Hundreds of work hours can be saved by using horizontal high-speed machining.

Continuous improvement is a state of constant change. Blair-HSM South has learnt this lesson directly, with the Wilmington, North Carolina-based shop’s ambitious overhauls of its people and machine strategies reaping benefits in terms of efficiency, retention, and profits.

Blair-HSM South was established in the early 1990s as a satellite shop for a Long Island aerospace manufacturing company. This shop was designed and operated by management to be a low-cost facility. The approach at the time, according to Jim Flock, the facility’s general manager, was “just getting warm bodies to press buttons,” with tasks that required more ability being dispatched to the Long Island location. Retention was dismal, with most employees moving for other opportunities as soon as they gained sufficient experience.

Flock was hired in 2015 to replace the facility’s previous manager, who was retiring. Around this time, upper management in New York began to shift its perspective and wanted to begin establishing its satellite site. Flock spearheaded this effort, advocating for more training, better pay, and additional benefits. Employee retention improved as a result of higher employee satisfaction, and the machinists at Blair-HSM South were better positioned to optimise their process.

When the Magnaghi Group (MA Group), a firm situated just north of Naples, Italy, purchased Blair-HSM, this transition accelerated. Blair-HSM has a long history of serving the defence markets, which MA Group hoped to expand into. Since then, the shop has used this push to improve inspection and quality standards, work conditions, repeatability and efficiency, and other areas that Flock and Blair-HSM’s management had identified for improvement.

Blair-HSM South now employs 16 employees, including eight machinists, two deburring specialists, four inspection personnel, one part-time trainee, and Flock. With such a small staff, Flock says cross-training is the norm, which has aided in filling in when employees take sick days or vacations.

In recent years, the breadth of what these staff handle has likewise expanded. Blair-HSM South has traditionally employed lathes, vertical mills, and manual machines, but its most recent efforts have concentrated on three Niigata horizontal machines: one HN63D with two pallets, one HN80D-II with eight pallets, and another HN63D with ten pallets. While the shop’s small lot sizes (20 pieces may be a large lot for the shop at this time) prohibit robotization, these pallets have allowed the shop to undertake some lights-out work. The controls on the machines have enabled an equally significant shift for the shop: high-speed machining.

Whole-Hog to High-Speed Milling High-speed machining began replacing hog milling techniques in eight separate parts last year. The first was machining the forging of an F-35 torque arm, a regular item for the shop. Hog milling made wide cuts around the part but was a sluggish solution, whereas high-speed machining made tiny, considerably faster waterfall cuts.

When Flock initially started at Blair-HSM South, hog milling these torque arms took 20 hours. Since then, optimisations have reduced hog milling cycle times to around six hours. While this was an improvement, the shop still had backlogs during times of strong production demand.

Finally, Shop Foreman John Lent and Production Manager Josh Garrett started looking into high-feed machining processes as a possible option. Garrett conducted time analyses after Lent chose adequate tooling and discovered that high-speed machining may reduce cycle durations to between 30 and 40 minutes.

Using high-speed machining on one version of the torque arm saved 824 hours per year. On the other hand, switching from an expensive hog mill — and the regrinding processes required to keep it running — to milling inserts saved $11,500 in tooling per year. It saved roughly 101 working days for the entire portion family.

While not every part in the original part family had a major improvement in cycle time and tooling cost, all of the parts saw some improvement. As a result, expanding the usage of high-speed machining to other part families is one of the shop’s 2023 priorities.

Manual Labour, Lights-Out, and the Need for VMCs
Blair-HSM South will be unable to substitute horizontal high-speed machining for all of its current milling activities. For starters, some of the parts handled by the shop are too heavy for the pallets. Others just require tooling holes to allow machinists to clamp ODs and IDs on both sides of the item.

These and other procedures are handled by the shop’s vertical machining centres. While the OKK HM-600 machine is used for holes, the shop’s machinists can use the rotary table on its Yama Seiki VP 2012 HD to machine flat surfaces on circular parts or simply to machine many sides of objects in a single clamping.