A Brief Guide To CNC Fixtures

Introduction

CNC machining involves a variety of tools with different functions. Without a proper understanding, it is difficult to understand the use of these tools. An example of such a tool is a CNC fixture, also known as a CNC workholding fixture.

This article will demystify CNC workholding fixtures in three steps. It will demonstrate their functions and applications. It will provide reliable information on the types of CNC workholding fixtures available. Finally, it will provide you with excellent information on how to achieve the best CNC fixture design or use custom CNC fixtures.

What is a CNC fixture?

The best definition of a CNC fixture is that it is a medium for stability and positioning. It is a widely used workholding device that is primarily used to properly hold, support, or mount a workpiece on a CNC machine tool.

CNC fixtures are important tools that ensure consistency and interchangeability during the manufacturing process. In other words, they facilitate a smooth manufacturing process.

You could also say that CNC workholding fixtures reduce the amount of human effort required in the manufacturing process. In this case, many people compare them to clamps. However, they are different. Clamps guide the movement of the tool. However, CNC workholding fixtures do not guide the tool. They simply hold, support, and stabilize the workpiece during the manufacturing process.

Furthermore, with CNC workholding, the tool moves as the workpiece moves. When using a clamp, the tool always remains stationary.

Application of CNC fixtures

CNC fixtures have a wide range of applications in any manufacturing industry that employs CNC machining. Their functionality is integrated with the type of CNC operation used in the manufacturing process.

It is used in CNC milling, CNC turning , CNC planning, CNC slotting and CNC grinding. This will also lead to the types of CNC fixtures we will reveal below.

Generally speaking, CNC fixture design is responsible for its application:

Positioning

CNC workpiece fixtures ensure that the workpiece is properly fixed to the machine relative to the machine tool. This is also to ensure that the machine surface meets the requirements.

Clamping

Once positioned, the CNC fixture applies force to the workpiece to securely clamp it during any manufacturing process.

CNC workholding fixtures utilize both of these characteristics in their functions. For example, positioning and clamping play a major production role in the automotive industry. There, they secure and guide vehicles through welding and assembly processes.

Types of CNC Jigs

Most people familiar with CNC workholding tools aren’t familiar with the various types of CNC workholding tools. Yes, it’s not that simple. Because it’s not simple, it can be difficult for beginners to grasp the concept. However, with this ultimate guide, you won’t have anything to fear. This section will introduce you to the different types of CNC workholding tools from different perspectives.

Based on CNC machining operations

According to the classification of CNC operations, there are five types of CNC fixtures. The following is a brief introduction to CNC fixtures.

Turning fixture

CNC turning is a CNC machining operation that removes a portion of a workpiece while rotating it on a single axis. A turning fixture is a CNC fixture used in this process.

Milling fixture

CNC milling is simply a CNC machining process. During this process, a computer directs the tool to remove the desired portion of the workpiece. Milling fixtures are CNC jigs used in this process.

Drilling jig

Drilling is a popular process in manufacturing, particularly in CNC machining. Simply put, it involves punching a hole in a workpiece. The CNC fixtures used for CNC drilling are called CNC drilling fixtures.

Boring fixture

CNC boring is a CNC machining process in which a tool is used to enlarge a hole that has been drilled using a CNC drill. The fixture used in this process is a CNC boring machine fixture.

Grinding fixture

CNC grinding involves removing a portion of a workpiece with the aid of a grinding machine. It is another popular CNC machining process, along with CNC milling for trimming. Grinding fixtures are fixtures suitable for CNC grinding operations.

Generally speaking, you can draw valuable conclusions about CNC fixtures based on the CNC machining operation. Each CNC machining operation that requires a fixture has an operation name. Therefore, you might have different names, such as CNC honing fixtures and CNC grinding fixtures.

According to the purpose

You can categorize CNC workholding fixtures based on their intended use. There are five types of these fixtures. Below is a brief introduction to each of them.

Universal fixture

Universal CNC fixtures can be used with any workpiece and are easily adjustable. Every part of the fixture is adjustable and interchangeable to accommodate any workpiece. As the name suggests, universal fixtures have a wide range of applications.

Special devices

Specialized fixtures are CNC fixtures designed to fit a specific workpiece. When used with this specialized workpiece, they offer significant advantages in stability and are quicker and more convenient to operate.

Assembly fixture

The assembled CNC fixtures are only created after the workpiece has been considered. The fixtures are tailored to the requirements of the workpiece. They are assembled using specialized methods. Depending on the needs, they can be removed or reused as needed.

Modular fixtures

Modular fixtures are easy to rebuild and reconfigure to accommodate any workpiece. They are made up of interchangeable components, making them ideal for handling many workpieces. You can also disassemble the fixture after completing the process. Modular fixtures provide a better, more flexible manufacturing process.

Combination fixture

Combination lamps are available in different sizes and shapes. They are ideal for processing a wide range of workpieces of varying sizes and shapes depending on the machine tool.

Based on power source

This is the last classification process, which is classified according to the power source of the CNC fixture and is divided into the following six types of CNC fixtures.

1. Manual clamp
2. Pneumatic clamp
3. Hydraulic clamp
4. Electrical fixtures
5. Magnetic clamp
6. Vacuum fixture

What you need to know when you want to design or use a CNC fixture

There are many things you need to know when using a CNC fixture or understanding the correct CNC fixture design. Here are some things you need to know whether you already have a CNC fixture platform or need a custom CNC fixture.

Improve tolerance levels

CNC workholding fixtures help improve the tolerances of manufacturing operations. Therefore, it is important to ensure that they are set up to improve accuracy.

When to clamp

The clamping method has a significant impact on product quality. While you might think that clamping is the best way to secure a workpiece, this isn’t necessarily the case.

Reference important surfaces

If you prioritize low operating time, you may want to reference important artifacts on the tool. However, you should not reference many surfaces to avoid confusion.

Affordable

Another important thing to consider when designing a custom CNC fixture is economics. You need to know the number of parts you are manufacturing and the number of fixtures you will need.