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Gun maker aims for a bull's-eye

March 28, 1999

5 Min Read
Gun maker aims for a bull's-eye

For a recent project at Remington, mold filling analysis determined the design with the best processing characteristics before tooling was cut. Melt-front advancement using 3D Quickfill, shown here, was combined with pressure and temperature distribution analyses to make the decision. Designer Todd Cook believes the savings offered by this upfront optimization reached $130,000 per year based on cycle time alone.

Molded plastics are not the first thing that comes to mind when you think of firearms. But Remington Arms Co., America's oldest gun maker, uses a combination of metals, woods, and yes, injection molded plastics, to deliver best-in-class products to its customers.

Remington designers, engineers, and others in product development use a variety of software technologies ranging from a mold filling package (C-Mold's 3D QuickFill) to structural FEA (Ansys). The combined solutions help Remington develop products faster and more cost-effectively. According to Todd Cook, Remington senior plastics research engineer, "Our customers demand performance and rugged reliability. Before implementing the complementary suite of software, we developed a design, tested it, improved it, and retested it several times. Time-to-market pressures have made this process obsolete."

Meeting Market Demands
Today, the CAE tools help Remington designers reduce the number of iterations and the amount of retesting required. "We find that by spending more time up front with CAE, we are able to produce a product that works well the first time, requiring much less improvement and retesting," says Cook. "Our standards haven't been lowered in 182 years, but, thanks to technology, we can meet those standards more often on the first try."

Cook is responsible for all plastics design and development efforts in new products, including product design, material selection, prototyping, product testing, troubleshooting, mold design, and mold development and evaluation. He also consults on manufacturing-related problems within the company.

Product development is most affected by customer requirements:

  • Product fit, feel, and finish-how the product looks and feels in the store.

  • Product reliability-how the product performs in the field.

  • Product cost.

Cooks says, "An attractive, reliable product is not enough. Affordability is a major issue."

Cook and his colleagues use 3D QuickFill to identify problem areas in the design of molded plastic components. He adds, "Since our CAD system (Cadds5) produces the files we need directly, we analyze every plastic part and decide what further effort is needed from there. The additional efforts range from simple design alterations to improved filling pressure or temperature distribution to complete redesign and in-depth mold filling analysis."

Remington's CAD system produces this STL file format for direct input to the mold filling software.

Optimum Designs
A recent project using 3D QuickFill involved three possible designs for a new product that contained plastic parts. The design with the best molding performance-lowest pressure to fill, smallest temperature distribution, and fastest cooling time-was selected, and mold filling analysis outputs were used to drive an economic model for comparison of the design. Cook says, "Having this depth of information at a very early stage in development is critical for us to avoid wasting resources chasing a design that can be inferior. It is nice to know where trouble lies before the design details are locked in and before much engineering time has been spent finding and setting those details."

The difference between the cycle time of the best and the worst designs alone was 35 percent, leading to potential savings of $130,000/year. Cook adds, "Design, especially preliminary design, is where most of the cost is set. Which process and design details you choose determines the cost, and changing those costs once the tooling is produced can require a lot of work."

A 3-D solid model of the part helps designers communicate their intent to molders and moldmakers.

Design Process Changes
Remington's new product design teams are led by a principal design engineer who is supported by engineering and material science disciplines-specialists in CAD, kinematics, finite element analysis, plastics, metallurgy, metrology, and testing. The principal design engineer pulls whatever resource is needed to evaluate the opportunity for business and market analysis. When the design is approved, the principal design engineer also delivers the design.

Cook says this approach to development speeds time-to-market and improves quality and customer satisfaction. "The benefit in time-to-market is felt mainly in the total development costs. A project that can be accomplished in only one year costs half of a two-year project for salaries and overhead. Product quality is improved because those items impacting quality can be identified early and given the proper attention. Customer satisfaction is ultimately affected by many factors, but having quality products that don't cost a fortune to develop is a great start."

Trends in Remington's market are very close to others: higher performance products offered at lower costs. "The only way to combine these goals and benefit from the trend is to use technological advantages to help provide products that are fundamentally less expensive to build," notes Cook. "Our product development must reduce manufacturing costs. In other words, we must integrate parts. Since integrated parts are often more complex and have higher performance demands, more needs to be known about their performance early in the design cycle."

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