What Is a Machining Center? The Basics on Structure, Types, Benefits, etc.

What Is a Machining Center?

Exactly what kind of machine tool is a machining center? To start, let's take a look at the basics on machining centers.

Various Cutting Operations With One Machine Tool

A machining center is a machine tool capable of performing multiple cutting operations, such as drilling and milling, with the same machine. Machining centers also feature an NC unit for numerical control and an automatic tool changer (ATC).

In other words, a machining center is like a milling machine, in which the table is moved by rotating a handle, equipped with a computer control unit and an automatic tool change feature. In recent years, 5-axis machining centers that can perform more advanced machining have gained in popularity, and demand has increased for eco-friendly energy saving machining centers.

Machining Center History: Starting in 1958 in the United States

The first machining center dates back to 1958 in the United States. That year marks the development of the world's first machining center. It revolutionized the manufacturing industry, which had been dominated by milling machines to that point.

At the time, Japan sent a delegation to the United States to study the latest technology. Domestically, Japanese machining center development started in around the 1970s and, together with the trend to motorization, machining centers took off. In 1982, Japan surpassed the United States in machine tool production to become the world's largest machine tool producer. As of 2022, Japanese production is still world class, and Japan holds the second largest global share after China.

How Do They Differ from Various Other Machine Tools? Features of the Machining Center

There are various types of machine tools, including machining centers, NC lathes, turning centers, and multi-tasking machines. Here, we will look at the differences and get to know the features of each.

Machining Centers vs. NC Machine Tools

The biggest difference between a machining center and NC machine tools is the automatic tool changer (ATC). Since NC lathes and NC milling machines can basically only mount a single tool at a time, the tool must be changed by hand as necessary between end mills, drills, taps, and so on. Meanwhile, machining centers are equipped with an ATC, allowing for tools to be changed automatically and enabling continuous machining.

Machining Centers vs. Turning Centers (Multi-Tasking Machines)

Machining centers and turning centers (multi-tasking machines) are machine tools developed based on different machining technologies. The machining center is an NC milling machine with added ATC feature, and it mainly performs machining of a fixed workpiece with a rotating tool. In this regard, the turning center is a machine tool based on the NC lathe that incorporates the functions of a machining center. Given their ability to perform both turning and milling processes, these are also called multi-tasking machines. However, in recent years, turning centers have diversified in their functions and types, making it difficult to clearly distinguish machining centers from turning centers.

For more information, see this article:
"What Is a Multi-Tasking Machine? Advantages of Multi-Tasking Machines and How They Differ from Machining Centers Explained"

Basic Structure, Part Names, and Terminology

An understanding of the basic structure of a machining center, the names of its parts, and the relevant terminology is essential for a better understanding of the machining center and how to operate it. In this section, we will explain the parts and terminology related to machining centers.

NC Unit/NC Control Panel

Base

Column

Spindle and Tooling

Cutting Tools (Milling Cutters, End Mills, Drills)

Automatic Tool Changers (ATC)

Machine Table

Machining Center Types

Machining centers are categorized into several types according to their structure and application. When considering what to introduce, it is vital to select the right machining center for your purpose and material being worked upon. This section will describe the main types of machining centers, their characteristics, and their suited applications.

Vertical Machining Centers

Vertical machining centers have the spindle and workpiece oriented vertically. The workpiece is processed from the top, making it easy to check the status for each machining process. Many are relatively compact, and are suitable for high-mix, low-volume production of small precision parts.

Click here for Brother vertical machining centers

Horizontal Machining Centers

Horizontal machining centers have their spindle and the workpiece oriented horizontally. These make side cutting easier and are suited to continuous multi-face machining. In addition, as chips fall naturally, these lower the risk of tool damage due to residual scraps. On the other hand, care must be taken when working with heavy workpieces as their own dead weight makes the workpieces susceptible to distortion and deflection.

Click here for Brother horizontal machining centers

Gantry Machining Centers

Gantry machining centers have a double column shape, making them suitable for cutting of larger workpieces. Generally, cutting is performed by moving the gantry columns and spindle with the workpiece fixed in place. These are mainly used for large, heavy workpieces, such as aircraft parts, large molds, and railway components.

5-Axis Machining Centers

The 5-axis machining center is a machine tool with two rotating axes in addition to travel in the X-, Y-, and Z-axes. Their wide range of axis movement makes these machining centers suited to machining of workpieces with curved surfaces and complex geometry. Also, 5-axis machining centers enable machining to be performed with fewer changeovers.

Advantages of Introducing a Machining Center

The machining center is one of the most used machine tools in Japan because of its advanced machining technology. Here are some of the advantages gained by introducing these machine tools.

Productivity Improvement

The biggest advantage of a machining center is the productivity improvement that can be expected. Machining centers can perform machining at higher speed and with higher accuracy than conventional machine tools. With their ability to setup the workpiece once and perform multiple processes, machining centers reduce the number of changeovers and greatly improve production efficiency. In addition, their shorter cycle times allow for shorter lead times and add flexibility to accept orders with short delivery times.

Stability of Quality

Introduction of a machining center will also help you maintain a constant product quality. Reducing the number of changeovers in turn reduces inconsistencies and defects from human error, and numerical control provides machining at a constant quality. The ability to produce high-quality products will increase brand reliability and reputation.

Employee Safety

Employee safety is a top priority for companies engaged in manufacturing. Introduction of a machining center can significantly reduce human work, which in turn reduces the risk of sudden accidents and injuries. In addition, automating work through the introduction of machining centers will help in resolving labor shortages and can be expected to improve the workplace environment for each worker.

Points to Note and Issues to Consider Before Introduction

While they do present many benefits, there are a number of issues to consider before introducing a machining center. To get the most out of your machining center, it's essential to understand those considerations and develop an appropriate and specific deployment plan.

Price Estimation

Pricing for machining centers varies depending on size, features, brand, and other factors. Prices range from under 10 million yen for smaller machining centers to hundreds of millions of yen for large machining centers. Therefore, when considering an introduction, first clarify the objectives and what kind of machining will be performed on what kind of workpieces, and then discuss a budget while considering what kind of machining center fits your company.

Machining Center Operation and Procedures

There are three main steps to machining at a machining center:

1. Create an NC program
Specify machining details, such as the geometry and size of the part to be machined, and the type(s) of tool to be used.
Instructions must be indicated in detail, such as tool coordinates and rotational speed. In that sense, NC program creation is a key part of machining centers.

For complex workpiece machining, CAD software (for drawing blueprints) or CAM software (for creating NC programs from blueprints) may be used to create the program.

2. Attach the tool(s) and workpiece specified in the program
3. Run the program using the control panel and start machining

Operating Difficulty? Training Operators a Must

A certain amount of knowledge and experience is required to work with a machining center properly. If this is your first machining center, it will take a certain amount of time for many operators to understand and become proficient in machine operation. Therefore, as a company, operator training and education alongside the introduction is a good idea. One method of doing so is to encourage your operators to get licensed as a machining center operator (certified machining technician). There are special, first, second, and third class certifications, through which operators can learn everything from basic operations to advanced techniques. In recent years, machining center e-learning courses have also been made available. Make the effort to create an environment in which your employees can take the initiative to learn.

Maintaining Consistent Productivity in an Era of Declining Working Population

Every passing day, the labor shortage on Japanese manufacturing floors worsens. For this reason, companies push for initiatives like IoT and automation in efforts to stay competitive. The machining centers showcased here are an effective means of alleviating labor shortages and improving productivity. In fact, many companies have accomplished results from their introduction of machining centers.

Still, it is also true that there are both financial and technical hurdles to machining center introduction. If you have any anxieties or concerns about introduction, contact one of our sales representatives.

For reference, it can also be a good idea to see the introduction status of your competitors and success stories of companies that have completed deployment.

The link below gives videos of actual accounts from companies that have introduced a machining center. They show the advantages of machining center as they actually felt them and their issues to introduction. Companies evaluating their own deployment are encouraged to check them out.

Customer Success Stories