When referring to CNC machine tools, the term high-speed machining (HSM) usually means making products or prototypes rapidly by using milling machines at higher spindle rates with lighter, shallower cuts to achieve greater metal removal rates and lower operating costs.
How Did HSM Develop?
HSM grew out of CNC techniques developed in aerospace manufacturing at companies such as McDonnell Douglas (now part of Boeing). Originally, one of the reasons for using HSM was to machine at specific speeds that would avoid what’s known as “chatter” (machine vibration that can become noisy and/or violent) by taking advantage of milling at natural frequencies. By keeping high speeds stable, parts could be more milled more accurately and have less “ribs,” resulting in a lower weight. Lighter parts meant less heavy, more efficient aircraft. The goal for McDonnell Douglas became reducing the weight of many of its sheet metal parts and combining pieces together for even more efficiency. Eventually, so dramatic was the success of HSM that a jet that formerly was built with 14,000 parts now required only half that number. This greatly reduced costs and allowed speedier production of finished airplanes. As such, HSM became an assembly solution for McDonnell Douglas and eventually other aircraft manufacturers.
What Makes HSM Effective?
Although it may seem counter-intuitive, the way HSM works is that a higher machine “spindle rate” (measured in rotations per minute of the tool) combined with lighter cutting will actually remove more material faster than slower spindle rates and heavier cutting. Lighter cutting also means more efficiency from a power perspective — some CNC machines may be rated at a high horsepower but can become overloaded if their cuts are too deep.
With HSM, cutting temperatures are actually reduced; surface finish is also improved, and the machines’ spindle and cutter acquire less wear-and-tear over time. This is especially true with harder materials. Cutting becomes more consistent and more reproducible. Often, HSM combines the roughing and finishing passes that are normally separate at lower speeds. This means that throughput generally increases when HSM is applied to process workflows.
What Are the Benefits of HSM?
In mold making, HSM allows for intricate cavity and core geometries and can enable the quick machining of large, complex components out of solid blocks of material. Material walls can be made very thin, and edges can be very sharp. Accuracy and precision are improved, and time spent polishing surfaces can be reduced. Automation can be improved because errors and interruptions are fewer. Molds and dies have more durability because fatigue cracks are lessened, hence there’s less risk of breakage. Assembly of finished products often can go faster. In general, customers are very satisfied with the output of pieces produced with HSM.
How Has HSM Helped Tag Team Manufacturing?
At Tag Team Manufacturing, HSM has allowed us to boost our capacity and handle more orders in a shorter timeframe. This, combined with our sophisticated MasterCam CAD/CAM programming system, makes us the leading provider of machined components in the Denver, Colorado region.