How Does a CNC Spindle Work? Full Working Explained | The Edge Cutter

CNC spindle is a primary component of  machining. A spindle is basically responsible for facilitating an efficiently faster processing of the workpiece. It also ensures that the end  product obtained is exactly what was desired.  

If any of you is looking for the best in class CNC spindle repairing services, then Superior Spindle is currently a leading voice in spindle repairment, replacement, and spindle taper grinding; serving any type of CNC spindle and their accessories repairment. Consequently, Superior Spindle Service provides all sorts of information concerning CNC spindle and its working principle, so that the readers stay updated about the modern spindle methodology.

How Does a CBC Spindle Work?

CNC machining spindles are generally electric-powered by Variable Frequency Drive (VFD or Vector Drive). Alternating current is passed by the AC motors through a pair of opposing magnets which creates a rotating magnetic field in the rotor part of the motor, spinning it around. However, the motors can also be actuated by compressed air. There is a wide variety of CNC spindle sizes available on the market, each of which is meant for different needs. 

A spindle is made of:

  • a taper to hold different cutting tools, 
  • a motor that rotates the spindle during operation, and 
  • a shaft that holds all the above parts and accessories together 

The spindle rotates on the axis that receives the operational feeds and movements from the associated CNC controller. Then the tool attached to the spindle functionals on the workpiece accordingly.

High-speed CNC Spindle Types

High-speed CNC machining spindles are widely preferred by the machine workshops, as their configurations are best suited for processing metals and other materials. 

High-speed CNC spindles are basically of two types, where each provides its unique set of advantages:

  • An integral motor spindle is composed of an internal motor that has the highest speed limit of 60,000 Revolution Per Minute. Such a speed range makes the spindle fit for numerous machining operations. However, it can also reduce the lifespan of the spindle. Other than that, the torque and power are also limited in an internal motor spindle due to its constricted motor housing.
  • Belt-driven CNC spindle is another high-speed spindle option with a maximum speed of 15,000 RPM. This speed range is lesser than the internal CNC motor spindle. Still, the design of the belt-driven spindle is such that it can attain higher power levels and torque. Additionally, this type of spindle is less costly and it is hence, an affordably ideal option for small-scale machine workshops. 

CNC Spindle Applications

Spindles have a myriad of practical applications across different industries, including the equipment related to automotive applications, aerospace applications, mold manufacturing, and even agriculture. Spindles play a crucial role in machining industries that require faster batch processing of goods.

For example, CNC metal lathes are utilized to cut through hard metals and materials including robust composite materials, plastics, etc. Lathes are also utilized in milling, which use rotary cutters for trimming a workpiece into a desired shape. Spindle based machines can also be utilized in making electrical components, computer parts manufacturing, and woodworking.

Repairing Spindle 

With time and usage, the CNC spindle will wear out and break. This is when you should avail a reliable spindle repairing service to get the issue sorted and get the broken one replaced by a new one if the previous one is not anymore fit for repairing. Not changing an-almost-worn-out spindle from the system and using it for further operation might cause operational disruptions. 

Rebuilding a CNC spindle entails a number of processes, starting with the analysis of the condition of the issued pieces to testing a newly rebuilt component. It is a strenuous process and should only be performed by highly skilled professionals. For instance, it requires a sterilized environment to re-configure the new spindle components so as to prevent any debris or dust particles from coming in contact with those components while re-assembling. Presence of dust or other contamination shortens the durability of the spindle by speeding up its degradation.

Regular upgradation of the equipment is an important step towards keeping your machine updated with the latest advanced  technologies that are emerging at rapid pace. Else, you have to lag behind your competitors if you do not make mandatory alterations to your existing equipment. Upgrading increases durability, cutting precision and speed of your CNC machine while improving machining tolerances. That means, all in all, your CNC spindle will be more cost-effective and futuristic. 

Spindle Vs Shaft 

Most people get confused between a CNC spindle and shaft. So, here is the answer: All spindles are shafts, but all shafts are not spindles. 

A CNC spindle acts as a driving shaft in the lathe, to which the chuck is connected directly.

On the other hand, a shaft or a driving shaft is a mechanical part that transmits torque and rotation. The shaft holds the other parts of a drive-train which, otherwise, cannot be directly attached because of the need for relative movement allowance or distance between them.


We hope you know now the exact difference between a spindle and shaft. Both may seem very confusing at the beginning but we hope now you are well aware of similarities and their differences.

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