1.Principle of primary before secondary: Process the surface of the workpiece and assemble the base surface first to promptly detect any surface defects. Then proceed with secondary surface machining.
2.Principle of base surface first: Machine the precise reference surface first, as more accurate positioning reference surfaces result in smaller clamping errors.
3.Principle of surface before hole: This principle applies to parts like brackets and enclosures. It is recommended to machine the flat surfaces first and then process the holes. Since the workpiece's flat surface is large and smooth, it serves as a stable and reliable reference to ensure the positional accuracy of the holes and surfaces.
4.Principle of rough before finish: Sequence the machining operations of roughing, semi-finishing, finishing, and polishing the workpiece surfaces. This approach gradually improves machining precision while reducing surface roughness.
5.Principle of internal cavity before external shape: Prioritize machining the internal cavities first, followed by clamping on the external shape. Then machine the outer profile, utilizing the holes in the internal cavity for clamping.
6.Principle of process concentration: Concentrate the machining operations within a few processes. This ensures production efficiency, reduces the number of clamping times, maintains the positional accuracy between surfaces, minimizes tool changes, shortens auxiliary machining time, and decreases the number of operators required for CNC machining centers.
7.Lastly, prioritize the sequencing of multiple operations conducted during the same setup based on the minimal risk of workpiece rigidity failure.
