Return on Investment

Alphacasting used Creaform’s HandySCAN 7000 handheld scanner to perform inspection on the Lube and Scavenge pump.

Original equipment manufacturers (OEMs) and suppliers in the aerospace industry are faced with more stringent standards than ever. The tight tolerances mean that even the slightest offset can render a part ineffective. This production requirement became critical when Alphacasting, a Quebec-based precision investment casting company, was contracted to investment cast the Lube and Scavenge Pump for General Electric’s Passport Engine.

Ultimately destined for duty on the Bombardier Global 7000 and 8000 series business jets, the pump collects oil from the engine, filters it and then distributes it into the various engine bearings during operation. According to General Electric Aviation, the part is integral to the Passport Engine’s performance. Capable of producing 16,500 pounds of thrust, the engine incorporates advanced technologies and materials to provide 8 percent lower specific fuel consumption than engines in its class, while also meeting CAEP/6 emissions and Stage 4 noise regulations.

Traditionally, heavier walled sand casting had been used to produce this part. However, Techspace Aero – the Belgium-based Safran Group subsidiary responsible for designing the Lube and Scavenge Pump housing – needed a better solution to improve part quality and meet General Electric Aircraft Engines’ requirements. As a result, they reached out to Alphacasting.

“The design is challenging to manufacture due to thin walls, complex cores and inaccessible areas for inspection,” explains Steven Kennerknecht, VP of Engineering for Alphacasting. “We can offer thinner walls, better surface finish and tighter geometric tolerances. All these factors save weight for the engine accessory.”

Kennerknecht says the Lube and Scavenge Pump is investment cast in A357 aluminum alloy and heat treated to yield optimal strength. However, to produce to design specifications, multiple iterations were undertaken to correct manufacturing inconsistencies. Each iteration underwent rigorous inspection it to ensure the final part met requirements.

The Passport 20 Engine’s Lube and Scavenge Pump housing – courtesy of GEAE – required tight tolerances to meet GE exacting specifications.

Geometry was verified using traditional tools such as coordinate measuring machines (CMM), x-ray, functional gauges and calipers. However, with so many iterations, Kennerknecht needed a new approach to shorten development time and part verification.

“It is important to take measurements of each iteration during the development of a new casting—particularly one as highly complex as this one—to better understand the impact of previous changes and determine what modifications need to be made for the next iteration,” Kennerknecht explains.

Alphacasting turned to Creaform’s HandySCAN 700 handheld scanner for quality control on the Bombardier project. This laser scanner allows Alphacasting to gather a complete 3D map of the entire part surface and analyze whether the surfaces are either nominal or on the high or low side of the tolerance envelope.

“Having this information during the development phase allows [us] to fine tune the molds and bring the process as close to nominal as possible…The quality of the scanned data enabled us to make better decisions and reduce development time,” Kennerknecht says.

The scanning process was done with the HandySCAN 700 along with the C-Track dual camera system. The output of the scan is an STL file. Alignment is used between the STL file and the CAD model with reference targets. A data color map is generated and shows deviations between the scan data and the CAD model. Alphacasting uses the scans to see areas of the part that lack material or have an overage of material.

“The color representation allowed the team to quickly evaluate the part geometry and make improvements to the process if needed,” Kennerknecht adds. “Scanning and processing the part was quick, but most importantly, the colored surfaces were easier to interpret than gauges or CMM reports.”

Alphacasting was able to manufacture the Lube and Scavenge Pump housing for Techspace Aero to the tight tolerances required for aerospace quality control with the help of Creaform’s HandySCAN and metrology services.
After the successes of this project, Kennerknecht says the company is transforming its manufacturing processes to take advantage of digital technology including rapid prototype patterns, robotic manipulation, radioscopic digital x-ray and CT inspection, as well as now laser scanning of the part surface.

“Laser scanning is an important tool in our toolbox, both for part development as well as production tracking and product validation.”

www.creaform3d.com