A new step forward

Health care equipment manufacturer takes control of product quality, availability, and cost with high-speed flying optics laser system

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Health care equipment manufacturer takes control of product quality, availability, and cost with high-speed flying optics laser system

Stefan Colle

When NuStep Inc. (www.nustep.com; Ann Arbor, MI) decided to gain greater control of its manufacturing operation, the company brought its sheet metal work in-house by adding a high-speed CO2 laser cutting system with integrated shuttle table and 4kW laser as the core of its investment in new fabrication equipment. The result has provided overall control and greater flexibility for this manufacturer of state-of-the-art exercise equipment used in health and wellness centers, hospital-based fitness centers, physical therapy centers, health clubs, cardiac rehab clinics, and private homes worldwide.

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Situated on a wooded site overlooking a pond and walking/running trail, NuStep is a leading manufacturer of exercise equipment.
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The company has a history of in-house and community participation in health and wellness, which was recently recognized with a Gold Level, Healthy Workplace Award for Washtenaw County. Its headquarters and manufacturing facilities are located on a wooded site overlooking a large pond and a one-mile walking/running trail. Although the company wasn’t incorporated until 1997, its philosophy started much earlier. Company founder and President, Dick Sarns, an engineer by trade, worked with cardiac surgeons to develop what is today’s most noted heart-lung machine-the machine used in the first human heart transplant in Cape Town, South Africa, in 1967.

Sarns believed that lifestyle played a role in cardiac disease. After years of research and development and work with exercise physiologists, ergonomic specialists, and health experts, in 1999 he and his team introduced the NuStep TRS 4000 Recumbent Cross Trainer, which is unique in the field of exercise equipment. The product provides a complete workout for all major muscle groups, offering simultaneous upper and lower body conditioning without stress on the joints and muscles. It is designed for nearly every body type and size and can accommodate a user weight capacity of up to 400 pounds. Equipped with a welded steel frame for durability, the Recumbent Cross Trainer is virtually maintenance free.

Because the product provides a safe and challenging workout, it is the equipment of choice for physical therapy centers, cardiac rehabilitation clinics, and health and wellness centers across the country, including the Mayo Clinic, Vanderbilt University, and The University of Michigan. Today product sales also extend to consumers and to international users-a growing market segment.

The company outsourced its sheet metal fabrication operations until it made a decision to vertically integrate sheet metal fabrication in April 2002. It purchased an Axel 3015 S laser cutting system with 4kW resonator from Strippit/LVD. NuStep’s drive to manufacture in-house was fueled by continuous improvement. “We made a business decision to get direct control of our quality, availability, and cost,” explains Michael Steiner, manufacturing manager. “We were single sourced with an outside supplier for our sheet metal fabricated components. Being single sourced for many complicated, custom fabricated components was a vulnerable position. If something were to happen with that supplier, it would have shut us down.

“Twenty percent of our total cost is materials and 80 percent is value added,” says Steiner. “If we could control cycle times and efficiencies, eliminate non-value added activity, minimize lot sizes, and realize a quick change over, we saw opportunity for improvement.”

NuStep made the decision to vertically integrate its sheet metal fabrication operations after visiting several equipment suppliers and considering punch and shear machinery versus a laser system. The equipment evaluation process took six months. “We chose the laser so that we could cut both complicated geometries and standard holes, and eliminate secondary operations,” says Steiner. “We’re working to incorporate lean manufacturing so we’re very much involved in lot size standardization/minimization-quick set-ups, versatility, nesting, and making good use of materials. We felt the laser was more versatile.”

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At the heart of NuStep’s fabrication facility is a high-speed CO2 laser system with integrated shuttle table and 4kW resonator.
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The 4kW system cuts a broad range of material types and thicknesses. The company processes primarily cold rolled steel in thicknesses from 24 gauge through ¼ inch, but has the capability to cut materials up to ¾ inch. The laser is utilized for 45 different components required for the current TRS 4000 cross trainer. It’s used to produce complex contours, standard holes and cutouts, and automatically calculate required bend allowances at the press brake. Features of the laser system help the company attain consistent accuracy and a high level of productivity even on complex parts. NuStep’s Axel features a unique constant beam length, which uses a system of mirrors to keep the optical length-and therefore the laser beam diameter-constant. This ensures a consistent edge quality throughout the complete work envelope, irrespective of the position of the cutting head on the table.

The addition of the laser has given the company direct control of its product quality and the ability to address any quality issue early on in the production process. “If there was a quality issue with our outside supplier it was difficult because of sheer logistics,” says Steiner. “Now we can respond very quickly and make changes as necessary within our own quality management system.

“In the past we committed to 1000-piece lot sizes with our outside supplier,” adds Steiner. “If there was a defect detected, it was oftentimes found throughout the entire lot. We would never jeopardize the quality of our product just to use that component. We would have to conduct substantial testing to evaluate if the nonconforming condition of a particular component could be corrected or used without impacting overall product quality or functionality.”

NuStep has minimized lot sizes to 80 to 90 pieces on most individual components. Full sheets of material are also used on other components totaling 230 pieces. The company is also working to develop standard lot sizes and is building its work-in-process inventory to optimum levels and will then replace inventory as it’s consumed in assembly, creating a pull system and a more efficient operation.

The decision to fabricate in-house involved moving into a new manufacturing facility adjacent to its administrative offices, adding 16 employees, and extensively training its work force. NuStep purchased all of its fabrication equipment at once-completely outfitting its facility with new machinery. The company has a Strippit/LVD PPEB 90/08 press brake with Easy-Form Laser adaptive bending system, CNC milling center, tube bending equipment, manual and robotic welding, and fully automated powder coat operation, among other equipment.

“When the fabrication side became operational, we moved assembly into the same plant and are working to develop a seamless, continuous flow pull system,” says Steiner. “Parts move through fabrication work centers with the eventual goal of moving directly to assembly in the order in which they are consumed.”

NuStep had no prior experience with laser cutting equipment. Ron Haas, the company’s manufacturing coordinator, was familiar with fabrication equipment and was responsible for equipment selection and plant layout. “We hired some very capable, talented, and dedicated people who have been able, with the help of Strippit/LVD training, hands-on operation, and a can-do attitude, to successfully integrate the process,” says Steiner.

Today four employees have been trained to operate the laser system. The company runs two fabrication shifts. The laser’s automated features and quick set-up helped NuStep make the transition to laser processing. A built-in capacitive height sensor maintains a constant distance between the head and the plate, compensating for any unevenness in the material. The control automatically adjusts the laser power delivered to the cutting head as it changes speed, providing total power control. This ensures an optimal cut at every contour width and minimizes the heat-affected zone. A database of cutting technology determines the optimal pierce sequence based on the material to be processed.

The laser system also incorporates a water-cooled quick-change lens that can be installed or exchanged easily using a self-centering system. Lens calibration is programmable and quick to achieve. In addition, a user-friendly GE Fanuc control provides exact reproduction of programmed contours, producing acute angles even at high speed. All parameters, service diagnostic, and start-up procedures are displayed on a color screen.

NuStep programs parts using Strippit/LVD’s Windows-based CADMAN-L 3D software package. This laser-cutting CAM package includes an integrated 3D design and unfolding module, which allows importing of 2D and 3D designs, automatic unfolding, and generation of flat patterns from 2D or 3D files. The software also incorporates fully automatic, semi-automatic, or manual nesting and optimizes cutting and machine parameters to maximize sheet utilization.

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The TRS 4000 Recumbent Cross Trainer provides a complete workout for all major muscle groups, offering simultaneous upper and lower body conditioning without stress on joints and muscles.
Click here to enlarge image

Steiner ultimately credits NuStep employees for a successful implementation. “We’ve succeeded because of our people,” says Steiner. “They are a very talented group.” Having overcome the learning curve, NuStep today counts manufacturing as one of its strengths. “We’ve made several changes based on the capability we now have to make the product more manufacturable, the process more robust, and to minimize variation by making engineering changes that enhance the overall product quality and manufacturability at the same time,” says Steiner.

“What we’ve seen is a phenomenal amount of consistency in the level of dimensional control,” say Steiner. “The quality level has become more consistent and more predictable. The long-term goal is to release fabricated components directly from fabrication to assembly as they are produced,” he adds.

With the addition of the laser, NuStep has taken a step forward in its efforts toward continuous improvement. The company has direct control of product quality, is reducing lot sizes and inventory levels, and is embracing lean manufacturing.

The laser system strengthens the NuStep brand as a high-quality product designed and built to fit the needs of its users and for reliable operation over years of use. Most importantly, it helps the company further its mission to transform lives by improving health and wellness.

Stefan Colle is laser products manager at Strippit/LVD, Akron, NY. For more information, e-mail info@strippit.com or visit www.lvdgroup.com.

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