Precision in a High Stress Environment

C/A Design utilizes Kitamura machines to remain efficient in the demanding aerospace industry.

In the heat of an aerospace mission, where high stress loads can test both man and machine, failure is simply not an option. Every single component has to work at least to specification, making the margin for error nano-thin.

As a result, the stresses associated with aerospace components aren't limited to the battlefield.

For the process of manufacturing the parts used for aerospace defense communications, countermeasures, jamming, recon and homeland defense create their own types of stress.

"Very tight, true positioning tolerances coupled with short production runs and even shorter delivery times can strain the capabilities of any shop if you're not set up properly," says Bob April, a principal with Dover, NH-based Costello and April Design (C/A Design). "Aerospace manufacturing really challenges you to have your act together."

Managing the Stresses

Founded in 1993, C/A Design specializes in electronic enclosures, liquid and air-cooled compact heat exchangers, and other small- to medium-size components for the aerospace industry.

The company provides both design engineering assistance and CNC machining/ production to its customers. It also has a full aerospace-oriented test lab and metallography lab to go along with a customer list that includes most of the top defense contractors in the U.S.

The tight, true positioning tolerances required for most of its work are the result of the additive effect of the way the finished parts are used.

"If there are 30 components to an assembly, the tolerances stack up," April says. "If everything runs on the high side of the spec it throws off the final unit. You have to be able to hold extremely tight tolerances in the manufacturing process to deliver a finished product that performs as required in the field." Because the work they do is highly specialized, most of the components they machine have small lot sizes - 100 parts or fewer. Yet production schedules often segment themselves even further.

"More often than not, the cycle times for delivery are complex," April says. "A customer may place an order for 100 pieces, but can't wait for the first 50 to be delivered.

They may ask to receive three or four in advance so they can test them. These extremely short runs can make it difficult to operate efficiently if you're not prepared to handle them." Prototypes of new, complex designs further add to the scheduling challenges.

These one-off projects have to be scheduled in between regular production runs.

Yet the long setup times that are often involved make it difficult to plan and execute without disrupting regular production.

After reviewing job flow data, it became apparent that C/A Design needed to find a more efficient way to manufacture than was possible within the confines of its current machining center configuration.

Kitamura Helps C/A Fly High

"Ours is a multi-tasking environment," April says. "We need to have some jobs running, others being set up, and a group standing by ready to run at any time. Naturally, that means having machines with pallet systems. We also need to know that when a repeating job comes up in the queue it will run with tight tolerances every time, without any extra effort. That requires a machining center with quality construction.

It needs to be capable of handling everything from low-torque cutting of heavy aerospace materials to highspeed machining." After looking at products from several manufacturers and comparing features and construction, C/A Design chose Kitamura.

"The quality of Kitamura machining centers is outstanding," April says. "They still hand-scrape the mating surfaces of every component to assure a proper fit, which minimizes vibration. Their solid boxway construction further minimizes vibration, while the geared spindle head allows us to increase cutting speeds and feeds, improving productivity. The geared head also allows us to work a wider range of materials and job types on one machine than we would be able to with a direct drive spindle." One feature C/A Design has taken advantage of is the high speed machining option - another function of the geared head.

April says the shop performs a lot of this type of work, and being able to do it on a machine with this high level of quality has been a large factor in the company's ability to produce tight tolerance work more quickly and accurately than before.

From a pure productivity standpoint, however, it is the factory-installed pallet changer systems that have made the most significant impact. C/A Design uses mostly two-pallet, shuttle-type changers on their Kitamura machining centers, although they do have one rotary type. The preference for shuttle-type is driven by the non-stop nature of the work.

"One of the pallets is for prototypes or short runs, while the other is for production," April says. "We use a lot of remanufacturing techniques so we can have multiple jobs ready for a machine at any given time.

C/A Design specializes in electronic enclosures, liquid and air-cooled compact heat exchangers, and other small- to medium-size components for the aerospace industry.

We can start with a production run on one pallet, then perform an inspection of the first piece while a prototype is being run. When we finish the prototype, we can go back and complete the production run, often at night when we have half as many people running the entire shop. We can also leave a particularly difficult short cycle time job set up on one pallet until we need it while we run other jobs on the second. It's made us very efficient." C/A Design is currently using eight Kitamura machining centers on the shop floor. These units include a Mycenter- 2XiFSP, a Mycenter-3X/APC, three (3) Mycenter-3Xi/APCs and a Mycenter- 3XiF/APC verticals, as well as two Mycenter- HX400iF horizontal machining centers.

According to April, the horizontal units can handle a minimum of eight different products between the two pallets, and as many as 20.

Blue Skies Ahead

The switch to Kitamura machining centers has had the desired results. Since adding the units, C/A Design has increased production capacity by 30% or more, without having to add staff to run the machines, and most importantly, without sacrificing quality. In fact, if anything, the ability to hold tight tolerances has improved along with the output. This has made April a very satisfied customer.

"After what these machines have done for us, we wouldn't think about changing to another brand," he says. "We've had other machines, and none of them could match what the Kitamuras are able to do.

I've also looked at more costly machines, and they don't do anything our Kitamuras can't do either. So why would you pay more for the same level of quality and productivity? When you come right down to it, you get a lot for the money."

Kitamura Machinery of USA, Inc.
Wheeling, IL
kitamura-machinery.com

Costello and April Design (C/A Design)
Dover, NH
c-a-design.com