CAM Software Plays Key Role in Shop’s 5‑axis Aerospace Machining Success

Linda Tool, a New York City machine shop, was searching for a solution to successfully machine 7075 aluminum landing gear forgings. They were evaluating hyperMILL^®, and focused on the hyperMILL^® MAXX Machining features, which was highly recommended, and learned that one of it’s innovative programming features was the ability to dramatically drive increased material removal rates via conical barrel cutters.

To grow in today’s manufacturing world, shops need to consolidate operations, automate, increase ef­fi­ci­en­cy, capture and analyze data and more, in order to fully leverage opportunities in thriving industries such as aerospace. Accomplishing this requires not only high precision equipment and advanced technology. It also requires a well-defined strategy and process approach. This is precisely the route that Linda Tool, a New York City machine shop traveled, even amid the throes of the great recession.

Mr. Mike DiMarino, owner of Linda Tool, reached this conclusion in 2008 when manufacturing, like many other industries, languished severely. “At the onset of the great recession when business had slowed to a trickle, we realized that the old model of one operator per machine was totally unsustainable,” said DiMarino. “So we took a long hard look at our situation and decided if we were to have a future, a totally new strategy would be required. “One of the initial triggers leading to this realization was driven by a decision we made to pursue more advanced machining after we were given an opportunity to make parts for a large aerospace supplier” continued DiMarino. “Although there was certainly an element of risk, we decided to go all in, become a qualified dock-to-stock aerospace tier-two supplier and be AS9102 certified.”

A lofty goal such as this would require many moves, beginning with 5-axis machining and advanced tooling. For a shop whose mainstay was turning, with secondary milling operations on conventional VMC’s, this was a major step. Unwavered, DiMarino plunged ahead and acquired the necessary technology. In the process, he and Mr. Dave Holmes, Linda Tool’s Production Manager, would learn that in addition to 5-axis and innovative tooling, aerospace machining success is equally impossible without the right CAM software program to execute the work.

Defying the Norm

Whether its precision machining in New York City, attaining eco-friendly status, or making about-face decisions during the great recession, Linda Tool defies the norm. Founded in 1952, today the 28-person shop, knitted into the Red Hook section of Brooklyn, is a quiet, inconspicuous building at the curb. But once inside, there is a hum of precision in the making from the packed shop floor’s state-of-the art equipment that ranges from 3, 4 and 5-axis machining centers, to multi-tasking lathes, CMM’s and more, for handling a steady flow of aerospace and defense, industrial, medical, oil and gas and communications work. What’s literally above the shop is even more interesting – the entire rooftop consists of a garden where employees grow vegetables and flowers in engineered soil. Linda Tool strives to have a small carbon footprint. All machines are equipped with mist collectors, an HVAC system with HEPA filtration runs around the clock, the green roof enables heating and cooling energy reductions, and all waste is recycled.
Perhaps the most important element of Linda Tool’s unconventional approach is the production process itself, which starts at the end, not the beginning. “A key facet of the new strategy we deployed in 2008 was to first carefully determine the finished part, and then map out every step throughout the shop that is required to ensure the part meets or exceeds spec,” explained Holmes.“ It begins when we decide to make the part and every step in the process throughout the whole shop is documented, saving time and maximizing quality and throughput. We work in teams, applying a manufacturing process approach.”

New CAM Solution to Discover A New Angle

The process approach is what led to Linda’s search for a solution to successfully machine 7075 aluminum landing gear forgings. “When a big aerospace opportunity came our way – a horseshoe-shaped planar part with tight pocketed inside corners, we tried to figure out a way to efficiently machine the part by face cutting, swarf milling or using a ball nose end mill,” said Holmes. “We had invested in leading 5-axis technology with a Hermle C22 machining center, the best machine for the part, but we weren’t sure how to attack it. We needed a more practical solution for maximum throughput and efficiency. We were evaluating the advanced CAM software package called hyperMILL^® from OPEN MIND Technologies, and focused on the hyperMILL^® MAXX Machining features, which was highly recommended, and learned that one of it’s innovative programming features was the ability to dramatically drive increased material removal rates via conical barrel cutters – also known as circle-segment end mills.” OPEN MIND developed the concept of conical barrel cutter machining with tapered tools that also have a large radius ground into the taper. Ultimately, the software combined with the end mills, shaves off up to 90% of the time it takes to machine conventionally with ball nose tools.
The Emuge Circle Segment end mills feature a conical form ground into the cutter blank which is further shaped with an extra large radius. The large radius in contact with the material dramatically reduces the number of stepovers required, because much wider paths can be made in each tool pass, removing more material per tool path on planar surfaces, ruled surfaces and inside pockets.
“We worked closely with Emuge and OPEN MIND to program the part and make test cuts” said Holmes. “We wanted a highly efficient, stable process and it fully worked. We were very pleased.”