Coordinate-measuring machines (CMMs) are precise measurement tools for measuring an objects’ size, shape, and position. While there are many CMMs available on the market, choosing the right machine for your needs can be daunting. This process becomes more challenging if you decide to buy a used CMM.
In this article, we’ll tackle the key factors to consider when buying a used CMM. After reading, you will be more confident about your purchasing decision.
What is a CMM, and what does it do?
A CMM is a machine used to measure the geometric features of an object. Manufacturers use them for different manufacturing and engineering applications to ensure that parts are within tolerance and meet specifications.
Although there are different types of CMMs, they all operate on the same basic principle. They project a pattern of known dimensions onto the object being measured. The CMM can calculate the size and position of features on the object.
Operators also use CMM to measure distances, angles, diameters, and other geometric features. Some people use them to measure surface finish and roughness.
Types of CMMs
CMMs can be divided into two categories: manual and automatic.
- Manual CMMs require the operator to move the measurement probe around the object they are measuring. This type of CMM is typically less expensive than an automated CMM but is also less accurate.
- Automatic CMMs use a motor to move the measurement probe around the object, which results in higher accuracy measurements. However, automated CMMs are more expensive.
Things you need to check when purchasing a used CMM
Price should not be the only factor you consider when you’re about to purchase a used CMM. It is also vital to keep the other pointers in mind:
Accuracy
Several factors affect the accuracy of a CMM, including the quality of the optics, the measurement system’s resolution, and the calibration’s accuracy. It is essential to ensure that the CMM you are considering is accurate to your needs.
Size
CMMs come in various sizes, so choosing one that will fit your needs is crucial. Some CMMs are small enough to be portable, while others are large and require a dedicated workspace.
Features
Some CMMs come with additional features such as touch probes, scanning systems, or articulating arms. It is essential to decide what features are important to you and ensure that the CMM you choose has them.
Warranty
Warranties can be an essential factor when deciding which CMM to purchase. Make sure to consider the warranty offered by the seller and read the terms and conditions carefully to ensure you are covered in the event of a failure.
Price
CMMs can vary in price significantly, so it is vital to set a budget and find one that fits your needs. Remember that you get what you pay for; a high-priced CMM will likely be more accurate.
Final thoughts on purchasing a used CMM
When purchasing a CMM, it is crucial to think about accuracy, size, features, price, and warranty. The equipment comes in different designs. You want to choose one that perfectly fits your needs.
