CNC Milling: How to Control the Accuracy of CNC Milled Parts?

 

 

 

The accuracy of CNC machined parts depends on many factors, including part design, tool selection, toolpath programming, how fixtures are held, and more.

 

Different industries have different precision requirements for CNC milling 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 have high precision requirements for CNC milling parts, and some industries do not have such high precision requirements for CNC milling parts, and pay more attention to the stability of CNC milling parts accuracy, that is, the size difference between parts should be as small as possible.

 

 

 

 

 

 

So how does a CNC machining factory ensure the accuracy of CNC milling parts?

 

CNC Milled Part Accuracy: 3D detection

 

The overall accuracy of a CNC milled part is determined by three different measurements: positional accuracy, repeatability and tolerance.

 

 

 

 

 

Position accuracy

 

Positional accuracy is equal to the difference between the distance between specified points on a CNC milled part and the actual measured distance of those points after milling. For CNC milled parts, accuracy depends on the ability to follow programmed paths. A CNC machining shop determines the positional accuracy of a milling machine by making multiple measurements and calculating the statistical average of the deviations.

 

 

Repeatability

 

Define the precision of a CNC milling machine by repeating the same commands exactly to get the same results one after the other. Similar to accuracy, the accuracy of CNC milled parts is calculated by taking multiple measurements when setting the cutting path. The measure of accuracy is the repeatability of cutting the same exact path, resulting in repeated accurate reproductions of CNC milled parts.

 

 

Tolerance

 

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 bullseye measures accuracy.

 

 

 

 

 

How to judge the accuracy of CNC machining?

 

To maintain the precision required for CNC machined parts, good CNC machining shops prioritize the following in their processes and procedures:

 

Working environment:

 

Accuracy depends on the operating environment that provides stable conditions, such as temperature and humidity.

 

 

Device status:

 

The precision of CNC milling machines requires ongoing preventive maintenance to keep all equipment in perfect working order.

 

 

Machine Calibration:

 

All precision CNC milling machines are periodically recalibrated to maintain factory settings.

 

 

Tool monitoring:

 

Cutting tools are monitored, maintained and replaced according to their condition.

 

 

Fixtures:

 

In order to minimize the effects of vibration, the workpiece needs to be held in place with suitable fixtures.

 

 

Mechanic Experience:

 

Experienced machinists are more likely to understand the nuances that lead to the manufacture of precise CNC machined parts.

 

 

Programming:

 

Experienced CNC machining manufacturing engineers understand how to use different tools at different methods and speeds to efficiently manufacture precise CNC milled parts.

 

 

 

 

 

 

The above are just the insights of VMT CNC machining factory on controlling the accuracy of CNC milling parts. If you have a better solution, you can contact us: [email protected] to discuss with us.

 

 

 

 

 

VMT is mainly engaged in custom precision CNC machining parts, metal and plastic prototype processing. Its business covers 62 countries around the world, covering military, medical, semiconductor, automotive and other fields. 40+ materials and 15+ surface finish options with free service design, project reviews and DFM analysis. To ensure the quality of parts, we passed the ISO9001 quality system and SGS on-site factory audit in 2015. No matter how complex your part structure is, or your product encounters technical problems, we can provide you with professional service! Save 15% of time cost and communication cost for you!