The accuracy of CNC machined parts depends on many factors, including part
design, tool selection, tool path programming, fixture fixation, and so on.
Different industries have different precision requirements for parts, such as
medical, aerospace, automotive, chemical and other industries have relatively
high precision requirements for parts. Of course, there are many other
industries that also have high precision requirements for parts, and some
industries do not have so high precision requirements for parts. They pay more
attention to the stability of parts accuracy, that is, the size difference
between parts should be as small as possible.
So how do CNC machining factories ensure the accuracy of parts?
CNC milling machine accuracy: 3 measurements
The overall accuracy of the milling machine is determined by three different
measurements: position accuracy, repetition accuracy, and tolerance.
Accuracy of position
Position accuracy is equal to the difference between the distance between the
specified points on the part and the actual measured distance between those
points after milling. For CNC milling machines, accuracy depends on the ability
to follow the programming path. The processing plant determines the position
accuracy of the milling machine by measuring and calculating the statistical
average of the deviation.
Accuracy of repetition
The precision of the milling machine is defined by precisely repeating the
same commands so that the same results are obtained one by one. Similar to
precision, the precision of a CNC milling machine is calculated by multiple
measurements when setting the cutting path. Accuracy is measured in the
repeatability of cutting the same exact path, resulting in repeated, exact
copies of parts.
The goal of CNC milling machines is to keep them within specified tolerances
by repeatedly maintaining high positioning accuracy. For example, imagine
shooting an arrow at a target. The distance between the arrow and the bull
's-eye measures accuracy.
How to judge the precision of NC machining
In order to maintain the accuracy required for parts, good machine processing
plants prioritize the following in their processes and procedures:
Accuracy depends on the working environment that provides stable conditions,
such as temperature and humidity.
The precision of a CNC milling machine requires continuous preventive
maintenance to keep all equipment in perfect working order.
Calibration of machine:
The machine periodically recalibrates all precision milling machines to
maintain factory Settings.
Monitor cutting tools, and maintain and replace them according to their
In order to minimize the impact of vibration, the workpiece needs to be
secured with a suitable fixture.
Experienced mechanics are more likely to understand the nuances that lead to
the manufacture of precise parts.
Experienced manufacturing engineers understand how to effectively make
precise CNC milling machine parts using different tools in different methods and
at different speeds.