Achieving precision at mach speed: tale of two companies has down-to-earth message.

Precision is a word that's thrown around a lot in manufacturing. Nowhere are the requirements and challenges for precision higher than in aerospace machining.

Despite their complex geometries and often ultra-thin tolerances, parts manufactured for the aerospace industry frequently have to stand up to high stress loads and vibration levels while surviving extreme environments. These factors--and the reality that some parts could wind up hundreds of millions of miles from earth, where there are no options for repair--make the margin for error nano-thin.

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Adding to the challenge is the fact that because they are used in such specialized, low-volume applications, more often than not these difficult-to-machine parts are manufactured on a just-in-time basis.

The aerospace industry is not something an operation jumps into on a whim. It takes the right combination of expertise, experience, and equipment to be successful.

Here are two companies that have built successful businesses serving the aerospace industry, and the steps they have taken to ensure that business keeps growing.

Costello and April Design

There is no margin for error when it comes to the work of Costello and April Design, an aerospace manufacturer that specializes in electronic enclosures, liquid and air-cooled compact heat exchangers, and other small- to medium-size components.

The nature of the business requires an ability to deliver precision parts reliably, handle multiple runs and set-ups--often at the same time--and the versatility to process a variety of jobs.

Founded in 1993, C/A Design provides both design engineering assistance and CNC machining/production to customers. Its Dover, NH, facility also has a full aerospace-oriented test lab and metallography lab. Its customers include many of the top defense contractors in the United States.

The majority of C/A Design's work requires tight, true position tolerancing. Much of this requirement is driven by the additive effect of the way the finished parts are used, says Bob April, one of the principals at C/A Design.

"If there are 30 components to the 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 remains within spec."

Small lots, big challenges

Because most of the machining that C/A Design performs is highly specialized, the lot sizes for a given finished part tend to be small--100 pieces or fewer. Parts themselves are complex, typically requiring time-consuming setups by highly experienced operators. These two factors, lot size and time, work against each other when trying to run an efficient operation.

Production cycle times are an additional issue that must be addressed.

"More often than not, the cycle times for delivery are so complex," April says. "A customer may place an order for 100 pieces, but can't wait for the first 50 to be delivered. And they may want three or four to test ahead of receiving the initial 50. That was a huge strain on our people and our profitability with the machines we were using."

Further complicating scheduling matters is that C/A Design regularly runs prototypes of new, complex designs, which have to be squeezed in between production runs.

"Whether it's a prototype or a production run, it still takes a given amount of time to set up and produce a finished piece," April says. "The constant stop-start was getting out of hand."

After reviewing job flow data, it became apparent that C/A Design needed to find a more efficient way to manufacture in order to thrive and grow in this demanding business.

Redefining space and time

When C/A Design started researching which machining centers could handle the company's most challenging work, it identified three absolute requirements:

* The machining centers had to be manufactured to the highest quality standards in order to deliver the precision parts while running reliably over many years.

* The pallet-changing system had to handle a run and a set-up simultaneously.

* The versatility to run a variety of jobs, from low-torque cutting of heavy aerospace materials to high-speed machining, was nonnegotiable.

After looking at the offerings from several manufacturers and comparing features and construction, C/A Design chose Kitamura.

The machining centers include six vertical units: a Mycenter-2XiFSP, a Mycenter-3X/APC, three Mycenter-3Xi/ APC's and a Mycenter-3XiF/APC, as well as two Mycenter-HX400iF horizontal machining centers.

C/A Design uses mostly two-pallet, shuttle-type changers on the Kitamura machining centers, although April says there is one rotary type. The preference for shuttle-type is driven by the type of work the company does more often.

Since adding the Kitamura machines, C/A Design has increased production capacity by 30 percent, all without having to add staff to run the machines and without sacrificing quality. In fact, if anything, the ability to hold right tolerances has improved along with the output--an important factor considering how critical are the components C/A Design manufactures to aircraft.

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St. Vrain's story

Raw materials are costing more than ever these days. However, for St. Vrain Manufacturing Inc., those materials can cost over $10,000 per piece. Getting it right quickly isn't enough. It has to be done right the first time.

St. Vrain is a company that performs prototyping and precision machining for the aerospace and medical industries, including Lockheed Martin Coherent Technologies, the National Center for Atmospheric Research, ATK Aerospace Co., and Starsys Corp.

The bulk of the Longmont, CO-based manufacturer's machining work is for space flight parts, satellites, and instrumentation. St. Vrain manufactured parts for both the Spirit and Opportunity space rovers on Mars.

"Some of the parts we're building are pushing the limits of the industry," says Bob Bergstrom, president of St. Vrain. "They have to be able to handle the unknown, and we have to be able to build to that.

"If a part on a Mars rover breaks, it's not like you can just pull it into the hangar and replace it."

Long setups

One of the great challenges St. Vrain faces as a manufacturer is the long setup times required for many of the parts it machines versus the small number of parts that are made once setup is complete.

"Once, we did a cover for a large aerospace manufacturer that was 15x12x3.5" and 0.040" thick," recalls Bergstrom. "It had a dome top and square radiused end with a flat back. We had to do 3D surfacing with screw threads on the inside with ports.

"It started out as a 127-pound piece of raw material and finished weighing just 1.5 pounds," he continues. "To make two parts, it took 200 hours total, most of which were for setup, although there were also six operations. This project was an extreme, but it gives you an idea of what we face on a regular basis."

Another challenge St. Vrain faces daily involves the materials, such as titanium, Invar and hardened stainless steel, used for many aerospace parts. As the difficulty involved in manufacturing the parts grew and customer lead times shrank, Bergstrom, operations manager David Lindsay, and shop supervisor Tim Henker determined that they needed to upgrade the available machinery in the shop.

One of their biggest goals was to find machining centers that would handle not only their existing jobs, but could also grow with the business.

Getting it right

"When we looked closely at our business, we realized we needed versatility in addition to quality and productivity," says Lindsay. "We needed machines where you could quickly move from aluminum one day to a titanium piece with a 2-inch cutter and rough with it the next day. And we needed to do this without sacrificing accuracy or compromising on either end."

Rigidity was also a key consideration in the machining center selection. Whether for high-speed, high production runs or low-speed, high-torque applications, any machine had to have a high degree of rigidity in order to satisfy the demands of the jobs they were running. St. Vrain found that Kitamura machining centers met those strict criteria.

The company purchased the HX400iF with its standard two-station automatic pallet changer, which has made a difference in productivity in two ways. The team can set up some of the low-volume, repeatable jobs once, and then run them again as needed. It also minimizes the time for work in progress.

Confidence is high

Adding the Kitamura machines has had a direct impact on not only the jobs in-house, but on the overall business.

"We have one project that we were running on a non-Kitamura vertical machine before," Bergstrom says. "It involved lots of 500 to 1,000. Eventually, though, we lost the business on the basis of price and efficiency. Since adding the Kitamura HX400iF horizontal unit, however, we have won that business back."

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The HX400iF has also allowed St. Vrain to move into lights-out manufacturing. Although the machine runs 24 hours a day, it is only attended for eight. That has created a huge improvement in productivity, allowing St. Vrain to lower its price on certain jobs to be competitive without sacrificing profitability. The company is looking for more of that type of work as well.

"The raw materials for many of our jobs cost well over $10,000 per piece, so getting it right the first time is critical," Bergstrom adds. "No shop can afford to redo a job like that. With our Kitamura machining centers, we know our finished products will hold up, not just on the test bench but in deep space."

Kitamura, www.rsleads.com/811tp-194