What is CMM Equipment for Machining & How Does it Work?

Precision geometrics are crucial for successful outcomes and satisfied clients when manufacturing parts and components.. Conventional methods, such as measuring by hand or using optical comparators, are time-intensive and require specialized skills and the outcomes can be prone to human error.  Today’s sophisticated Coordinate Measuring Machines (CMM) minimize the risk of such errors and maintain the tight tolerances needed for today’s complex parts.

What is CMM Equipment?

Coordinate Measuring Machines check to ensure the dimensions of manufactured parts meet product specifications. Generally an automated or semi-automated process, it surpasses human quality control checks in both speed and accuracy. CMM equipment may use a custom stylus, non-contact laser or other non-contact methods to measure the height, width and depth of the X, Y and Z axes. The measurements can then be compared to the original part design parameters, ensuring consistent and accurate outputs.

How Does CMM Work?

A prototype or component part is placed on a rigid base in the machine. This rigidity stabilizes the part and prevents vibrations and other movement from affecting the measuring process, ensuring the most accurate results. The machine sends its specialized probes along the X, Y and Z axes to determine the component’s height, width and depth at various spots, mapping the component part and recording the information for computer analysis.

CMM provides a fast, economical quality control mechanism that quickly and accurately assesses whether or not your parts match the original design and maintain the required tolerances.

What are the Different Types of CMM Equipment?

CMM Equipment is classified by style, but the measuring process remains similar across machines regardless of structure. There are four basic types of CMMs commonly used in machine shops.

Bridge-Style CMM

This is the most common type of CMM equipment. They are known for their stability during measurement and are used for small components or mid-sized parts that can be lifted onto the measuring surface.

Bridge-style CMMs are available as fixed units or portable machines. 

Gantry-Style CMM

Gantry-style CMM equipment measures large products or components that can’t be lifted onto a measuring platform. Oversized, heavy and awkward parts or projects can be measured while they sit on or close to the floor.

Since these CMMs are designed to tackle large items, the machines are considerably larger than other CMM styles. 

Cantilever-Style CMM

Although stable, cantilever CMM equipment has only one point of support instead of the two found in other machines. With this in mind, cantilever machines measure small parts where the machine’s rigidity isn’t as crucial to the overall process. 

Horizontal Arm CMM

As the name implies, horizontal arm CMMs have horizontally mounted probes. They are excellent for measuring long objects that fall beyond the probe range of vertical CMM equipment. 

Other CMM Options

In addition to the 3-axis machines, CMM manufacturers produce 5-axis machines. These additional axes can allow for more complex measurements without the need to change probe configurations. This makes the 5-axis machine attractive for shops where changing setups creates unwanted downtime or other bottlenecks due to part complexity. 

Do I Need a CMM Machine?

Given the limitations of traditional measuring methods and the complexity of modern components, CMM equipment is superior in terms of required operator skill, operating efficiency and quality control. 

The speed and accuracy of CMM equipment saves time, minimizes errors and provides the consistent, high-quality output your customers demand. 

Selecting the right CMM equipment for your machine shop can be daunting, but partnering with a reliable and experienced machine sales and service provider will ensure you get the machine you need to increase productivity and meet your other needs. Contact Accurate Machine Tool Services to inquire how CMM equipment can work for you.