Makino A99S and Innovative Magnetic Tool Holding Processes Give Special Mold a Competitive Edge

Technology plus creative expertise often equals manufacturing innovation. And, such innovation allows machine shops to compete and thrive in even the most tenuous of economic situations.

Special Mold Engineering, Incorporated, in Rochester Hills, Michigan, has combined non-conventional utilization of horizontal machining centers in mold and mold base production with unique magnetic tool holding devices. This combination has been so well integrated into the day-to-day business operations of Special Mold that the two Makino A99s are now dictating the processes and utilization of the 25 other CNC machining centers and jig grinders.

"I truly believe if we had not purchased the Makino A99s and learned how to maximize use of this new technology, we would be obsolete and out of business," says David MacDonald, vice president of Special Mold. "We were looking initially just to increase capacity during solid economic times when we purchased them in 1999. Now we are using the Makino machines to change and improve our processes in order to stay competitive and find new ways to drive out operational costs and maintain profitability.

"That is a huge consideration in today's marketplace. Customers demand that you lower prices to keep their business. And if you can't, you are going to be out of business. So you have to lower prices and still find a way to make a profit, and we've done that with Makino."

Combined with a state-of-the-art magnetic tool holding device from the Italian firm Tecnomagnete, Makino has helped Special Mold cut up to 75 percent from their production cycle times and eliminate 100 percent of their bench times to finish the molds and mold bases. The use of the magnetic tool holders eliminates work clamp interference, enhances faster setups and operational cycles and takes maximum advantage of the Makino horizontals superior metal cutting abilities.

Becoming Special [back to top]
Special Mold is a 30-year-old company that produces molds and mold bases for the plastic injection industry. In the past five years, they have changed their focus toward high-tolerance tooling, rotary tools and molds and bases that are designed for "two-shots," combining different types of plastic. They also produce die cast and compression molds, rubber molds and they have begun cutting and finishing cavity and core inserts as a service for customers.

Gail and Marta MacDonald started the company in 1973 in Warren, Michigan. Marta still serves as company president, with her three sons serving as vice presidents and running the business. David manages the company; Keith is in charge of estimating and Darin heads purchasing. Eddie Elliott serves as operation manager and applications engineer for the company with complete control over production of the facility.

Special Mold purchased the two Makino A99s after three years of researching how to become more competitive, according to David MacDonald. "Before that, we were feeling the crunch. The three variables that always come into play are high quality, fast delivery and low cost. The old saying of the past was that you could have any two of the three; today, customers demand all three on every job.

"We needed technologically advanced machinery that could help us achieve these demands, and we selected Makino because of the way they are designed and the capabilities they offer. They are often 80 percent faster in finishing parts versus our jig grinding operations, and that alone has allowed us to be more economical and more competitive when we quote our tools."

The Makino machines are set up in their own department. Special Mold experimented on how best to fully learn and utilize the capabilities of the Makino machines in order to drive their other operational processes, says MacDonald. "We have really explored high-performance machining. There are no aspects we have overlooked in re-inventing our processes.

"High-performance is a combination of the way that you program your machines, the way that you fixture the workpiece, the way that you probe it, the type of tooling that you use as well as how you maximize a tools operation. We have the complete package now with Makino and a turnkey operation that is flexible enough to add future machinery."

The Pull of Horizontal Over Vertical [back to top]
Elliot had some experience with Makino machines which helped him judge capabilities and select the right tools. After committing to Makino, Elliott elected to build their operation with horizontals over vertical machining centers that had been a standard tool for molds and bases at Special Mold.

"There were several factors that favored the horizontal over the vertical for our needs," says Elliott. "The ability to do fourth axis milling was a real key, which is more limited on vertical. Angled milling is a constant demand for high-tech molds and bases. Moving to linear guide ways from box-ways provides improved stability, machining quality and repeatability, which were also key factors in the decision. Rapid traverse and high spindle speeds, through-spindle coolant, a big work envelope and superior chip evacuation likewise led to the selection of a horizontal in a market historically dominated by verticals.

"An advanced pallet changer for easy loading and changes, as well as the flexibility for future automation integration was another key factor. We would like to add a third, larger Makino horizontal in the future, as well as a Makino Machining Complex (MMC) automation system, to continue to take advantage of unattended machining time and production.

"It was a two-year transition period for Special Mold to learn how to deal with different applications and different steels on Makino machines in order to adequately meet our special customer demands," says Elliott. "Makino helped in our process development and transition far beyond just teaching us about the machine operations, including the development of numerous different programming techniques.

Magnetic Work Piece Holding [back to top]
A big plus for going to horizontals at Special Mold was the chance for Elliott to utilize the unique magnetic tool holding system of Tecnomagnete to eliminate work clamp interference in high-speed machining. "With the work we do, we often need to access three sides to the workpiece from one set up.

"We use aluminum tombstones with the magnets mounted to them. Taking about 15 minutes to load our magnetic pole extensions, we lift the plate to the poles and activate the electronic magnet and core-cooled tombstone. The magnet can hold up to 4,000 pounds, and the workpiece doesn't move even under the highest milling thrust. You can even direct the magnetic energy to the sides of the plate for special adherence demands."

"With the productivity we gained, the technological costs were no more than other conventional tool holding methods," says Elliott. "We are now able to machine thin or thick plates, allowing for faster setups and loading/unloading processes, as well as maintaining continuous cutting due to the pallet system of the A99."

"We would never consider changing back to old tool holding methods. With the magnetic system, we no longer have to fight with workpiece clamps, changing them around to finish different angles. And we don't have to fight gravity to put clamps on a large workpiece. One person can easily handle the setup as opposed to two. This allows the machine to maintain the speed, quality and accuracy for which it was built. The magnetic system also helps protect the machine and spindle during unattended operations. The chance for a collision between the workpiece holder and the machine spindle is eliminated."

Producing Results [back to top]
MacDonald says the Makino's are best suited for the multiple molds and multiple interchangeable mold bases and rotary tools, to service the high-quality and hard materials that are Special Mold's staple.

"We mostly mill 420-series stainless steel and the hard milling of inserts," says MacDonald. "The reason is, our customers desire to run these molds and bases for years in order to maximize their investment by using corrosive-resistant material.

"Even with this tough material, we are able to reduce the time it takes to finish a part by up to 35 percent faster than conventional CNC machinery. This is usually work with critical and tight tolerances."

MacDonald had numerous stories of successful utilization of Makino technology and processes. Two parts that Special Mold built had deep pockets and angled walls that would have required four setups with conventional machining. With overall tolerance demands of +/- 0.0002, the stainless steel mold would have taken 44 hours to mill, prep and finish.

But, due to the customer demand for a 5-degree continuous wedge block cut, conventional machining could not have even been considered. Without the flexibility of the A99, Special Mold would have had to decline the job.

Utilizing Makino technology permitted them to mill the job and all details in one setup. Most importantly, production time will be cut to 18 hours, and no prep or finish bench work is even required.

Another example is that a Special Mold customer ran into delivery problems with a wire spool cavity plate. They had only one week to meet their delivery, but over 200 hours of EDM work necessary in order to finish the ribs in the cavity. By utilizing Makino's hard milling capabilities, Special Mold was able to finish mill the spool ribs in just under 60 hours and eliminate 90 percent of the EDM work.

And, a third example is a complex 16-cavity, plastic injection inkjet print cartridge mold base. Special Mold lost money on this job when they originally ran it on conventional machinery. When they ran it the second time utilizing Makino's high performance machining, the job became profitable. This is due to the speed, quality and flexibility of the A99s.

"With conventional machining, it took 120 hours to jig grind and 200 hours in prep work and drilling," says MacDonald. "We found a way to turn it around and actually make money on the job with dedication to a Makino-driven process. The entire job was completed in 110 hours and the jig grinding process was completely eliminated."

Unattended Machining Time Pays Off [back to top]
Beyond the physical capabilities of the Makino A99s, it is the unattended machining time that makes the machines profitable for Special Mold. It is even better than they expected.

"Once the operator sets up the work piece and the machine starts the cycle, the operator involvement is limited," says Elliott. "All the tools are preset off-line and loaded into the 90-tool magazines. On more conventional machining, there is much more operator involvement and more chance for error because it is more labor-intensive."

Elliott says Special Mold can run the Makino machines at 18,000 rpm for 24-hours without fear of spindle failure due to the interface cooling design. The ball screws are also core-cooled. This allows the positioning accuracy of the machine to maintain perfect cutting accuracy because the spindle and the ballscrews are maintained at a constant temperature.

One of the keys to performance of the A99s is SGI.3, Makino's proprietary technology software that allows long, complex mold processing that operates the machines at extreme speeds with high accuracy and superior finishes. This helps reduce cycle times in complex mold cavities and cores by as much as 40 percent while reducing benching and eliminating the potential for scrap.

"I would like to buy ten brand new Makinos and then sell off the rest of my machinery," says MacDonald. "We were running within a week of machine delivery. Makino and their distributor, Single Source Technologies (SST), have the people and support available to continue to teach us more about future application needs. They have created a partnership that we are counting on to succeed.

"We are able to offer quicker deliveries to our customers that are requiring higher tolerance tools. We can ship a completed mold base within ten business days. In the past, it would take us at least twice as much time. We can offer our customers high quality, fast service, quick turnaround and lower prices. The molds and mold bases are produced more efficiently using high performance machining, eliminating hours and even days of machining time.

"They generate twice the hourly rate of any other machine in our shop," adds MacDonald. "We are able to quote tools now that we would not be able to quote two years ago. We are open 24-hours, five and-a-half days a week. We can program during the day and streamline our nighttime operations.

"When it comes down to producing the final product, the quality and the reduced cycle time achieved through Makino technology reduces a tremendous amount of our operational costs. Makino has opened doors for new types of work for us to quote and produce. Plus, it allows us to compete for work with overseas competitors, as we are able to make substantial time and costs savings."

Special Mold uses Makino to produce what they call the perfect and complete package. That generates a magnetic and special customer response,

Special Mold Engineering, Inc. can be contacted at 1900 Production Drive, Rochester Hills, Michigan 48309. Phone: 248-652-6600 FAX: 248-652-1130 e-Mail: davemacdonald@specialmold.com, or visit their website at www.specialmold.com.

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