Quality Applications

Virtek Vision Corp.'s LaserQC Benefits Captures up to 580 data points per second Accuracy to ±0.05 mm in typical production environments Automatically generates history of part inspection www.virtek.com

Quick Flat-Part Inspection Aids Sheet Metal Plant
Virtek Vision Corp.'s LaserQC

Vermont-based Mack Molding recently moved into the sheet-metal fabrication business. Before the operation's first open house, however, manufacturing engineer Bill Kelley wanted to ensure that quality inspection was fully operational.

  Mack Molding is a leading supplier of contract manufacturing services and injection molded plastic parts to high-technology companies, including the server/mass storage, business equipment, medical, telecommunications, industrial and consumer products markets.

 When the shop first started production in the summer of 2000, parts had to be sent a few miles away to Mack's plant in East Arlington, Vermont, where quality technicians checked setups with a coordinate measuring machine. The round-trip sometimes took as long as two days. And, if a problem in the setup appeared, two days worth of work would have to be scrapped.

 At the sheet-metal operation, Kelley concluded that operating its own CMM would be too labor-intensive. Because his staff members had worked with camera-based systems in the past, he decided on a seven-camera optical inspection system. However, time constraints became an issue. "The open house was approaching and we couldn't get the optical system delivered for 12 weeks or more," Kelley explains. "Plus, there was setup time, and I wanted to have the shop at 100-percent when our customers came through." This concern led to the company's decision to purchase a LaserQC laser inspection system from Virtek Vision Corp.

 Although Mack's staff was less familiar with laser inspection, Kelley found that his people adjusted quickly to the system. "Having more people qualified to do inspections is a huge advantage," he says. "Now our off-shift can check its own setups without waiting for a specially trained technician to give operators the go-ahead."

 The LaserQC is located on the shop floor, where the laser head scans the flat part, and its computer monitor displays it as an outline image. It's capable of capturing more than 580 data points per second with accuracy to ±0.05 mm in typical production environments. The image is overlaid with the corresponding CAD drawing, and color codes indicate whether the scanned part is within tolerances.

 The LaserQC automatically generates a continuous history of part inspections so shop staff can track when a machine is drifting and then take the necessary steps. The same documentation also simplifies a shop's SPC and ISO 9000/QS-9000 reporting, whether it's for internal quality control or per-customer specifications.

 "As fast as you can lay the part down, you get the information you need, which means we can run more inspections without interrupting production," adds Kelley. Mack now does its own first-article inspections for every setup and again at the beginning of every shift. Additional in-process checks are done throughout the production run.

 Kelley notes that the inspection system has emerged as a profit-producing asset because faster inspections result in "fatter pipeline" to deliver more parts in less time. The quick setup and automatic calibration upon start-up also speeds up the company's return on investment, providing Mack a level of productivity that is weeks ahead of schedule.