User Story

Coin Acceptors, Inc. : Moldflow Plastics Insight

St. Louis-based Coin Acceptors, Inc. (Coinco) is a world leader in the design and manufacture of coin mechanisms, bill acceptors and control systems for vending machines for the global food and beverage vending industry.

Senior Coinco engineer, Max Molenaar, supervises the tool design and drafting departments, model shop, prototyping, and computer-aided engineering (CAE) activities, including the use of Moldflow Plastics Insight (MPI) software. The company also uses Pro/ENGINEER Mechanica for stress analysis, as well as Unigraphics and Solid Edge for computer aided design. He says a major challenge to designing the company's products is molding plastic parts that require close tolerances. "Typically, coin changers are restricted in size and require small and accurate components." says Molenaar. "Designing and molding a plastic part to meet our expected criteria can be challenging."

Coinco customers demand products that are reliable and tamper-proof. "A combination of good design, careful analysis, and testing helps us achieve reliability and tamper proof devices for our customers," adds Molenaar.

Using Moldflow Plastics Insight software
Molenaar and his peers have been using MPI/Fusion software since September 2001. However, the tool design department had already been using flow analysis software at Coinco since the early 1990s, when the company introduced software from C-MOLD for flow analysis. (Moldflow acquired C-MOLD in 2000.) Molenaar migrated to MPI as a beta customer for Synergy, the revolutionary new user interface that debuted with MPI 3.0. "We use MPI for analyzing each newly designed plastic part," adds Molenaar. "The software is an integral part of the overall design process, it allows us to achieve the accuracy, the reliability and the consistency that our customers expect. The company established a policy several years ago to perform flow and cooling analyses on each new part during tool design.

"The other benefit derived from those activities include optimizing the design accurately at the beginning of the design cycle, and eliminating subsequent design cycles. In addition, the analysis allows us to plan and position the cooling lines before machining them. This effort helps prevent very costly and time consuming retooling."

He says that upfront analysis also helps him make more informed decisions. "We could have a scenario where instead of cooling the mold with water, we could opt for using beryllium copper. The software helps us save time and money because it eliminates the trial and error out of the design cycle. MPI allows us to establish a process for the production floor so operators can easily initiate the start-up process for the mold. They have a processing window ready for them."

Applying MPI to Coinco's projects
Molenaar and his team are currently using MPI to design new plastic parts - some as large as 6-inches wide by 18-inches long, and as small as gear pieces with quarter-inch diameters.

He says, "Using Synergy for a current project is particularly helpful because we are almost 99 percent sure that the gate locations and cooling lines are accurate. There are aesthetic issues with any product so we make sure that unsightly nit and weld lines do not appear in critical areas that could be visible to the outside. That's why it's also very important to perform MPI analysis during the design cycle -- to make sure that we don't have imperfections in cosmetically critical areas."

Benefits of using MPI
Molenaar figured out that he and his colleagues were spending up to eight hours per model to generate meshes and clean them up using midplane meshing tools. Using MPI for a current project, he's realized savings so far of 120 man-hours. Over time, he calculated that the company would save more than $26,000 per year as a result of implementing MPI. "The company's return on this investment will be realized in less than a year," adds Molenaar.

He says that he and his colleagues have been able to reduce modeling time by 80 percent. "When we participated in the beta test for MPI/Fusion," explains Molenaar, "I selected a small, complex gear as a test model. It required a mesh with a large number of triangles. Using C-MOLD Express, it took four hours to generate a mesh and another three hours of manual labor to correct the mesh. Moldflow's Mesh Generator generated the mesh in about five minutes, but the mesh didn't look any better than the Mesh Express version. Both products caused significant frustration and required additional labor to create something half-way decent."

However, using MPI/Fusion, Molenaar generated the mesh in just two minutes and spent just 15 minutes cleaning it up. "MPI/Fusion is a revolutionary product. It is saving Coinco time and money in more ways than one."

The choice of Moldflow's new state of the art software is in perfect harmony with Coinco's tradition of being on the leading edge of designing and manufacturing plastic components for it's end products.

For more information about Moldflow, visit Visit for more information about Coin Acceptors, Inc.

Author: Laura Carrabine

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Page last modified on January 22, 2002
Copyright 2002 by John Stark