1. Improper Tools or Settings

Improper cutting tool, the tool tip is damaged and not sharp, or improper cutting coolant/lube, these will cause the poor surface finish on the part, and even leave cutter mark on the material, which speeds up the tool wear at the same time. In addition, when the feed rate is too low, the part will remain in the path of cutting tool longer than the required time, resulting in the workpiece being burnt. If the feed rate is too high or the cutter needs to be replaced, it’s easy to leave rough edges and raised marks. Wrong specifications may cause burns to tools.

Solutions: 

– Replace the tool with a new one if it’s blunt 

– Choose the right tool and setting according to the characteristics of the material

– Adjust the settings to proper specification for particular cutting tool

2. Programming Errors

CNC machines are controlled by computers through the programming language, so there may be some issues due to errors in CNC programming. The lack of knowledge of G-codes, M-codes, CAD, and CAM software, incorrect programming such as wrong set-up and data, will lead to product errors and wrong motion sequencing. These problems can be difficult to diagnose for new operators.

Solutions:

– Train new employees comprehensively and adequately 

– Experienced programmers oversee operations

– Provide detailed user manuals and instructions to new operators

– In rare cases, simply turn off the machine and reboot the system 

– Properly set up and align mechanically

3. Poor Maintenance

If the CNC machines are not been cleaned and lubricated, dirt and debris will be built up on the equipment and affect the location and clamping of parts, and output of the machine, then causes reduced accuracy and precision. In addition, poor output and blockage prevent air circulation, resulting in spindle overheating during the process, and the machine is easy to be damaged. 

Solutions:

– Clean and maintain the machine in use regularly

– Check levels of coolants or airflow

4. Chatter or Vibration

The excessive vibration or chatter in the CNC machine will lower the quality of the piece, affect the accuracy of dimensions, reduce tool life and durability, and even affect the service life of your machine. Chatter may occur to workpiece or tool, you can listen if there is the noise generated.  

Solutions:

– Ensure the cut width or depth keeps deflection below 1/1000th of an inch

– Adjust the RPM of the machining process

– Use balanced tool holders when using spindle speeds above 8,000rpm