20 Jun 2012
Aerospace engineering at AeroCison
American sub-contractor says choosing the right CNC machine has been key to the company’s success
The development of numerical control (NC) is closely linked to the rise of the aerospace sector in the USA, and to resolving the technical challenges faced by engineers as they designed and developed aircraft to fly further, faster and higher — and with greater safety.
The aircraft builders put pressure on their suppliers, and for a while the technical challenges out-stripped manufacturing capability. It was in the 1970s that with the availability of low-cost microprocessors saw NC evolve to become CNC, and thereby allow manufacturing technology and aircraft design to progress apace.
Today, air travel is burgeoning, aircraft and engines are becoming more efficient and reliable, and airlines are buying planes in greater numbers. As a result, parts manufacturers willing to invest in the right technology, people and processes, can find themselves working for some of the biggest and best-known names in the sector. When Connecticut-based AeroCision was founded 50 years ago, the company’s owners relied mostly on local business for their livelihoods; it is unlikely they would have thought that one day the company would be making parts for the latest passenger jet engines, let alone for a customer more than 3,000 miles away.
AeroCision’s CEO, Andrew Gibson (right), says: “There are no borders any more. When my business partner and I took over this company a few years back, the big names in the aerospace sector were rationialising their supplier lists. To have a chance of being on a short-list meant investing heavily in quality control, new-product introduction processes and the best-available machining technology. It didn’t matter to the customer that we are here in Connecticut, it only mattered that we could achieve the precision, quality and efficiencies that they were demanding.”
AeroCision specialises in turned ‘ring’ parts for turbofan engines — parts that are typically between 150 and 750mm in diameter. Operations manager Glen Fournier says orders for the larger components are becoming more common, simply because engines are getting bigger. “We’re making turned and milled parts for the hot areas of a high-bypass aero engine built by a major engine manufacturer. These are the engines being used to power the large new planes such as the Boeing 787.”
AeroCision’s workshop is spotless, as you’d expect from a company with aerospace standards. The company has two Haas-based manufacturing cells (www.haascnc.com), one with CNC vertical machining centres, the other with CNC lathes.
Mr Fournier says: “Two of the most important things for us and our customers are on-time delivery and zero defects. There are strictly applied penalties for not delivering on time, so the biggest challenges for me are scheduling, controlling and reducing set-up and cycle times. Speeds and feeds are critical, because there’s a lot of material removal. Our runs are normally 20-25 pieces, so we need to be quick when we’re changing set-ups. The larger parts necessitate well-designed set-ups and shuttle plates, and our latest Haas machines have tool setters. We’re also moving towards SPC and certifying our operators as inspectors, which will help us enormously. SPC will allow us to gather appropriate data, and we’ll be able to chart out trends live on the shopfloor screens. On-machine probing will allow us to measure the parts and send those measurement to our
database, so the operators will be able to move the parts through the shop that much more efficiently.”
Live schedule downloads
AeroCision has a continuous and live link to its UK customer, whose system downloads a schedule to the company every Monday morning. The data is imported into AeroCision’s ERP system, allowing people, machines and other resources to be scheduled for the week.
During the development phase of one particularly complex ring-part, Mr Fournier managed to develop the process and have the first-off component made well ahead of schedule. “We took the job on in the October, and it was supposed to be delivered in April of the following year, but we had the first finished part ready just before Christmas. We had all four Haas mills running but needed more turning capacity, so we bought some Haas ST30s. We took a photograph of the guys on the shopfloor holding the part and sent it to the customer with the message ‘Happy Christmas’! They were very pleased.”
Mr Gibson believes that choosing the right CNC machine tools was critical in enabling AeroCision to exceed customer expectations, adding that such choices will be just as important for the future success of the company. “Many of the large aerospace companies are sourcing parts from lower-cost regions. We have to focus on making higher-value more-complex parts and assemblies and using our resources to make the processes more efficient. Our parts are complex and difficult to make, and tolerances are very tight, but having a robust and reliable process means that we can still be strong and competitive in Connecticut.”
Guy Nigro, AeroCision’s lathe cell supervisor, says: “We had been using Haas SL lathes for five years, and in all that time we didn’t have any problems. They were good, rigid, reliable machines, but our new ST lathes are even better. They are more rigid, which means we can easily achieve tolerance on materials such as Inconel. They are also easy to programme, either manually or from our programming room — and they are straightforward to operate.”
In conclusion, Mr Gibson says: “When OEMs rationalise their supplier bases, there’s usually only a brief opportunity for a company to be included. Our customers are moving some of their production and assembly to countries like India, where they will build for the local market. We hope to move with them, setting up new, adjacent facilities, so we can deliver parts quickly and to the same high-standards they expect from this plant. We also want to use Haas CNC machines wherever we are in the world.”