- High precision and efficiency: Computer control manages position and speed precisely, enabling highly accurate machining. It handles prototypes as well as production parts.
- Complex shapes: Shapes and fine details that are difficult to produce by hand can be machined, and parts of many shapes and sizes can be produced consistently.
- Automation: Because the process is automated, operator workload falls while accuracy and productivity improve.
NC Machining
Overview of NC Machining
NC machining cuts metal and plastics to precise dimensions under numerical control. Tool paths are programmed, so complex shapes can be reproduced with high accuracy, which also suits high-mix, low-volume production.
Features of NC Machining
The NC Machining Process
The basic NC machining workflow is as follows.
- Design data: An NC program is prepared from 3D data designed in CAD (computer-aided design).
- CAM programming: CAM (computer-aided manufacturing) software defines the tool paths from the design data and generates the program for the NC machine.
- Machine setup and loading: The material is loaded into the NC machine and the tools and cutting conditions are set.
- Machining: Running the NC program, the machine cuts the material automatically to the specified shape.
- Finishing and inspection: Finishing is performed as required, and dimensions and quality are inspected.
Types of NC Machining
NC machining includes several methods, depending on the purpose and type of cut.
- Milling: A rotating cutter removes material. Suited to flat surfaces, slots, and complex shapes.
- Turning: The workpiece rotates against a stationary tool. Used for cylindrical parts and shafts.
- Drilling: A drill bit produces through holes and stepped holes in the material.
- Grinding: A grinding machine and abrasive wheel remove material precisely. Used for finishing and fine work.
- 5-axis machining: The tool moves with five degrees of freedom, including rotary axes, to machine complex 3D shapes in one setup. Used for demanding geometries in aerospace, medical, and similar fields.
Advantages of NC Machining
Suited to parts that demand high precision.
Consistent quality: Computer control keeps quality consistent from part to part, which suits volume production.
Lower labor cost: Automation minimizes manual work and reduces labor cost.
Complex shapes: Shapes that are difficult to produce by hand can be machined accurately, enabling complex, precise parts.
High productivity: The same program can be run for volume production, improving efficiency.
Key Points in NC Machining
- Tool wear management: High cutting speeds accelerate tool wear. Timely replacement and maintenance are required.
- Cutting conditions: Cutting conditions (speed, feed, depth of cut, and so on) must match the material and geometry. Poor conditions not only wear the tool faster but also affect finish and accuracy.
- Heat control: Frictional heat from high-speed cutting can affect dimensional accuracy and finish. Coolant and other measures keep the temperature under control.
- Vibration control: Vibration roughens the surface and reduces accuracy, so machine rigidity and secure workholding are essential.
- Program verification: Program errors cause machining mistakes and tool breakage, so programs are verified by simulation or trial cuts.
- Material selection: Choosing a material suited to machining is important. Some materials are hard to cut and consume tools quickly, so material is selected with care.
Typical Applications of NC Machining (industry-wide)
NC machining is widely used in the following fields.
- Automotive: High-precision parts such as engine components, gears, and shafts.
- Aerospace: Lightweight, complex parts, turbine blades, and structural components.
- Medical devices: Implants, prosthetics, and precision components.
- Electronics: Smartphone housings and precision case components.