Manufacturer Cuts 90% Off Inspection Time Using 3-D Measurement

Troubleshooting and effort is now directed toward innovation

Published: Wednesday, June 8, 2011 - 15:13

Ariel Corp. is an innovative manufacturer of gas compression equipment. Based in Mt. Vernon, Ohio, Ariel has been at the forefront of modern compression technology with market-driven innovation. The company takes pride in its manufacturing processes and product designs. Quality is the foundation of Ariel’s success and is deeply embedded in its company culture. Maintaining its reputation requires the company to design products that can be manufactured, installed, and serviced with ease.

To design a world-class compressor, nothing can be left to chance. Because the compressor is at the center of an integrated system that includes the driver, cooler, piping, and other components, each Ariel design carefully integrates the compressor with the driver and the package system; this lowers lifetime cost. Maximum driver power and efficiency, and precise piston stroke coordinated with valve design for optimum valve efficiency and life, are all part of the design integrity. Every design considers the feasibility of patterns, castings, and machining. Integrating the technical design of the compressor with an understanding of manufacturing technology has been a key to Ariel’s success.

Ariel machines parts anywhere from just a few pounds up to 20,000 lb. These parts are machined out of steel and cast iron, both grey and ductile. Machined parts such as compressor-connecting rods can be 8¼ in. center to center and weigh about 13 lb, or can be up to 23 in. center to center and weigh almost 300 lb. Crossheads vary in size from 8 lb (6 in. overall × 6 in. diameter) up to 800 lb (19 in. overall × 17 in. diameter). The largest single-part Ariel machine is more than 13 ft long, 5 ft wide, and 4 ft tall.

Previously, hand gauging was used to verify smaller products, while larger products were verified directly on the machine tools—mostly CNC equipment. These methods were time-consuming and, more important, tied up the machine for inspection rather than production. This was a waste of both capacity and money. Also, by using the machine tool to inspect its own work, there was no independent verification of the readings.

“At Ariel, individual machinists are always expected to produce good products, but there are some geometric features that they can’t measure themselves at the machine tool,” says quality analyst Ned White. “At manufacturing’s request, the quality department instituted a program where we would verify parts off of certain machines. Under this program, we can provide a complete dimensional report in about 30 minutes. Previously, this was something that was not easily done.”

In addition to this in-house verification, Ariel also checks certain dimensions on every frame that is machined outside of its main facility in Mt. Vernon. Checking as many as 30 frames a week—taking two hours per frame or longer—is a full-time job for at least two people.

To implement this new program, Ariel considered adding additional hand gauging, height gauges, or even more people. The company also considered using a traditional coordinate measuring machine (CMM), but that was both cost- and size-prohibitive to its needs. Arial was looking for a device with a large measuring envelope, and the tolerance they hold ruled out using any laser scanning equipment.

Flexibility, portability, ease of use, and accuracy were the final deciding factors for Ariel. After looking at a couple of different articulating arm manufacturers, Ariel ultimately decided on FARO and its lines of portable CMMs.

What Ariel found at FARO was a full family of solutions to best suit specific needs throughout its facility. Each of the devices that have been implemented provide a true 3-D picture of what Ariel produces. In fact, the equipment gives the company a good, independent, 3-D verification of its machined parts. Taking coordinates and then comparing those readings to a CNC program is now easy and allows for simple corrections and offsets in the machining process.

The first solution implemented was the FARO Gage, a small, highly accurate (up to 0.0002 in.) articulating arm. Ariel uses two GagePlus units to pass/fail product in manufacturing. These units are used directly in the machining cells. Because of the similarity in design and the flexibility of the software, Ariel is able to use one custom tool for all of its connecting rods and crossheads.

The tool has also been used to assist in troubleshooting dimensional issues. By verifying and reporting dimensions of a feature after each step of machining, Ariel is able to pinpoint where and when in the manufacturing process a potential error could be made that would result in scrap. Not only is the measurement process fast, but the Gage also gives Ariel data that it simply couldn’t obtain any other way.

Ariel also has a FaroArm Platinum that it uses to measure “just about everything.” Specifically, the company uses the FaroArm in its inspection department to verify both incoming product and product made internally. For the internal parts, the arm is used to verify features that otherwise could not be checked, such as geometric dimensioning and tolerancing (GD&T) and larger dimensions where hand tools lose accuracy. They also use the FaroArm to assist with verifying machine tool adjustments as well as tracking any changes in machine accuracy. Parts off of certain machines are completely checked and verified at set intervals. This provides Ariel with a good history of what a particular machine tool is doing over time and helps them better plan preventive maintenance and repairs.

For parts that are too large to be easily measured with an arm, the inspection department uses the FARO Laser Tracker. The Laser Tracker is also used by maintenance for machine alignments and large dimensional verifications. As part of the product verification system using the FaroArm, the Laser Tracker is also used as a quick way to improve the consistency and accuracy of their machine tools.

“For us, the fact that both CMM solutions can run on the same software is a great feature,” says White. “It dramatically speeds up training and allows us to use pre-set inspection programs from either device interchangeably. Many of our parts are of a similar design—usually just different sizes—and so we can use the same program to measure all sizes within a family of parts. For instance, we can use the same program to measure six different frames—some with the FaroArm and the larger ones with the Tracker—all using the same program.”

One particular feature of the FaroArm that is especially beneficial to Ariel is its wireless capability through Bluetooth. A user can take a laptop and with the extended-use battery of the FaroArm they can literally climb up and into the machines and verify parts in production without having to take them off of the fixtures or worrying about tripping over any external cords or knocking over the computer. Ariel often needs to check just a few features on a part during the machining process and the wireless capability allows them to leave the part fixed in the machine for additional verification and saving them repeat setup time.

Ariel is leading the world in the development and utilization of new technology. They were an early adopter of internationally-recognized quality programs and both their design and manufacturing processes conform to the highest quality standards. It is then not altogether surprising that Ariel’s implementation of the technologies provided by FARO was quick.

In less than a week, Ariel was able to have the Gage up and running and used in production. The training of individual users in basic operations takes less than 15 minutes. The training to build custom tools can be done in less than an hour. Implementation of the FaroArm took less than a month and the Laser Tracker in even less time since it uses the same software as the FaroArm (FARO’s CAM2 Measure X).

Ariel uses their CMMs every day in production. They use their FaroArm several hours per week, while the Laser Tracker is used at least once a week for part inspection and several hours a month for machine alignments.

Checking the connecting rods used to take up to 30 minutes using traditional hand gauging. Using the FARO Gage has dropped that time down to under three minutes—a 90-percent time savings. Since 2009, Ariel has saved about 260 hours of inspection time using the Gage.

Checking the dimensions of every frame that is machined outside its facility used to take more than two hours per frame. Using the FaroArm, this time was reduced to just 20 minutes, an 85-percent reduction in time. Now, these verifications are a job that can be done in a couple of hours each day by one person. The process frees up valuable man-hours that can be better used on other projects and tasks.

Smaller frames were checked using a height gauge and hand tools and would take more than three hours to finish. These frames can weigh about 2,500 pounds and had to be rolled on their side to completely check the features. Not only was this time-consuming, it could also be sometimes dangerous. The FaroArm allows Ariel to check these same parts in just 20 minutes, a 90-percent reduction in time.

The larger frames used to take up to a full shift (10 hours) to check using a height gauge and hand tools. And that still did not give Ariel a complete picture of its part. Using the FARO Laser Tracker, this can be done in just two hours—an 80-percent time savings, including laser setup and warm-up.

“Using FARO has saved Ariel countless hours of inspection time,” says White. “The capabilities these devices offer really have no counterpart with other CMM equipment and provide us functions we did not have prior to acquiring them. Our process inspection time has been greatly reduced using FARO. In addition, the ability to save the inspection reports has allowed us to go back and review the initial measurement of some parts where we might have had issues during assembly. FARO has allowed us to focus our troubleshooting and best efforts in the right direction.”

Ariel’s traditions of quality and integrity have produced the best compressors in the world. Today, the Ariel compressor is considered the world standard for performance and reliability. Ariel continues to set the world standard in gas compression and is shaping the future of the compression industry.

About The Author

FARO

FARO develops and markets computer-aided coordinate measurement and imaging devices and software. FARO’s portable equipment permits high-precision 3-D measurement, imaging, and comparison of parts and compound structures within production and quality assurance processes. The devices are used for inspecting components and assemblies, production planning, 3-D documentation, as well as for investigation and reconstruction of accident sites or crime scenes, and to generate digital scans of historic sites. Principal products include the FaroArm, the FARO Laser Tracker ION, FARO Laser ScanArm, FARO Laser Scanner, FARO Gage, and the CAM2 family of advanced CAD-based measurement and reporting software.