California Shop Reduces Cycle Times, Increases Productivity
In order to survive in today's competitive marketplace, small job shops must find ways to cut costs and increase productivity--all without sacrificing quality.
In order to survive in today's competitive marketplace, small job shops must find ways to cut costs and increase productivity--all without sacrificing quality. "People aren't going to accept second best any more," said David Goodreau, president of Newman Machine Works in Burbank, California. "You have to exceed the customer's expectations, or they're going to go somewhere else."
Founded in 1939, Newman Machine Works services the commercial and military aerospace industry. Their customer base is the prime aerospace contractor market-Boeing, Northrup, Rockwell, and so on. At present, Newman employs ten people, and has 13 machine tools in their 3300 square-foot shop. "We are very much a traditional, family-owned, small job shop," Mr. Goodreau said.
Faced with a shop full of aging machines that finally started to cause financial troubles, Mr. Goodreau and co-owner Gene Newman knew it was time to rebuild the company. "Between the downtime, and trying to find service people to come fix our machines, it was putting us out of business," Mr. Goodreau said. "We just could not afford to wait for these people to return our phone calls-if they did at all."
"There aren't many options for companies our size. If you're going to stay busy, and continue to meet the customer's needs, you have to invest in new technology and equipment. It's like continuing your education," Mr. Goodreau said. "For small companies, the future depends on modernization."
"We needed to replace old, used CNC equipment, and felt that by buying locally, we would have the prompt service we need to keep our machines running," said Gene Newman, co-owner of the shop. "We knew the reliability of Haas machining centers from talking to people in our industry. Price, financing and availability of the machines made it easier to select Haas," he said.
Newman Machine Works purchased their first Haas VF-2 vertical machining center (travels of 30 inches by 16 inches by 20 inches) in April, and another VF-2 in July of 1996. They then installed a Haas HL-4 lathe (14.5 inches by 34 inches) in January, 1997, and have plans to purchase a Haas VF-3 VMC (40 inches by 20 inches by 25 inches).
"Where the Haas machines have really helped us is in precision," Mr. Goodreau said. "They've helped us cut out many operations, and allowed us to bring other operations in-house," he said. "That saves a lot of money and time. It's made a huge difference in our company. Plus, our people like running state-of-the-art equipment, and are much more excited about work."
"Our productivity is up about 30 percent," said Harold Howell, Newman's general manager. The Haas machines have enabled them to produce quality aluminum parts faster, and with better surface finishes, he said. And, the geared head allows heavier, deeper rough cuts without stalling the machine, which further shortens cycle times.
One of the main challenges for Newman Machine Works is machining complex shapes out of stainless steels, while maintaining high accuracy and cycle times that will keep them profitable.
"Predominantly, our work is 15-5PH stainless," Mr. Howell said. "We do a lot of three-axis machining and blending, with heavy roughing in hard materials, combined with complex shapes. Just about everything we do requires multiple set ups," he said.
A recent military job is a perfect example of the challenges faced by Newman. The task was to machine a 109-lb piece of 15-5PH stainless plate, 8 inches by 39 inches by 1.25 inches, into a mount for a new missile being adapted to the Navy's F-14 fighter. The finished part weighed a mere 6 lbs, and had to meet stringent military specifications.
From the blueprint, Mr. Howell worked out the tooling needed for the part, which consisted of a base plate and a main fixture plate. Since the part's length exceeded the X-travel of the VF-2, re-fixturing was required half-way through the operation. To insure accuracy and repeatability, location pins were set using the Haas. "I'm able to trust this machine (VF-2) to give me locations that are jig-bore accurate," Mr. Howell said.
With the tooling determined, the part was laid out on a CAM system, the data was translated and the operations extracted. The program was uploaded to the Haas VF-2 via the 3.5-inch floppy drive. Then, the part was proved out, first in wood, then in aluminum.
The first step was to rough cut the part and get it ready for heat treating. "We hogged off all the excess material, bringing the part to 21 lbs and leaving approximately 0.100-inch per surface," he said. "The original program for this operation clocked out at ten hours," he said, " but with the Haas, I was able to increase my feed rates and knock that down to seven hours per part." The result was nearly a 30 percent reduction in cycle time.
"I was surprised at the rigidity I was seeing, and the cuts we were taking," Mr. Howell said. "I like to program aggressively, and on other machines I would have to pull back on my program feeds and speeds to keep from stalling the spindle. On the Haas, I didn't have to pull back my feed rates. In fact, I was able to increase my aggressive programming," he said.
When asked about problems stalling the Haas machines, he replied "I've tried. I've pushed it right up to a constant 80 percent spindle load, and it ran for hours with a one-inch end mill taking a pretty good cut in 15-5 stainless. The geared head allows heavier, deeper rough cuts without stalling the machine. Other machines would have stalled under the same conditions. I definitely can say I push harder on the Haas machines," Mr. Howell said.
Once roughed out, the part was sent for heat treating, and a blanch and grind operation to ensure straightness. The next step was to finish cut the 21-lb piece down to the final weight of 6 lbs. "After heat treating the material was harder, but we still didn't have any trouble," he said. "We switched to carbide end mills, and TiCN-coated cobalt, and were able to finish the parts in four hours." Feed rates on the finish cuts were close to 10 ipm using a 3/4-inch carbide end mill at 800-900 rpm.
"Considering the tool life I got, I probably could have gone faster," Mr. Howell said. "I probably could have increased my rpm and feed rate and cut another 30-45 minutes off each part. Even at the faster rates, we're able to get a finer finish (than on other machines)."
Machining a 109-lb plate down to a 6-lb finished part creates a lot of chips, so Howell was grateful their Haas VF-2's were fitted with the optional chip conveyor. This auger-style conveyor automatically removes chips from the enclosure to eliminate down-time.
"The chip conveyor is a great idea," Mr. Howell said. "I just use M codes to turn it on and off during the program, and we are able to haul chips out the whole time without opening the doors."
"I think the coolant nozzle's the best, though," he said, referring to P-Cool, Haas' programmable coolant nozzle option. Controlled via the program, P-Cool automatically directs coolant precisely at the part.
He goes on to say,"We have the coolant nozzle changing its position with each tool, and we have the ability to program coolant location changes incrementally as tool depths change. Using M codes, we are able to fine tune the coolant during the cut. And, anyone who's ever gotten a soggy armpit from reaching inside a machine (to adjust coolant nozzles) would appreciate P-Cool." Because the operator doesn't have to open the door, cycle time is reduced. Plus, once programmed, P-Cool makes the changes automatically for each subsequent part.
"When we started this transition, we had six CNC machines, and every one had a different control. It was a nightmare," Mr. Goodreau said. "We could hire people who had experience with one control or another, but nobody had experience with all of them. Now, with the Haas machines, it's all the same control, all the same programming-everybody understands it."
"Our interest is high profitability, and I think that standardization . . . really is a strategic move for us that will pay dividends," Mr. Goodreau said.
At Newman Machine Works, they have invested in their future by purchasing new CNC equipment. Their improved ability to machine stainless steels into complex shapes, while maintaining good cycle times, will assure their success in the long term. Through the use of Haas VF-2 vertical machining centers, Newman has increased their productivity, reduced cycle times, improved accuracy and surface finish, and increased tool life. All this adds up to higher profits.
"We're pretty confident we can push the part enough to make money on it, and still give our customer a good price," said general manager Harold Howell. "You have to be able to give the customer a high-quality part at a good price, or you're not going to be doing the part anyway." MMS
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