Case Studies: Laser Trackers Optimized
September 29, 2009
Developing and refining the advanced processes for its manufacturing and assembly operation is no small task for Coast Composites Inc. (Irvine, CA), a supplier of tooling for large, complex composite parts for the defense, commercial aerospace and space/satellite industries.
“Some of the high-precision tooling we produce for customers is really huge, up to 100 feet long,” says Steve Anthony, Coast’s IT manager. Size also has led Coast to its recent plant expansion from 85,000-square-feet to more than 200,000. “When you build huge tooling you need lots of room,” says Anthony.
Even though the molds it produces are extremely large, typically 2 to 60 feet long, Coast still must meet precise tolerance requirements to satisfy its customers’ specifications. “We’re talking fine finishes and tolerances of four to five thousandths over a 50- to 60-foot length,” says Anthony. “And, like any other quality control requirement, we have to be able to prove to our customers that we have met or exceeded their specs. To do that has taken us into some interesting new technologies.”
Originally, Coast’s quality control was accomplished using probes on its mills. “The problem was probing tied up our machines,” says Anthony. “We did in-process inspection, then pulled the parts off to do final assembly. Then we had to put the assembly back on the machine to do final inspection. That was time consuming. We needed a better way to do it.”
That better way turned out to be portable coordinate measuring machines (CMMs).
“In a regular job shop, when a part is machined, you either check it on a machine using probing or you take it to a CMM somewhere,” says Anthony. “In our case, though, the parts are just too big to move. We long ago figured out we had to bring the CMM to the parts. So, when the technology for portable CMMs became available, we jumped on it.”
After investing in early-generation portable laser tracker CMMs, Coast found the technology good but not perfect.
“Laser trackers are a great concept,” says Anthony, “because they’re fast and accurate over very long distances. But in the beginning the CAD [computer-aided design] software that drove those machines wasn’t very powerful. We’d been using laser trackers for several years, which was a major improvement over on-machine probing, but there were still drawbacks in software capabilities.”
Software SolutionThe introduction of Verisurf Software Inc. (Anaheim, CA) added control and power to Coast’s processes. “We were approached by Verisurf, which had created very specific software that had a lot of promise,” says Anthony.
Verisurf President Ernie Husted told Coast that his software was a model-based manufacturing inspection solution that could interface with nearly any measurement metrology device, including Coast’s laser trackers.
“We were skeptical at first but very pleased with the results,” says Anthony. “They solved most of the problems we faced at the time. Verisurf actually sits on top of Mastercam, so it had all the import capabilities of Mastercam. Basically, when you buy Verisurf, you’re buying a seat of Mastercam, too, which provides a full suite of CAD modeling features, including solids, surfaces, wireframe and drafting, plus all the translators we needed for our customers’ CAD platforms. But the main thing was that Verisurf made those arms do everything they’re mechanically capable of doing.
“All of our customers require different reporting,” says Anthony. “Verisurf has an HTML-based report format that you can customize. We can give customers any kind of report they want, including raw point data. If Verisurf collects data, it can report it.”
Offline InspectionFor most of its projects, Coast receives a solid model of the component, including the critical dimensions and inspection points.
“For quality control purposes, we import the model into Verisurf, and then our guys move the reflective mirror to collect all the points that have to be verified,” says Anthony. “They push a button on their pendant and Verisurf records the point. Or they can scan thousands of points to get a point cloud in a given area. Either way, Verisurf records it all and compares the data against the model. If there’s a problem, it lets the operator know immediately.
“When you’re inspecting really huge projects, the operator can get too far from the PC monitor to read it,” says Anthony. “Verisurf has come up with the ability to transmit the data via wireless to a PDA device. We use Dell Axims, so now the operator can look at his PDA and see what’s happening. It’s fast and very efficient.”
More UsesCoast also uses the Verisurf and laser tracker combo during mold assembly. “The system works perfectly to help us locate points on the mold for brackets, holes, you name it,” says Anthony. “The model tells you where it wants a hole or a part to be assembled. The operator moves the little mirror to find the exact location on the assembly. He marks the spot and he’s done. It’s that simple. It’s a fantastic time saver. No more measuring and checking the old-fashioned way.”
In addition, Coast uses the Verisurf and laser tracker combo at customer sites to help set up molds. “We use them for leveling, dimensioning and inspection,” says Anthony. “The whole setup consists of the laser tracker and a PC on wheels. It’s very portable.”
Making Offline Inspection PositiveCoast has seen significant benefits since it began using Verisurf with its laser trackers.
“In a nutshell, the offline system has made our life a lot easier,” says Anthony. “First, it speeds up our manufacturing process by eliminating the need for on-machine inspection. Second, it greatly speeds the mold assembly process by allowing us to quickly locate holes and components and to level the molds. Third, our customers make a lot of revisions. Verisurf can read those and give us the new data we need for checking. I really can’t put a number on our savings, but it has been significant. It can easily equate to weeks in terms of faster throughput.”
Verisurf Software Inc.