The CMM, or coordinate-measuring machine, has become essential for many manufacturers. This machine uses coordinate technology to conduct precise measurements of particular objects. It accomplishes this by sensing specific points on the object using a probe.
These machines have several essential applications and are often used in the quality assurance stage in manufacturing processes. Some typical applications include electronics, machine tools, aerospace, defence, and heavy machinery manufacturing.
Below is a quick guide for choosing the right CMM for your manufacturing needs.
Factors To Consider
There are different types of CMMs best suited for specific purposes. You can consider the following criteria to select the best one for your needs:
Measuring Range
Your CMM needs to be big enough to measure the components you work with at your site. Your smallest required measuring range consists of the dimensions that accommodate each measured object.
Make sure your measuring range is at least double the dimensions of your largest components. Note the X, Y, and Z dimensions of each object. This guideline helps provide a safe buffer that ensures accurate measurements.
Accuracy
Several CMMs are more accurate than others. For example, a CMM used for aerospace manufacturing requires higher precision. Various applications have different tolerances for measurement uncertainties.
Verification and performance testing are the most effective ways to find uncertainties for CMMs. Most CMMs have their uncertainties and procedures described in ISO 10360-2.
Environmental Conditions
A CMM’s performance is highly dependent on its environmental conditions. Different factors could affect the CMM’s inspection process. These factors include temperature and physical vibrations.
When choosing a CMM, make sure that you consider your workspace. Can you accommodate a sensitive CMM? Can you control temperature, vibrations, and other potential disturbances?
Types of CMMs
Aside from your company’s needs, it would help if you also looked at the types of CMMs you could get.
You could buy new or quality used CMM machines depending on your needs and resources. You can contact different vendors to see what they offer regarding equipment and assistance.
Bridge
The bridge is the most popular CMM type or style. It is known for its stability and versatility. Companies could find anchored and portable bridge-style units available.
Unlike more sensitive CMMs, bridge-style machines could withstand vibrations and other conditions on the shop floor.
However, these CMMs often have limited dimensions. They are best suited for measuring small to medium-sized components.
Gantry
Gantry CMMs are like bridge-style CMMs, except they are bigger. The machine is mounted on pillars, increasing its measuring range. It is often used in manufacturing heavy machine parts, such as aerospace applications.
Due to their size and high measuring range, gantry CMMs are more expensive than other types. Still, they benefit manufacturers that need to churn out large components.
Cantilever
Cantilever-style CMMs are only supported at one point by a stable base. This structure sets them apart from other CMM styles with two-point support.
Due to their structure, cantilever CMMs can only measure small components. Their design limits their measuring range, particularly on the X axis.
Horizontal Arm
Other CMM styles mount their probes vertically. As its name suggests, a horizontal arm CMM has its probe mounted horizontally. This structure allows them to measure large-volume components.
Some of its most common applications include measuring sheet metal and vehicle panels. However, horizontal arm CMMs are not as accurate as the other types.
CMMs are large, highly specialized pieces of equipment. Due to their specific and high-tech function, they usually cost a lot of money. They are a significant investment for any manufacturer, so buying one requires careful consideration.