Coordinate measuring machines (CMMs) play a vital role in gathering high level metrological data that can be used to do everything from reverse engineer parts to ensure quality control, and millions of assembly lines around the world rely on their CMMs to provide accurate measurements of new parts and products.
The power of CMMs lies in their ability to create accurate data point clouds quickly and automatically, often measuring down to the level of the micron. They are incredibly sensitive and sophisticated machines, and like any such machine that operates under shop floor conditions in real time, CMMs need to be regularly calibrated if they are to continue providing reliable information.
CMM Calibration Should Be Rigorous And Regular
There are a variety of different theories as to how often CMMs need to be calibrated, but a good rule of thumb is to make sure any CMM on your assembly line is serviced and calibrated after every two thousand hours of work.
But it is important to bear in mind that results may vary based on environmental factors — CMMs that are more exposed to atmospheric conditions, for example, may require more regular servicing, and quality standards also play a role. In situations where a CMM is measuring extremely small and delicate parts like circuit boards, it might need to be calibrated more regularly than if it is measuring larger, more straightforward parts where a difference of a few microns will not affect performance.
When it comes to actually having calibration done, it is important to leave it in the hands of CMM measurement equipment services professionals who know how to make your machine as accurate as possible. Given that this is equipment your production line relies on for quality control, it is important not to take any chances.
Calibration Should Be Routine, But Shouldn’t Just Be Routine
It is important to keep track of when you last booked maintenance or calibration services for your CMM, but it is also important to remember that you may also need to have your CMM calibrated between maintenance cycles.
CMMs are notoriously sensitive to temperature changes, which is why it is best to keep them in as controlled an environment as possible. If there is a significant change in temperature on your shop floor for whatever reason, make sure to have a certified technician check your CMM to make sure it is still providing accurate results.
It is likewise important to have your CMM calibrated after every move, even if it is simply a move from one part of your plant to another.
While these are good guidelines for keeping your CMM operating in the best possible condition, probably the most important piece of maintenance advice is simply to exercise common sense. If your CMM starts returning data that seems incorrect, or if part defects are not being caught in the quality control process, make sure to call a CMM expert who can help you ensure that your CMM is providing accurate information serving the needs of your production line to the best of its ability.