a real difference. We can take a fl at-bottom drill at a rate of four ipm and pop the center hole through the stainless in seven sec-onds. Without the through-spindle coolant, we couldn’t do that. It would heat up so quickly that the tool would burn into the material.

“It keeps the holes, angles, and other characteristics free of chips, making the cutting zone easy to see and helping to move the chips into the swarf removal system, which separates chips from coolant.”

Critical milling characteristics sold Fries on the Bridgeport. The 25-hp, 12,000-rpm spindle provides power, rigidity, and radial stiffness. He said he appreciates the large and precise spindle bearings. The table rides on large twin ballscrews – X- and Y-axis.

“Instead of having a single nut at an end,” Fries said, “the 760 has two nuts at either end, and the lead nuts on the two ball screws are enormous,” he said.

Fries said when he needs to machine a 1,500 lb stain-less blank, which was required on a recent order, the 760’s 35.4"×23.6" table and axis provides accuracy. Axis travel in X, Y, and Z are 29.9"×24"×24", with rapids of 1,690 ipm × 1690 ipm × 1410 ipm.

Weighing In

Other features Fries likes about the 760 is the C-frame casting and ribbing in the sides.

“The casting weighs 14,300 lb,” Fries said, “This makes a huge difference. Our previous machine weighed half as much and raised all kinds of questions as to what we could run on it and what would push the weight limit.”

Machining requirements for jobs at Wright & Sons now include holding tolerances in Inconel, titanium, stainless, and a group of alloys offering an array of machinability difficulties.

“The importance of a rigid base is that all the energy the spindle is producing is absorbed into the casting and not into the workpiece,” Fries said. 

Planning, Prosperity, Posterity

“I think opportunities are there for a shop that employs newer and higher-quality technology,” he said. “Technology will open doors. The name of the game is speed: process parts as fast as possible at the highest level of quality. If we can’t do that, we’re done, no matter how rich a history the company has,” Fries said.

“In the past, the Chinese didn’t have the technology to compete, but they’re acquiring it and getting better at using it,” he said.

 “A U.S. shop using the same equipment it has been for 20 or 30 years may say ‘The equipment on our shop floor has always worked. It makes the parts, we hold the tolerances, so why invest in new machinery?’ But that won’t cut it anymore. A shop can’t be passive. It has to be active.”

Fries said he expects to see work return to this country. “At the same time, shops go out of business because they’re not employing the latest technology,” he said. “They’re not willing to make the investment. So, there’s a thinning of the herd.

“A company must look toward the future so it can keep the business going. It must create a business that will last for generations.

“I believe I’m just a caretaker of this company,” Fries said. “I’m the first person outside of the Wright family to own and operate Greg Wright & Sons. It started making stencils and marking devices. We still make marking devices in one form or another. We still do what we did in 1860, but I’ve built on that with the CNC technology: Bridgeport in a matter on months, and more to come. I own a good portion of the company, but I’m only a blink of the eye in the long history of this company. I’ve been here for four years. I’m going to continue to invest in the best technology, and then I’m going to win jobs from China. If I don’t, then who will? It’s my future.” Hardinge

Visit www.rsleads.com/704mn-207 for more information

What do you think?
Will the information in this article increase efficiency or save time, money, or effort? Let us know by e-mail from our website at www.ModernApplicationsNews.com or e-mail the editor at pnofel@nelsonpub.com.