Over the past five years, Motion Dynamics, a US-based manufacturer of precision springs, coils and wire forms, has advanced its in-house inspection capabilities with the implementation of five Keyence image dimension measurement systems and two Keyence digital microscopes.
Motion Dynamics, headquartered in Fruitport, Michigan, supplies markets such as aerospace, automotive, electronics and medical. Founded in 1992, the company has grown quickly and today employs 175 people at its 6,782 m2 custom-built facility. Commenting on this, John McManus, vice president of engineering, said, “We are focused on solving customer problems in the shortest possible time, no matter how complex or seemingly impossible, which is what leads to our growth.
“We like to be innovative and take on projects that others avoid. No one here believes in saying no. We’re not afraid to invest in new technology if that’s what it takes to deliver the solution. As a result, we’ve developed some of the industry’s most innovative products; products no one else in the world can make.”
Small parts, big innovation
With Motion Dynamics manipulating wire as small as 0.0127 mm in diameter, some of the springs and coils that it produces measure less than a grain of salt. Of course, high levels of quality control are required to ensure such parts meet the demanding specifications of customers.
The company’s primary market, the medical industry, sets out an acceptable quality level (AQL), which specifies how many parts require measurement in relation to the lot size and for which features. Motion Dynamics holds ISO 13485 Medical devices—Quality management systems—Requirements for regulatory purposes accreditation.
General tolerances for outside diameter (OD) measurements at Motion Dynamics include ±0.005 mm for microsprings and ±0.05 mm for standard-sized springs. Length is also closely controlled, typically to ±0.05 mm for microsprings. “The type of measurement equipment used is determined by the part features, tolerances and lot sizes being inspected,” explained McManus.
Image-based dimension measurement
Until recently, Motion Dynamics performed its inspection using manual vision systems, which typically feature X, Y, Z stages with glass scales and high-resolution cameras. While accurate, growing throughput requirements and increased demand for 100 percent inspection prompted the company to investigate automated inspection systems, and it acquired a Keyence IM series image dimension measurement system in December 2016.
Motion Dynamics has two Keyence LM-1100 high-accuracy image dimension measurement systems.
Motion Dynamics has since purchased two additional IM units to further accelerate quality inspection as well as two Keyence LM-1100 high-accuracy image dimension measurement systems, capable of delivering ±0.001 mm accuracy. Motion Dynamics also owns two Keyence VHX series digital microscopes. “The most recent arrival, in February 2021, was our second LM-1100,” said McManus. “Every time we look to invest in a new Keyence system, there are new advancements, which is great, as we’re always looking to improve our capabilities for the benefit of our customers.”
Motion Dynamics’ parts are difficult to measure. Using round wire most of the time means the springs and coils have 3D depth, which presents a challenge in the 2D plane because of the silhouette around the component. Keyence’s metrology equipment has helped the company overcome this challenge. “Our focus has always been to invest in the best equipment, as it ensures we can measure very challenging part geometry,” continued McManus. “The Keyence LM-1100 models are the most powerful systems on site for accuracy. We can inspect multiple components simultaneously without having to define how many parts are on the stage, making it a very flexible resource. In addition, we can collect and export data automatically for part validations and analyses, helping us to improve gauge R&R (repeatability and reproducibility) results on difficult-to-measure components.”
Safety-critical applications
Quality is critical because of the demanding markets served by Motion Dynamics and because lives quite literally depend on it. Whether it be parts for medical devices, aerospace assemblies or springs for high-precision defence applications, customers expect very high quality.
“The Keyence systems have brought automation to our mainstream inspection activities,” stated McManus. “Additionally, customers can count on accurate and consistent results as the Keyence solutions remove the potential for differences between operators when using manual inspection systems.”
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Spring pitch measurements using a Keyence image dimension measurement system.
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Critical dimensions of a wire form produced by Motion Dynamics.
Future requirements
Motion Dynamics continually looks to improve its levels of innovation and capability. The company’s business model is based on solving challenging problems in short lead times, which is where the Keyence systems prove invaluable.
McManus concluded: “We have a large mix of high-precision and wide-field part applications, which is why we have a variety of Keyence instant measurement systems in use. However, the high-precision travel of the LM units cover more of our precision part measurement needs. In the future, we could very well look at the latest version of the IM or LM Series at the time as yet another advance.”
Motion Dynamics
Keyence