High speed machining typically refers to making light milling passes at high spindle speed and feed rate to achieve a high metal removal rate. This practice can be effective for machining intricate core and cavity geometries in mold machining, and for quickly machining large, complex aircraft structural components out of solid blocks of aluminum.
High speed machining is a hot topic. But, is it simply running at maximum feed rates and taking multiple shallow passes? This strategy is often less efficient than taking few passes at slightly greater depths! Achieving the shortest cutting time is related to feed rate, but the relationship is not necessarily ‘fastest feed rates = most efficient.” High-efficiency machining, cutting a part in the least amount of time, is the real goal. The key to achieving high-efficiency machining is to vary the feed rates to achieve the result each cutting condition encountered.
For most steel parts that are quenched to about 32-42 HRC, the current cutting options include:
• Roughing and semi-finishing of materials under soft (annealed) conditions
• Heat treatment to a final hardness of 63 HRC
• Electrode machining and electrical discharge machining (EDM) for some parts of the mold
• Finishing and super finishing of cylindrical/flat/recessed surfaces with a suitable cemented carbide, cermet, monolithic carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN) tool
For many parts, the production process involves a combination of these options.
HSM prefers to combine roughing and finishing passes. This is really only possible with higher speed spindles, so if you're trying to get by with a slower spindle, you'll have to split into the more traditional roughing and finishing passes. For the finishing pass, use tooling with as many flutes as possible. Finishing assumes all the inside corners have been roughed out, so there will be plenty of chip clearance available. The more flutes you have, the faster you can feed through the work for a given chipload. Hence, productivity goes up. The only reason to use fewer flutes is to improve chip clearance.
As a CNC Machining Supplier, ByTune can make complicated parts with high speed machining in accord with your drawings and samples.