What could be a reason for a consistent size error on parts?

A consistent size error on parts can often be attributed to incorrect tool settings. When the tool settings, such as diameter or offsets, are not precisely calibrated for the specific machining operation, it can lead to parts being cut larger or smaller than intended. This is because the CNC machine relies on these settings to guide its movements accurately.

If the tool settings reflect incorrect measurements, the machine may not execute the intended dimensions, resulting in a consistent size error across multiple machined parts. Proper calibration of tool settings is essential in achieving the right tolerances and dimensions for the finished product.

While recalibrating the machine, improper coolant usage, and incorrect feed rates can also cause issues in the machining process, they usually manifest as surface finish problems, tool wear, or irregular wear patterns, rather than consistent dimensional errors across all parts. Therefore, focusing on the accuracy of tool settings is critical when diagnosing size errors.