Precision Mold-Making Capabilities Define Reputation for Custom Mold & Design

When entering the lobby of Custom Mold & Design (CMD), the impressive display of precision injection molded components is definitely eye-catching. A plaque that hangs nearby is also hard to miss. It reads, “The bitterness of poor quality remains long after the sweetness of cheap price has been forgotten.”

For CMD, inspiration and satisfaction are derived through achieving only the tightest tolerance requirements and overcoming the most complex geometric challenges. The company shares little interest in designing and building “everyday” molds. As such, CMD values advanced engineering and design, and arms its people with the equipment they need to produce quality molds.

“What matters most is our ability to provide the highest level of customer satisfaction, quality products and on-time delivery,” said Ray Newkirk, President and CEO of CMD. “In order to accomplish this, we need the talent, customers and technologies that allow us to break boundaries. We strategically plan our investments around what our customers are doing and continually seek out opportunities for improvement. Our recent investments in four Makino vertical machining centers are illustrative of this strategy, enabling us to shrink lead-times and produce liquid silicone rubber injection molds [LSR] and metal injection molds [MIM] with shutoff tolerances within tenths.”

A History of Precision Mold Making

For over 45 years, CMD of Minneapolis, Minn., has been a trusted partner in high-precision mold making for industry-leading medical device companies, as well as the automotive, aviation, pharmaceutical, defense and electronics industries worldwide.

The company is known for its expertise in producing precision molds with full interchangeability. Some of the molding processes that CMD supports include thermoplastic, metal injection, silicone injection, die casting and rubber. The company handles multi-cavity, two-shot, unscrewing, stack molds and insert molds. Its operation also encompasses versatile mold sizes, including applications with features as small as a grain of sand, as well as molds that are the size of a chair that can sometimes weigh up to 8 tons.

Not every shop can boast of employing a talented group of engineers and mold manufacturers with a combined industry experience in excess of 1,000 years. But that experience, joined with having designed and manufactured over 5,000 molds since 1965, sets CMD apart. It is because of this expertise that Newkirk bought the company in 2003.

“One reason why I purchased the company was due to its great reputation and the vision I saw for potential growth,” said Newkirk. “After the acquisition, we immediately started investing in people and equipment. And while the old company focused its services on building and selling molds, we decided to bring added value to the table by focusing on building relationships with our customers and positioning ourselves as an extension of their business. This has been one of the keys to our success.”

In addition to CMD, Newkirk is the owner of Teamvantage, a product development, engineering and contract manufacturing service that serves within the medical device, electronics, defense and industrial markets. CMD also has a division called CMD Express, which handles quick-turn molds, prototype molds, mold components, fixtures and machined components. Together, these operations offer customers a fully integrated molding solution from design to final part production that, if needed, can be replicated for a growing number of global customers pursuing localized manufacturing.

As CMD has grown, so too has the demand for additional space. To accommodate the growth, the company is set to relocate from its current 22,000-square-foot facility into a new facility expected to double the company’s footprint. CMD also plans to continue growing its capacity and capability with investments in skilled personnel and high-performance equipment.

Fine Finishes; Precision Tolerances

According to CMD, the last decade of business was defined by increased customer demand for shorter lead-times in precision hard-milling applications. Recognizing these needs and rising interest in micro- and nano-machining capabilities, the company sought a high-performance machining solution that would efficiently produce tight tolerances and high-quality surface finishes while creating opportunities to enter into new markets. In 2011, CMD purchased a Makino V33i vertical machining center with a 30,000-rpm spindle.

“The quality of our finish is critical,” said Lester Jones, Vice President at CMD. “We want to machine the workpiece complete, eliminating potential errors and inconsistencies resulting from handwork. In our LSR and MIM applications, the injection process is highly sensitive to flash, which can occur within shutoffs of only 0.0002 inches. As such, the fit between the A and B sides of the mold has to be very tight. This is some of the most challenging work that we do, using 0.004- to 0.006-inch-diameter end mills. To produce these tolerances, we require the highest level of rigidity and stability.”

The V33i’s spindle features a unique core-cooling and under-race lubrication system that minimizes thermal distortion at high spindle speeds for sustained dynamic accuracy. These features have been crucial to CMD’s precision hard-milling applications, many of which feature highly contoured surfaces in 60 HRC materials.

“Any inaccuracies on either side of the mold are unacceptable,” said Jones. “The cores must be interchangeable—even on a 16-cavity tool, each part must be identical. While we care about speed and efficiency, maintaining that accuracy to plus or minus 0.0001 inch or less is critical. The rigidity and repeatability of the V33i allow us to maintain a Cpk [process capability index] of 1.33 or better on all critical dimensions.”

Graphite Machining for Complex Feature EDMing

CMD acknowledges that hard milling often reduces the need for EDM, and realizes that many shops may be moving away from EDM processes. However, the company has never been busier in its EDM work.

“While we routinely search for opportunities to substitute EDMing with milling processes, there are simply some specific features that demand EDM,” said Thomas Caron, Vice President of Sales at CMD. “The sharp corners and thin ribs that we receive necessitate the unique benefits of EDM technology and inherently require a precision machining solution for electrode production.”

The company describes its EDM performance as a stacked process that relies first on the capabilities of its graphite machining centers. The precision achieved during EDMing is only as good as the accuracy of the electrode.

“We performed a test-cut regimen with several leading manufacturers of graphite machining centers and found the Makino V22 with graphite package to be more accurate and 20 to 30 percent faster than our current equipment,” said Jones. “Today, we push as much graphite work as we can through the V22 and have established plans to add a robot to keep the machine fed over weekends to further lower costs.”

Hogging Out Time in Mold Prep

In 2013, CMD rounded out its enhancements to the mold-building process with two 14,000-rpm PS95 vertical machining centers. Based on the machines’ flexible combination of speed, power and torque, the company found the PS95 machines to be an ideal solution for improving the productivity and quality of its preheat-treated mold preparation.

“Prior to our PS95 investments, we were performing all mold preparation on a horizontal machining center,” said Jones. “While many might find our decision to move toward a vertical machining center platform strange, the truth is that the PS95 spindle is more capable of handing our diverse product mix. For all intents and purposes, we’re getting the benefits of a high-performance horizontal machining center spindle at the value of a standard vertical.”

The majority of the work performed on the PS95 machines includes roughing of various steels, including P20. As a result, the machine’s standard power (33.5 hp), torque (140 ft-lbs), through-spindle coolant (435 psi) and scraper-style lift-up chip conveyor facilitate high metal-removal rates and efficient chip removal for improved lead-times.

“With the PS95, you get your money’s worth in standard features that normally factor in as added costs on most other vertical machines,” said Caron. “It’s a value package that has improved our mold-prep efficiency and overall workflow. We never thought we would experience this level of performance from a standard vertical machining center.”

Relationships Matter

As the plaque in the company lobby reinforces, the precision and quality that CMD strives for in its work remains a driving force, and its investments in high-performance machining technologies are integral to that mission. The company already has nearly a half-century of mold-making experience, and it intends to remain a leader in quality products into the next 50 years.

“We’ve come to find that some of our best relationships are formed when overcoming a challenge that no one else can,” said Newkirk. “If this work were easy, everyone would do it. That is why we make a strategic effort to invest in game-changing technologies. We see these investments as a long-term decision, because the machine, like our people, has to be compatible with the work we do.”

Caron adds that investing in equipment from Makino and building a partnership with local distributor Productivity Inc. enable them to successfully anticipate the ever-changing needs of their customers, keeping CMD abreast of new technology and helping them push the boundaries in precision mold making.

“We are always looking for ways to solve unique problems, and that usually means providing tooling with closer tolerances, shorter lead-times and the highest quality,” said Caron. “To get involved with our customers early on in order to assist them with their designs and to bring all of that to fruition is what we really are focused on, now and into the future.”