Understanding CNC Spindles: Meaning, Types and Uses

CNC machining is the process of making parts out of solid materials in different shapes with a computer-driven CNC machine. It produces myriads of intricate parts for industries like electronics, aerospace, medical, transportation, oil and gas, building and construction, and others. It is in high demand in these industries because it enables them to create precise designs and produce high-quality parts. The CNC Spindle is a very important component of these machines. CNC Spindles come in various types.

This article will delve a bit deeper into the types of CNC spindles.

What Is a CNC Spindle?

A CNC spindle is the heart of every CNC machine. It consists of a shaft, a motor and a taper. The taper is the end of the spindle where the cutting tool is held. The shaft is the spindle’s body, which houses the other two important components. The spindle motor then drives the high-speed rotation that provides power to the spindle’s selected cutting tool. The form of the spindle dictates the speed and cutting force.

A machine tool can have multiple spindles, but the main spindle is used for the primary processing of a workpiece. A machine with multiple spindles is known as a multi-spindle machine, and it is frequently used for producing precision parts as well as high-volume orders because it can be fitted with six spindles and machine five components at once, thereby increasing the rate of production.

A single-spindle machine, on the other hand, has a single spindle and is commonly used for smaller operations.

What Are the Different Types of CNC Spindles?

CNC spindles can be found in a wide variety of designs and configurations, but they can be broadly classified into two types: integral motor spindle and belt-in spindle.

The Integral Motor Spindle

The integral motor spindle is also commonly called a built-in spindle or motorized spindle. It can reach speeds of 100,000 rpm and higher. It combines all three elements—motor, spindle, and tooling together into a single unit. However, packing all of these features into a small space makes it a more complex device and expensive than a belt-driven spindle.

Almost all high-speed spindles on the market are integral-motor spindles. Because of its high speed, this machine can be employed in a wide range of applications, but it also burns out quickly as a result. However, the motor housing can decrease its power and torque.

Belt-Driven Spindle

In a belt-driven spindle, the motor and spindle are installed separately but are still connected via a belt-and-pulley system. It is less complicated than a motor spindle and also less expensive. Spindle pulley combinations can also be fitted to it to change ratios on the fly, in order to boost high end RPM and low-end torque.

This type of spindle has a maximum rotational speed of 15,000 RPM. As a result, it is slower than a built-in motor spindle. Its external motor also makes it provide higher power and torque.

When using a belt-driven spindle, ensure that the belt is easily maintained and readily accessible to reduce maintenance costs. Furthermore, the type of belt will also influence the machine’s noise level. Belts with herringbone are more quiet than others due to how it disperses trapped air to reduce noise.

It is also less costly than a built-in motor spindle. If you are on a tight budget, this is a better option.

CNC Spindle: What Is It Used for?

Spindles are used in enterprises and manufacturing units that employ CNC grinding machines as well as other types of machine tools. Its principal functions are as follows.

  • Maintain continuous power in a specific speed range to maintain enough cutting force
  • Maintain the right positioning for tool changing, boring tool withdrawal and specific project requirements
  • Concurrent tapping
  • Simultaneous operation, even if the machine has multiple spindles fitted on it, they can operate simultaneously.

How to Choose a CNC Spindle

The right CNC spindle plays a huge role in successful production of your workpiece. Hence, when choosing a spindle for your CNC machine, there are a few things to keep in mind, including the type of CNC machine you have, the materials you work with, the spindle size, power, run out, build and bearing.

Also, you need to take into consideration the size of the cutters you will use, whether or not you will eventually need an automatic tool changer, and the spindle torque and speed. These factors will go a long way in choosing the right CNC spindle.

Which Type of Spindle Should You Consider?

There is no such thing as a universal spindle. You typically choose a CNC spindle with the revolution per minute, cooling, and power required for your material. A spindle with 24,000 RPM and 1kW power is perfect for wood and aluminum but for steel, RPMs of 15,000-18,000 and power of 5.6 kW are appropriate for tool sizes up to 12 mm.

While high speed is ideal for materials like aluminum, wood, composite materials, laminates and so on, it is not appropriate for metals, especially stainless steel and thermoplastics.

Any grinder spindle that is not made of metal should be avoided. This is because they cannot survive the pressure and vibrations of machining and can break.

Also Read: CNC Spindles: How to Make Them Last Longer?

How GCH Tool Group’s Spindle Repair Services Can Help You

Under normal operating conditions, good spindles can last at least 10 to 15 years. However, like anything, spindles can wear down and need to be repaired. Regular spindle maintenance can help you avoid downtime and high repair costs. Unfortunately, you cannot do this on your own. You need experts who have years of experience in that field.

At GCH Tool Group, this is our specialty. We can assist you with keeping your CNC spindles, grinding spindles and machine tool spindles in good working order.

CNC Spindle Repair and Rebuilding Services

Picking the right spindle repair and rebuilding services for your spindle can save you thousands of dollars in the long run. At GCH Tool Group, we service and rebuild spindles of all makes and models. We also have grinder parts and components that can fit your needs. Among the many types of spindles we repair are:

  • CNC spindles
  • Motorized spindles
  • Belt-driven spindles
  • High-speed spindles
  • Cantilever spindles
  • Hydrodynamic spindles
  • Integral spindles
  • Roller bearing spindles
  • Sleeve spindles
  • Twin grip spindles
  • Filmatic spindles
  • Hydrostatic spindles

Contact GCH Tool Group for High-Quality Grinder Spindles and Repair Services

Contact GCH Tool Group if you are experiencing issues with the spindle on your CNC machine. We are a reliable source for grinder spindle rebuild and repair. You can trust that our skilled technicians will collaborate with you and help you find a solution to your CNC spindle at a competitive price.

About Ellen Kominars

Ellen joined GCH Tool in 2013 as director of marketing. She is responsible for digital marketing, media relations, website development, event planning, advertising, communications and graphic design. A long-time resident of Mexico City, Ellen speaks Spanish fluently, and often assists with the many GCH customers located in Latin America. Ellen has worked in industrial marketing for over 20 years. She’s now added grinding components and grinders to the list of products she’s marketed, which includes induction furnaces, hand tools, magnetic separators and diesel-truck axles.