Accuracy in geometric and physical dimensions is essential for every manufacturing process. In the world of CNC machining, there are two methods are available to achieve these goals. The conventional method involves using measuring tools and optical comparators. These tools are difficult to use and can make mistakes. Another option is to use a CMM machine.
CMM stands for Coordinate Measuring Machine. This tool can measure the dimensions of machine/tool parts by using coordinate technology. Dimensions that are open for measurements include height, width, and depth along the X, Y, and Z axes. You can measure the target or record the measured data depending on how sophisticated the CMM machine is.
What is a CMM Machine?
Answering the question “What is a CMM Machine?” will help you understand why they are important for every machining manufacturer. Understanding the differences between the new and traditional operations is key to answering the question.
There are many limitations to the traditional method of measuring parts. It requires skill and experience from the operator who inspects the parts. This can result in parts not being supplied if it is not clear.
Another reason is the increased sophistication of parts produced today. The technology sector has seen the development of more complicated parts. A CMM machine is a better choice for this process.
CMM machines are faster and more accurate than traditional methods, so they can accurately measure parts. The machine increases productivity and reduces the chance of making mistakes in the measurement process. It is important to understand what a CMM machine does, why it is necessary, and how you can use them. This will help save time and money, as well as improve your company’s image and reputation.
How to use the CMM Machine?
There are two types of CMM machines. First type uses touch probes (contact mechanism) to measure the tool part. The second type uses other methods, such as lasers or cameras for measuring the tools. It can also measure different sizes of parts. Some models (automotive CMM machine) can measure parts greater than 10m.
The CMM machine’s moving axle mounts a touching probe that measures the object’s dimension and physical geometry. It also checks the parts to ensure that they are the correct design. These are the steps that the CMM machine follows.
Place the part to be measured on the base of the CMM. The measurement site is the base. It is made from dense, rigid material that is both stable and rigid. This ensures that measurements are accurate regardless of any external forces. A movable gantry, equipped with a touch probe, is also mounted above the CMM plates. The CMM machine controls the gantry so that the probe is directed along the Z, X, and Y axes. It replicates every aspect of the parts being measured by doing this.
The probe transmits an electric signal to the computer when it touches a part. You can measure the part by doing this continuously at many points on your part.
The next stage after measurement is the analysis stage. After the probe has captured part’s coordinates X,Y and Z, the probe will take the data. For the purpose of constructing features, the information is analysed. CMM machines using the laser or camera system have the same mechanism of action.
CMM Machine Components
Understanding the functions of a CMM machine is key to understanding its capabilities. These are the most important parts of the CMM-machine.
Test
The most important and popular component of a CMM machine is the probe. It measures action. Other CMM machines can use optical light, lasers, cameras, and other technologies.
The probes’ tips are made from a stable and rigid material due to their nature. It must be resistant to temperature changes so that its size doesn’t change. The most common materials are ruby or zirconia. You can make the tip spherical, or needle-like.
Granite Table
Granite tables are an integral part of the CMM machine. They are very stable and therefore important. Granite is stable and does not change with temperature. It also has a lower rate of wear than other materials. Granite is ideal because it retains its shape over time, making it an excellent choice for precise measurement.
Fixtures
Also, fixtures are very important tools that provide stability and support for most manufacturing operations. These are part of the CMM machine’s fixation system. Because a moving part could cause measurement errors, it is necessary to fix the part. Fixture plates, clamps and magnets are other options for fixing the part.
Dryers and air compressors
CMM machines that use air compressors or dryers, such as the standard bridge and gantry-type CMMs, are commonly made up of these components.
Software
Although the software is not considered a physical component, it will still be classified as one. It analyzes probes and other sensitive components.
Benefits and limitations of CMM
CMM machines should be an integral component of every production process. These machines have many advantages that outweigh their limitations. We will talk about both of these in the next section.
Benefits
Here are some reasons why you should use a CMM in your production process.
You can save time and money
Because of its speed, accuracy and precision, the CMM machine is an integral part of the production flow. Complex tools are becoming more common in the manufacturing industry. The CMM machine is perfect for measuring their dimensions. They reduce production time and costs.
Quality Assurance Is Guaranteed
The CMM machine is more reliable than the traditional method of measuring machine parts’ dimensions. The CMM machine can digitally measure your part and provide other services, such as dimensional analysis and CAD comparison, tool certificates, reverse engineers, and tool certifications. All this is necessary for quality assurance purposes.
Multi-purpose with multiple probes and techniques
CMM machines can be used with many different types of components and tools. A CMM machine can measure any part, regardless of its complexity.
Operator involvement is less
CMM machines are computer-controlled machines. It reduces the need for human intervention. This reduces the risk of operational errors that could lead to problems.
Limitations
CMM machines can improve production processes and play a critical role in manufacturing. There are some limitations to CMM machines that you need to be aware of. Here are some of its limitations.
The Probe must Touch the Surface
The probe is used by every CMM machine. The probe must be in contact with the part being measured to ensure it functions properly. For very durable parts, this is not an issue. For parts with fragile or delicate finishes, repeated touching can cause parts to deteriorate.
Defects could be caused by soft parts
A probe may be necessary for parts made from soft materials such as rubbers or elastomers. This can result in the parts settling. Digital analysis will show this error.
Select the Right Probe
CMM machines can use different types and styles of probes. To get the best results, it is important to choose the right probe. The part’s dimensions, the design and the probe’s ability will all play a role in choosing the right probe.
