What Is Automatic Tool Changing?

Automatic tool changing is simply the fastest way to manipulate multiple tool options on a single production machine. As technology advances at an ever-faster rate, production capacity grows, and human beings are not always able to keep up. So we develop even better machines and support systems to meet the demand. 

One of these is the automatic tool changer, or ATC, which is a widely used enhancement to many industrial systems. You can use an ATC to increase the tool carrying capacity of, for example, a CNC machine, and thereby enhance its productivity and ensure a consistently smooth and reliable performance. 

Automatic tool changers come in various types, each with its own advantages and ways of working, and are suitable for a variety of industrial applications. You can also use them to replace damaged or broken tools.

Common Uses For Automatic Tool Changers

The major advantage of an ATC is that you don’t need a manual operator to change the tools on your CNC machine. Its rapid performance means it reduces downtime by a significant amount on any given project. Many people also deploy ATCs so that their machines can handle many different tools at the same time. The number of tools that any one ATC can manage varies according to which type you choose.

Automatic tool changers are typically made up of a base, upon which are mounted the tool holder, the gripper arm(s), support arms and the storage units or magazines that hold the tools. To ensure your ATC performs with maximum reliability, you need to synchronise all its component systems with the tool path strategy and motion of your CNC. 

Types of ATC

When you’re looking for an ATC, you’ll find that they usually come in two main options – either a linear type or a rotary type. These types are defined by the shape of the magazine, which can provide either straight or curved travel. Tool racks on rotary holders obviously travel on a curve, while linear tool racks are straight and static. This type is more mechanically straightforward, but tends to express a far better value. Furthermore, you can change your tools over with the ATC in either a vertical or horizontal axis, depending on the positioning of your magazine.

Whichever type of ATC and tool magazine you decide on, you’ll find that they all change tools in the same way. A tool change signal is sent to the ATC, which causes the spindle to stop rotating and halt at the precise position for the tool change. The tool currently in use is discharged, and a new tool in the magazine is moved to the tool-changing position. The tool changing operation is completed by clamping the spindle with the new tool and returning it to its initial processing position. The spindle rotates the new tool into action, while the old tool is rotated to fill the empty slot in the tool magazine.

Applications of An ATC

The types of machines that benefit the most from ATC use are those that remove material to create a product. These include things like CNC routers, lathes and mills.

They’re particularly useful in sheet metal and mould machining applications, where tools are frequently being rearranged, involving costly downtime. Using an ATC to manage the transition automatically will instantly improve operator efficiency and throughput. You’ll no longer have to halt operations manually to swap out tools like drills, engraving bits, reamers or end mills.

ATC Advantages

The advantages of using an ATC are noteworthy, and include:

1. Greater precision
2. Improved effectiveness
3. More versatile machines
4. Fewer interruptions, so greater total production time
5. No human operator required to switch between a range of different instruments
6. Reduced labour costs
7. Improved safety for staff and equipment
8. Greater capacity for storing tools
9. Easier switching for bigger and heavier tools
10. Enhanced tooling selection for every process

Several types of machines benefit from ATC use, including:

• Horizontal machining centres (HMCs) with ATCs can handle higher tool counts and run longer unattended, enabling them to carry out complex multi-face machining.

• Vertical machining centres (VMCs) can significantly reduce cycle times when paired with ATCs for rapid tool changes.

• 5-axis machining centres use ATCs for high-speed, multi-angle tool swaps, so they can perform multi-surface machining with consistent quality and optimal tool access.

• Turn-mill and mill-turn machines combine turning and milling: ATCs maintain speed and accuracy by providing rapid tool transitions without spindle halts.

• Double-column/gantry machines use high-capacity ATC systems for large components and structural parts, requiring long machining cycles and diverse tooling.

Industry applications of ATCs include:

• Automotive applications, which produce high volumes of very varied components. ATCs minimise downtime between tool changes, contributing to safe, non-stop production.

• Aerospace applications, which demand multi-tool strategies to handle high-precision, lightweight components. ATC systems maintain extreme accuracy and provide seamless transitions between tool types.

• Medical applications, especially in sensitive operations which demand repeatability with extreme precision. ATCs ensure the exact positioning of tools and avoid potentially dangerous human error.

• Mould die making applications, which demand frequent, critical tool changes to ensure surface quality and geometry transitions. ATC systems offer improved tool life and smooth, vibration-free tool changing.

• Energy applications such as gas, oil or wind, which require the machining of complex profiles and large castings. Heavy-duty ATC systems can maintain stability while handling even long or large-diameter tools.

Why Choose an ATC?

While they were first designed to supersede manual tool changing, ATCs have evolved into the mainstay of today’s production industry. Forming a core component of modern CNC automation, ATCs enable fast and reliable tool changes that increase precision and avoid any chance of human error. They’ve boosted production by increasing the number and variety of tools you can use, and entirely automating the tool-changing process. 

Basic 3-axis machines have developed into technologically advanced multi-axis systems that can streamline your operations and improve throughput. By integrating ATCs into your industrial operations, you can eliminate manual errors, reduce cycle times and maximise the full potential of many types of CNC machines.