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FARO Technologies Inc. FaroArm

Benefits

  • Four-foot to 12-foot arm lengths available
  • System accuracy to ±0.001 in.
  • Allows instant comparison between part dimensions and drawings or CAD files

www.faro.com

Aircraft Component Inspection Improved with Measuring Arm
FARO Technologies Inc. FaroArm

 

Avica Inc. of San Fernando, California, which manufactures a variety of auxiliary pneumatic and ground support cooling equipment for North American and European aircraft makers, must be able to perform dimensional inspections both as accurately and as quickly as possible in order to meet strict tolerance standards while following production schedules. To speed measurements, cut down on operator error and ease the inspection of difficult-to-measure parts, Avica switched from mechanical instruments to the FaroArm digital measuring system from FARO Technologies Inc.

 Almost all of the equipment produced at Avica involves air, fluid handling or heat-transfer systems. For this reason, Avica's products are characterized by numerous lengths of tubing or ducting that are bent, in some cases with multiple compound bends, to specific shapes. Once tube pieces are formed, hardware may be welded to them. Then, these subassemblies of parts are joined to other parts to complete the product.

 Onboard aircraft systems, such as air conditioning condensers, must work in the extreme environments to which high-

flying jets are subjected. In addition to handling thermal shock, the systems must withstand the repeated mechanical shock of landings.

 As a result of their innate complexity, the need for them to tolerate harsh conditions and the need to fit into the space allocated, these systems must be held to exact dimensional tolerances. Typically, individual tubes or ducts are manufactured to overall tolerances of 0.030 in. on endpoints.

 Manufacturing a typical fuel or air conditioning system begins by building the tools to shape component parts, then subassembling the parts, performing "top assembly" of components prior to final welding, and performing first-article inspection of the operating system prior to shipping it to the customer. At each step, from tooling to first-article check, every piece of each product is inspected to ensure that the dimensions are within specifications. For a typical pneumatic system that includes numerous pieces of tubing, this can total hundreds of measurements.

 Avica engineers used to manually take each of these hundreds of quality measurements using mechanical gages, surface comparators, squares and rules. Blueprints of design drawings would be laid out, and parts would be checked with gages against blueprint dimensions.

 This method is not only slow, it's also prone to operator error in the form of misread scales or dial indicators. To get accurate, secure readings, technicians had to repeat measurements. Additionally, some key dimensions of complex assembled units were difficult to measure because manual tools cannot always be rotated in and out of specific planes to reach certain points.

 The fast, flexible FaroArm, however, greatly simplified inspections because the portable digital measuring arm can articulate freely in all directions. The unit employed at Avica is one of a series of measuring arms built with optical encoders at each of the arm's joints. This configuration gives spherical freedom of movement at the measuring tip and in all directions along the length of the arm. As a result, the arm has seven degrees of freedom and provides data to a host computer for XYZ location and IJK positioning.

 A technician takes measurements by touching the stylus of the arm to points on an Avica prototype tool or product. Then, this data is processed by CAM2 Design--one of a family of computer-aided manufacturing measurement software programs offered by FARO. Additional programs for CAD viewing, simple measurement, graphical report writing and SPC requirements are available. CAM2 Design is ideal for both inspection and reverse engineering. As an operator collects data with the arm probe, the software processes the data and literally draws the part or tool as it's measured. In most cases, the arm and the software sit on the shop floors of manufacturing facilities, providing a continuous link between design and production and instantly validating components as they're produced.

 Because the tooling at Avica must meet dimensional specifications before it's released for use by production, technicians check key tooling dimensions against blueprint drawings with the FaroArm and CAM2 software. "The arm has enabled us to proof our tooling prior to releasing it to production," notes Frank Paulson, a manufacturing engineer at Avica. "This has resulted in the detection of tool-design errors so we avoid the cost associated with manufacturing out-of-spec units." Once the tooling has been released to production, the arm is moved from the tooling area and used to inspect details of component manufacturing.

 In addition to being able to get into spots that they could not easily access with manual measuring tools, Avica engineers estimate that the FaroArm has reduced the hours spent inspecting parts and assemblies by 50 percent to 60 percent. Rework associated with measuring errors has also dropped noticeably.

 "The arm and software have made it much easier for us to hold the quality standards that the aircraft industry requires," confirms Paulson. "The ability to perform our inspections in three axes has really simplified the task."

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