What is a CMM?

New to CMM (Co-ordinate Measuring Machines)? Have a look through our guide to CMM. From the very basics to something slightly more complicated.

What is a CMM?

What is a CMM imageWhat is a CMM: A coordinated measuring machine consists of 4 main components:

  • The machine body, including the measuring bed
  • Measuring probe and stylus
  • Control or computing system
  • Measuring software

It is used to create models or prototypes from design drawings, or create design drawings from prototypes in reverse engineering. It may also be used to check the quality and accuracy of a factory machine that is producing parts on an assembly line by measuring the produced parts for accuracy and comparing their dimensions to the original design drawings or CAD software.

A CMM is also use to look at the form of an object, taking measurements that would be nearly impossible to do accurately by hand such as the roundness of a hole, for example.

It can be used in conjunction with CAD software throughout the product development process to create 3D design models, for quality control and to modify designs and specifications. The use of CMMs alongside CAD can shorten the time between design revisions.

By collecting the data and sending it straight to software on your computer, the CMM allows you to analyse, manipulate future processes and produce reports quickly.

Coordinated measuring machines save time and money in the manufacturing process by highlighting anomalies and errors, allowing for incremental adjustments and corrections, checking the quality of output and highlighting future efficiencies in the manufacturing process.

What is a CMMWhat is it used for?

There are several types of coordinated measuring machine, designed to work on different styles and sizes of inspection projects.

  • The Cantilever type is suitable for small ranges only. This type would be used for when there is a small range of measurements to be taken.
  • A Moving Bridge type is where the CMM table is stationary and only the bridge moves. This would be used where the movement of the object to be measured is not appropriate or ideal.
  • A Fixed Bridge CMM is where the CMM table moves and the bridge remains stationary.
  • A Horizontal Arm machine works by moving the arm in a horizontal direction. This is used for large work pieces like car bodies.
  • A Gantry CMM is used for very large parts like an entire car.
  • The Column Type CMM is where movement in the X & Y directions is achieved by moving the table. The construction of the Column Type provides good rigidity and high accuracy.

Now you know what is a CMM, you know if it fits your business needs, call QCT on 01332 572882 for more information on our machines.

More from the beginners guide here:

  1. What does a CMM do?
  2. What is CMM programming?
  3. What is CMM calibration?
  4. What does a CMM operator do?
  5. How do CMM probes work?
  6. How do CMMs measure flatness?
  7. How do portable CMMs work?
  8. How accurate are CMM machines?
  9. How to use a CMM