June 2, 2025 BY
IN Blogs , CNC Machinery

How do I change tools on a CNC machine?

The main pillar for CNC machining is the cutting or milling tool working inside of it. One of the most important skills for any machinist is to know how to change the tools for the machining work. No matter if it is in a small home shop or a large industrial setup, knowing how to change the tool in the CNC machine is highly important. Though experienced machinists are able to do this easily, new ones often struggle a bit to understand the nuances of changing the tools on a CNC machine. So, if you are also someone struggling to understand the details of changing the tools on a CNC machine, then you have landed on the right page. 

Understanding tool changing system

Before we go into knowing how you can change the tools, here are the two main types of tool changing – 

  1. Manual tool changer – In this method, the operator physically removes and replaces the tool in the spindle. 
  2. Automatic tool changer – In this case, the machine is equipped with a tool magazine and a robotic arm, which helps in swapping the tool automatically following the programmed instructions. 

Process of changing tools on the CNC machines

Now, we will deep dive into the step-by-step process of swapping tools of the CNC machines – 

Preparation steps

Before you start the main process of changing the tools on your CNC machine, you need to start with some basic preparation steps –

  • Ensure the machine is turned off or, at the very least, in a safe mode to prevent any accidental starts. 
  • Make sure you go through the machine’s manual once to find out if there is any particular requirement for changing the tool of the CNC machine. 
  • Wear all the necessary safety glasses and gloves before you start the whole machining process. 
  • Clean the work area and remove all the chips and debris accumulated there from previous operations. 

This is common and important for both manual and automatic tool changing. 

Manual tool change procedure

Once you are done with the precautionary measures, here are some steps that you need to follow to manually change the tool on your CNC machine – 

  • In the first step move the spindle to a safe place. You can use the machine’s control to raise the spindle to prevent any collisions.
  • Then loosen the collet or the chuck, you can use a wrench or a tool holder to loosen the chuck. 
  • In the next step, you should remove the old tool. You should do it with proper care and remove the tool from the spindle in a way that doesn’t cause any collision or damage. 
  • Then you can just clean the spindle once before you insert the new tool. 
  • Once the spindle is cleaned, you should insert the new tool on the spindle or the tool holder. Make sure it is properly aligned otherwise it may damage the whole machining process. 
  • Tighten the tool in the right way, you can use a wrench to secure the tool in the right place to ensure a hundred percent safety during machining. 
  • Then, make sure to update the tool offsets in necessary situations. Reassure and input the tool length offset to make sure the machine knows the exact length. 

Automatic tool change procedure

Now, if your machine has automatic features and you are curious about what to do to change the tool on your CNC machine. Here are the steps for that – 

  • In the first step, the CNC program triggers an M-Code to initiate a tool change.
  • The machine will then automatically move the spindle to a safe position for the whole tool changing process.  
  • As automatic machines have robotic arms you can make the next tool call and it will automatically retrieve the needed tool from the tool magazine, and the old tool will be returned to its original slot. 
  • Finally, the automatic drawbar system will securely lock the new tool holder into the spindle taper and then the machine is ready for the whole machining process. 

Troubleshooting common issues

Now, you may face some issues during the whole process of changing the tool of your CNC machine. So here are some best solutions to the most commonly faced problems during the tool changing process – 

  1. Tool not seated properly – The most common problem faced during the tool changing process is this one. Check for debris in the spindle or the tool holder and clean them to solve this problem. 
  2. Error messages – Sometimes there can be some mistake with the tool number or the command is incorrect and in those cases, the machine may halt or display an error. 
  3. Tool runout – People often face problems with the tool’s runout, you can just adjust the tool holder and the spindle as per the requirement. 

 

Conclusion

In conclusion, tool changing is not a tough job to do. People often get confused about how to do it but it is actually very easy work to do. You just need to follow the above mentioned steps in the right way while also following all the necessary safety precautions.

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