Randoverfrezen

Randoverfrezen is a term found in some Dutch-language discussions of CNC milling that describes irregular overcutting at or beyond the intended edge of a part. The word combines rand (edge), over (over), and frezen (to mill). In practice, it refers to material removal that extends beyond the target boundary in a non-uniform or random pattern, rather than a clean, well-defined edge.

Causes of randoverfrezen include tool deflection due to insufficient part rigidity, machining chatter, improper tool compensation or path programming, worn or damaged cutting tools, inappropriate feeds and speeds, poor workholding, and misalignment between CAM output and the actual machine. Environmental factors such as thermal expansion and machine backlash can also contribute.

The effects are typically dimensional inaccuracies near the edges, degraded edge quality, burr formation, and potential interference with mating features. In precision parts, randoverfrezen can compromise fit, function, and surface finish, particularly on features that require tight tolerances.

Detection and measurement are usually performed by comparing machined edges with reference CAD models or coordinate measurement machine (CMM) data, sometimes aided by optical or profilometric inspection to assess edge location and surface integrity. Tolerances are evaluated to determine whether overcut exceeds acceptable limits.

Mitigation strategies focus on process control: improving workholding and machine rigidity, selecting appropriate cutting parameters, reducing tool overhang, ensuring accurate tool compensation, and refining CAM strategies to prevent edge overcut. Finishing passes or secondary operations may be used to clean and bring edges within specification.

Notes: the term randoverfrezen is not universally standardized; similar phenomena are often described as overcut, edge overmilling, or edge burr issues in broader machining literature.