ShopSolutions Case Histories of Manufacturing Problem Solving Tooling Improves Aerospace Shop’s Processes M
ikelson Machine Shop Inc. (South El Monte, CA) is a 100% aerospace contract manufacturer that con- tinually looks for ways to improve production of its highly complex manifolds, valve blocks, and other hydraulic aircraft components. Founded in 1953 by owner James Mikel- son’s grandfather in his garage, the shop occupies a 12,000 ft2 (1115-m2) facility and employs 26 people, including James Mikelson’s wife Josie, his son James and his fiancé Kathy, and daughter Jackie.
As head of Mikelson’s Continuous Improvement Depart- ment, Jackie Mikelson keeps a close watch on its part manu- facturing processes. In her role as process and improvement planner, she monitors all individual part manufacturing opera- tions, including evaluating part drawings, CNC programs, machine setups, and machining cycle times in an effort to reduce overall job leadtimes. According to Mikelson, his daughter’s work has paid off.
The shop’s overall leadtimes for jobs from start to finish have dropped from between 16 and 18 weeks down to 8 weeks or less. He credits a big part of this improvement to incorporating the best tooling possible for every part operation, no matter how secondary some of those may seem. “We have all high-end machine tools, and we don’t use run-of-the-mill tooling on them,” said Mikelson. “A general- purpose machine running general-purpose cutting tools will yield general-purpose results. We’re doing a lot of high-feed milling and plunge milling as a result of our customers transi- tioning from castings and forgings to components manufac- tured from solid block and bar materials. And those machin- ing techniques require advanced tooling, which is why we get almost all of our tooling from Seco Tools.”
Mikelson family continues tradition of aerospace shop man- agement: Front row, James Mikelson (left) and son; front to back: wife Josie; daughter Jackie; son’s fiancé Kathy.
Mikelson uses Seco’s high-feed/plunge cutters, aluminum router cutters, solid carbide drills for hole sizes from 0.070 to 1.00" (1.8–25.4 mm) in diameter and indexable tooling for 0.750 to 4" (19-101.6-mm) diameter bores 8" (203-mm) deep. In addition, the shop runs Seco 4" (101.6 mm) and 5" (127-mm) disk cutters, square-shoulder slotting cutters, Jabro solid-carbide end mills from 0.039 to 0.787" (1–20 mm) diameters, thread mills, shrink-fit toolholders, and Seco’s Jetstream tooling high-pressure coolant-delivery technology for turning operations.
For a long time we operated under the assumption that we knew everything about cutting tools and how to use them
Job lot sizes are typically 8–48 pieces, and the lion’s share of Mikelson’s part processing is milling on five-axis horizon- tal machining centers and four-axis horizontal and vertical
When considering the incorporation of a new tooling
technology, Jackie Mikelson evaluates it by comparing previous runs versus runs with the change in tooling to determine if a
machines. Components are made from nitride and carburiz- ing steels, stainless steels such as 15-5 and 17-4, and 6061, 7075, and 2024 aluminum. Part sizes range from 2 to 14" (51–356 mm) and 10" (254-mm) long, with required toler- ances between ±0.001 and 0.00005" (0.03–0.001 mm) and surface finishes from 32 to 2 Rms.