Streamlined Revolution

AMA ACHIEVES SOLUTIONS FROM VERTICAL MACHINING CENTER TECHNOLOGY

Time is a huge factor in running an in-house tooling operation for a major plastic injection operation. Tim Andreas, tooling manager at AMA Plastics in Corona, California, says that time pressures have led the company to undertake a revolutionary streamlining of design and tooling operations.

“We are now a smaller organization than we were a few years ago,” says Andreas. The economics of our industry now require we have a smaller engineering group and more competitive processes.

“We don’t have 20 guys working on jobs and machining tools anymore. We have a two-man engineering operation that includes mold design, programming and manufacturing. Because of this, we now find we need more efficiency in machining solutions.”

With extensive experience in engineering and building plastic injection molds, Andreas helped lead AMA Plastics in finding more innovative ways to determine what machines and capabilities the company should pursue. “We ventured into high-speed milling about 10 years ago. And, while it has come a long way, we knew we needed to make an errorless decision on acquiring new technology.

“Time-to-market with customers is everything. Our machine tool performance and processes needed to be able to cut out days and weeks of machine preparation and tweaking, as well as generate the level of quality that would eliminate benchwork on the molds. We needed to find a machine tool partner that would help us successfully lead such a revolutionary streamlining of processes.”

Beginning To Streamline

AMA is a family-owned business that has been operating for nearly 35 years. The company runs on a 24-hour-a-day, seven-day-a-week basis, and specializes in medium- to high-volume precision and custom injection molding.

The company is QS 9000 (ISO 9002) certified, serving a variety of industries including medical, telecommunications, electronics, automotive, consumer and industrial plastic parts. AMA does its own tool building, molding and assembly—with a focus on service, quality and flexibility.

"Time-to-market with customers is everything. Our machine tool performance and processes needed to be able to cut out days and weeks of machine preparation."

Mark Atchison, president of AMA Plastics, says extensive research was done to help the company find a partner to work on streamlining its moldmaking process. “We did our homework and spent six months talking to industry contacts, interviewing users, getting specs and then did the difficult testing of machine cutting capability.

“The results all led to Makino, which more than did its job in successfully cutting our test part and winning that effort. Its performance and follow-through was even more impressive, and the V56 vertical machining center really sold itself.”

Maintaining the Expectation

The Makino V56 vertical machining center provided AMA Plastics with the versatility of making EDM electrodes or going directly to high-speed milling in making its molds. “The machine saves us 50 to 60 percent of our previous electrode cutting time,” says Andreas.

“We have actually eliminated the necessity for other machines, as we can mill both copper and graphite for electrodes on the V56. We primarily use copper electrodes, which can be milled six times faster and much more cleanly than graphite.

“Desired finish determines whether we mill or EDM,” says Andreas. “For the difficult finishes and sharp corner features, we mill electrodes and burn the mold to achieve the standard, textured finish. If we can get away with a fine-polish, A-1 finish at RMS 15 or 20, I’ll generally high-speed mill the part if the geometry permits.

"We are able to throw material for molds into the machine months later and get the same accuracy and the same tolerance."

“We can simply eliminate processes by going straight from a piece of steel to a finished component versus premachining.

If you were to have a three-day debugging sequence on a mold that had not been polished, you can reduce that to a one-day debugging operation and reduce benchwork and processing time by 67 percent.”

That high-quality finish is a major asset in mold release, which has substantially reduced injected scrap. “Polishing is always a challenge with brand new molds, as areas of the mold often get missed,” says Ken Pravitz, process engineering manager at AMA. “The finish coming directly out of the V56 is pretty amazing.

“In the way it reacts during processing, you would never have guessed it had not gone through the polisher. The parts from a Makino-made mold are good and out the door. That is really a time savings to the customer in getting product to market.”

Quality Performance

Pravitz notes that the Makino V56 performance on a variety of molds has been exceptional. “An ear-loop microphone mold piece done in 42 HRc steel for a telecommunications client has a wire inside of it that runs out of the 12 nylon material.

“The RMS 20 finish was so good, we were able to complete the prototype without any adjustments. Tolerances were +/-0.0002-inches. We were able to hold tighter than that with Makino’s Super Geometric Intelligence (SGI) control.”

AMA converted a gate mold initiated on another machine to the V56 to help minimize the appearance of parting lines. “The hardness of the material we were cutting would have formerly required us to cut electrodes and burn it with EDM,” says Andreas. “Because of the V56, we had the capability of hard milling the mold.

“For both the core and cavity side, cut times were about one hour and 15 minutes combined, compared to 40 hours for EDM burning. We often have to make fine adjustments on the gates to make sure the part flows properly, and that the knit lines aren’t there to eliminate jetting and worming. With Makino we can input the information and it’s done.”

AMA also produced an eyeglass stem sock mold that had an extremely difficult geometry. “With all the complex shutoffs and the cosmetics, it just basically fell right in place,” says Andreas. “Once we get all the upfront work done, in terms of what we can do with runners and gates, we know we have a good mold with the V-Series. It basically takes whatever you put on paper and puts it right into the steel.”

Rapid Prototyping and Tooling

Getting a production-ready prototype for tooling is a significant issue in saving time and cost, as well as making quick changes and alterations. “Rapid prototyping has become an integral part of building and altering tooling,” says Andreas.

"We are all in competition with Asian toolmakers, and rapid development is a way to maintain our competitive posture in North America."

“We are all in competition with Asian toolmakers, and rapid development is a way to maintain our competitive posture in North America. Customers can reduce tooling costs by having them manufactured in China, but many times they lose the quality and control.”

Andreas adds, “With our responsive engineering capability and the ability to make quick modifications on advanced technology machinery like the V56, we can make it prohibitive to send tooling overseas. If a customer has a problem with its industrial design or other issues, they need help to develop solutions and make quick modifications to a mold. AMA can service that need and get a tool back out to the press immediately, so the customer can get the parts.

“The mold industry in North America requires strong, engineering-based companies that are able to make changes on the fly to molds and parts. Since AMA has a Makino machine, combined with our value-added engineering services, we can make those modifications to the customer’s time margin and be more quality- and cost-responsive.

“When I first started in this trade, a 16-week tool build was normal,” says Andreas. “Now, if you have eight to 10 weeks, that is considered long. The average tool build is somewhere between four and six weeks, with rapid prototypes between two to three weeks.

“One of our first success stories with the Makino V56 was an extension for the earpiece mentioned earlier. The high-speed milling eliminated so many process steps we were able to make a capable prototype in a three-week period, essentially producing a preproduction tool of high enough quality that it was immediately approved.”

“Customers are going to get way more production out of one of our rapid prototype tools than they will from competitive processes,” says Andreas. “Getting 500 shots out of a prototype is normal; we build prototypes that can run 10,000 shots because we are able to ramp up tooling time quickly with the Makino V56.”

Machining Solutions

“The sheer fact that we can save days in producing a mold is absolutely beneficial and a tremendous help,” says Andreas. “The Makino V56 is pretty much doing all of our mold work. Our three other CNC mills just can’t produce the level of speed and quality of the Makino advanced vertical machining center technology.

“I am so impressed, we are looking to replace other machines in the shop with Makinos. We’d like to start turning our machine shop into a Makino shop. That’s the direction we are going, with our people being able to go from one machine to the other and know the basic control operations, which Makino makes very easy.”

“The seed was planted a long time ago for us to look at Makino and its full complement of machines,” says Atchison. “I am a fanatic about dedicating myself to one supplier for cost efficiency, training and all of my people working on the same brand of equipment. We want to ‘swing a big hammer’ with them, and we want the relationship.”

Andreas notes, “I’ve been running machines in machine shops for 15 years, and I have personally purchased many different machines. The first-rate process with Makino in revolutionizing and streamlining our processes has been an experience that is unparalleled.”

For additional information on AMA Plastics, and how the company can service your needs using Makino V-Series high-speed milling, contact them at 350 West Rincon Street, Corona, California, 92880-2004. Phone: 951-734-5600, Fax: 951-734-5666, Web: www.amaplastics.com, E-mail: sales@amaplastics.com.