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Streamlining Quality Inspection



Metrology lab at EVCO Plastics. A Romer arm and 3-D scanning software supplied by Exact Metrology are used to scan an injection molded part, capture the data, compare it to the CAD file and make any adjustments needed to the mold or injection press settings. The data are also integrated with the output from the bridge CMM equipment to feed the point cloud.

Auto Surfacing

Auto Surfacing involves taking a scan of a physical object and completing mesh conversion (hole filing smoothing). The Auto Surface feature wraps a surface around a free-form object.

Solid Model Process

This was a failed injection molding machine part that had a long lead time. By using reverse engineering and EVCO's machining centers, this process was completed in 48 hours and its molding machine was back up and running production.

The Solid Model process begins by scanning the physical part. Scanned mesh will be brought into Design X for mesh conversion (smoothing, hole filling, modeling prep).

Take a cross section and start the sketch (one tooth was drawn and revolved around center point to make all of the teeth). The cross section will show where to cut through the mesh.

Extrude sketch to make a solid body.

Color map solid body to see how close the solid is to the scanned mesh. Adjust sketches to make the solid as close to the mesh as required.

Solid Model Use

Create a clean solid model that reflects the physical tool. This can be used to set up automation, cut a new tool with the same geometry or address any engineering change to accommodate part needs.

Scan tool and run mesh conversion.

EVCO Plastics is a global injection molder based in DeForest, WI. Part of EVCO's strategy, according to the head of the metrology lab Rich Duval, is ".to have the ability to take a part, scan it, compare it to the CAD/CAM files as early as possible in the process and allow the customer to observe how the plastic product compares to the solid model." Duval also noted that by using scanning technology and reverse engineering, the EVCO metrology team has been able to recreate the surface of tooling where solid models do not exist and provide this data to a tool shop for steel revisions.

Recently, owing to the volume of work coupled with the challenges of collecting and processing point cloud data in the lab, the EVCO team turned to its supplier partner, Exact Metrology (Brookfield, WI) for assistance. The company had been researching earlier generation scanning, but saw more advanced Romer and other brands of scanning arms in the Exact product offering. "As a dual-purpose vendor, Exact both sells metrology equipment and also performs very complex scanning services for customers, including use of the first industrial-grade CT scanner in America, which enables geometric views inside molded, cast and forged parts to check for porosity, hot spot and material flow issues," said an Exact spokesperson.

Exact Vice President Dean Solberg and his team of metrology technicians and application support specialists reviewed the EVCO scenario and provided several new Romer arms to its customer. One example involved the staff taking a damaged tool component and reconstructing the cogs on a machine gear. Once rechecked through design, a suitable alternative could be 3-D printed. In this way, noted Duval, the metrology solution proposed by Exact has reduced inspection time in the lab and provided reverse engineering as an additional option to customers.

Similarly, older molds used at EVCO are being evaluated with the scanning techniques for position of runners, pins, cores and other components. A solid model is produced from the scans to show auto-surfacing, solid model processing and solid model in-use characteristics. Often, reverse engineering from existing parts is also performed in the EVCO lab for production issue resolution or part validation.

While EVCO continues to use the conventional CMM technology in its metrology department, Duval said that his team of technicians has been able to "marry" the Romer arm and CMM technologies. In practice, the combination of the 3-D scans with the bridge CMM plates gives the EVCO technicians and design engineers the necessary comparative data to resolve any issues that arise.

Support from the Exact team has aided EVCO during this ramp-up of the new scanning technologies, according to Duval. "We had some lurking questions after the initial training session, but Dean was very pro-active and amended the training protocol to suit our specific requirements," he said. "It has produced a very positive outcome here."

As a supplier to major OEMs in many industries, EVCO is routinely expected to supply considerable part and production data to its customers, according to Duval. "We are planning to utilize the Exact equipment to support tooling as well, so there will be a seamless capture and transmission of data from part design through production," he said.

One of the strongest abilities at EVCO is the company's production of near-finish prototypes. These prototypes are often produced with conventional CNC machining or through the use of the rapidly expanding 3-D printing technologies. At EVCO, fused deposition modeling (FDM), with and without carbon fiber, is performed. Here, too, the 3-D scanning techniques supplied by Exact Metrology produce the necessary data files, such as STL, that can reside in the point cloud for use by these advanced 3-D prototype production technologies. Millions of data points provide the 3-D printing equipment with all necessary information to produce highly accurate prototypes and concurrently anticipate challenges that might arise in the transition from design to tool to production, according to Duval, who noted that the Exact team has continued its high level of service and pro-active suggestion to keep pace with the EVCO team's expectations.

The new metrology equipment used at EVCO is helping the company attain its stated goal of supplying world-class plastic products and assemblies.

EVCO Plastics has plants throughout the USA as well as Mexico and China. Since 1948, the company has produced parts for a variety of industries, including powered sports equipment, lawn and garden devices, agricultural and construction machinery, appliances and plumbing fixtures, plus medical and packaging machinery, general industrial products and more.

EVCO has over 150 presses in the 28-3,500 ton range, its own mold production and a world-class metrology lab for quality evaluation. To see the EVCO metrology lab in action, go to youtu.be/5uhGA-dmOkM.

EVCO performs ISO Class 8 Cleanroom, large part, thin-walled, metal-to-plastic insert, gas-assist, multi-shot and overmolding operations, plus in-mold decorating and labeling in highly automated and robotic facilities. EVCO produces parts in various thermoplastic materials, ranging from basic polypropylene to engineering grade materials. The company currently employs over 1,000 people at its nine locations worldwide.

Exact Metrology, with facilities in Cincinnati and Milwaukee and affiliated offices throughout the Midwest, is a comprehensive metrology services provider, offering customers 3-D and CT scanning, reverse engineering, quality inspection, product development and 2-D drawings. The company also provides turnkey metrology solutions, including equipment sales and lease/rental arrangements. The company is ISO 9001:2008 and AS9100 certified.

For more information contact:

EVCO Plastics

100 West North Street

DeForest, WI 53532

800-507-6000

www.evcoplastics.com

Exact Metrology, Inc.

20515 Industry Avenue

Brookfield, WI 53045

262-533-0800

www.exactmetrology.com

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