Pattern maker improves accuracy with laser measurement technology

Situation

Located in Butler, Wis., Accurate Pattern Inc. produces prototypes that make new products possible. The company creates patterns, tools, and models for industry, as well as checking fixtures and gauges, plugs, and molds. It also offers CAD/CAM, toolpath, and CNC development.

Originally known as Accurate Pattern & Model Inc., it was founded by brothers Bruce and Brian Williams in February 1985. The company supplied its first customers with precision patterns for urethane molded parts. In 1986 the company was incorporated, and Bruce Williams became president. In November 2007 it moved to its current location, a plant featuring 19,000 sq. ft. of shop/office space and 5,000 sq. ft. of mezzanine.

Williams met Dean Solberg, Exact Metrology co-president, when he was looking to buy an Elm CMM/layout machine with PC-DMIS software. Solberg was in contact with a sales representative at Elm Systems and helped set up Accurate Pattern with the right machine, configuration, and software for its needs.

Workers had only been able to use height gauges and calipers and weren’t able to certify their work, but the new machine allowed them to start building quality fixtures and helped improve accuracy to +/-0.004 in. in all their work.

In 2014, at Solberg’s suggestion, Williams purchased a Wenzel CNC CMM with Open DMIS software. Switching from Elm to Wenzel increased checking accuracy and efficiency tenfold to better than 0.0003 in.

However, personnel still were only able to perform spot checks with hand tools, which was time-consuming and inefficient.

Resolution

In 2015 Williams attended an Exact Metrology Open House and saw the Romer Absolute Arm in action. He purchased the Hexagon Absolute Arm 7-Axis, then worked with the company to change the Open DMIS software on the Wenzel system to PolyWorks|Inspector.

“The Romer arm with PolyWorks|Inspector was a game-changer for inspecting patterns and molds 100% to reference CAD data,” Williams said. The large reach of the model (about 13 ft. diameter) allows personnel to check patterns like truck hoods, wind turbine blades, and boat hulls in a single setup. If necessary, users can shift the scanner on its portable stand, and the software stitches the scan data together.

Accurate Pattern also added PolyWorks|Inspector software to its Wenzel DCC CMM. Now the company can certify quality-inspection fixtures in half the time it took with the previous software.

The company has used the Romer arm to complete first-article inspections for fiberglass and vacuum-formed parts and to change the pattern on a model car. The scanner was used to align on a 5-axis router and recut within 0.005 in. Then while painting, personnel used laser inspection to determine how much hand sanding they could do while still maintaining accuracy.

Recently Accurate Pattern needed to modify a cast aluminum tool. To determine wall thickness and the position of water lines, workers laser-scanned the tool and compared the results to the CAD data. This allowed them to machine within the wall without damaging water lines.

“We have been able to greatly reduce our customer nonconformances by inspecting our patterns in-house,” said Daniel Jones, Accurate Pattern’s model shop manager. “This has gained us greater confidence from our customers and has helped us produce more accurate patterns. We have also been able to re-machine jobs with more precision thanks to the capabilities of scanning the job in position on the machine.”

“We would not be the company we are without the likes of Dean and the crew at Exact,” Williams concluded. “They have given us a great competitive advantage in the world of metrology that applies to all our patterns, molds, fixtures, and tools.”