Reducing Motor-Component Inspection Time
InnovMetric’s Polyworks 3-D Metrology Software
Weatherford International Ltd. products are used by petroleum-producing companies throughout the world. The company’s Edmonton, Alberta, facility designs and manufactures two products for petroleum production--fluid power sections and progressing cavity pumps used in the production of oil after the well is drilled. The fluid power section is the motor that provides the power to drill the well. To help improve production efficiency, the company sought a more efficient way to inspect the complexly shaped fluid power sections.
In the past, inspections required four people to dimensionally inspect the fluid power sections after machining. The inspection process took approximately one hour to gather the dimensional data and manually compare it to the original design as created using computer-aided design (CAD) software. Machine offsets were relayed to the shop floor, where changes were made in the machining process. Another section of the same component was machined, and the inspection process was repeated to determine if the corrections had improved the dimensional accuracy of the part.
“This was a very time-consuming process,” says Wayne Pilgrim, Weatherford’s senior project engineer. “Plus, we had to restrict our inspection operations to normal business hours, since that was when the engineering department was available to compare the measured geometry with the CAD drawing.”
The company re-evaluated its approach to inspecting these parts with the goal of finding a more efficient method of gathering and analyzing dimensional data. Part of that program was the installation of PolyWorks 3-D metrology software, which automates and streamlines many of the operations associated with gathering and comparing dimensional data with design intent. The PolyWorks software is used in conjunction with a FARO Laser Line probe mounted on the Platinum FaroArm. The hardware/software combination cut inspection and analysis time in half and required only two people to run the operation.
The FARO Laser ScanArm (with a fully integrated FARO Laser Line Probe) collects dimensional data at up to 19,000 points per second. During the 10 to 15 minutes it takes to perform the inspection of the fluid power sections, a point cloud of millions of data points is collected to create a highly detailed dimensional picture of a part feature.
“We let the PolyWorks software do the work--the mathematics--of determining how to take the proper cross section,” Pilgrim says. “Because of its auto-alignment capabilities, PolyWorks software assures consistent results, eliminating operator influence during data gathering.”
The company uses an in-process inspection approach on a batch basis. “For example, if a batch of five parts is being produced, operators will perform the PolyWorks/FARO Laser Line probe-inspection process on the first piece and then use the same CNC [computer numeric control] program to make the next four with no PolyWorks/FARO laser inspection,” says Pilgrim. “We inspect the finished product only if it is considered questionable by other inspection methods.”
“The automated features of the software really set it apart,” said Travis Chometsky, Weatherford’s product designer and PolyWorks software expert at the facility.
The inspection process is always the same. After the first machining cut on a new fluid power section model, a raw-data point cloud is collected through the 3-D-scanning process. From the point cloud, the software generates a mesh that is loaded into the PolyWorks/Inspector module. Using data-to-CAD alignment techniques, the operator aligns the mesh with the reference object--to register both models in the coordinate system. Once the two are perfectly aligned, the operator specifies a cross-section where the data-to-CAD comparisons need to be performed. For each cross-section selected, PolyWorks automatically compares the data model to the CAD reference model and computes a series of measurements, including standard deviation, maximum error, minimum error, and others.
PolyWorks also creates a PDF report of the results of the data-to-CAD comparison. Based on the information in the report, the machine operator makes adjustments, and another section is machined and scanned to determine if the adjustments have brought it closer to design intent.
PolyWorks’ macro-programming capabilities make performing alignment and comparison tasks for each new part unnecessary. The complete inspection process, from alignment to comparisons and report generation, can be automatically performed for every scanned section.
“You don’t need a lot of programming experience to be able to quickly set up a process,” says Chometsky. “The macro-programming language is easy to use and records actions in a command window.”
InnovMetric’s PolyWorks 3-D Metrology Software
- Compatible with probing devices and laser trackers
- Fully customizable menus, toolbars, and docking windows
- Optimized visual layouts
- Polygonal meshing distributed over computer network
- Parallel computing on dual-core and multi-CPU systems
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