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  • Writer's pictureMako Precision

Common issues with CNC Machines

Updated: Jul 9, 2018


CNC machines come at a large price often upwards of £100,000 so luckily, they are very durable and long lasting, after all why would you purchase one if it needed to be replaced every couple of years?

Unfortunately, just because they are durable and long lasting it doesn't mean you will never experience any issues with them so in this blog we will go over the most common issues, why they happen and how they can be prevented.

With CNC machines most issues come down to three different factors.


CNC machines need to be lubricated and cleaned properly and regularly because if they aren't then several issues may come about.

The main problem is normally issues with the material. Swarf getting stuck around the job can be caused by several different things, however one of the main reasons would be if there was a limited amount of air being blasted or if there wasn't enough coolant left to blast the swarf away. The user should maintain a continuous air flow and ensure the coolant levels are not low. Debris and a build-up of swarf could create issues for the locating and holding parts which could cause the machine to be inaccurate and even damage it over time.

The user of the machine should ensure that regular maintenance takes place and keeps the machine clean, tidy and prepared for the jobs ahead.

Tools & Settings

When there is an issue with the tools or settings it will often result in problems when you are cutting material.

Cutting coolant, blunt tools or an incorrect feed speed can often be the cause of material coming out burnt around the edges. An example of this would be if the feed speed was too slow it would cause the material to be under the cutting tool for too long causing it to burn. Similarly, if there isn't enough coolant then things would get too hot also causing burns to the material. If the tool is burnt however this could mean that the settings would need adjusting for the tool to work correctly, it could also be that the tool is too blunt and needs replacing.

To ensure that there are no problems when cutting material before starting the job ensure that the tool that will be used isn't blunt or worn out, ensure that there is enough coolant to use on the job and check the feed speed to ensure it is correct for the job at hand.


There is also a list of issues that could arise if the user doesn't programme the machine correctly.

Programming a machine incorrectly will result in most other cutting errors, these errors are normally hard to set right with more unexperienced machinists as they may not understand how their program caused the errors. Sometimes restarting the machine may fix these errors however if it does the program should still be checked as it is easier to blame the issue on the machine when the program may still have been the cause.

Anybody using a CNC machine should be able to fully understand the codes for the controller on the machine. If a machine is setup correctly and aligned with no issues the only way you will get errors is through the user who is programming and running the machine.


Mako Precision Engineering Ltd.



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